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Mark Hassall

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DOI: 10.1038/s41588-019-0556-y
2020
Cited 200 times
Multitrait analysis of glaucoma identifies new risk loci and enables polygenic prediction of disease susceptibility and progression
Glaucoma, a disease characterized by progressive optic nerve degeneration, can be prevented through timely diagnosis and treatment. We characterize optic nerve photographs of 67,040 UK Biobank participants and use a multitrait genetic model to identify risk loci for glaucoma. A glaucoma polygenic risk score (PRS) enables effective risk stratification in unselected glaucoma cases and modifies penetrance of the MYOC variant encoding p.Gln368Ter, the most common glaucoma-associated myocilin variant. In the unselected glaucoma population, individuals in the top PRS decile reach an absolute risk for glaucoma 10 years earlier than the bottom decile and are at 15-fold increased risk of developing advanced glaucoma (top 10% versus remaining 90%, odds ratio = 4.20). The PRS predicts glaucoma progression in prospectively monitored, early manifest glaucoma cases (P = 0.004) and surgical intervention in advanced disease (P = 3.6 × 10-6). This glaucoma PRS will facilitate the development of a personalized approach for earlier treatment of high-risk individuals, with less intensive monitoring and treatment being possible for lower-risk groups.
DOI: 10.1038/s41594-019-0357-0
2020
Cited 49 times
A bipartite structural organization defines the SERINC family of HIV-1 restriction factors
The human integral membrane protein SERINC5 potently restricts HIV-1 infectivity and sensitizes the virus to antibody-mediated neutralization. Here, using cryo-EM, we determine the structures of human SERINC5 and its orthologue from Drosophila melanogaster at subnanometer and near-atomic resolution, respectively. The structures reveal a novel fold comprised of ten transmembrane helices organized into two subdomains and bisected by a long diagonal helix. A lipid binding groove and clusters of conserved residues highlight potential functional sites. A structure-based mutagenesis scan identified surface-exposed regions and the interface between the subdomains of SERINC5 as critical for HIV-1-restriction activity. The same regions are also important for viral sensitization to neutralizing antibodies, directly linking the antiviral activity of SERINC5 with remodeling of the HIV-1 envelope glycoprotein.
DOI: 10.1016/j.ophtha.2020.11.021
2021
Cited 39 times
Corneal Stiffness Parameters Are Predictive of Structural and Functional Progression in Glaucoma Suspect Eyes
Purpose To investigate corneal stiffness parameters (SPs) as predictors of future progression risk in glaucoma suspect eyes. Design Prospective, longitudinal study. Participants Three hundred seventy-one eyes from 228 primary open-angle glaucoma suspects, based on optic disc appearance, with normal baseline Humphrey Visual Field (HVF; Carl Zeiss Meditec) results. Methods Baseline corneal SPs were measured using Corvis ST (Oculus Optikgeräte GmbH). Participants were followed up every 6 months with clinical examination, HVF testing, and OCT. The baseline SP at first applanation (SP-A1) and highest concavity predicted the prospective outcome measures. Main Outcome Measures Structural progression was measured by the OCT rate of thinning of the retinal nerve fiber layer (RNFL) and ganglion cell–inner plexiform layer (GCIPL). Functional progression was assessed by permutation analysis of pointwise linear regression criteria on HVF testing. Results Stiffness parameters correlated positively with central corneal thickness (CCT), which was adjusted for in all analyses. A higher SP-A1, suggestive of a stiffer cornea, was associated with a faster rate of RNFL thinning (P < 0.001), synergistic with thinner CCT (P = 0.004) over a mean follow-up of 4.2 years. Eyes with higher SP-A1 and thinner CCT (thin and stiff corneas) showed accelerated RNFL thinning by 0.72 μm/year relative to eyes with lower SP-A1 and thicker CCT (95% confidence interval [CI], 0.17–1.28; P = 0.011) and were at 2.9-fold higher likelihood of fast RNFL progression of more than 1 μm/year (95% CI, 1.4–6.1; P = 0.006). Consistent results also were observed with GCIPL thinning. Furthermore, a higher SP-A1 was associated with a greater risk of visual field progression (P = 0.002), synergistic with thinner CCT (P = 0.010). Eyes with higher SP-A1 and thinner CCT were at 3.7-fold greater risk of visual field progression relative to eyes with thicker CCT and lower SP-A1 (95% CI, 1.3–10.5; P = 0.014). Conclusions Glaucoma suspect eyes with higher corneal SPs and lower CCT, suggestive of thin and stiff corneas, are at greater risk of progression. Corneal SPs seem to act synergistically with CCT as risk factors for glaucoma progression. To investigate corneal stiffness parameters (SPs) as predictors of future progression risk in glaucoma suspect eyes. Prospective, longitudinal study. Three hundred seventy-one eyes from 228 primary open-angle glaucoma suspects, based on optic disc appearance, with normal baseline Humphrey Visual Field (HVF; Carl Zeiss Meditec) results. Baseline corneal SPs were measured using Corvis ST (Oculus Optikgeräte GmbH). Participants were followed up every 6 months with clinical examination, HVF testing, and OCT. The baseline SP at first applanation (SP-A1) and highest concavity predicted the prospective outcome measures. Structural progression was measured by the OCT rate of thinning of the retinal nerve fiber layer (RNFL) and ganglion cell–inner plexiform layer (GCIPL). Functional progression was assessed by permutation analysis of pointwise linear regression criteria on HVF testing. Stiffness parameters correlated positively with central corneal thickness (CCT), which was adjusted for in all analyses. A higher SP-A1, suggestive of a stiffer cornea, was associated with a faster rate of RNFL thinning (P < 0.001), synergistic with thinner CCT (P = 0.004) over a mean follow-up of 4.2 years. Eyes with higher SP-A1 and thinner CCT (thin and stiff corneas) showed accelerated RNFL thinning by 0.72 μm/year relative to eyes with lower SP-A1 and thicker CCT (95% confidence interval [CI], 0.17–1.28; P = 0.011) and were at 2.9-fold higher likelihood of fast RNFL progression of more than 1 μm/year (95% CI, 1.4–6.1; P = 0.006). Consistent results also were observed with GCIPL thinning. Furthermore, a higher SP-A1 was associated with a greater risk of visual field progression (P = 0.002), synergistic with thinner CCT (P = 0.010). Eyes with higher SP-A1 and thinner CCT were at 3.7-fold greater risk of visual field progression relative to eyes with thicker CCT and lower SP-A1 (95% CI, 1.3–10.5; P = 0.014). Glaucoma suspect eyes with higher corneal SPs and lower CCT, suggestive of thin and stiff corneas, are at greater risk of progression. Corneal SPs seem to act synergistically with CCT as risk factors for glaucoma progression.
DOI: 10.1016/j.ophtha.2019.12.025
2020
Cited 38 times
An Intraocular Pressure Polygenic Risk Score Stratifies Multiple Primary Open-Angle Glaucoma Parameters Including Treatment Intensity
<h3>Purpose</h3> To examine the combined effects of common genetic variants associated with intraocular pressure (IOP) on primary open-angle glaucoma (POAG) phenotype using a polygenic risk score (PRS) stratification. <h3>Design</h3> Cross-sectional study. <h3>Participants</h3> For the primary analysis, we examined the glaucoma phenotype of 2154 POAG patients enrolled in the Australian and New Zealand Registry of Advanced Glaucoma, including patients recruited from the United Kingdom. For replication, we examined an independent cohort of 624 early POAG patients. <h3>Methods</h3> Using IOP genome-wide association study summary statistics, we developed a PRS derived solely from IOP-associated variants and stratified POAG patients into 3 risk tiers. The lowest and highest quintiles of the score were set as the low- and high-risk groups, respectively, and the other quintiles were set as the intermediate risk group. <h3>Main Outcome Measures</h3> Clinical glaucoma phenotype including maximum recorded IOP, age at diagnosis, number of family members affected by glaucoma, cup-to-disc ratio, visual field mean deviation, and treatment intensity. <h3>Results</h3> A dose–response relationship was found between the IOP PRS and the maximum recorded IOP, with the high genetic risk group having a higher maximum IOP by 1.7 mmHg (standard deviation [SD], 0.62 mmHg) than the low genetic risk group (<i>P</i> = 0.006). Compared with the low genetic risk group, the high genetic risk group had a younger age of diagnosis by 3.7 years (SD, 1.0 years; <i>P</i> < 0.001), more family members affected by 0.46 members (SD, 0.11 members; <i>P</i> < 0.001), and higher rates of incisional surgery (odds ratio, 1.5; 95% confidence interval, 1.1–2.0; <i>P</i> = 0.007). No statistically significant difference was found in mean deviation. We further replicated the maximum IOP, number of family members affected by glaucoma, and treatment intensity (number of medications) results in the early POAG cohort (<i>P</i> ≤ 0.01). <h3>Conclusions</h3> The IOP PRS was correlated positively with maximum IOP, disease severity, need for surgery, and number of affected family members. Genes acting via IOP-mediated pathways, when considered in aggregate, have clinically important and reproducible implications for glaucoma patients and their close family members.
DOI: 10.1016/j.ophtha.2020.06.067
2021
Cited 27 times
Cardiovascular Disease Predicts Structural and Functional Progression in Early Glaucoma
<h3>Purpose</h3> To investigate the association between cardiovascular disease and baseline structural defects and disease progression in glaucoma. <h3>Design</h3> Prospective, longitudinal study of preperimetric and perimetric glaucoma. <h3>Participants</h3> Two thousand six hundred twenty-eight eyes from 1314 participants recruited to the Progression Risk of Glaucoma: Relevant SNPs with Significant Association (PROGRESSA) study were evaluated for baseline and longitudinal structural thinning using spectral-domain OCT and for visual field progression on Humphrey visual field (HVF) assessment. <h3>Methods</h3> Patients were classified as either predominantly macula ganglion cell–inner plexiform layer (mGCIPL), predominantly peripapillary retinal nerve fiber layer (pRNFL), or both mGCIPL and pRNFL structural change at enrollment, and then evaluated for longitudinal OCT or HVF progression. Cardiovascular disease and medication characteristics of the participants were compared with a reference group of stable patients. <h3>Main Outcome Measures</h3> OCT and HVF baseline status and longitudinal progression. <h3>Results</h3> After accounting for age and cardiovascular characteristics, patients with predominantly mGCIPL thinning at baseline showed a higher prevalence of hypertension (odds ratio [OR], 2.70; 95% confidence interval [CI], 1.66–4.41; <i>P</i> < 0.001), antihypertensive use (OR, 2.03; 95% CI, 1.20–3.46; <i>P</i> = 0.008), and statin use (OR, 1.98; 95% CI, 1.07–3.66; <i>P</i> = 0.029) than reference patients. Patients with predominantly pRNFL thinning exhibited a comparable prevalence of cardiovascular disease or medication with reference patients. Review of longitudinal OCT and HVF data (mean follow-up, 5.34 ± 1.29 years) showed that hypertension was associated with an increased risk of both OCT (OR, 1.79; 95% CI, 1.17–2.75; <i>P</i> = 0.006) and HVF progression (OR, 1.92; 95% CI, 1.18–3.15; <i>P</i> = 0.013). A 1-standard deviation (approximately 21 mmHg) increase in systolic blood pressure at baseline was associated with a greater risk of OCT progression (OR, 1.27; 95% CI, 1.01–1.63; <i>P</i> = 0.041) and HVF progression (OR, 1.32; 95% CI, 1.01–1.73; <i>P</i> = 0.043). The association between systolic blood pressure and structural progression was comparable to that observed between intraocular pressure and structural progression (OR, 1.30; 95% CI, 1.01–1.67; <i>P</i> = 0.039). <h3>Conclusions</h3> Cardiovascular disease is an important risk factor for glaucoma progression.
