Critical Dependence on Area in Relationship between ARMS2/HTRA1 Genotype and Faster Geographic Atrophy Enlargement: Age-Related Eye Disease Study 2 Report Number 33.

PURPOSE: To analyze ARMS2/HTRA1 as a risk factor for faster geographic atrophy (GA) enlargement according to (1) GA area and (2) contiguous enlargement versus progression to multifocality. DESIGN: Age-Related Eye Disease Study 2 (AREDS2) cohort analysis. PARTICIPANTS: Eyes with GA: 546 eyes of 406 participants. METHODS: Geographic atrophy area was measured from color fundus photographs at annual visits. Mixed-model regression of square root of GA area and proportional hazards regression of progression to multifocality were analyzed by ARMS2 genotype. MAIN OUTCOME MEASURES: Change in square root GA area and progression to multifocality. RESULTS: Geographic atrophy enlargement was significantly faster with ARMS2 risk alleles (P < 0.0001) at 0.224 mm/year (95% CI, 0.195-0.252 mm/year), 0.298 mm/year (95% CI, 0.271-0.324 mm/year), and 0.317 mm/year (95% CI, 0.279-0.355 mm/year), for 0 to 2 risk alleles, respectively. However, a significant interaction (P = 0.011) was observed between genotype and baseline area. In eyes with very small area (< 1.9 mm2), enlargement was significantly faster with ARMS2 risk alleles (P < 0.0001) at 0.193 mm/year (95% CI, 0.162-0.225 mm/year) versus 0.304 mm/year (95% CI, 0.280-0.329 mm/year) for 0 versus 1 to 2 risk alleles, respectively. With moderately small (1.9-3.8 mm2) or medium to large (≥ 3.8 mm2) area, enlargement was not significantly faster with ARMS2 risk alleles (P = 0.66 and P = 0.70, respectively). In nonmultifocal GA, enlargement was significantly faster with ARMS2 risk alleles (P = 0.001) at 0.175 mm/year (95% CI, 0.142-0.209 mm/year), 0.226 mm/year (95% CI, 0.193-0.259 mm/year), and 0.287 mm/year (95% CI, 0.237-0.337 mm/year) with 0 to 2 risk alleles, respectively. ARMS2 genotype was not associated significantly with progression to multifocal GA. CONCLUSIONS: The relationship between ARMS2/HTRA1 genotype and faster GA enlargement depends critically on GA area: risk alleles represent a strong risk factor for faster enlargement only in eyes with very small area. They increase the growth rate more through contiguous enlargement than progression to multifocality. ARMS2/HTRA1 genotype is more important in increasing risk of progression to GA and initial GA enlargement (contiguously) than in subsequent enlargement or progression to multifocality. These findings may explain some discrepancies between previous studies and have implications for both research and clinical practice. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

The Impact of ARMS2 (rs10490924), VEGFA (rs3024997), TNFRSF1B (rs1061622), TNFRSF1A (rs4149576), and IL1B1 (rs1143623) Polymorphisms and Serum Levels on Age-Related Macular Degeneration Development and Therapeutic Responses.

