Haplotype-tagging interleukin-10 promoter polymorphism is associated with reduced risk of retinal artery occlusion

PURPOSE Pro- and anti-inflammatory cytokines, including interleukin 10 (IL-10), play an essential role in atherogenesis. Increased IL-10 production has been found among carriers of the IL10 [TCATA] haplotype, which is formed by five polymorphisms at position -3575, -2763, -1082, -819, and -592 in the promoter region of the IL10 gene. Due to linkage disequilibrium, the presence of the [TCATA] haplotype can be unequivocally determined by analysis of the IL10-592C>A polymorphism. The purpose of the present study was to investigate a hypothesized association between the haplotype-tagging IL10 -592C>A polymorphism and the presence of retinal artery occlusion (RAO). METHODS The present case-control study was comprised of 194 patients with RAO and 257 normal control subjects. Genotypes of the IL10 -592C>A polymorphism were determined by fluorogenic exonuclease (TaqMan) assay. RESULTS Carriers of the IL10 -592A-allele, indicating the presence of the IL10 [TCATA] haplotype, were found significantly more often in controls than among patients with RAO (48.6% versus 36.1%; p=0.008). In a logistic regression analysis after adjusting for age, sex, arterial hypertension, diabetes mellitus, hypercholesterolemia, and smoking habits, carriage of the IL10 -592A-allele was associated with an odds ratio of 0.65 (95% CI: 0.44-0.97) for RAO. CONCLUSIONS Our data suggest that the IL10 [TCATA] haplotype, identified by the presence of the IL10 -592A-allele, may exert a protective effect against RAO.