DOI: 10.1016/j.vaccine.2016.11.083
2017
Cited 33 times
Comparison of platform technologies for assaying antibody to Ebola virus
The recent Ebola outbreak in West Africa led to the use of a variety of different platform technologies for assaying antibodies because of the difficulties of handling the live virus. The same types of method could be applied rapidly to other infections when they emerge. There is a need to compare quantitative results of different assays, which means that the assays must measure similar parameters and give comparable results.A collaborative study was carried out to establish an International Reference Reagent through WHO. Nine samples were sent to 16 laboratories and the results from 22 different assays compared to those obtained by neutralisation assays using the wild type virus.Quantitative correlation with the wild type neutralisation assays was very variable but generally poor, with only five of the twenty-two assays giving a correlation coefficient of 0.7 or greater; the five best assays included methods based on wild type and VSV pseudotype neutralisation and ELISA. They could be applicable to other rapidly emerging diseases. The remaining assays including neutralisation of lentiviral pseudotypes need further development.The assay platform should be chosen with care to ensure that it is fit for purpose. Many of the assays were not suitable for quantitation of antibody levels, a finding that is not surprising given the urgency with which they had to be implemented but some may be of generic value. Antibody titres in samples from a vaccine trial were comparable to those from convalescent patients or lower.Funding was from the UK DoH and the Wellcome Tust.
DOI: 10.1016/j.ophtha.2019.03.016
2019
Cited 32 times
Macular Ganglion Cell–Inner Plexiform Layer Loss Precedes Peripapillary Retinal Nerve Fiber Layer Loss in Glaucoma with Lower Intraocular Pressure
Purpose To investigate which clinical measures influence whether an individual demonstrates earliest glaucomatous structural progression on peripapillary retinal nerve fiber layer (pRNFL) or macular ganglion cell–inner plexiform layer (mGCIPL). Design Prospective, longitudinal cohort study. Participants Two hundred seventy-one eyes from 207 individuals with statistically significant evidence of glaucomatous progression on OCT Guided Progression Analysis (GPA) software were drawn from a total of 1271 eyes from 686 individuals categorized as glaucoma suspect or having early manifest glaucoma undergoing glaucoma surveillance. Methods Individuals demonstrating earliest evidence of longitudinal progression on mGCIPL GPA event analysis were compared with individuals demonstrating evidence of earliest longitudinal progression on pRNFL GPA event analysis. Main Outcome Measures Correlation of OCT event change analysis with intraocular pressure (IOP), clinical variables, and baseline thickness of the pRNFL and mGCIPL. Results Intraocular pressure, baseline pRNFL thickness, baseline mGCIPL thickness, and systemic hypertension were associated with location of first progression. Eyes demonstrating earliest longitudinal progression on mGCIPL had significantly lower maximum-recorded pretreatment IOP (mean difference, 3.90 mmHg; 95% confidence interval [CI], 2.37–5.43 mmHg; P < 0.001). The interval between progression on pRNFL and progression on mGCIPL increased by 12.4 months for every 5-mmHg increase in IOP (95% CI, 10.32–15.72 months). Eyes demonstrating earliest longitudinal progression on mGCIPL showed significantly lower baseline average pRNFL thickness than eyes progressing on pRNFL first (mean difference, 7.07 μm; 95% CI, 4.38–9.77 μm; P < 0.001). Eyes progressing first on mGCIPL parameters were 3.03 times more likely to demonstrate a new paracentral field defect than eyes progressing first on pRNFL parameters (odds ratio, 3.03; 95% CI, 1.26–7.28; P = 0.01). Conclusions Clinical features, particularly pretreatment IOP, influence whether structural glaucoma progression is detected earlier with mGCIPL or pRNFL imaging. These data support the usefulness of mGCIPL imaging in addition to pRNFL analysis for detection of glaucoma progression, particularly in patients with normal IOP. To investigate which clinical measures influence whether an individual demonstrates earliest glaucomatous structural progression on peripapillary retinal nerve fiber layer (pRNFL) or macular ganglion cell–inner plexiform layer (mGCIPL). Prospective, longitudinal cohort study. Two hundred seventy-one eyes from 207 individuals with statistically significant evidence of glaucomatous progression on OCT Guided Progression Analysis (GPA) software were drawn from a total of 1271 eyes from 686 individuals categorized as glaucoma suspect or having early manifest glaucoma undergoing glaucoma surveillance. Individuals demonstrating earliest evidence of longitudinal progression on mGCIPL GPA event analysis were compared with individuals demonstrating evidence of earliest longitudinal progression on pRNFL GPA event analysis. Correlation of OCT event change analysis with intraocular pressure (IOP), clinical variables, and baseline thickness of the pRNFL and mGCIPL. Intraocular pressure, baseline pRNFL thickness, baseline mGCIPL thickness, and systemic hypertension were associated with location of first progression. Eyes demonstrating earliest longitudinal progression on mGCIPL had significantly lower maximum-recorded pretreatment IOP (mean difference, 3.90 mmHg; 95% confidence interval [CI], 2.37–5.43 mmHg; P < 0.001). The interval between progression on pRNFL and progression on mGCIPL increased by 12.4 months for every 5-mmHg increase in IOP (95% CI, 10.32–15.72 months). Eyes demonstrating earliest longitudinal progression on mGCIPL showed significantly lower baseline average pRNFL thickness than eyes progressing on pRNFL first (mean difference, 7.07 μm; 95% CI, 4.38–9.77 μm; P < 0.001). Eyes progressing first on mGCIPL parameters were 3.03 times more likely to demonstrate a new paracentral field defect than eyes progressing first on pRNFL parameters (odds ratio, 3.03; 95% CI, 1.26–7.28; P = 0.01). Clinical features, particularly pretreatment IOP, influence whether structural glaucoma progression is detected earlier with mGCIPL or pRNFL imaging. These data support the usefulness of mGCIPL imaging in addition to pRNFL analysis for detection of glaucoma progression, particularly in patients with normal IOP.
DOI: 10.1136/bjophthalmol-2020-317461
2021
Cited 16 times
Normal-tension glaucoma is associated with cognitive impairment
Recent research suggests an association between normal-tension glaucoma (NTG) and dementia. This study investigated whether cognitive impairment is more strongly associated with NTG than high tension glaucoma (HTG) using cognitive screening within an Australiasian Glaucoma Disease Registry.The authors completed a case-control cross-sectional cognitive screening involving 290 age-matched and sex-matched NTG participants and HTG controls aged ≥65 randomly sampled from the Australian and New Zealand Registry of Advanced Glaucoma. Cognitive screening was performed using the Telephone Version of the Montreal Cognitive Assessment (T-MoCA). The T-MoCA omits points requiring visual interpretation, accounting for confounding factors related to vision loss in visually impaired participants. Cognitive impairment was defined by a T-MoCA score of <11/22. Cognition was compared between NTG and HTG participants using predetermined thresholds and absolute screening scores.A total of 290 participants completed cognitive assessment. There were no differences in NTG (n=144) and HTG (n=146) cohort demographics or ocular parameters at baseline. Cognitive impairment was more prevalent in the NTG cohort than the HTG cohort (OR=2.2; 95% CI 1.1 to 6.7, p=0.030). Though a linear trend was also observed between lower absolute T-MoCA scores in the NTG cohort when compared with the HTG cohort, this association was not statistically significant (p=0.108).This study demonstrated an association between NTG status and poor cognition, supporting the hypothesis that there exists a disease association and shared pathoaetiological features between NTG and dementia.
DOI: 10.1167/tvst.10.6.14
2021
Cited 14 times
Risk Stratification and Clinical Utility of Polygenic Risk Scores in Ophthalmology
Combining genetic and clinical data into an informative risk prediction profile has been an important ambition of personalized medicine. Single-nucleotide polymorphisms are commonly found throughout the genome and account for the majority of interindividual genetic variation. To date, genome-wide association studies have led to the discovery of thousands of disease-associated loci, including across dozens of ophthalmic diseases and traits. However, compared with the clinical utility of identifying rare Mendelian variants, the translation of these results to clinical practice has so far been limited because such variants are found commonly in the population, and individually account for a very small risk. Recently, combining large numbers of these genetic variants into polygenic risk scores (PRS) has shown clinically meaningful risk prediction across several common diseases. PRS have the potential to translate the discovery of common risk variants into individualized disease risk prediction, prognostication, and may enable targeted treatments. In this context, we review the clinical utility of PRS in three common, genetically complex ophthalmic conditions: primary open angle glaucoma, age-related macular degeneration, and myopia. Translational Relevance: Common genetic variants can be used to effectively stratify the risk of disease development and progression and may be used to guide screening, triaging, monitoring, or treatment thresholds.
DOI: 10.1016/j.xops.2023.100287
2023
Cited 3 times
No Strong Association between the Apolipoprotein E E4 Allele and Glaucoma
PurposeTo elucidate a potential association between the apolipoprotein E (APOE) E4 allele and glaucoma prevalence in large cohorts.DesignA cross-sectional analysis of baseline and prospectively collected cohort data.ParticipantsUK Biobank (UKBB) participants of genetically determined European ancestry (n = 438 711). Replication analyses were performed using clinical and genotyping data collected from European participants recruited to the Canadian Longitudinal Study of Aging (CLSA; n = 18 199), the Australian and New Zealand Registry of Advanced Glaucoma (ANZRAG; n = 1970), and the Blue Mountains Eye Study (BMES; n = 2440).MethodsApolipoprotein E alleles and genotypes were determined, and their distributions were compared on the basis of glaucoma status. Similar analyses were performed using positive control outcomes associated with the APOE E4 allele (death, dementia, age-related macular degeneration) and negative control outcomes not associated with the APOE E4 allele (cataract, diabetic eye disease). Outcome phenotypes were also correlated with Alzheimer’s dementia (AD), a clinical outcome highly associated with the APOE E4 allele.Main Outcome MeasuresResults of APOE E4 genotype-phenotype comparisons were reported as odds ratios (ORs) with 95% confidence intervals (CIs). Replication analyses investigated APOE E4 associations in 2 replication cohorts (CLSA and ANZRAG/BMES).ResultsThe APOE E4 allele was inversely associated with glaucoma (OR, 0.96; 95% CI, 0.93–0.99; P = 0.016) and both negative controls (cataract: OR, 0.98; 95% CI, 0.96–0.99; P = 0.015; diabetic eye disease: OR, 0.92; 95% CI, 0.87–0.97; P = 0.003) in the UKBB cohort. A paradoxical positive association was observed between AD and both glaucoma (OR, 1.30; 95% CI, 1.08–1.54; P < 0.01) and cataract (OR, 1.15; 1.04–1.28; P = 0.018). No association between the APOE E4 allele and glaucoma was observed in either replication cohort (CLSA: OR, 1.03; 95% CI, 0.89–1.19; P = 0.66; ANZRAG/BMES: OR, 0.97; 95% CI, 0.84–1.12; P = 0.65).ConclusionsA small negative association observed between APOE E4 and glaucoma within the UKBB was not evident in either replication cohort and may represent an artifact of glaucoma underdiagnosis in APOE E4 carriers.Financial Disclosure(s)The author(s) have no proprietary or commercial interest in any materials discussed in this article. To elucidate a potential association between the apolipoprotein E (APOE) E4 allele and glaucoma prevalence in large cohorts. A cross-sectional analysis of baseline and prospectively collected cohort data. UK Biobank (UKBB) participants of genetically determined European ancestry (n = 438 711). Replication analyses were performed using clinical and genotyping data collected from European participants recruited to the Canadian Longitudinal Study of Aging (CLSA; n = 18 199), the Australian and New Zealand Registry of Advanced Glaucoma (ANZRAG; n = 1970), and the Blue Mountains Eye Study (BMES; n = 2440). Apolipoprotein E alleles and genotypes were determined, and their distributions were compared on the basis of glaucoma status. Similar analyses were performed using positive control outcomes associated with the APOE E4 allele (death, dementia, age-related macular degeneration) and negative control outcomes not associated with the APOE E4 allele (cataract, diabetic eye disease). Outcome phenotypes were also correlated with Alzheimer’s dementia (AD), a clinical outcome highly associated with the APOE E4 allele. Results of APOE E4 genotype-phenotype comparisons were reported as odds ratios (ORs) with 95% confidence intervals (CIs). Replication analyses investigated APOE E4 associations in 2 replication cohorts (CLSA and ANZRAG/BMES). The APOE E4 allele was inversely associated with glaucoma (OR, 0.96; 95% CI, 0.93–0.99; P = 0.016) and both negative controls (cataract: OR, 0.98; 95% CI, 0.96–0.99; P = 0.015; diabetic eye disease: OR, 0.92; 95% CI, 0.87–0.97; P = 0.003) in the UKBB cohort. A paradoxical positive association was observed between AD and both glaucoma (OR, 1.30; 95% CI, 1.08–1.54; P < 0.01) and cataract (OR, 1.15; 1.04–1.28; P = 0.018). No association between the APOE E4 allele and glaucoma was observed in either replication cohort (CLSA: OR, 1.03; 95% CI, 0.89–1.19; P = 0.66; ANZRAG/BMES: OR, 0.97; 95% CI, 0.84–1.12; P = 0.65). A small negative association observed between APOE E4 and glaucoma within the UKBB was not evident in either replication cohort and may represent an artifact of glaucoma underdiagnosis in APOE E4 carriers.