Age-related macular degeneration (AMD) is a major global health problem as it is the leading cause of irreversible loss of central vision in the aging population. Anti-vascular endothelial growth factor (anti-VEGF) therapies are effective but do not respond optimally in all patients. This study investigates the genetic factors associated with susceptibility to AMD and response to treatment, focusing on key polymorphisms in the ARMS2 (rs10490924), IL1B1 (rs1143623), TNFRSF1B (rs1061622), TNFRSF1A (rs4149576), VEGFA (rs3024997), ARMS2, IL1B1, TNFRSF1B, TNFRSF1A, and VEGFA serum levels in AMD development and treatment efficacy. This study examined the associations of specific genetic polymorphisms and serum protein levels with exudative and early AMD and the response to anti-VEGF treatment. The AA genotype of VEGFA (rs3024997) was significantly associated with a 20-fold reduction in the odds of exudative AMD compared to the GG + GA genotypes. Conversely, the TT genotype of ARMS2 (rs10490924) was linked to a 4.2-fold increase in the odds of exudative AMD compared to GG + GT genotypes. In females, each T allele of ARMS2 increased the odds by 2.3-fold, while in males, the TT genotype was associated with a 5-fold increase. Lower serum IL1B levels were observed in the exudative AMD group compared to the controls. Early AMD patients had higher serum TNFRSF1B levels than controls, particularly those with the GG genotype of TNFRSF1B rs1061622. Exudative AMD patients with the CC genotype of TNFRSF1A rs4149576 had lower serum TNFRSF1A levels compared to the controls. Visual acuity (VA) analysis showed that non-responders had better baseline VA than responders but experienced decreased VA after treatment, whereas responders showed improvement. Central retinal thickness (CRT) reduced significantly in responders after treatment and was lower in responders compared to non-responders after treatment. The T allele of TNFRSF1B rs1061622 was associated with a better response to anti-VEGF treatment under both dominant and additive genetic models. These findings highlight significant genetic and biochemical markers associated with AMD and treatment response. This study found that the VEGFA rs3024997 AA genotype reduces the odds of exudative AMD, while the ARMS2 rs10490924 TT genotype increases it. Lower serum IL1B levels and variations in TNFRSF1B and TNFRSF1A levels were linked to AMD. The TNFRSF1B rs1061622 T allele was associated with better anti-VEGF treatment response. These markers could potentially guide risk assessment and personalized treatment for AMD.

Current Views on Chr10q26 Contribution to Age-Related Macular Degeneration.

Age-related macular degeneration (AMD) is the leading cause of blindness in the global aging population. Familial aggregation and genome-wide association (GWA) studies have identified gene variants associated with AMD, implying a strong genetic contribution to AMD development. Two loci, on human Chr 1q31 and 10q26, respectively, represent the most influential of all genetic factors. While the role of CFH at Chr 1q31 is well established, uncertainty remains about the genes ARMS2 and HTRA1, at the Chr 10q26 locus. Since both genes are in strong linkage disequilibrium, assigning individual gene effects is difficult. In this chapter, we review current literature about ARMS2 and HTRA1 and their relevance to AMD risk. Future studies will be necessary to unravel the mechanisms by which they contribute to AMD.

Binding of Gtf2i-ß/δ transcription factors to the ARMS2 gene leads to increased circulating HTRA1 in AMD patients and in vitro.

The disease-initiating molecular events for age-related macular degeneration (AMD), a multifactorial retinal disease affecting many millions of elderly individuals worldwide, are still unknown. Of the over 30 risk and protective loci so far associated with AMD through whole genome-wide association studies (GWAS), the Age-Related Maculopathy Susceptibility 2 (ARMS2) gene locus represents one of the most highly associated risk regions for AMD. A unique insertion/deletion (in/del) sequence located immediately upstream of the High Temperature Requirement A1 (HTRA1) gene in this region confers high risk for AMD. Using electrophoretic mobility shift assay (EMSA), we identified that two Gtf2i-ß/δ transcription factor isoforms bind to the cis-element 5'- ATTAATAACC-3' contained in this in/del sequence. The binding of these transcription factors leads to enhanced upregulation of transcription of the secretory serine protease HTRA1 in transfected cells and AMD patient-derived induced pluripotent stem cells (iPSCs). Overexpression of Htra1 in mice using a CAG-promoter demonstrated increased blood concentration of Htra1 protein, caused upregulation of vascular endothelial growth factor (VEGF), and produced a choroidal neovascularization (CNV)-like phenotype. Finally, a comparison of 478 AMD patients to 481 healthy, age-matched controls from Japan, India, Australia, and the USA showed a statistically increased level of secreted HTRA1 blood concentration in AMD patients compared with age-matched controls. Taken together, these results suggest a common mechanism across ethnicities whereby increased systemic blood circulation of secreted serine protease HTRA1 leads to subsequent degradation of Bruch's membrane and eventual CNV in AMD.

The Phenotypic Course of Age-Related Macular Degeneration for ARMS2/HTRA1: The EYE-RISK Consortium.

