Tina Schick

HISTORY OF SUNLIGHT EXPOSURE IS A RISK FACTOR FOR AGE-RELATED MACULAR DEGENERATION

Purpose: To evaluate effects of current and past sunlight exposure and iris color on early and late age-related macular degeneration (AMD). Methods: Of 3,701 individuals from the EUGENDA database, 752 (20.3%) showed early AMD, 1,179 (31.9%) late AMD, and 1,770 (47.8%) were controls. Information about current and past sunlight exposure, former occupation type, subdivided in indoor working and outdoor working, and iris color were obtained by standardized interviewer-assisted questionnaires. Associations between environmental factors adjusted for age, gender, and smoking and early and late AMD were performed by multivariate regression analysis. Results: Current sunlight exposure showed no association with early AMD or late AMD, but past sunlight exposure (≥8 hours outside daily) was significantly associated with early AMD (odds ratio: 5.54, 95% confidence interval 1.25–24.58, P = 0.02) and late AMD (odds ratio: 2.77, 95% confidence interval 1.25–6.16, P = 0.01). Outside working was found to be associated with late AMD (odds ratio: 2.57, 95% confidence interval 1.89–3.48, P = 1.58 × 10−9). No association was observed between iris color and early or late AMD. Conclusion: Sunlight exposure during working life is an important risk factor for AMD, whereas sunlight exposure after retirement seems to have less influence on the disease development. Therefore, preventive measures, for example, wearing sunglasses to minimize sunlight exposure, should start early to prevent development of AMD later in life.

Rare Genetic Variants Associated With Development of Age-Related Macular Degeneration

IMPORTANCE Rare variants in the complement genes CFH, CFI, C9, and C3 have been found to be highly associated with age-related macular degeneration (AMD); however, the effect on clinical characteristics and familial segregation by these variants is lacking. OBJECTIVES To determine the contribution of rare CFH Arg1210Cys, CFI Gly119Arg, C9 Pro167Ser, and C3 Lys155Gln variants in the development of AMD in 22 multiplex families and to describe clinical differences in carriers vs noncarriers in these families and a large case-control cohort. DESIGN, SETTING, AND PARTICIPANTS This retrospective case-control study included 114 affected and 60 unaffected members of 22 multiplex families with AMD as well as 1589 unrelated patients with AMD and 1386 unrelated control individuals enrolled in the European Genetic Database (EUGENDA). Patients were recruited from March 29, 2006, to April 26, 2013, and data were collected from April 20, 2012, to May 7, 2014. All participants underwent an extensive ophthalmic examination and completed a questionnaire. Venous blood samples were obtained from all participants for genetic analysis, including whole-exome sequencing and measurements of complement activation. Data were analyzed from September 23, 2014, to November 4, 2015. MAIN OUTCOMES AND MEASURES Differences between carriers and noncarriers of rare variants in age at onset of symptoms, the family history of AMD, complement activation levels (C3d:C3 ratio), the presence of reticular pseudodrusen, and AMD phenotype. RESULTS Among the 114 affected and 60 unaffected members of 22 multiplex families with AMD and the 1598 unrelated patients with AMD and 1386 controls in the EUGENDA cohort who underwent analysis, the presence of the CFI Gly119Arg, C9 Pro167Ser, or C3 Lys155Gln variant was confirmed in 18 individuals in 5 families but did not completely segregate with the disease. In the case-control cohort, the 91 affected carriers of these variants were younger at symptom onset (mean [SD] age, 67.4 [8.5] vs 71.3 [8.9] years; P = .01) and more often reported a positive family history (35 of 79 [44.3%] vs 367 of 1201 [30.6%]; P = .008) compared with the 1498 noncarriers. Patients with advanced atrophic AMD carried these rare variants more frequently than patients with neovascular AMD (11 of 93 [11.8%] vs 40 of 835 [4.8%]; P = .04). CONCLUSIONS AND RELEVANCE Previously reported rare variants do not completely segregate within families with AMD. However, patients carrying these rare variants differ clinically from noncarriers by an earlier age at symptom onset, higher prevalence of a positive family history, and AMD phenotype. These results suggest that genetic tests for AMD might be designed to detect common and rare genetic variants, especially in families, because rare variants contribute to the age at onset and progression of the disease.