DOI: 10.1016/j.ophtha.2023.03.028
2023
Cited 3 times
High Polygenic Risk Is Associated with Earlier Initiation and Escalation of Treatment in Early Primary Open-Angle Glaucoma
Purpose To assess whether a glaucoma polygenic risk score (PRS) was associated with treatment commencement or escalation in early primary open angle glaucoma. Design Prospective longitudinal observational cohort study. Participants Participants from the PROGRESSA study (Progression Risk of Glaucoma: RElevant SNPs with Significant Association) were divided into a cohort of glaucoma suspects who were treatment naive at enrolment, and early manifest and suspect glaucoma cases on treatment at enrolment. Methods A per-allele weighted glaucoma PRS was calculated for 1,107 participants. Multivariable mixed effects Cox proportional regression analysis assessed the association between PRS and time to commencement of intraocular pressure (IOP) lowering therapy in 416 glaucoma suspects who were treatment naive at study enrolment. Secondary analysis evaluated the association between PRS and escalation of IOP lowering therapy amongst 691 suspect and early manifest glaucoma cases who were on IOP lowering therapy at enrolment. Main Outcome Measures Commencement or escalation of IOP lowering therapy. Results A higher glaucoma PRS was associated with a greater risk of commencing IOP-lowering therapy within 5 years (HR: 1.45/Standard Deviation (SD) 95% Confidence Interval (CI) [1.27, 1.62] P<0.001). This finding persisted after adjustment for relevant demographic and clinical parameters (adjusted HR: 1.23/SD 95%CI [1.07, 1.43] P=0.005). Participants in the upper population-based quintile had a 3.3 times greater risk of commencing therapy by 5 years than the lowest quintile (HR: 3.30 95%CI [1.63, 6,70] P<0.001), and a 5.4 greater risk of commencing IOP lowering therapy by 2 years than the lowest quintile (HR: 5.45 95%CI [2.08, 14.25] P<0.001). A higher glaucoma PRS was associated with a greater risk of treatment escalation amongst cases on treatment at enrolment (HR: 1.19/SD 95%CI [1.09, 1.31] P<0.001). In combined analysis of treatment naive suspects and treated cases, participants in the top population-based quintile were at 2.3 times greater risk of requiring initiation or escalation of IOP lowering therapy than the lowest quintile (HR: 2.33 95%CI [1.75, 3.01] P<0.001). Conclusions This study demonstrates novel associations between glaucoma polygenic risk and risk of commencement or escalation of IOP lowering therapy, building upon previous work highlighting the potential clinical utility of genetic risk stratification in glaucoma. To assess whether a glaucoma polygenic risk score (PRS) was associated with treatment commencement or escalation in early primary open angle glaucoma. Prospective longitudinal observational cohort study. Participants from the PROGRESSA study (Progression Risk of Glaucoma: RElevant SNPs with Significant Association) were divided into a cohort of glaucoma suspects who were treatment naive at enrolment, and early manifest and suspect glaucoma cases on treatment at enrolment. A per-allele weighted glaucoma PRS was calculated for 1,107 participants. Multivariable mixed effects Cox proportional regression analysis assessed the association between PRS and time to commencement of intraocular pressure (IOP) lowering therapy in 416 glaucoma suspects who were treatment naive at study enrolment. Secondary analysis evaluated the association between PRS and escalation of IOP lowering therapy amongst 691 suspect and early manifest glaucoma cases who were on IOP lowering therapy at enrolment. Commencement or escalation of IOP lowering therapy. A higher glaucoma PRS was associated with a greater risk of commencing IOP-lowering therapy within 5 years (HR: 1.45/Standard Deviation (SD) 95% Confidence Interval (CI) [1.27, 1.62] P<0.001). This finding persisted after adjustment for relevant demographic and clinical parameters (adjusted HR: 1.23/SD 95%CI [1.07, 1.43] P=0.005). Participants in the upper population-based quintile had a 3.3 times greater risk of commencing therapy by 5 years than the lowest quintile (HR: 3.30 95%CI [1.63, 6,70] P<0.001), and a 5.4 greater risk of commencing IOP lowering therapy by 2 years than the lowest quintile (HR: 5.45 95%CI [2.08, 14.25] P<0.001). A higher glaucoma PRS was associated with a greater risk of treatment escalation amongst cases on treatment at enrolment (HR: 1.19/SD 95%CI [1.09, 1.31] P<0.001). In combined analysis of treatment naive suspects and treated cases, participants in the top population-based quintile were at 2.3 times greater risk of requiring initiation or escalation of IOP lowering therapy than the lowest quintile (HR: 2.33 95%CI [1.75, 3.01] P<0.001). This study demonstrates novel associations between glaucoma polygenic risk and risk of commencement or escalation of IOP lowering therapy, building upon previous work highlighting the potential clinical utility of genetic risk stratification in glaucoma.
DOI: 10.1016/j.parkreldis.2014.02.008
2014
Cited 23 times
The NK1 receptor antagonist N-acetyl-l-tryptophan reduces dyskinesia in a hemi-parkinsonian rodent model
Background Dyskinesia or abnormal involuntary movements (AIMs) are a disabling effect of chronic l-DOPA administration and consequent pulsatile stimulation of dopamine receptors. This abnormal activation causes maladaptive changes including upregulation of FosB expression in dynorphin containing striatal cells. Substance P (SP) is co-localized within dynorphin positive cells and is increased within the substantia nigra by l-DOPA (l-3,4-dihydroxyphenylalanine) treatment. Accordingly, we determined if treatment with a SP NK1 receptor antagonist reduced the onset of l-DOPA induced dyskinesia (LID) in the hemi-parkinsonian rodent model. Methods Adult male Sprague–Dawley rats underwent unilateral 6-OHDA (6-hydroxydopamine-hydrobromide) lesions of the medial forebrain bundle. At day 21, daily administration commenced of either l-DOPA (6 mg/kg plus 15 mg/kg of benseraside), l-DOPA with the NK1 antagonist N-acetyl-l-tryptophan (NAT) or equal volume of saline. Animals were tested with the rodent AIM scale assessing axial, contralateral forelimb and orolingual AIMs. Assessment of l-DOPA induced turning was undertaken, and motor function determined using the accelerating rotarod and adjusting step test. Dopaminergic neuronal counts and immunoreactivity for SP and FosB were undertaken. Results All animals treated with l-DOPA alone developed dyskinesia, whereas combined administration of NAT with l-DOPA significantly reduced onset of AIMs and prevented mild to moderate dyskinesia. In non-dyskinetic NAT treated animals, similar numbers of FosB+ striatal cells were recorded as in saline treated animals. Importantly NAT treatment did not interfere with the anti-parkinsonian effect of l-DOPA. Conclusion Daily administration of a SP NK1 receptor antagonist may represent a novel treatment regime that reduces the onset of LID whilst conserving motor function.
DOI: 10.1093/hmg/ddz193
2019
Cited 19 times
Genome-wide association analysis of 95 549 individuals identifies novel loci and genes influencing optic disc morphology
Abstract Optic nerve head morphology is affected by several retinal diseases. We measured the vertical optic disc diameter (DD) of the UK Biobank (UKBB) cohort (N = 67 040) and performed the largest genome-wide association study (GWAS) of DD to date. We identified 81 loci (66 novel) for vertical DD. We then replicated the novel loci in International Glaucoma Genetic Consortium (IGGC, N = 22 504) and European Prospective Investigation into Cancer–Norfolk (N = 6005); in general the concordance in effect sizes was very high (correlation in effect size estimates 0.90): 44 of the 66 novel loci were significant at P &amp;lt; 0.05, with 19 remaining significant after Bonferroni correction. We identified another 26 novel loci in the meta-analysis of UKBB and IGGC data. Gene-based analyses identified an additional 57 genes. Human ocular tissue gene expression analysis showed that most of the identified genes are enriched in optic nerve head tissue. Some of the identified loci exhibited pleiotropic effects with vertical cup-to-disc ratio, intraocular pressure, glaucoma and myopia. These results can enhance our understanding of the genetics of optic disc morphology and shed light on the genetic findings for other ophthalmic disorders such as glaucoma and other optic nerve diseases.
2017
Cited 18 times
Gene Therapy for Color Blindness.
Achromatopsia is a rare congenital cause of vision loss due to isolated cone photoreceptor dysfunction. The most common underlying genetic mutations are autosomal recessive changes in CNGA3, CNGB3, GNAT2, PDE6H, PDE6C, or ATF6. Animal models of Cnga3, Cngb3, and Gnat2 have been rescued using AAV gene therapy; showing partial restoration of cone electrophysiology and integration of this new photopic vision in reflexive and behavioral visual tests. Three gene therapy phase I/II trials are currently being conducted in human patients in the USA, the UK, and Germany. This review details the AAV gene therapy treatments of achromatopsia to date. We also present novel data showing rescue of a Cnga3-/- mouse model using an rAAV.CBA.CNGA3 vector. We conclude by synthesizing the implications of this animal work for ongoing human trials, particularly, the challenge of restoring integrated cone retinofugal pathways in an adult visual system. The evidence to date suggests that gene therapy for achromatopsia will need to be applied early in childhood to be effective.
DOI: 10.3201/eid2510.190497
2019
Cited 17 times
Comparison of Serologic Assays for Middle East Respiratory Syndrome Coronavirus
Middle East respiratory syndrome coronavirus (MERS-CoV) was detected in humans in 2012. Since then, sporadic outbreaks with primary transmission through dromedary camels to humans and outbreaks in healthcare settings have shown that MERS-CoV continues to pose a threat to human health. Several serologic assays for MERS-CoV have been developed globally. We describe a collaborative study to investigate the comparability of serologic assays for MERS-CoV and assess any benefit associated with the introduction of a standard reference reagent for MERS-CoV serology. Our study findings indicate that, when possible, laboratories should use a testing algorithm including >2 tests to ensure correct diagnosis of MERS-CoV. We also demonstrate that the use of a reference reagent greatly improves the agreement between assays, enabling more consistent and therefore more meaningful comparisons between results.
DOI: 10.1016/j.ogla.2020.12.002
2021
Cited 11 times
A Polygenic Risk Score Predicts Intraocular Pressure Readings Outside Office Hours and Early Morning Spikes as Measured by Home Tonometry
Intraocular pressure (IOP) elevations may occur in early morning or outside office hours and can be missed during routine in-clinic IOP measurements. Such fluctuations or peaks likely contribute to glaucoma progression. We sought to investigate the relationship between an IOP polygenic risk score (PRS) and short-term IOP profile. Cross-sectional study. Four hundred seventy-three eyes from 239 participants with suspected or established primary open-angle glaucoma sampled from 4 outpatient clinics in Australia between August 2016 and December 2019. Participants underwent Icare HOME (Icare Oy, Vanda, Finland) tonometer measurements to record IOP 4 times daily for 5 days. Unreliable measurements were excluded. A minimum of 2 days with at least 3 reliable measurements were required. We used a validated IOP PRS derived from 146 IOP-associated variants in a linear regression model adjusted for central corneal thickness and age. Highest recorded early morning IOP and mean IOP within and outside office hours. Early morning IOP spikes were defined by a higher early morning IOP than the maximum in-office hours IOP. Reliable measurements were obtained from 334 eyes of 176 participants (mean age, 64 ± 9 years). Eyes in the highest IOP PRS quintile showed an early morning IOP increase of 4.3 mmHg (95% confidence interval [CI], 1.4–7.3; P = 0.005) and mean increase in IOP outside office hours of 2.7 mmHg (95% CI, 0.61–4.7; P = 0.013) than the lowest quintile, which were significant independently after accounting for a recent in-clinic IOP measured by Goldmann applanation tonometry. Eyes in the highest PRS quintile were 5.4-fold more likely to show early morning IOP spikes than the lowest quintile (odds ratio 95% CI, 1.3–23.6; P = 0.023). A validated IOP PRS was associated with higher early morning IOP and mean IOP outside office hours. These findings support a role for genetic risk prediction of susceptibility to elevated IOP that may not be apparent during in-clinic hours, requiring more detailed clinical phenotyping using home tonometry, the results of which may guide additional interventions to improve IOP control.