PURPOSE: Age-related maculopathy susceptibility 2 (ARMS2) is considered the most enigmatic of the genes for age-related macular degeneration (AMD). We investigated the phenotypic course and spectrum of AMD for the risk haplotype at the ARMS2 and high-temperature requirement A serine peptidase 1 (HTRA1) locus in a large European consortium. DESIGN: Pooled analysis of 4 case-control and 6 cohort studies. PARTICIPANTS: Individuals (N = 17 204) aged 55 years or older participating in the European Eye Epidemiology consortium. METHODS: Age-related macular degeneration features and macular thickness were determined on multimodal images; data on genetics and phenotype were harmonized. Risks of AMD features for rs3750486 genotypes at the ARMS2/HTRA1 locus were determined by logistic regression and were compared with a genetic risk score (GRS) of 19 variants at the complement pathway. Lifetime risks were estimated with Kaplan-Meier analyses in population-based cohorts. MAIN OUTCOME MEASURES: Age-related macular degeneration features and stage. RESULTS: Of 2068 individuals with late AMD, 64.7% carried the ARMS2/HTRA1 risk allele. For homozygous carriers, the odds ratio (OR) of geographic atrophy was 8.6 (95% confidence interval [CI], 6.5-11.4), of choroidal neovascularization (CNV) was 11.2 (95% CI, 9.4-13.3), and of mixed late AMD was 12.2 (95% CI, 7.3-20.6). Cumulative lifetime risk of late AMD ranged from 4.4% for carriers of the nonrisk genotype to 9.4% and 26.8% for heterozygous and homozygous carriers. The latter received the diagnosis of late AMD 9.6 years (95% CI, 8.0-11.2) earlier than carriers of the nonrisk genotype. The risk haplotype was not associated with hard or soft drusen < 125 µm (OR, 1.2; 95% CI, 0.9-1.7), but risks increased significantly for soft drusen ≥ 125 µm (OR, 2.1; 95% CI, 1.5-3.0), up to an OR of 7.2 (95% CI, 3.8-13.8) for reticular pseudodrusen. Compared with persons with a high GRS for complement, homozygous carriers of ARMS2/HTRA1 showed a higher risk of CNV (OR, 4.1; 95% CI, 3.2-5.4); risks of other characteristics were not different. CONCLUSIONS: Carriers of the risk haplotype at ARMS2/HTRA1 have a particularly high risk of late AMD at a relatively early age. Data suggest that risk variants at ARMS2/HTRA1 act as a strong catalyst of progression once early signs are present. The phenotypic spectrum resembles that of complement genes, only with higher risks of CNV.

Protective chromosome 1q32 haplotypes mitigate risk for age-related macular degeneration associated with the CFH-CFHR5 and ARMS2/HTRA1 loci.

BACKGROUND: Single-variant associations with age-related macular degeneration (AMD), one of the most prevalent causes of irreversible vision loss worldwide, have been studied extensively. However, because of a lack of refinement of these associations, there remains considerable ambiguity regarding what constitutes genetic risk and/or protection for this disease, and how genetic combinations affect this risk. In this study, we consider the two most common and strongly AMD-associated loci, the CFH-CFHR5 region on chromosome 1q32 (Chr1 locus) and ARMS2/HTRA1 gene on chromosome 10q26  (Chr10 locus). RESULTS: By refining associations within the CFH-CFHR5 locus, we show that all genetic protection against the development of AMD in this region is described by the combination of the amino acid-altering variant CFH I62V (rs800292) and genetic deletion of CFHR3/1. Haplotypes based on CFH I62V, a CFHR3/1 deletion tagging SNP and the risk variant CFH Y402H are associated with either risk, protection or neutrality for AMD and capture more than 99% of control- and case-associated chromosomes. We find that genetic combinations of CFH-CFHR5 haplotypes (diplotypes) strongly influence AMD susceptibility and that individuals with risk/protective diplotypes are substantially protected against the development of disease. Finally, we demonstrate that AMD risk in the ARMS2/HTRA1 locus is also mitigated by combinations of CFH-CFHR5 haplotypes, with Chr10 risk variants essentially neutralized by protective CFH-CFHR5 haplotypes. CONCLUSIONS: Our study highlights the importance of considering protective CFH-CFHR5 haplotypes when assessing genetic susceptibility for AMD. It establishes a framework that describes the full spectrum of AMD susceptibility using an optimal set of single-nucleotide polymorphisms with known functional consequences. It also indicates that protective or preventive complement-directed therapies targeting AMD driven by CFH-CFHR5 risk haplotypes may also be effective when AMD is driven by ARMS2/HTRA1 risk variants.

rs10490924 surrounding HTRA1/ARMS2 regulates the susceptibility of age-related macular degeneration.

