FcRL3 gene promoter variant is associated with peripheral arthritis in Crohn's disease

Background: The mechanisms responsible for the pathogenesis of peripheral arthropathies (PA) in Crohn's disease (CD) are largely unknown, although many studies indicate that genetic and environmental factors are likely to contribute to risk. Methods: Because variants in the Fc receptor-like 3 (FcRL3) gene have recently been associated with rheumatoid arthritis and several other autoimmune diseases, we tested 2 FcRL3 promoter variants (−169 C>T and −110 G>A) for association with PA in Spanish CD patients that were recruited from a single center and followed for at least 4 years (mean follow-up time, 11 years). Results: Among the 342 CD patients evaluated, there were 88 cases of peripheral arthropathy; 31 were classified as arthritis and 57 were classified as arthralgia. We used contingency tables and logistic regression to test for association between PA or either subtype and FcRL3 and other factors that have previously been associated with extraintestinal manifestations in CD. Conclusions: We found that female sex, colonic involvement, and the AA genotype at −110 G>A were associated with increased risk of both subtypes of PA, although the association appears to be stronger for arthritis than for arthralgia. (Inflamm Bowel Dis 2009)