DOI: 10.1038/s41598-023-37855-x
2023
Phenotypic consequences of a nanophthalmos-associated TMEM98 variant in human and mouse
Nanophthalmos is characterised by shorter posterior and anterior segments of the eye, with a predisposition towards high hyperopia and primary angle-closure glaucoma. Variants in TMEM98 have been associated with autosomal dominant nanophthalmos in multiple kindreds, but definitive evidence for causation has been limited. Here we used CRISPR/Cas9 mutagenesis to recreate the human nanophthalmos-associated TMEM98 p.(Ala193Pro) variant in mice. The p.(Ala193Pro) variant was associated with ocular phenotypes in both mice and humans, with dominant inheritance in humans and recessive inheritance in mice. Unlike their human counterparts, p.(Ala193Pro) homozygous mutant mice had normal axial length, normal intraocular pressure, and structurally normal scleral collagen. However, in both homozygous mice and heterozygous humans, the p.(Ala193Pro) variant was associated with discrete white spots throughout the retinal fundus, with corresponding retinal folds on histology. This direct comparison of a TMEM98 variant in mouse and human suggests that certain nanophthalmos-associated phenotypes are not only a consequence of a smaller eye, but that TMEM98 may itself play a primary role in retinal and scleral structure and integrity.
DOI: 10.1146/annurev-genom-121222-105817
2024
Polygenic Risk Scores Driving Clinical Change in Glaucoma
Glaucoma is a clinically heterogeneous disease and the world's leading cause of irreversible blindness. Therapeutic intervention can prevent blindness but relies on early diagnosis, and current clinical risk factors are limited in their ability to predict who will develop sight-threatening glaucoma. The high heritability of glaucoma makes it an ideal substrate for genetic risk prediction, with the bulk of risk being polygenic in nature. Here, we summarize the foundations of glaucoma genetic risk, the development of polygenic risk prediction instruments, and emerging opportunities for genetic risk stratification. Although challenges remain, genetic risk stratification will significantly improve glaucoma screening and management.
DOI: 10.1128/jvi.00900-18
2018
Cited 15 times
Characterization of Antibody Interactions with the G Protein of Vesicular Stomatitis Virus Indiana Strain and Other Vesiculovirus G Proteins
VSVind.G is currently regarded as the gold-standard envelope glycoprotein to pseudotype lentiviral vectors. However, recently other G proteins derived from vesiculoviruses have been proposed as alternative envelopes. Here, we investigated two commercially available anti-VSVind.G monoclonal antibodies for their ability to cross-react with other vesiculovirus G proteins, identified the epitopes they recognize, and explored their neutralization activity. We have identified 8G5F11, for the first time, as a cross-neutralizing antibody against several vesiculovirus G proteins. Furthermore, we elucidated the two different neutralization mechanisms employed by these two monoclonal antibodies. Understanding how cross-neutralizing antibodies interact with other G proteins may be of interest in the context of host-pathogen interaction and coevolution, as well as providing the opportunity to modify the G proteins and improve G protein-containing medicinal products and vaccine vectors.
DOI: 10.1136/bcr-2015-212733
2016
Cited 14 times
Single-eye trial of a topical carbonic anhydrase inhibitor versus intravitreal bevacizumab for the treatment of taxane drug-induced cystoid macula oedema
Taxanes are a class of microtubule stabilising agents used to treat a wide range of malignancies. Taxane drug-induced cystoid macula oedema (TDICMO) is a known but rare complication of therapy. First reported with Docetaxel in 2003 and Paclitaxel in 2007, there are currently less than 20 cases of TDICMO in the literature. Although most cases resolve following taxane cessation, several authors have tried using carbonic anhydrase inhibitors or intravitreal bevacizumab to accelerate resolution or when taxane therapy cannot be discontinued. We report the first published case of TDICMO treated with a single-eye trial of topical dorzolamide versus intravitreal bevacizumab.
DOI: 10.1038/s41541-019-0135-3
2019
Cited 14 times
Harmonization of Zika neutralization assays by using the WHO International Standard for anti-Zika virus antibody
During outbreaks of emerging viruses, such as the Zika outbreak in 2015-2016, speed and accuracy in detection of infection are critical factors to control the spread of the disease; often serological and diagnostic methods for emerging viruses are not well developed and validated. Thus, vaccines and treatments are difficult to evaluate due to the lack of comparable methods. In this study, we show how the 1st WHO International Standard for anti-Zika antibody was able to harmonize the neutralization titres of a panel of serological Zika-positive samples from laboratories worldwide. Expression of the titres in International Unit per millilitre reduced the inter-laboratory variance, allowing for greater comparability between laboratories. We advocate the use of the International Standard for anti-Zika virus antibodies for the calibration of neutralization assays to create a common language, which will permit a clear evaluation of the results of different clinical trials and expedite the vaccine/treatment development.
DOI: 10.1111/ceo.13686
2019
Cited 13 times
Using Icare HOME tonometry for follow‐up of patients with open‐angle glaucoma before and after selective laser trabeculoplasty
Abstract Importance Monitoring the results of selective laser trabeculoplasty (SLT) on intraocular pressure (IOP) using a home rebound tonometry. Background To evaluate the role of Icare HOME tonometry in open‐angle glaucoma patients being treated with SLT. Design A clinic‐based prospective case study. Participants Fourteen eyes from 14 patients diagnosed with primary open‐angle glaucoma were recruited. Methods The trabecular meshwork of each eye was treated 360° with a frequency‐doubled Q‐switched Nd:YAG laser. IOP was measured four times a day for a week before and after SLT. On the day of SLT, the patients were required to measure the IOP in the evening to record any IOP spikes. Main Outcome Measures The use of Icare HOME in following up patients post‐laser trabeculoplasty without the need for clinic attendance. Results Icare HOME recorded a significant reduction of 5.12 mmHg in the mean IOP post‐SLT (95% confidence interval [CI] 3.75‐6.50 mmHg, P &lt; .001). The maximum IOP was also reduced by 6.14 mmHg (95% CI 3.07‐9.21, P &lt; .001) with no IOP spikes recorded post‐SLT. There was a reduction in IOP fluctuation post‐SLT by 1.07 mmHg (95% CI 0.24‐1.89 mmHg, P = .021). No adverse effects for using the Icare HOME were reported by the study participants. Conclusions and Relevance This methodology could be highly useful for facilitating safe follow‐up of patients residing in remote and rural areas, thus reducing healthcare cost with better information on IOP.
DOI: 10.1167/iovs.63.3.26
2022
Cited 5 times
RNA Sequencing of Lens Capsular Epithelium Implicates Novel Pathways in Pseudoexfoliation Syndrome
Pseudoexfoliation syndrome (PEX) is a common systemic disease that results in severe and often irreversible vision loss. Despite considerable research effort, PEX remains incompletely understood. This study sought to perform the first RNAseq study in elucidate the pathophysiology of PEX, and contribute a publicly available transcriptomic data resource for future research.Human ocular lens capsular epithelium samples were collected from 25 patients with PEX and 39 non-PEX controls undergoing cataract surgery. RNA extracted from these specimens was subjected to polyadenylated (mRNA) selection and deep bulk RNA sequencing. Differential expression analysis investigated protein-coding gene transcripts. Exploratory analyses used pathway analysis tools, and curated class- and disease-specific gene sets.Differential expression analysis demonstrated that 2882 genes were differentially expressed according to PEX status. Genes associated with viral gene expression pathways were among the most upregulated, alongside genes encoding ribosomal and mitochondrial respiratory transport chain proteins. Cell adhesion protein transcripts including type 4 collagen subunits were downregulated.This comparative transcriptomic dataset highlights novel and previously recognized pathogenic pathways in PEX and provides the first comprehensive transcriptomic resource, adding an additional layer to build further understanding of PEX pathophysiology.
DOI: 10.1016/j.xops.2022.100159
2022
Cited 5 times
The APOE E4 Allele Is Associated with Faster Rates of Neuroretinal Thinning in a Prospective Cohort Study of Suspect and Early Glaucoma
To investigate the association between the apolipoprotein E (APOE) E4 dementia-risk allele and prospective longitudinal retinal thinning in a cohort study of suspect and early manifest glaucoma.Retrospective analysis of prospective cohort data.This study included all available eyes from participants recruited to the Progression Risk of Glaucoma: Relevant SNPs [single nucleotide polymorphisms] with Significant Association (PROGRESSA) study with genotyping data from which APOE genotypes could be determined.Apolipoprotein E alleles and genotypes were determined in PROGRESSA, and their distributions were compared with an age-matched and ancestrally matched normative cohort, the Blue Mountains Eye Study. Structural parameters of neuroretinal atrophy measured using spectral-domain OCT were compared within the PROGRESSA cohort on the basis of APOE E4 allele status.Longitudinal rates of thinning in the macular ganglion cell-inner plexiform layer (mGCIPL) complex and the peripapillary retinal nerve fiber layer (pRNFL).Rates of mGCIPL complex thinning were faster in participants harboring ≥1 copies of the APOE E4 allele (β = -0.13 μm/year; P ≤0.001). This finding was strongest in eyes affected by normal-tension glaucoma (NTG; β = -0.20 μm/year; P = 0.003). Apolipoprotein E E4 allele carriers were also more likely to be lost to follow-up (P = 0.01) and to demonstrate a thinner average mGCIPL complex (70.9 μm vs. 71.9 μm; P = 0.011) and pRNFL (77.6 μm vs. 79.2 μm; P = 0.045) after a minimum of 3 years of monitoring.The APOE E4 allele was associated with faster rates of mCGIPL complex thinning, particularly in eyes with NTG. These results suggest that the APOE E4 allele may be a risk factor for retinal ganglion cell degeneration in glaucoma.
DOI: 10.1371/journal.pone.0206684
2018
Cited 12 times
Prevalence and type of artefact with spectral domain optical coherence tomography macular ganglion cell imaging in glaucoma surveillance
Purpose The ganglion cell analysis (GCA) of the CIRRUSTM HD-OCT (Carl Zeiss, Meditec; Dublin, CA) provides measurement of the macular ganglion cell-inner plexiform layer (GCIPL) thickness. This study determined the frequency of scan artefacts and errors in GCIPL imaging in individuals undergoing HD-OCT surveillance for glaucoma. Method A total of 1439 eyes from 721 subjects enrolled in a prospective study assessing predictors of glaucoma progression underwent macular GCIPL imaging with the CIRRUS HD-OCT at recruitment. The prevalence of acquisition errors, segmentation errors, and co-morbid macular pathology was determined. Results A total of 87 (6.0%) of the 1439 scans had either acquisition errors, segmentation artefacts, or other macular pathology. The most common co-morbid macular pathology was epiretinal membrane in 2.2% of eyes. Conclusion The macular GCIPL scan was artefact free in 94% of eyes. However, epiretinal membrane and high myopia can cause scan artefact and should be considered when interpreting the results.
DOI: 10.1371/journal.pone.0088735
2014
Cited 11 times
Complement-Mediated Virus Infectivity Neutralisation by HLA Antibodies Is Associated with Sterilising Immunity to SIV Challenge in the Macaque Model for HIV/AIDS
Sterilising immunity is a desired outcome for vaccination against human immunodeficiency virus (HIV) and has been observed in the macaque model using inactivated simian immunodeficiency virus (SIV). This protection was attributed to antibodies specific for cell proteins including human leucocyte antigens (HLA) class I and II incorporated into virions during vaccine and challenge virus preparation. We show here, using HLA bead arrays, that vaccinated macaques protected from virus challenge had higher serum antibody reactivity compared with non-protected animals. Moreover, reactivity was shown to be directed against HLA framework determinants. Previous studies failed to correlate serum antibody mediated virus neutralisation with protection and were confounded by cytotoxic effects. Using a virus entry assay based on TZM-bl cells we now report that, in the presence of complement, serum antibody titres that neutralise virus infectivity were higher in protected animals. We propose that complement-augmented virus neutralisation is a key factor in inducing sterilising immunity and may be difficult to achieve with HIV/SIV Env-based vaccines. Understanding how to overcome the apparent block of inactivated SIV vaccines to elicit anti-envelope protein antibodies that effectively engage the complement system could enable novel anti-HIV antibody vaccines that induce potent, virolytic serological response to be developed.
