Background Complement Factor I (CFI) and the CD46 complement regulator (CD46) play an important role in the complement activation pathways, which is known to affect the development of uveitis. The present study was performed to investigate the association of the CFI and CD46 genes with acute anterior uveitis (AAU).

Methods A total of 600 subjects (300 patients with AAU and 300 healthy controls) were recruited for this case-control study. Six CFI single nucleotide polymorphisms (SNP) (rs7356506, rs10029485, rs11726949, rs12512308, rs7438961, rs998538) and four CD46 SNPs (rs12138764, rs2466571, rs2796278, rs7545126) were genotyped using Sequenom MassARRAY technology. Allele and genotype frequencies were compared between patients and controls using the χ² test. Analyses were stratified for gender, human leukocyte antigen (HLA)-B27, and ankylosing spondylitis status.

Results Rs7356506 in the CFI gene was found to be protective against AAU. There was a significant increase in the frequency of the A allele (p=0.003, pc=0.03, OR=0.684, CI 0.534 to 0.876) and AA homozygosity (p=0.004, pc=0.04, OR=0.624, CI 0.452 to 0.862) in AAU patients as compared to controls. Stratified analysis, according to gender and HLA-B27 status for AAU, also revealed the association with CFI-rs7356506. None of the tested SNPs of CD46 were associated with AAU.

Conclusions This study has revealed a significant association between AAU and CFI-rs7356506, suggesting that CFI is involved in the pathogenesis of AAU, and that its influence on AAU may differ depending on gender and HLA-B27 status.