Large maculopapular cutaneous lesions are associated with favorable outcome in childhood-onset mastocytosis

BACKGROUND Mastocytosis, characterized by pathologic accumulation of mast cells, can manifest itself in adulthood or childhood. Pediatric patients usually have cutaneous mastocytosis (CM) with mast cell infiltrates limited to the skin and spontaneous improvement of skin lesions after several years. However, there are some patients with persistent disease resembling adulthood-onset mastocytosis. OBJECTIVE The current classification of CM differentiates between 3 subforms. In clinical practice we noticed that different variants of these subforms might exist, particularly in patients with childhood-onset mastocytosis. Therefore, in the present study, we aimed to investigate whether specific cutaneous lesions in patients with childhood-onset mastocytosis are associated with other disease parameters. METHODS We analyzed 144 patients with a disease onset of less than age 17 years using a systematic dermatologic approach. RESULTS One hundred twenty-two patients presented with maculopapular cutaneous mastocytosis (MPCM), 12 patients presented with diffuse CM, and 10 patients presented with solitary mastocytoma of the skin. Patients with MPCM showed particularly heterogeneous cutaneous lesions and were therefore grouped into 3 variants presenting either with small lesions (MPCM-small, skin lesions <1 cm in diameter; n = 19), large lesions (MPCM-large, skin lesions ≥ 1 cm in diameter; n = 89), or atypical lesions (MPCM-other, n = 14). Patients with MPCM-large lesions, compared with those with MPCM-small lesions, were characterized by significantly lower tryptase levels, shorter disease duration, and earlier disease onset. In addition, more patients with MPCM-large lesions exhibited spontaneous regression of cutaneous lesions. CONCLUSION Our data show that patients with MPCM-large lesions compared with those with MPCM-small lesions have a more favorable disease course and suggest exploring the size of cutaneous lesions as a prognostic parameter in childhood-onset MPCM.

A Circulating MicroRNA Profile Is Associated with Late-Stage Neovascular Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is the leading cause of severe vision impairment in Western populations over 55 years. A growing number of gene variants have been identified which are strongly associated with an altered risk to develop AMD. Nevertheless, gene-based biomarkers which could be dysregulated at defined stages of AMD may point toward key processes in disease mechanism and thus may support efforts to design novel treatment regimens for this blinding disorder. Circulating microRNAs (cmiRNAs) which are carried by nanosized exosomes or microvesicles in blood plasma or serum, have been recognized as valuable indicators for various age-related diseases. We therefore aimed to elucidate the role of cmiRNAs in AMD by genome-wide miRNA expression profiling and replication analyses in 147 controls and 129 neovascular AMD patients. We identified three microRNAs differentially secreted in neovascular (NV) AMD (hsa-mir-301-3p, pcorrected = 5.6*10−5, hsa-mir-361-5p, pcorrected = 8.0*10−4 and hsa-mir-424-5p, pcorrected = 9.6*10−3). A combined profile of the three miRNAs revealed an area under the curve (AUC) value of 0.727 and was highly associated with NV AMD (p = 1.2*10−8). To evaluate subtype-specificity, an additional 59 AMD cases with pure unilateral or bilateral geographic atrophy (GA) were analyzed for microRNAs hsa-mir-301-3p, hsa-mir-361-5p, and hsa-mir-424-5p. While we found no significant differences between GA AMD and controls neither individually nor for a combined microRNAs profile, hsa-mir-424-5p levels remained significantly higher in GA AMD when compared to NV (pcorrected<0.005). Pathway enrichment analysis on genes predicted to be regulated by microRNAs hsa-mir-301-3p, hsa-mir-361-5p, and hsa-mir-424-5p, suggests canonical TGFβ, mTOR and related pathways to be involved in NV AMD. In addition, knockdown of hsa-mir-361-5p resulted in increased neovascularization in an in vitro angiogenesis assay.