DOI: 10.1016/s1164-5563(01)01124-4
2002
Cited 21 times
Effects of spatial heterogeneity on feeding behaviour of Porcellio scaber (Isopoda: Oniscidea)
Foraging behaviour of Porcellio scaber was observed in laboratory arenas in which the spatial distribution of patches of high quality food (powdered dicotyledonous leaf litter) was varied within a matrix of lower quality food (powdered grass leaf litter). The hypotheses that feeding behaviour of isopods would vary with the degree of clumping of high quality food patches and with the density of conspecifics, were tested. In more clumped treatments, animals spend less time on high quality food and more on a low quality one. At higher densities more time was spent searching. This effect was more pronounced in clumped treatments, but negligible in homogeneous ones. The effects of variation in the spatial heterogeneity of high quality foods on the trade-off between searching costs and intake-rate benefits for saprophages are discussed in the context of predictions from optimal foraging theory for scenarios in which intake-rate maximisation is constrained by nutrient limitation.
DOI: 10.1002/humu.24214
2021
Cited 7 times
A novel <i>GSN</i> variant outside the G2 calcium‐binding domain associated with Amyloidosis of the Finnish type
Gelsolin (GSN) variants have been implicated in amyloidosis of the Finnish type. This case series reports a novel GSN:c.1477T>C,p.(Trp493Arg) variant in a family with ocular and systemic features consistent with Finnish Amyloidosis. Exome sequencing performed on affected individuals from two families manifesting cutis laxa and polymorphic corneal stromal opacities demonstrated the classic GSN:c.654G>A,p.Asp214Asn variant in single affected individual from one family, and a previously undocumented GSN:c.1477T>C variant in three affected first-degree relatives from a separate family. Immunohistochemical studies on corneal tissue from a proband with the c.1477T>C variant identified gelsolin protein within histologically defined corneal amyloid deposits. This study reports a novel association between the predicted pathogenic GSN:c.1477T>C variant and amyloidosis of the Finnish type, and is the first to provide functional evidence of a pathological GSN variant at a locus distant to the critical G2 calcium-binding region, resulting in the phenotype of amyloidosis of the Finnish type.
DOI: 10.1002/mgg3.2023
2022
Cited 4 times
Diagnostic yield of candidate genes in an Australian corneal dystrophy cohort
Abstract Corneal dystrophies describe a clinically and genetically heterogeneous group of inherited disorders. The International Classification of Corneal Dystrophies (IC3D) lists 22 types of corneal dystrophy, 17 of which have been demonstrated to result from pathogenic variants in 19 identified genes. In this study, we investigated the diagnostic yield of genetic testing in a well‐characterised cohort of 58 individuals from 44 families with different types of corneal dystrophy. Individuals diagnosed solely with Fuchs endothelial corneal dystrophy were excluded. Clinical details were obtained from the treating ophthalmologist. Participants and their family members were tested using a gene candidate and exome sequencing approach. We identified a likely molecular diagnosis in 70.5% families (31/44). The detection rate was significantly higher among probands with a family history of corneal dystrophy (15/16, 93.8%) than those without (16/28, 57.1%, p = .015), and among those who had undergone corneal graft surgery (9/9, 100.0%) compared to those who had not (22/35, 62.9%, p = .041). We identified eight novel variants in five genes and identified five families with syndromes associated with corneal dystrophies. Our findings highlight the genetic heterogeneity of corneal dystrophies and the clinical utility of genetic testing in reaching an accurate clinical diagnosis.
DOI: 10.1167/iovs.64.3.11
2023
Physical Activity Is Associated With Macular Thickness: A Multi-Cohort Observational Study
To assess the association between physical activity and spectral-domain optical coherence tomography (SD-OCT)-measured rates of macular thinning in an adult population with primary open-angle glaucoma.The correlation between accelerometer-measured physical activity and rates of macular ganglion cell-inner plexiform layer (GCIPL) thinning was measured in 735 eyes from 388 participants of the Progression Risk of Glaucoma: RElevant SNPs with Significant Association (PROGRESSA) study. The association between accelerometer-measured physical activity and cross-sectional SD-OCT macular thickness was then assessed in 8862 eyes from 6152 participants available for analysis in the UK Biobank who had SD-OCT, ophthalmic, comorbidity, and demographic data.Greater physical activity was associated with slower rates of macular GCIPL thinning in the PROGRESSA study (beta = 0.07 µm/y/SD; 95% confidence interval [CI], 0.03-0.13; P = 0.003) after adjustment for ophthalmic, demographic and systemic predictors of macular thinning. This association persisted in subanalyses of participants characterized as glaucoma suspects (beta = 0.09 µm/y/SD; 95% CI, 0.03-0.15; P = 0.005). Participants in the upper tertile (greater than 10,524 steps/d) exhibited a 0.22-µm/y slower rate of macular GCIPL thinning than participants in the lower tertile (fewer than 6925 steps/d): -0.40 ± 0.46 µm/y versus -0.62 ± 0.55 µm/y (P = 0.003). Both time spent doing moderate/vigorous activity and mean daily active calories were positively correlated with rate of macular GCIPL thinning (moderate/vigorous activity: beta = 0.06 µm/y/SD; 95% CI, 0.01-0.105; P = 0.018; active calories: beta = 0.06 µm/y/SD; 95% CI, 0.006-0.114; P = 0.032). Analysis among 8862 eyes from the UK Biobank revealed a positive association between physical activity and cross-sectional total macular thickness (beta = 0.8 µm/SD; 95% CI, 0.47-1.14; P < 0.001).These results highlight the potential neuroprotective benefits of exercise on the human retina.
DOI: 10.1016/s0031-4056(24)01411-2
1994
Cited 20 times
Effects of headland management on carabid beetle communities in Breckland cereal fields
DOI: 10.1111/ceo.13466
2019
Cited 8 times
Long‐term survival rates of patients undergoing vitrectomy for diabetic retinopathy in an Australian population: a population‐based audit
Five-year survival rates in patients undergoing vitrectomy for diabetic retinopathy (DR) vary from 68% to 95%. No study has been conducted in an Australian population.We aimed to determine the survival rates of patients undergoing diabetic vitrectomy in an Australian population.Retrospective audit, tertiary centre hospitals and private practices.All individuals in South Australia and the Northern Territory who underwent their first vitrectomy for diabetic complications between January 1, 2007 and December 31, 2011.An audit of all eligible participants has been completed previously. Survival status as of July 6, 2018 and cause of death were obtained using SA/NT DataLink. Kaplan-Meier survival curves and multivariate cox-regressions were used to analyse survival rates and identify risk factors for mortality.Five-, seven- and nine-year survival rates.The 5-, 7- and 9-year survival rates were 84.4%, 77.9% and 74.7%, respectively. The most common cause of death was cardiovascular disease. Associated with increased mortality independent of age were Indigenous ethnicity (HR = 2.04, 95% confidence interval [CI]: 1.17-3.57, P = 0.012), chronic renal failure (HR = 1.76, 95% CI: 1.07-2.89, P = 0.026) and renal failure requiring dialysis (HR = 2.32, 95% CI: 1.25-4.32, P = 0.008).Long-term survival rates after diabetic vitrectomy in Australia are similar to rates reported in other populations. Indigenous ethnicity and chronic renal failure were the most significant factors associated with long-term mortality. This information can guide allocation of future resources to improve the prognosis of these high risk groups.
DOI: 10.1186/1742-4690-9-56
2012
Cited 6 times
Heterologous protection elicited by candidate monomeric recombinant HIV-1 gp120 vaccine in the absence of cross neutralising antibodies in a macaque model
Current data suggest that an efficacious human immunodeficiency virus type 1 (HIV-1) vaccine should elicit both adaptive humoral and cell mediated immune responses. Such a vaccine will also need to protect against infection from a range of heterologous viral variants. Here we have developed a simian-human immunodeficiency virus (SHIV) based model in cynomolgus macaques to investigate the breadth of protection conferred by HIV-1W61D recombinant gp120 vaccination against SHIVsbg and SHIVSF33 challenge, and to identify correlates of protection.High titres of anti-envelope antibodies were detected in all vaccinees. The antibodies reacted with both the homologous HIV-1W61D and heterologous HIV-1IIIB envelope rgp120 which has an identical sequence to the SHIVsbg challenge virus. Significant titres of virus neutralising antibodies were detected against SHIVW61D expressing an envelope homologous with the vaccine, but only limited cross neutralisation against SHIVsbg, SHIV-4 and SHIVSF33 was observed. Protection against SHIVsbg infection was observed in vaccinated animals but none was observed against SHIVSF33 challenge. Transfer of immune sera from vaccinated macaques to naive recipients did not confer protection against SHIVsbg challenge. In a follow-up study, T cell proliferative responses detected after immunisation with the same vaccine against a single peptide present in the second conserved region 2 of HIV-1 W61D and HIV-1 IIIB gp120, but not SF33 gp120.Following extended vaccination with a HIV-1 rgp120 vaccine, protection was observed against heterologous virus challenge with SHIVsbg, but not SHIVSF33. Protection did not correlate with serological responses generated by vaccination, but might be associated with T cell proliferative responses against an epitope in the second constant region of HIV-1 gp120. Broader protection may be obtained with recombinant HIV-1 envelope based vaccines formulated with adjuvants that generate proliferative T cell responses in addition to broadly neutralising antibodies.
DOI: 10.1111/ceo.13083
2017
Cited 6 times
Visual outcomes following vitrectomy for diabetic retinopathy amongst Indigenous and non‐Indigenous Australians in South Australia and the Northern Territory
Abstract Importance Visual outcomes following diabetic vitrectomy have not previously been studied in an Australian population. Background This analysis aimed to determine the rate of, and factors associated with visual success following diabetic vitrectomy performed for Indigenous and non‐Indigenous Australians, and investigate factors predisposing to early progression to diabetic retinopathy (DR) requiring vitrectomy. Design Retrospective, population‐based audit. Participants All patients undergoing vitrectomy for the complications of DR in South Australia (SA) and the Northern Territory (NT) between 2007 and 2011. Methods Medical records were audited and data collected, including demographics, diabetic history, past treatment for DR, indication for vitrectomy and visual acuity pre and postoperatively. Main Outcome Measures Visual success (gain of ≥15 ETDRS letters) at 6 and 12 months, postoperatively. Results A total of 495 diabetic vitrectomies, for 404 eyes of 335 patients were performed in SA and NT between 2007 and 2011. 77 (23%) patients requiring diabetic vitrectomy were Indigenous Australians. 87% of patients undergoing diabetic vitrectomy had stable or improved vision at 1 year, postoperatively. There was no significant difference between indigenous and non‐indigenous eyes achieving visual success ( P = 0.929). Timely preoperative laser treatment ( P = 0.03) and preoperative visual acuity ( P = 0.01) were the predominant factors associated with visual success. Conclusions and Relevance Indigenous patients are just as likely to have improved vision following diabetic vitrectomy as non‐Indigenous Australians. However, the small subset of indigenous patients with blind eyes prior to vitrectomy are significantly less likely to improve from surgery. The underlying factors associated with poor outcomes in this group requires further exploration.
DOI: 10.1016/b978-0-12-820472-6.00151-1
2022
Cited 3 times
Cystoid Macular Edema
Cystoid macular edema (CME) is a common ophthalmic condition, resulting from heterogenous ophthalmic and systemic conditions. Globally, CME is estimated to affect at least 21 million people each year secondary to diabetes and 3 million secondary to retinal vein occlusion. It is also responsible for visual impairment in around 40% of patients with uveitis. The pathogenesis of CME is still not fully understood but is primarily caused by the breakdown of the inner blood-retinal barrier. Most current therapies are reserved for treating visual impairment due to CME, which occurs later in the disease. Treatment of CME varies according to the underlying cause, most commonly with combinations of corticosteroids and anti-vascular endothelial growth factor inhibitors. Many patients with CME require frequent, repeated treatments for extended periods with not all eyes responding optimally. There is clearly an unmet need for new pharmaceutical therapies for sight-threatening CME. Current research and development strategies are focused on improving drug efficacy, prolonging effectiveness and targeting alternative molecular targets for CME.