Multiple studies have assessed the contribution of rs10490924 on chromosome 10q26 surrounding HTRA1/ARMS2 gene to age-related macular degeneration (AMD) risk. However, the causal allele at this locus is still inconclusive. In this meta-analysis, we systematically characterized the potential association between rs10490924 polymorphism and AMD risk. Data available from 12 case-control studies, including a total of 5244 cases and 2755 controls in three different ethnic populations, were used to evaluate the correlation between rs10490924 G/T polymorphism (Ala69Ser) and AMD risk. In overall populations, the results indicated the Ala69Ser polymorphism was significantly associated with AMD under allelic (OR = 0.35, 95% CI = 0.30-0.40), homozygous (OR = 0.12, 95%CI = 0.09-0.17), dominant (OR = 0.18, 95%CI = 0.14-0.24), recessive (OR = 0.33, 95%CI = 0.28-0.39), and heterozygous genetic models (OR = 0.26, 95% CI = 0.21-0.33). Similar results were observed in subgroup analysis. This meta-analysis suggests that rs10490924 (Ala69Ser) polymorphism was significantly associated with the susceptibility of AMD in all ethnicities, Ala69 carriers are resistant to AMD risk.

Ongoing controversies and recent insights of the ARMS2-HTRA1 locus in age-related macular degeneration.

Age-related macular degeneration (AMD) is the most common cause of central vision loss among elderly populations in industrialized countries. Genome-wide association studies have consistently associated two genomic loci with progression to late-stage AMD: the complement factor H (CFH) locus on chromosome 1q31 and the age-related maculopathy susceptibility 2-HtrA serine peptidase 1 (ARMS2-HTRA1) locus on chromosome 10q26. While the CFH risk variant has been shown to alter complement activity, the ARMS2-HTRA1 risk haplotype remains enigmatic due to high linkage disequilibrium and inconsistent functional findings spanning two genes that are plausibly causative for AMD risk. In this review, we detail the genetic and functional evidence used to support either ARMS2 or HTRA1 as the causal gene for AMD risk, emphasizing both the historical development and the current understanding of the ARMS2-HTRA1 locus in AMD pathogenesis. We conclude by summarizing the evidence in favor of HTRA1 and present our hypothesis whereby HTRA1-derived ECM fragments mediate AMD pathogenesis.

Meta-Analysis of the Pharmacogenetics of ARMS2 A69S Polymorphism and the Response to Advanced Age-Related Macular Degeneration.

Age-related macular degeneration (AMD) causes irreversible vision loss, and targeted anti-vascular endothelial growth factor (VEGF) therapy is now the most common and effective treatment. The aim of this meta-analysis is to discuss whether genetic polymorphism of ARMS2 A69S could confer susceptibility to advanced AMD with the response to anti-VEGF treatment. We performed a meta-analysis of relevant published studies selected through electronic databases. A total of 21 preferred studies regarding the association between ARMS2 gene and anti-VEGF treatment response in advanced AMD were generally included in the meta-analysis. The pooled results demonstrated that the carriage of G allele for ARMS2 A69S presented a better clinical prognosis for advanced AMD treated with anti-VEGF drugs (OR = 1.38, 95% CI = 1.13-1.69, p = 0.002). In addition, in the subgroup analysis based on ethnicity, ARMS2 polymorphisms were more likely to be a positive responder for East Asian patients (OR = 1.67, 95% CI = 1.29-2.16, p < 0.001). This meta-analysis through a series of rigorous methodology data demonstrated a significant association between ARMS2 A69S polymorphism and the anti-VEGF treatment response in advanced AMD, especially among East Asian population. Numerous well-designed, randomized, multicenter clinical trials with large sample size are required to validate the association.

Drusenoid Pigment Epithelial Detachment: Genetic and Clinical Characteristics.