Local complement activation in aqueous humor in patients with age-related macular degeneration

PurposeTo investigate complement activation in aqueous humor and in plasma of patients with neovascular age-related macular degeneration (nAMD).Patients and methodsAqueous humor and EDTA-plasma of 31 nAMD patients and 30 age-matched controls was collected. The levels of the complement factor 3 (C3), the regulators factor H (FH), and factor I (FI), and of the complement activation products Ba, C3a, and the terminal complement complex (sC5b-9) were measured. Associations between complement levels and phenotype were determined using Mann–Whitney U-test.ResultsIn plasma, no significant differences were found between the nAMD group and the control group. In aqueous humor, significantly increased levels of Ba (P=0.002), and C3a (P=0.002) indicate local complement activation in nAMD patients and a trend for a concomitant upregulation of the complement regulators FH (P=0.02) and FI (P=0.04).ConclusionsOur findings provide strong evidence for a local complement dysregulation in nAMD patients.

GWAS study using DNA pooling strategy identifies association of variant rs4910623 in OR52B4 gene with anti-VEGF treatment response in age-related macular degeneration

Pooled DNA based GWAS to determine genetic association of SNPs with visual acuity (VA) outcome in anti-vascular endothelial growth factor (anti-VEGF) treated neovascular age-related macular degeneration (nAMD) patients. We performed pooled DNA based GWAS on 285 anti-VEGF treated nAMD patients using high density Illumina 4.3 M array. Primary outcome was change in VA in Early Treatment Diabetic Retinopathy Study (ETDRS) letters after 6 months of anti-VEGF treatment (patients who lost ≥5 ETDRS letters classified as non-responders and all remaining classified as responders). GWAS analysis identified 44 SNPs of interest: 37 with strong evidence of association (p < 9 × 10−8), 2 in drug resistance genes (p < 5 × 10−6) and 5 nonsynonymous changes (p < 1 × 10−4). In the validation phase, individual genotyping of 44 variants showed three SNPs (rs4910623 p = 5.6 × 10−5, rs323085 p = 6.5 × 10−4 and rs10198937 p = 1.30 × 10−3) remained associated with VA response at 6 months. SNP rs4910623 also associated with treatment response at 3 months (p = 1.5 × 10−3). Replication of these three SNPs in 376 patients revealed association of rs4910623 with poor VA response after 3 and 6 months of treatment (p = 2.4 × 10−3 and p = 3.5 × 10−2, respectively). Meta-analysis of both cohorts (673 samples) confirmed association of rs4910623 with poor VA response after 3 months (p = 1.2 × 10−5) and 6 months (p = 9.3 × 10−6) of treatment in nAMD patients.

A Novel Complotype Combination Associates with Age-Related Macular Degeneration and High Complement Activation Levels in vivo

The complement system is the first line of defense against foreign intruders, and deregulation of this system has been described in multiple diseases. In age-related macular degeneration (AMD), patients have higher complement activation levels compared to controls. Recently, a combination of three single nucleotide polymorphisms (SNPs) in genes of the complement system, referred to as a complotype, has been described to increase complement activation in vitro. Here we describe a novel complotype composed of CFB (rs4151667)-CFB (rs641153)-CFH (rs800292), which is strongly associated with both AMD disease status (p = 5.84*10−13) and complement activation levels in vivo (p = 8.31*10−9). The most frequent genotype combination of this complotype was associated with the highest complement activation levels in both patients and controls. These findings are relevant in the context of complement-lowering treatments for AMD that are currently under development. Patients with a genetic predisposition to higher complement activation levels will potentially benefit the most of such treatments.

Whole Exome Sequencing in Patients with the Cuticular Drusen Subtype of Age-Related Macular Degeneration

Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in elderly people worldwide. Cuticular drusen (CD) is a clinical subtype of AMD, which typically displays an earlier age at onset, and has a strong genetic component. Genetic studies support a role for rare sequence variants in CD susceptibility, and rare sequence variants in the CFH gene have been identified in 8.8% of CD cases. To further explore the role of rare variants in CD, we performed whole exome sequencing (WES) in 14 affected members of six families and 12 sporadic cases with CD. We detected rare sequence variants in CFH and FBLN5, which previously were shown to harbor rare variants in patients with CD. In addition, we detected heterozygous rare sequence variants in several genes encoding components of the extracellular matrix (ECM), including FBLN1, FBLN3/EFEMP1, FBLN5, FBLN6/HMCN1, FBN2, and COL15A1. Two rare pathogenic variants were identified in the COL15A1 gene: one in a sporadic case and another was found to segregate in a family with six affected individuals with CD. In addition, two rare pathogenic variants were identified in the FGL1 gene in three unrelated CD cases. These findings suggest that alterations in the ECM and in the coagulation pathway may play a role in the pathogenesis of CD. The identified candidate genes require further analyses in larger cohorts to confirm their role in the CD subtype of AMD. No evidence was found of rare sequence variants in a single gene that segregate with CD in the six families, suggesting that the disease is genetically heterogeneous.