DOI: 10.1167/iovs.18-24328
2018
Cited 5 times
A Novel Achromatopsia Mouse Model Resulting From a Naturally Occurring Missense Change in Cngb3
Purpose A local colony of inbred mice (129S6/SvEvTac origin), in isolation for over a decade, were found to have absent light-adapted electroretinogram (ERG) responses. We investigated the inheritance and genetic basis of this phenotype of cone photoreceptor function loss. Methods An affected 129S6/SvEvTac colony animal was outcrossed to a C57BL/6J mouse and intercrossed to investigate inheritance in the F2 generation. We performed ERG testing and targeted resequencing on genes of interest (Gnat2, Cnga3, Cngb3, Pde6c, Hcn1, Syne2). The eyes of a subset of animals underwent histologic immunostaining. Results All 129S6/SvEvTac colony animals tested lacked cone pathway function by ERG testing (n = 12), although rod pathway-based ERG responses remained unaffected. Outcross-intercross breeding showed a recessive inheritance pattern. A novel missense mutation was identified in the Cngb3 gene, which causes an amino acid substitution at a conserved residue (NM_013927)c.692G>A; p.(R231H). The recessive phenotype only affected homozygotes (χ2 = 39, P = 3.2e-10). Cones had normal morphology at postnatal day (PND) 70, but cone cell counts declined from PND 30 to PND 335 (P = 0.038), indicating progressive cone photoreceptor death. Conclusions We identified the spontaneous occurrence of a 10th model of cone photoreceptor function loss (cpfl10) in an isolated line of inbred mice. Our results indicate that this is caused by a novel missense mutation in the Cngb3 gene, with a fully recessive inheritance pattern. This mouse may provide a more appropriate background against which to assess CNGB3 achromatopsia gene therapy for missense mutations.
DOI: 10.1128/jvi.00606-19
2019
Cited 5 times
Vaccination of Macaques with DNA Followed by Adenoviral Vectors Encoding Simian Immunodeficiency Virus (SIV) Gag Alone Delays Infection by Repeated Mucosal Challenge with SIV
The simian immunodeficiency virus (SIV) macaque model represents the best animal model for testing new human immunodeficiency virus type 1 (HIV-1) vaccines. Previous studies employing replication-defective adenovirus (rAd) vectors that transiently express SIV internal proteins induced T cell responses that controlled virus load but did not protect against virus challenge. However, we show for the first time that SIV gag delivered in a DNA prime followed by a boost with an rAd vector confers resistance to SIV intrarectal challenge. Other partially successful SIV/HIV-1 protective vaccines induce antibody to the envelope and neutralize the virus or mediate antibody-dependent cytotoxicity. Induction of CD8 T cells which do not prevent initial infection but eradicate infected cells before infection becomes established has also shown some success. In contrast, the vaccine described here mediates resistance by a different mechanism from that described above, which may reflect CD4 T cell activity. This could indicate an alternative approach for HIV-1 vaccine development.
DOI: 10.1111/ceo.13838
2020
Cited 4 times
Updating the model of eye care for Aboriginal populations in remote Central Australia
Abstract Eye disease is the third‐highest contributor towards health inequality for Aboriginal Australians. Understanding how the Central Australian ophthalmology service addresses complexities of remote eye care is crucial in understanding how expansion can meet current and future needs. The present study analyses findings from the MEDLINE database and Governmental reports, and descriptive information from stakeholders in Central Australia and the Australian Department of Health. We describe the current Central Australian ophthalmology model at three levels; (a) the healthcare service level (specialized primary care, local/outreach optometry and ophthalmology services, and intensive extended surgical weeks), (b) the community level (local community staff, clinics and initiatives, and eye “champions” and mutual support), and (c) the healthcare system level (federal and state government, and private funding). We conclude that building full‐time specialist availability, and system‐wide approaches to increase patient utilisation, will facilitate overcoming barriers of remoteness, and create enduring improvements in Central Australian eye care and health‐inequality.
DOI: 10.3390/ijms21176055
2020
Cited 4 times
Analysis of Early Cone Dysfunction in an In Vivo Model of Rod-Cone Dystrophy
Retinitis pigmentosa (RP) is a generic term for a group of genetic diseases characterized by loss of rod and cone photoreceptor cells. Although the genetic causes of RP frequently only affect the rod photoreceptor cells, cone photoreceptors become stressed in the absence of rods and undergo a secondary degeneration. Changes in the gene expression profile of cone photoreceptor cells are likely to occur prior to observable physiological changes. To this end, we sought to achieve greater understanding of the changes in cone photoreceptor cells early in the degeneration process of the Rho−/− mouse model. To account for gene expression changes attributed to loss of cone photoreceptor cells, we normalized PCR in the remaining number of cones to a cone cell reporter (OPN1-GFP). Gene expression profiles of key components involved in the cone phototransduction cascade were correlated with tests of retinal cone function prior to cell loss. A significant downregulation of the photoreceptor transcription factor Crx was observed, which preceded a significant downregulation in cone opsin transcripts that coincided with declining cone function. Our data add to the growing understanding of molecular changes that occur prior to cone dysfunction in a model of rod-cone dystrophy. It is of interest that gene supplementation of CRX by adeno-associated viral vector delivery prior to cone cell loss did not prevent cone photoreceptor degeneration in this mouse model.
DOI: 10.1128/msphere.00568-22
2023
VelcroVax: a “Bolt-On” Vaccine Platform for Glycoprotein Display
Having varied approaches to the design and manufacture of vaccines is critical in being able to respond to worldwide needs and newly emerging pathogens. Virus-like particles (VLPs) form the basis of two of the most successful licensed vaccines (against hepatitis B virus [HBV] and human papillomavirus). They are produced by recombinant expression of viral structural proteins, which assemble into immunogenic nanoparticles. VLPs can be modified to present unrelated antigens, and here we describe a universal "bolt-on" platform (termed VelcroVax) where the capturing VLP and the target antigen are produced separately. We utilize a modified HBV core (HBcAg) VLP with surface expression of a high-affinity binding sequence (Affimer) directed against a SUMO tag and use this to capture SUMO-tagged gp1 glycoprotein from the arenavirus Junín virus (JUNV). Using this model system, we have solved the first high-resolution structures of VelcroVax VLPs and shown that the VelcroVax-JUNV gp1 complex induces superior humoral immune responses compared to the noncomplexed viral protein. We propose that this system could be modified to present a range of antigens and therefore form the foundation of future rapid-response vaccination strategies. IMPORTANCE The hepatitis B core protein (HBc) forms noninfectious virus-like particles, which can be modified to present a capturing molecule, allowing suitably tagged antigens to be bound on their surface. This system can be adapted and provides the foundation for a universal "bolt-on" vaccine platform (termed VelcroVax) that can be easily and rapidly modified to generate nanoparticle vaccine candidates.
DOI: 10.21203/rs.3.rs-2768991/v1
2023
Phenotypic consequences of a nanophthalmos-associated TMEM98 variant in human and mouse
Abstract Nanophthalmos is characterised by shorter posterior and anterior segments of the eye, with a predisposition towards high hyperopia and primary angle-closure glaucoma. Variants in TMEM98 have been associated with autosomal dominant nanophthalmos in multiple kindreds, but definitive evidence for causation has been limited. Here we used CRISPR/Cas9 mutagenesis to recreate the human nanophthalmos-associated TMEM98 p.Ala193Pro (A193P) variant in mice. The A193P variant was associated with ocular phenotypes in both mice and humans, with dominant inheritance in humans and recessive inheritance in mice. Unlike their human counterparts, A193P homozygous mutant mice had normal axial length, normal intraocular pressure, and structurally normal scleral collagen. However, in both homozygous mice and heterozygous humans, the A193P variant was associated with discrete white spots throughout the retinal fundus, with corresponding retinal folds on histology. This direct comparison of a TMEM98 variant in mouse and human suggests that certain nanophthalmos-associated phenotypes are not only a consequence of a smaller eye, but that TMEM98 may itself play a primary role in retinal and scleral structure and integrity.
DOI: 10.1080/01658107.2020.1867873
2021
Pallid Disc Oedema in a Young Patient: Clinical and Diagnostic Challenge
A mid-thirties male with end-stage renal failure receiving haemodialysis on a background of four failed renal transplants, post-transplant lymphoproliferative disorder,and autonomic dysfunction presented with acute vision change in his left eye. Over days his vision in that eye deteriorated from 20/25 to no light perception. Given his complex medical background he was extensively investigated for infective, inflammatory, infiltrative and vasculitic aetiologies to explain acute vision loss with pallid disc swelling. A final diagnosis of non-arteritic anterior ischaemic optic neuropathy secondary to refractive hypotension and haemodialysis was reached.
DOI: 10.1111/ceo.13400
2018
Sunday 18 November
Surgical correction of ametropias and the identification and management of corneal ectasias are separate but tightly intertwined issues of major significance.Corneal morphologic imaging (topography and tomography) is critical to identify corneal ectatic disorders such as keratoconus and to appropriately screen patients to determine suitability for corneal refractive surgery.A variety of devices and strategies have been used with varying degrees of success, but discrepancy exists in terms of the relative importance of various screening technologies and variables to identify the earliest manifestations of keratoconus.Placido-based corneal topography, Scheimpflug imaging, and anterior segment optical coherence tomography, especially epithelial thickness variations, all play a significant role in identifying keratoconic eyes in earlier stages.Despite multiple available technologies, there remains a gap in identifying ectatic corneal disease at its earliest manifestation, and there remains significant controversy and discrepancy in the literature about the relative value of different evaluations in distinguishing keratoconus suspect eyes from normal populations.The latest research shows that combining technologies provides better discriminating capability than using any device in isolation.Early identification of corneal ectasias using current technology is critical, but current tests in the clinic are morphological, not biomechanical, and therefore do not allow a definitive diagnosis at the earliest stages, resulting in some patients incorrectly receiving refractive surgery while others lose vision before cross-linking treatment is initiated.Thus, the need for accurate identification of subclinical ectasia has never been greater.The next step in corneal imaging will address direct biomechanical measurements in an accurate, reproducible way.
2016
WHO collaborative study to assess the suitability of an interim standard for antibodies to Ebola virus
In support of the WHO response to the Ebola crisis, NIBSC is undertaking a project to develop an International Standard for use in the calibration and control of Ebola antibody assays. The availability of International Standards (IS) for antibodies would facilitate the standardization of Ebola serological methods used in epidemiological studies to measure past or present Ebola virus disease and in vaccinology studies to measure antibodies elicited by vaccination in humans. In the absence of such standards, individual laboratories apply their own reference standards which are not harmonized with other laboratories and methods and thus cannot serve to improve the reproducibility between laboratories. Recommendations made by participants attending the Technical Workshop on the Standardisation of Serological and PCR assays for the detection of Ebola virus (NIBSC, UK, 5-6 March 2015), included the urgent prioritization of the development of an interim Ebola standard for serology assays while perusing the longer-term goal of establishing an International Standard according to published WHO guidelines and formally endorsed by the WHO Expert Committee on Biological Standardization (ECBS). This report describes the development and worldwide collaborative study evaluation of a panel of candidate Ebola antibody preparations for the selection of the most appropriate candidate to serve as the interim WHO standard for Ebola antibody assays.
DOI: 10.1016/j.jviromet.2013.08.011
2013
The production, characterisation and application of monoclonal antibodies generated by immunisation with HIV-1C clade RGP140 envelope protein
The native HIV-1 envelope spike exists as trimers on the virion surface. Therefore antibodies elicited following immunisation with trimeric envelope vaccines may be directed against epitopes found on functional envelope spikes. Novel monoclonal antibodies were produced by priming mice with plasmid DNA expressing either HIV-1 CN54 or ZM96 gp140 sequences, and boosting with CN54 trimeric rgp140. Spleen cells were fused with NS-0 cells and hybridomas were screened for production of antibodies which bound trimeric rgp140. 18 monoclonal antibodies (MAbs) were isolated from 16 colonies, which were characterised by binding in ELISA and Western blotting, neutralisation of pseudotyped viruses and isotype. Specificity for the third variable (V3) region was detected in 5 of these antibodies, suggesting that the trimeric protein did not alter the main focus of the response compared with monomeric protein. 3 MAbs were identified as neutralising in a pseudotype assay, all of which were mapped to the V3 region. Although cross clade binding of antibodies was detected the neutralisation was C clade specific.
