Is Complement Factor H Tyr402His Variant a Potential Cause of Ankylosing Spondylitis?

Aim: Ankylosing spondylitis (AS) is an autoimmune disease caused by chronic inflammatory response. Complement system is the major component of the innate immune defence. In this study, we investigated the potential association between complement factor H (CFH) gene Tyr402His variant (rs1061170) with AS in a Turkish population. Methods: Seventy-eight AS patients and 80 healthy individuals were enrolled in the present study as case and control subjects, respectively. The Tyr402His variant of CFH gene was analysed by PCR-RFLP method. Results: There was no statistically significant difference between AS patients and healthy controls in terms of CFH Tyr402His genotype and allele frequencies. However, the visual analogue scale (VAS) daytime and the AS Quality of Life (ASQoL) were significantly different according to CFH Tyr402His genotype distribution (p=0.032 and p=0.036, respectively). VAS of daytime and ASQoL were higher in subjects carrying Tyr402His variant Tyr/Tyr + Tyr/His genotypes compared to those carrying His/His genotype. Conclusion: This is the first study evaluating the association between CFH Tyr402His and susceptibility to AS in a Turkish population. Although CFH Tyr402His variant was not considered a candidate gene for AS susceptibility in our samples, some clinical findings seem to be associated with genotype distribution of CFH Tyr402His variant.