Few studies report drusenoid pigment epithelial detachment (DPED) in Asians. In this multicenter study, we report the clinical and genetic characteristics of 76 patients with DPED, and, for comparison, 861 patients with exudative age-related macular degeneration (AMD) were included. On the initial presentation, the mean best-corrected visual acuity was 0.087 ± 0.17 (logMAR unit), and mean DPED height and width were 210 ± 132 and 1633 ± 1114 µm, respectively. Fifty-one (67%) patients showed macular neovascularization in the contralateral eye. The risk allele frequency of both ARMS2 A69S and CFH I62V was significantly higher in DPED than in typical AMD and polypoidal choroidal vasculopathy (PCV) (ARMS2 A69S risk allele frequency: DPED 77% vs. typical AMD 66% vs. PCV 57%, CFH I62V risk allele frequency: DPED 87% vs. typical AMD 73% vs. PCV 73%), although the risk allele frequency of both genes was similar between the DPED group and retinal angiomatous proliferation (RAP) group (ARMS2 A69S: p = 0.32, CFH I62V, p = 0.11). The prevalence of reticular pseudodrusen (RPD) was highest in RAP (60%), followed by DPED (22%), typical AMD (20%), and PCV (2%). Although the prevalence of RPD differs between DPED and RAP, these entities share a similar genetic background in terms of ARMS2 and CFH genes.

Association of CRP levels with ARMS2 and CFH variants in age-related macular degeneration.

PURPOSE: To investigate whether plasma high sensitivity C-reactive protein (hs-CRP) level is associated with exudative age-related macular degeneration (AMD) as well as variants of ARMS2 A69S and CFH I62V in patients with exudative AMD. METHODS: A case-control study was done comparing CRP among patients with exudative AMD including those with polypoidal choroidal vasculopathy, typical AMD and retinal angiomatous proliferation, and CRP were also compared between cases and controls. Plasma CRP was measured from peripheral blood using latex nepherometry for all participants. Genotyping of ARMS2 A69S and CFH I62V was performed for all patients with exudative AMD using TaqMan technology. RESULTS: Among 125 patients with exudative AMD, including 31 with typical neovascular AMD, 73 with PCV and 21 with RAP lesions and 150 controls, CRP levels were higher in exudative AMD than in controls. (P = 2.7 × 10-5) There was not a significant difference in hs-CRP levels among AMD subtypes. Neither variants of ARMS2 nor CFH was associated with hs-CRP level in patients with exudative AMD. A multiple regression analysis revealed that gender male, presence of exudative AMD and presence of cardiovascular diseases were associated with increased plasma hs-CRP. CONCLUSIONS: Plasma hs-CRP was elevated independent of variants of ARMS2 A69S and CFH I62V in patients with exudative AMD.

Association of rs10490924 in ARMS2/HTRA1 with age-related macular degeneration in the Pakistani population.

Age-related macular degeneration (AMD) is a disease of the elderly in which central vision is lost because of degenerative changes of the macula. The current study investigated the association of single-nucleotide polymorphisms (SNPs) with AMD in the Pakistani population. Four SNPs were analyzed in this study: rs1061170 in the CFH, rs429608 near CFB, rs2230199 in the C3, and rs10490924 in ARMS2/HTRA1. This case-control association study was conducted on 300 AMD patients (125 wet AMD and 175 dry AMD) and 200 unaffected age- and gender-matched control individuals. The association of the SNP genotypes and allele frequency distributions were compared between patients and healthy controls, keeping age, gender, and smoking status as covariates. A significant genotype and variant allele association was found of rs10490924 in ARMS2/HTRA1 with wet AMD, while the SNPs in CFH, CFB, and C3 were not associated with AMD in the current Pakistani cohort. The lack of association of CFH, CFB, and C3 may be attributed to limited sample size. This study demonstrates that genetic causative factors of AMD differ among populations and supports the need for genetic association studies among cohorts from various populations to increase our global understanding of the disease pathogenesis.

Comparison of ARMS2/LOC387715 A69S and CFH Y402H risk effect in wet-type age-related macular degeneration: a meta-analysis.