DOI: 10.1016/j.xops.2021.100108
2022
Genetic Risk of Cardiovascular Disease Is Associated with Macular Ganglion Cell–Inner Plexiform Layer Thinning in an Early Glaucoma Cohort
PurposeTo evaluate the association between genetic risk for cardiovascular disease and retinal thinning in early glaucoma.DesignProspective, observational genetic association studyParticipantsMulticohort study combining a cohort of patients with suspect and early manifest primary open-angle glaucoma (POAG), a cohort of patients with perimetric POAG, and an external normative control cohort.MethodsA cardiovascular disease genetic risk score was calculated for 828 participants from the Progression Risk of Glaucoma: Relevant SNPs [single nucleotide polymorphisms] with Significant Association (PROGRESSA) study. Participants were characterized as showing either predominantly macular ganglion cell–inner plexiform layer (GCIPL), predominantly peripapillary retinal nerve fiber layer (pRNFL) or equivalent macular GCIPL and pRNFL spectral-domain OCT thinning. The cardiovascular disease genetic risk scores for these groups were compared to an internal reference group of stable suspected glaucoma and of an external normative population. Replication was undertaken by comparing the phenotypes of participants from the Australia New Zealand Registry of Advanced Glaucoma (ANZRAG) with the normative control group.Main Outcome MeasuresSpectral-domain OCT and Humphrey Visual Field (HVF) change.ResultsAfter accounting for age, sex, and intraocular pressure (IOP), participants with predominantly macular GCIPL thinning showed a higher cardiovascular disease genetic risk score than reference participants (odds ratio [OR], 1.76/standard deviation [SD]; 95% confidence interval [CI], 1.18–2.62; P = 0.005) and than normative participants (OR, 1.32/SD; 95% CI, 1.12–1.54; P = 0.002). This finding was replicated by comparing ANZRAG participants with predominantly macular GCIPL change with the normative population (OR, 1.39/SD; 95% CI, 1.05–1.83; P = 0.022). Review of HVF data identified that participants with paracentral visual field defects also demonstrated a higher cardiovascular disease genetic risk score than reference participants (OR, 1.85/SD; 95% CI, 1.16–2.97; P = 0.010). Participants with predominantly macular GCIPL thinning exhibited a higher vertical cup-to-disc ratio genetic risk score (OR, 1.48/SD; 95% CI, 1.24–1.76; P < 0.001), but an IOP genetic risk score (OR, 1.12/SD; 95% CI, 0.95–1.33; P = 0.179) comparable with that of the normative population.ConclusionsThis study highlighted the relationship between cardiovascular disease and retinal thinning in suspect and manifest glaucoma cases. To evaluate the association between genetic risk for cardiovascular disease and retinal thinning in early glaucoma. Prospective, observational genetic association study Multicohort study combining a cohort of patients with suspect and early manifest primary open-angle glaucoma (POAG), a cohort of patients with perimetric POAG, and an external normative control cohort. A cardiovascular disease genetic risk score was calculated for 828 participants from the Progression Risk of Glaucoma: Relevant SNPs [single nucleotide polymorphisms] with Significant Association (PROGRESSA) study. Participants were characterized as showing either predominantly macular ganglion cell–inner plexiform layer (GCIPL), predominantly peripapillary retinal nerve fiber layer (pRNFL) or equivalent macular GCIPL and pRNFL spectral-domain OCT thinning. The cardiovascular disease genetic risk scores for these groups were compared to an internal reference group of stable suspected glaucoma and of an external normative population. Replication was undertaken by comparing the phenotypes of participants from the Australia New Zealand Registry of Advanced Glaucoma (ANZRAG) with the normative control group. Spectral-domain OCT and Humphrey Visual Field (HVF) change. After accounting for age, sex, and intraocular pressure (IOP), participants with predominantly macular GCIPL thinning showed a higher cardiovascular disease genetic risk score than reference participants (odds ratio [OR], 1.76/standard deviation [SD]; 95% confidence interval [CI], 1.18–2.62; P = 0.005) and than normative participants (OR, 1.32/SD; 95% CI, 1.12–1.54; P = 0.002). This finding was replicated by comparing ANZRAG participants with predominantly macular GCIPL change with the normative population (OR, 1.39/SD; 95% CI, 1.05–1.83; P = 0.022). Review of HVF data identified that participants with paracentral visual field defects also demonstrated a higher cardiovascular disease genetic risk score than reference participants (OR, 1.85/SD; 95% CI, 1.16–2.97; P = 0.010). Participants with predominantly macular GCIPL thinning exhibited a higher vertical cup-to-disc ratio genetic risk score (OR, 1.48/SD; 95% CI, 1.24–1.76; P < 0.001), but an IOP genetic risk score (OR, 1.12/SD; 95% CI, 0.95–1.33; P = 0.179) comparable with that of the normative population. This study highlighted the relationship between cardiovascular disease and retinal thinning in suspect and manifest glaucoma cases.
DOI: 10.1101/330910
2018
Characterisation of Antibody Interactions with the G Protein of Vesicular Stomatitis Virus Indiana Strain and Other Vesiculovirus G Proteins
ABSTRACT Vesicular stomatitis virus Indiana strain G protein (VSVind.G) is the most commonly used envelope glycoprotein to pseudotype lentiviral vectors (LV) for experimental and clinical applications. Recently, G proteins derived from other vesiculoviruses (VesG), for example Cocal virus, have been proposed as alternative LV envelopes with possible advantages compared to VSVind.G. Well-characterised antibodies that recognise VesG will be useful for vesiculovirus research, development of G protein-containing advanced therapy medicinal products (ATMPs), and deployment of VSVind-based vaccine vectors. Here we show that one commercially available monoclonal antibody, 8G5F11, binds to and neutralises G proteins from three strains of VSV as well as Cocal, and Maraba viruses, whereas the other commercially available monoclonal anti-VSVind.G antibody, IE9F9, binds to and neutralises only VSVind.G. Using a combination of G protein chimeras and site-directed mutations, we mapped the binding epitopes of IE9F9 and 8G5F11 on VSVind.G. IE9F9 binds close to the receptor binding site and competes with soluble low-density lipoprotein receptor (LDLR) for binding to VSVind.G, explaining its mechanism of neutralisation. In contrast, 8G5F11 binds close to a region known to undergo conformational changes when the G protein moves to its post-fusion structure, and we propose that 8G5F11 cross-neutralises VesGs by inhibiting this. IMPORTANCE VSVind.G is currently regarded as the gold-standard envelope to pseudotype lentiviral vectors. However, recently other G proteins derived from vesiculoviruses have been proposed as alternative envelopes. Here, we investigated two anti-VSVind.G monoclonal antibodies for their ability to cross-react with other vesiculovirus G proteins, and identified the epitopes they recognise, and explored the mechanisms behind their neutralisation activity. Understanding how cross-neutralising antibodies interact with other G proteins may be of interest in the context of host-pathogen interaction and co-evolution as well as providing the opportunity to modify the G proteins and improve G protein-containing medicinal products and vaccine vectors.
DOI: 10.1111/ceo.13332
2018
Canaloplasty case series for primary open‐angle glaucoma in rural Australia
Clinical & Experimental OphthalmologyVolume 46, Issue 9 p. 1095-1097 Letter to the Editor Canaloplasty case series for primary open-angle glaucoma in rural Australia Deric W De Wit FRANZCO, Deric W De Wit FRANZCO Tamara Private Hospital, Tamworth, New South Wales, AustraliaSearch for more papers by this authorMark M Hassall MBBS DPhil(Oxon), Corresponding Author Mark M Hassall MBBS DPhil(Oxon) m.hassall@gmail.com orcid.org/0000-0002-6180-7954 Tamara Private Hospital, Tamworth, New South Wales, AustraliaCorrespondence: Dr Mark M Hassall, Department of Ophthalmology, Flinders University, Level 3 Carpark Offices, Flinders Medical Centre, Bedford Park, SA 5042, Australia. Email: m.hassall@gmail.comSearch for more papers by this author Deric W De Wit FRANZCO, Deric W De Wit FRANZCO Tamara Private Hospital, Tamworth, New South Wales, AustraliaSearch for more papers by this authorMark M Hassall MBBS DPhil(Oxon), Corresponding Author Mark M Hassall MBBS DPhil(Oxon) m.hassall@gmail.com orcid.org/0000-0002-6180-7954 Tamara Private Hospital, Tamworth, New South Wales, AustraliaCorrespondence: Dr Mark M Hassall, Department of Ophthalmology, Flinders University, Level 3 Carpark Offices, Flinders Medical Centre, Bedford Park, SA 5042, Australia. Email: m.hassall@gmail.comSearch for more papers by this author First published: 01 June 2018 https://doi.org/10.1111/ceo.13332Citations: 1 Conflict of interest: None declared. Funding sources: None declared. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume46, Issue9December 2018Pages 1095-1097 RelatedInformation
DOI: 10.1016/j.ijid.2018.11.035
2019
Use of Pseudotyped viruses for the production of reference materials as part of emerging viral outbreak preparedness
Purpose: The recent public health emergencies of international concern (PHEIC), caused by Ebola and Zika virus, have highlighted the lack of prophylactic treatments and need for effective diagnostics for emerging viruses. In response to this, we established International Reference Reagents for antibody detection, which enables the comparison of results from laboratories worldwide undertaking treatment/vaccine efficacy clinical trials. The requirement for high containment facilities to handle viruses with outbreak potential, such as BSL4 for Ebola virus, is a constraining challenge. We have developed serological assays using replication defective pseudotyped viruses (PV) for the evaluation of reference material to avert high containment requirements. Methods & Materials: The preferred candidate material is a pool of plasma or sera from convalescent patients as this provides a commutable standard. For the reference material for Ebola antibody, several donations were received at NIBSC and solvent-detergent treated to ensure inactivation of virus. Characterisation is performed in-house using both PV neutralisation assays and ELISA platforms. PV is produced via plasmid transfection of 293T cells, with plasmids encoding a lentiviral core component, a reporter gene which is packaged within the core and the sequence of the envelope protein for the virus of interest. The ability of candidate material to block PV entry into target cells is measured via reporter signal reduction. Results: Following a WHO-sponsored International Collaborative study, the 1st WHO International Standard for Ebola virus antibodies was established in 2017. Participants in the collaborative study evaluated the candidate materials using assays available in their laboratories. Data from neutralisation assays employing PV with either a lentiviral or vesiculoviral core component was correlated with the wildtype assay and showed a better correlation coefficient when the vesiculovirus PV system was used. Conclusion: To support preparedness activities, antibody reference materials are now being established for other WHO priority pathogens such as Lassa and Nipah virus. To characterise the serological material at a low containment level, we have established assays using PV generated with both the lentiviral and vesiculovirus platforms. The two systems are currently being investigated to determine the most appropriate for each high containment virus.
DOI: 10.1111/ceo.13531
2019
Long‐term survival rates of patients undergoing vitrectomy for diabetic retinopathy in an Australian population: A population‐based audit—Response
None delcared.
DOI: 10.1097/apo.0000000000000356
2021
Ruptured Retinal Arterial Macroaneurysm
A 76-year-old female presented with a 2-week history of floaters in the left eye on a background of hypertension. Her vision was 6/6 in both eyes with a normal anterior segment. Posterior segment showed a well-demarcated pale retinal lesion, with corresponding auxiliary imaging confirming the diagnosis of a ruptured retinal arterial macroaneurysm (RAM) (Fig. 1). RAMs are acquired vascular abnormalities of the retinal arterioles. Main risk factors for RAMs are advancing age and hypertension.1 Although most RAMs do not require treatment, they can often mimic other more sinister conditions, such as choroidal melanoma.2FIGURE 1: A, Colour fundus photograph showing a pale, well-demarcated area of subretinal blood and intraretinal haemorrhage overlying it, with B, corresponding autofluorescence. C, Fluorescein angiogram shows the focal area of leakage and surrounding blocked fluorescence. D, Hyperreflective areas on OCT are consistent with subretinal haemorrhage.
2016
Are Indigenous Australians more likely to require vitrectomy for end-stage diabetic retinopathy? : A 5 year audit of vitreoretinal surgery for diabetic retinopathy.
2016
Identification of a potential new mouse model of chromatopsia through spontaneous occurrence of cone pathway function loss
2017
A naturally occurring mouse model of achromatopsia caused by a novel missense change in Cngb3.
