HLA-B and rheumatoid arthritis: The association between HLA-B and RA was odds ratio (OR) 1.9; 95% confidence interval (CI), 1.2–3.1, between DPB1 and RA OR 1.8; 95% CI, 1.2–2.6 and OR 1.8; 95% CI, 1.2–2.7 between DQB1 and RA.