PURPOSE: We designed this meta-analysis to pool studies which have analyzed both CFH (Y402H or I62V) and ARMS2 A69S in the same samples to compare the effect of CFH and ARMS2 in neovascular AMD. METHODS: Relevant studies identified and reviewed separately in order to select those for inclusion. Included studies had genotype data of studied groups for both ARMS2 A69S and CFH. To modify the heterogeneity in the variables, we used random effects model. Meta-analysis was performed using STATA. Funnel plot and Egger's regression test used for evaluation of the possible publication bias. RESULTS: Overall, we included 6676 neovascular AMD cases and 7668 controls. Pooled overall odds ratios (ORs) (95% CI) for neovascular AMD/control were ARMS2 A69S: OR = 2.35 (2.01-2.75) for GT versus GG; OR = 8.57 (6.91-10.64) for TT versus GG; CFH Y402H: OR = 1.94 (1.73-2.18) for CT versus TT; OR = 4.89 (3.96-6.05) for CC versus TT. ARMS2 A69S genotype OR/CFH Y402H genotype OR (homogeneous genotypes): Asia = 2.14, Europe: 1.87, America: 1.82, Middle East: 3.56, pooled: 1.75. ARMS2 A69S genotype OR/CFH Y402H genotype OR (heterogeneous genotypes): Asia = 0.93, Europe: 1.39, America: 2.06, Middle East: 1.20, pooled: 1.21. ARMS2 A69S risk genotypes have stronger predisposing effect on neovascular AMD compared to CFH Y402H risk genotypes. CONCLUSION: Our inclusion criteria to select those studies which have analyzed the effect of these two loci in the same case-control samples showed much stronger effect of ARMS2 A69S in neovascular AMD compared to the CFH Y402H.

AREDS simplified severity scale as a predictive factor for response to aflibercept therapy for typical neovascular age-related macular degeneration.

PURPOSE: To investigate whether the severity of the condition in the untreated fellow eye is a predictive factor for the response to intravitreal aflibercept injection (IAI) for exudative age-related macular degeneration (AMD). METHODS: A retrospective medical chart review was conducted for 88 patients with treatment-naïve neovascular AMD, who were initially treated with three monthly IAIs, followed by monthly monitoring and re-injection as needed for at least 12 months. Subjects were classified into three groups according to the severity of the condition in their untreated eye, based on the severity scale in the Age-Related Eye Disease Study (AREDS): group 0, AREDS severity level 1 (no drusen); group 1, AREDS severity level 2 or 3 (any drusen); group 2, AREDS severity level 4 (advanced AMD). Genotyping was performed in all cases for ARMS2 A69S and CFH I62V. RESULTS: Fellow-eye severity was associated with age and the risk variant of ARMS2 A69S (P = 0.005 and 0.001, respectively). Although best-corrected visual acuity (BCVA) had improved significantly after 12 months in all groups, this improvement was significantly greater in group 0 than in the other groups (P = 0.008). The retreatment-free period was also significantly longer for group 0 than for the other groups (P = 0.016), and the number of additional injections was significantly associated with fellow-eye severity (P = 0.007). CONCLUSIONS: Fellow-eye severity was associated with treatment response in terms of visual improvement and retreatment and may be a predictive factor for response to IAI for neovascular AMD.

Retreatment of Exudative Age-Related Macular Degeneration after Loading 3-Monthly Intravitreal Ranibizumab.

PURPOSE: The aim of this study was to investigate the clinical implications of required retreatment after 3-monthly intravitreal ranibizumab (IVR) injections followed by as-needed reinjections up to 5 years in eyes with exudative age-related macular degeneration (AMD). METHODS: A retrospective cohort study was conducted for 165 treatment-naïve eyes from 165 patients with exudative AMD. Visual changes were investigated in terms of the required retreatments. RESULTS: Retreatment-free proportions were 37.0, 23.7, 16.6, 12.1, and 10.5% at 12, 24, 36, 48, and 60 months, respectively. Visual changes were significantly better in eyes which did not require retreatment at every yearly checkpoint within the 5 years. A multivariate logistic regression analysis revealed that requirement of additional IVR treatments in the first 12-24 months was associated with the T allele (risk allele) of ARMS2 A69S (p = 0.010 and 0.015, respectively). Cox regression analysis revealed that older age (p = 0.046) and the T allele of ARMS2 A69S (p = 0.036) were associated with required retreatment within the 5-year follow-up period. CONCLUSIONS: Age and the T allele of ARMS2 A69S are the risk factors requiring retreatments, leading to poor visual change in eyes with exudative AMD following the initial 3-monthly IVR.