2017
Cone opsins and Crx are gene therapy candidates for the revival of cone photoreceptors in an RP mouse model
2017
AN IMPROVED MODEL OF ACHROMATOPSIA FOR PRE-CLINICAL DEVELOPMENT OF GENE AND CELL THERAPIES
2017
WHO collaborative study to assess the suitability of the 1st International Standard and the 1st International Reference Panel for antibodies to Ebola virus. WHO Expert Committee On Biological Standardization
DOI: 10.1016/s2055-6640(20)30764-0
2017
P23 Strategies towards the elimination of viral hepatitis in Queensland
DOI: 10.1016/b978-0-12-820472-6.00154-7
2022
Gene Therapy, Diet and Drug Approaches to Treating Inherited Retinal Disease
Inherited retinal diseases are the commonest cause of vision loss in the working-age populace. They comprise a heterogeneous group of conditions, with over 300 genes and loci identified to date. The general aim of treatment until recently had been to slow progression: however, some degree of functional restoration is possible with specific therapies (e.g., gene therapy). Medical treatments include vitamins and nutritional supplements, but the evidence for their utility is weak. Methods of neuroprotection of remaining photoreceptors include neurotrophic factors, inhibitors of apoptosis, calpain inhibitors and rod-derived cone viability factor; none have yet to reach the clinic. Clinical trials are underway investigating therapies for visual cycle modulation, anti-oxidant medications, anti-inflammatory agents, complement inhibitor and microglial modulation. Some of these have the advantage of repurposing medications widely prescribed for other indications, such as N-acetylcysteine. There has been considerable progress in retinal gene therapy, culminating in the first approved gene therapy for RPE65-associated retinopathy, affecting around 1% of patients with inherited retinal degeneration. Future directions are likely to involve an expansion of causative mechanism-independent approaches, such as neuroprotection, optogenetics and photoswitches, which address the issue of genetic diversity. Furthermore, in the field of retinal gene therapy, payload delivery continues to undergo significant development to address current limitations, such as payload size, tropism and immunogenicity. The concept of combination therapies—which are well developed in other fields—are also yet to be explored fully in retinal gene therapy.
DOI: 10.1101/2022.04.22.489148
2022
VelcroVax: a ‘bolt-on’ vaccine platform technology improves antibody titres against a viral glycoprotein in mice
Abstract Having varied approaches to the design and manufacture of vaccines is critical in being able to respond to worldwide needs and to newly emerging pathogens. Virus-like particle (VLP) vaccines form the basis of two of the most successful licensed vaccines (against hepatitis B virus (HBV) and human papillomavirus). They are produced by recombinant expression of viral structural proteins, which self-assemble into immunogenic nanoparticles. VLPs can also be modified to present unrelated antigens, and here we describe a universal ‘bolt-on’ vaccine platform (termed VelcroVax) where the capturing VLP and the target antigen (hapten) are produced separately. We utilise a modified HBV core (HBcAg) VLP, with surface expression of a high-affinity binding sequence (Affimer) directed against a SUMO tag and use this to capture SUMO-tagged gp1 glycoprotein from the arenavirus, Junín virus (JUNV). Using this model system, we have solved high-resolution structures of VelcroVax VLPs, and shown that the VelcroVax-JUNV gp1 complex induces superior humoral immune responses compared to the non-complexed viral protein. We propose that this system could be modified to present a range of haptens and therefore form the foundation of future rapid-response vaccination strategies.
2018
Mechanisms of cone dysfunction in inherited retinal degenerations
This thesis examines the mechanisms of cone dysfunction in two different inherited retinal diseases: Achromatopsia and Retinitis Pigmentosa (RP). The first, minor, component of the thesis explored and characterised the loss of cone function in a novel mouse model of achromatopsia (cpfl10). The second, major, component of the thesis explored the loss of cone function in a mouse model of RP. I hypothesised that the cone function lost in RP could be restored using AAV vectors to over-express down regulated cone genes. This thesis subsequently developed and tested two AAV vectors delivering CRX and OPN1LW genes to photoreceptors in RP mice. Achromatopsia is a congenital condition characterised by absent or diminished cone function due to mutations of a single gene, typically those involved in the cone phototransduction cascade. This thesis provides a detailed phenotype of a novel cpfl10 mouse model of Achromatopsia that arose spontaneously in a local mouse colony. The causative (NM_013927)c.692G>A; p.(R231H) missense mutation in Cngb3 was also identified and explored. Retinitis pigmentosa (RP) is an inherited retinal degeneration in which secondary loss of cones follows the initial death of genetically abnormal rod photoreceptors. Strategies to prolong cone photosensitivity or survival would offer an important treatment. Such universal interventions could be effective regardless of which genetic mutation is underlying primary rod death. The molecular mechanisms by which cone photoreceptors lose photosensitivity in RP are poorly understood. I examined the gene expression profile of the cone phototransduction cascade in the Rho-/- mouse model of RP and correlated these changes to declining retinal function. The cone opsins were substantially down-regulated, as was the photoreceptor transcription factor Crx. I hypothesised that the cone function lost in RP could be restored using AAV vectors to over-express these down regulated cone genes. Using an AAV gene therapy vectors, I delivered the human homologs CRX and OPN1LW to the retinas of the same Rho-/- mouse model. Both vectors successfully transduced photoreceptors and RPE cells across three different doses. Transduced retinas did not show any improvement in cone function or survival. Whilst the observed down-regulation of cone genes correlates with cone function loss, it appears that both down-regulation and dysfunction arise from an unknown common cause. Ongoing research into mechanisms of metabolic starvation, oxidative stress and trophic factors in cone cell death offer promise for a common intervention to rescue cone photoreceptors.
DOI: 10.1016/j.ijid.2018.11.314
2019
Production and application of reference materials for high containment RNA viruses
Purpose: Accurate diagnosis in an outbreak scenario is crucial for the provision of appropriate healthcare and treatments. For emerging pathogens, the assays used for the diagnosis are either absent or poorly developed. A vital tool is the provision of appropriate reference standards, which allows for harmonisation of results from laboratories worldwide. Use of killed virus will be ideal, but for high containment level pathogens (BSL4) proving inactivation may be challenging, and their distribution globally hampered by bureaucratic requirements and legislation. As an alternative we evaluated a lentiviral vector platform to package RNA of the pathogen of interest within an HIV-like particle to act as reference material in nucleic acid amplification technology (NAT)-based tests. Methods & Materials: During the Ebola outbreak in Western Africa in 2013–15, we developed a chimeric virus by incorporating Ebola virus RNA into virus-like particles for use with diagnostic kit or in house quantitative PCR and digital PCR. Ebola virus Makona strain sequences were synthesised in vitro and incorporated within a lentiviral vector plasmid. This was transfected into 293T cells together with a packaging plasmid containing HIV-1 gag and pol. The chimeric particles were harvested, purified and formulated in a universal buffer before lyophilisation. Results: The freeze-dried preparations were evaluated in an WHO-sponsored International Collaborative study in which participants were asked to test the candidate material using assays routinely used in their laboratories. The HIV-Ebola chimeric particles were able to harmonise data received from the participants and reduce the inter-laboratory variation. Based on these results, the WHO Expert committee on Biological Standardisation established the material as an International Reference Reagent. Conclusion: The lentiviral packaging system represent an enabling technology to assist the development and calibration of diagnostic kits. It is a safe alternative to handling a high containment level pathogen and obviates the issues related to bioterrorism law. Furthermore, this type of reference material can be prepared contemporaneously or in advance of any viral outbreak to assist calibration of sensitive and specific assays and their harmonisation through standardisation at the time of the emergency when they are most urgently needed.
2018
Assessment of adjunctive gene therapy to dormant cones in end-stage retinitis pigmentosa
2018
A POLYGENIC RISK SCORE THAT PREDICTS FAMILIAL GENETIC RISK IN GLAUCOMA
2019
A glaucoma polygenic risk score strongly associated with disease prediction and treatment intensity.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.
2019
The correlation between Glaucoma polygenic risk score and IOP measured by Icare (R) HOME tonometry within and outside of office hours
2020
Normal tension glaucoma is associated with cognitive impairment
2019
Glaucoma polygenic risk score predicts treatment intensity and RNFL loss in glaucoma suspects
2020
A polygenic risk score predicts intraocular pressure fluctuation and readings outside office hours as measured by home tonometry
DOI: 10.1111/ceo.13627
2019
Saturday 09 November
In this talk she describes how Australian astronomers are leading the world in creating innovative new 'eyes' through which
DOI: 10.1111/ceo.13628
2019
Sunday 10 November
Purpose: Blindness from retinopathy of prematurity (ROP) is largely preventable with timely detection and treatment.Treatment is predominantly indicated by the presence of plus disease, defined by posterior retinal vessel tortuosity and dilation.This study describes the development of a deep-learning algorithm, ROP.AI, able to automatically diagnose plus disease in fundal images.Methods: ROP.AI was trained using 6974 fundal images from Australasian image databases.Each image was assigned a diagnosis per real-world routine ROP screening and classified as nil plus or plus disease.The algorithm was trained using 80% of the images and validated against its remaining 20% within a holdout test set.Performance in diagnosing plus disease was evaluated within an independent set of 90 images.As a screening tool, the algorithm's operating point was optimised for sensitivity and negative predictive value, and performance re-evaluated.Results: Of 6974 fundal images, 5336 (76.5%) were graded as nil plus and 1638 (23.5%), plus disease.For plus disease diagnosis within the holdout test set, the algorithm achieved a 96.6% sensitivity, 98.0% specificity, and 97.3±0.7% accuracy.AUROC was 0.99.Within the independent set, the algorithm achieved a 93.9% sensitivity, 80.7% specificity and 95.8% negative predictive value.Following operating point optimisation, the algorithm diagnosed plus disease with a 97.0%sensitivity and 97.8% negative predictive value.Conclusion: ROP.AI is a deep-learning algorithm able to automatically diagnose plus disease with high sensitivity and negative predictive value.With ROP's growing global disease burden, its future development may allow for novel models of screening and care. P0402
DOI: 10.1007/978-981-15-7644-7_35
2020
Retinal Gene Therapy
DOI: 10.1016/j.ijid.2020.11.041
2020
Evaluation of a serological reference panel for Lassa virus
Background: Lassa virus (LASV) is endemic in several West African countries, causing seasonal outbreaks. While about 80% of infections are asymptomatic, it can result in severe haemorrhagic fever. The disease incidence has been increasing each year, with more than 700 confirmed cases in 2019. As identified in the WHO R&D Blueprint, there is a lack of, and therefore a need, to develop effective treatments and vaccines. The availability of an antibody reference reagent early in this process is of value, allowing assay harmonisation by calibration to the reference which is given an arbitrary unitage. This will enable the comparison of Lassa serological data reported between laboratories and at different stages of vaccine efficacy clinical trials. Currently, the Coalition for Epidemic Preparedness Innovations (CEPI) is funding the development of six vaccines against LASV. We are working with CEPI to make available LASV serological reference reagents for use by developers. Methods and materials: We received donations of sera from individuals recovered from LASV in Nigeria and Sierra Leone. Before arrival at NIBSC, samples were certified as negative for LASV. Characterisation was performed to confirm the presence of specific antibodies using the Zalgen ReLASV® pan-Lassa pre-fusion GP and NP ELISA kits and using an in-house VSV-based pseudotyped virus neutralisation assay, incorporating either a lineage II or IV LASV glycoprotein. In partnership with CEPI a feasibility study was launched, with vaccine and assay developers testing the candidate samples in a variety of assays. Results: A Lassa convalescent serum panel containing high, medium and low titer antibodies from two distinct geographical areas, have been evaluated in a feasibility study by six participants, using serological assays in use in their laboratories. Data returned has been statistically analysed to access whether the use of a common reference reagent can reduce inter-laboratory variation and harmonise results from different laboratories. Conclusion: We have established a Working Standard and Reference Panel for LASV serology for the harmonization and calibration of Lassa serological assay to support vaccine development, diagnostics and research. We are also sourcing material towards the establishment of a WHO International Standard, the highest order reference reagent, with a Collaborative Study involving laboratories worldwide.
2021
A novel gelsolin variant associated with Familial Amyloidosis of the Finnish type in an Australian family
2021
Hypercholestolaemia predicts disease progression in primary open-angle glaucoma