HLA-DRB1 and rheumatoid arthritis: The DRB1*08-DQB1*03 haplotype was also associated with RA susceptibility (2.8% vs. 1.4%, P = 0.03, (95% CI) = 2.97 (1.09-8.15)), and ACPA seropositivity (OR (95% CI) = 0.09 (0.01-0.70), P = 0.01, Pc = 0.05), while the DRB1*13-DQB1*06 haplotype was associated with RA protection (3.9% vs. 10.4%).