ARMS2 A69S polymorphism is associated with the number of ranibizumab injections needed for exudative age-related macular degeneration in a pro re nata regimen during 4 years of follow-up.

PURPOSE: To investigate whether single-nucleotide polymorphisms (SNPs) known to be strongly associated with the development of age-related macular degeneration (AMD) have an influence on recurrence rate of choroidal neovascularization (CNV) activity during 4-year ranibizumab treatment for exudative AMD. METHODS: This prospective study included 103 treatment-naïve patients (103 eyes) that received initially a loading dose of 3 monthly ranibizumab injections and thereafter, were treated according to an as-needed regimen for a 4-year follow-up period. Baseline values, visual outcome, and recurrence rate were examined. CFH Y402H and ARMS2 A69S polymorphisms were determined and their association with lesion recurrence and visual outcome was analyzed using a one-way analysis of variance (ANOVA) with post hoc comparison tested by Fisher's LSD method. Multivariate linear regression analysis was then used to identify factors associated with recurrence rate. RESULTS: The cumulative total mean number of ranibizumab injections at the end of each year of the follow-up was 5.3 ± 1.8, 9.2 ± 2.9, 12.6 ± 4.6, and 15.7 ± 6.1. There was great inter-patient variability. Nineteen eyes (18.5%) did not experience recurrence during the first year, and five (4.8%) still displayed inactive CNV after 4 years of follow-up. No significant association was found between the number of injections and mean best corrected visual acuity (BCVA) change or final BCVA at the end of the study period. Genotypes had no influence on baseline characteristics or visual outcome but a significant association was found between the A69S polymorphism and the number of injections needed by the patients. Homozygous for the T risk allele required more retreatments over the 48-month follow-up. CONCLUSIONS: The ARMS2 A69S polymorphism was associated with CNV recurrence rate in our patient cohort. Prediction of a greater risk of recurrence could help to design more appropriate follow-up treatment strategies for patients with neovascular AMD.

Placental Up-Regulation of Leptin and ARMS2 is Associated with Growth Discordance in Monochorionic Diamniotic Twin Pregnancies.

Fetal growth discordance is a relatively common complication of monochorionic diamniotic (MCDA) twin pregnancies and is caused by a combination of maternal and placental factors. The aim of the study was to survey placental gene expression patterns and identify genes associated with growth discordance. Clinical samples comprised eight growth-discordant MCDA twin placentas (31+3-34+4 weeks gestational age) and six growth-concordant twin placentas (31+2-37 weeks gestational age). Gene expression libraries were constructed from placental biopsy samples and analyzed by RNA-sequencing. The distribution and relative abundance of mRNA transcripts expressed in the smaller and larger placentas from growth-discordant and concordant MCDA twins was remarkably similar. However, leptin (LEP) and age-related maculopathy susceptibility 2 (ARMS2) mRNA levels were exclusively up-regulated in all of the eight smaller growth-discordant twin placentas. Quantitative real-time PCR of independent biopsy samples confirmed the levels of differential mRNA expression for both genes. Immunohistochemical analysis of tissue sections from matching twin placentas showed increased leptin expression in 5-10% of blood vessel cells of the smaller placenta and marginally higher levels of ARMS2 expression in the microvillous membrane of the smaller placenta. Based on these findings, we speculate that up-regulation of leptin and ARMS2 forms part of an important survival mechanism to compensate for placental growth discordance. Since, leptin and ARMS2 are both expressed as soluble proteins, they may have clinical potential as measurable biomarkers for predicting the onset of growth discordance in MCDA twin pregnancies.

Association of ARMS2/LOC387715 A69S, CFH Y402H, and CFH I62V polymorphisms with retinal angiomatous proliferation compared with typical age-related macular degeneration: a meta-analysis.

