Abstract
Purpose: :
Association of rs800292 (I62V) in the complement factor H (CFH) gene with anterior uveitis (AU) has been identified in our previous study. We therefore further investigated whether polymorphisms of two tightly linked genes in the complement pathway-complement component 2 (C2) and complement factor B (CFB)-are associated with AU.
Methods: :
98 Chinese AU patients and 291 unrelated controls were recruited in the study. Five SNPs (rs1048709, rs537160, rs4151657 and rs2072633 in CFB and rs3020644 in C2) were detected using TaqMan Genotyping Assays. Analyses were also adjusted for gender and stratified according to clinical manifestations and human leukocyte antigen (HLA)-B27 status.
Results: :
Three SNPs (rs1048709, rs2072633 and rs3020644) were found to be associated with AU. Among them, CFB-rs1048709 is the most significantly associated SNP in this region. Logistic regression analysis showed none of the 5 SNPs had significant interaction with gender. Stratified analyses showed that four SNPs, including the above three plus CFB-rs537160, were found to be associated with AU in HLA-B27 positive patients, whereas only rs1048709 remain significant in HLA-B27 negative patients. No association was found in the five tested SNPs with clinical manifestations of AU. Meanwhile, one haplotype block across CFB (AATA) significantly predisposes to AU with increased risk of 1.89 (95% CI: 1.35-2.65; Pcorr=0.0017). Additive effect of CFB-rs1048709 and CFH-rs800292 was also identified with an OR of 8.5 (95%CI: 1.84-39.23).
Conclusions: :
Our results revealed an association between AU and C2-CFB polymorphisms in Chinese patients. The influence on AU might differ depending on HLA-B27 status. The joint effect in CFB and CFH strengthens the concept that complement system plays an important role in the pathogenesis of AU. Further studies to enrich the understanding of complement in uveitis are warranted.
Keywords: genetics • inflammation • immunomodulation/immunoregulation