Investigation of the human FCRL1, 2, and 4 gene expressions in patients with rheumatoid arthritis.

The Fc receptor-like (FCRL) molecules have recently been shown to contribute to the pathogenesis of certain autoimmune disorders. In this study, we investigated the expression levels of FCRL1, 2 and 4 in blood mononuclear cells from rheumatoid arthritis patients using real-time PCR. The mRNA of these molecules was detected in 44.4 % (FCRL1), 53.3 % (FCRL2) and 31.1 % (FCRL4) of patients. Comparatively, 31.1 % (FCRL1), 51.1 % (FCRL2) and 26.6 % (FCRL4) of controls expressed these genes. Analysis of gene expressions in FCRL-positive patients demonstrated a lower FCRL4 gene expression in patients compared to controls (P < 0.001). In FCRL2-positive patients, a significant positive correlation between FCRL2 expression and the erythrocyte sedimentation rate (P < 0.001), anti-cyclic citrullinated peptide antibody (P = 0.033) level and disease activity score (DAS28, P = 0.016) was found. In conclusion, decreased FCRL4 expression and association of FCRL2 expression with inflammatory markers and disease activity suggested the contribution of these molecules to RA inflammatory processes.