PURPOSE: To compare the published results of studies on the genotype association of ARMS2/LOC387715 A69S, CFH Y402H, and CFH I62V in cases diagnosed as retinal angiomatous proliferation (RAP) versus neovascular age-related macular degeneration (AMD) or healthy controls. METHODS: Heterogeneity of studies was evaluated using Cochran's Q test and I-square index. To modify the heterogeneity in the variables, we used random effects model. Meta-analysis was performed using STATA. RESULTS: Four studies were included with 1076 neovascular AMD patients, 222 RAP cases, and 2276 control subjects. Pooled overall odds ratios for RAP/AMD were 1.15 (95% CI 0.60-2.18) for GT versus GG, 3.52 (95% CI 1.25-9.91) for TT versus GG ARMS2, 0.98 (95% CI 0.22-4.29) for GA versus AA, 1.00 (95% CI 0.25-4.02) for GG versus AA CFHI62V, 0.57 (95% CI 0.35-0.93) for CT versus TT CFH Y402H, and 0.40 (95% CI 0.22-0.74) for CC versus TT CFH Y402H. Regression analysis showed that ARMS2 TT genotype has a statistically significant effect on RAP versus AMD compared to CFH genotypes (P < 0.001). CONCLUSION: This meta-analysis disclosed a stronger effect of ARMS2 genotypes in RAP cases compared with CFH Y402H and I62V genotypes.

HTRA1 (high temperature requirement A serine peptidase 1) gene is transcriptionally regulated by insertion/deletion nucleotides located at the 3' end of the ARMS2 (age-related maculopathy susceptibility 2) gene in patients with age-related macular degeneration.

Dry age-related macular degeneration (AMD) accounts for over 85% of AMD cases in the United States, whereas Japanese AMD patients predominantly progress to wet AMD or polypoidal choroidal vasculopathy. Recent genome-wide association studies have revealed a strong association between AMD and an insertion/deletion sequence between the ARMS2 (age-related maculopathy susceptibility 2) and HTRA1 (high temperature requirement A serine peptidase 1) genes. Transcription regulator activity was localized in mouse retinas using heterozygous HtrA1 knock-out mice in which HtrA1 exon 1 was replaced with ß-galactosidase cDNA, thereby resulting in dominant expression of the photoreceptors. The insertion/deletion sequence significantly induced HTRA1 transcription regulator activity in photoreceptor cell lines but not in retinal pigmented epithelium or other cell types. A deletion construct of the HTRA1 regulatory region indicated that potential transcriptional suppressors and activators surround the insertion/deletion sequence. Ten double-stranded DNA probes for this region were designed, three of which interacted with nuclear extracts from 661W cells in EMSA. Liquid chromatography-mass spectrometry (LC-MS/MS) of these EMSA bands subsequently identified a protein that bound the insertion/deletion sequence, LYRIC (lysine-rich CEACAM1 co-isolated) protein. In addition, induced pluripotent stem cells from wet AMD patients carrying the insertion/deletion sequence showed significant up-regulation of the HTRA1 transcript compared with controls. These data suggest that the insertion/deletion sequence alters the suppressor and activator cis-elements of HTRA1 and triggers sustained up-regulation of HTRA1. These results are consistent with a transgenic mouse model that ubiquitously overexpresses HtrA1 and exhibits characteristics similar to those of wet AMD patients.

Gene Structure of the 10q26 Locus: A Clue to Cracking the ARMS2/HTRA1 Riddle?

Age-related macular degeneration (AMD) is a sight-threatening disorder of the central retina. Being the leading cause of visual impairment in senior citizens, it represents a major public health issue in developed countries. Genetic studies of AMD identified two major susceptibility loci on chromosomes 1 and 10. The high-risk allele of the 10q26 locus encompasses three genes, PLEKHA1, ARMS2, and HTRA1 with high linkage disequilibrium and the individual contribution of the encoded proteins to disease etiology remains controversial. While PLEKHA1 and HTRA1 are highly conserved proteins, ARMS2 is only present in primates and can be detected by using RT-PCR. On the other hand, there is no unequivocal evidence for the existence of the encoded protein. However, it has been reported that risk haplotypes only affect the expression of ARMS2 (but not of HTRA1), making ARMS2 the best candidate for being the genuine AMD gene within this locus. Yet, homozygous carriers of a common haplotype carry a premature stop codon in the ARMS2 gene (R38X) and therefore lack ARMS2, but this variant is not associated with AMD. In this work we aimed at characterizing the diversity of transcripts originating from this locus, in order to find new hints on how to resolve this perplexing paradox. We found chimeric transcripts originating from the PLEKHA1 gene but ending in ARMS2. This finding may give a new explanation as to how variants in this locus contribute to AMD.