The imbalance between proinflammatory and anti-inflammatory cytokines is a feature of rheumatoid arthritis (RA). The role of interleukin-4 (IL-4) and its receptor in the pathogenesis of RA is conflicting. We aim to investigate the role of polymorphisms in the IL-4Rα gene in susceptibility and severity of RA.
One hundred and seventy-two RA patients and 172 controls were enrolled in the study. Genotyping of IL-4Rα I50V (rs1805010) and IL-4Rα Q576R (rs1801275) was determined by restriction fragment length polymorphism-polymerase chain reaction (PCR-RFLP).
IL-4Rα I50V genotype was significantly more frequent in patients with RA than in controls (OR: 1.97, 95% CI: 1-3.7, P: 0.035). Subjects with IL-4Rα V50V genotype were significantly more likely to have erosive arthropathy (OR: 2.6, 95% CI: 1.1-6.1, P: 0.02). The frequencies of IL-4Rα Q576R genotype were significantly decreased in patients with erosive RA compared to patients with nonerosive RA (31.6% versus 48.2%, OR: 2.7, 95% CI: 1-7.7, P: 0.04).
IL-4Rα polymorphisms were associated with susceptibility to RA and may be helpful in early detection of erosive RA.