Clinical characteristics of familial and sporadic age-related macular degeneration: differences and similarities

PURPOSE We describe the differences and similarities in clinical characteristics and phenotype of familial and sporadic patients with age-related macular degeneration (AMD). METHODS We evaluated data of 1828 AMD patients and 1715 controls enrolled in the European Genetic Database. All subjects underwent ophthalmologic examination, including visual acuity testing and fundus photography. Images were graded and fundus photographs were used for automatic drusen quantification by a machine learning algorithm. Data on disease characteristics, family history, medical history, and lifestyle habits were obtained by a questionnaire. RESULTS The age at first symptoms was significantly lower in AMD patients with a positive family history (68.5 years) than in those with no family history (71.6 years, P = 1.9 × 10(-5)). Risk factors identified in sporadic and familial subjects were increasing age (odds ratio [OR], 1.08 per year; P = 3.0 × 10(-51), and OR, 1.15; P = 5.3 × 10(-36), respectively) and smoking (OR, 1.01 per pack year; P = 1.1 × 10(-6) and OR, 1.02; P = 0.005). Physical activity and daily red meat consumption were significantly associated with AMD in sporadic subjects only (OR, 0.49; P = 3.7 × 10(-10) and OR, 1.81; P = 0.001). With regard to the phenotype, geographic atrophy and cuticular drusen were significantly more prevalent in familial AMD (17.5% and 21.7%, respectively) compared to sporadic AMD (9.8% and 12.1%). CONCLUSIONS Familial AMD patients become symptomatic at a younger age. The higher prevalence of geographic atrophy and cuticular drusen in the familial AMD cases may be explained by the contribution of additional genetic factors segregating within families.

Analysis of Risk Alleles and Complement Activation Levels in Familial and Non-Familial Age-Related Macular Degeneration

Aims Age-related macular degeneration (AMD) is a multifactorial disease, in which complement-mediated inflammation plays a pivotal role. A positive family history is an important risk factor for developing AMD. Certain lifestyle factors are shown to be significantly associated with AMD in non-familial cases, but not in familial cases. This study aimed to investigate whether the contribution of common genetic variants and complement activation levels differs between familial and sporadic cases with AMD. Methods and Results 1216 AMD patients (281 familial and 935 sporadic) and 1043 controls (143 unaffected members with a family history of AMD and 900 unrelated controls without a family history of AMD) were included in this study. Ophthalmic examinations were performed, and lifestyle and family history were documented with a questionnaire. Nine single nucleotide polymorphisms (SNPs) known to be associated with AMD were genotyped, and serum concentrations of complement components C3 and C3d were measured. Associations were assessed in familial and sporadic individuals. The association with risk alleles of the age-related maculopathy susceptibility 2 (ARMS2) gene was significantly stronger in sporadic AMD patients compared to familial cases (p = 0.017 for all AMD stages and p = 0.003 for advanced AMD, respectively). ARMS2 risk alleles had the largest effect in sporadic cases but were not significantly associated with AMD in densely affected families. The C3d/C3 ratio was a significant risk factor for AMD in sporadic cases and may also be associated with familial cases. In patients with a densely affected family this effect was particularly strong with ORs of 5.37 and 4.99 for all AMD and advanced AMD respectively. Conclusion This study suggests that in familial AMD patients, the common genetic risk variant in ARMS2 is less important compared to sporadic AMD. In contrast, factors leading to increased complement activation appear to play a larger role in patients with a positive family history compared to sporadic patients. A better understanding of the different contributions of risk factors in familial compared to non-familial AMD will aid the development of reliable prediction models for AMD, and may provide individuals with more accurate information regarding their individual risk for AMD. This information is especially important for individuals who have a positive family history for AMD.