Table 4 Association of rs2476601 (PTPN22*C1858T) polymorphism with presence of autoantibodies in patients with inflammatory polyarthritis (IP) and in the subset satisfying ACR classification criteria for rheumatoid arthritis (RA) Autoantibody at baseline RF present RF absent Comparison: p value Anti-CCP present Anti-CCP absent Comparison: p value IP Cohort PTPN22*CC, n (%) 185 (74.0) 442 (78.2) 109 (68.5) 388 (78.1) 0.19 0.09 p Values are uncorrected. ACR, American College of Rheumatology; CCP, cyclic citrinulated peptide; RF, rheumatoid factor. RA subset 155 (74.5) 231 (79.4) 102 (69.4) 207 (82.1) 0.20 0.003 PTPN22*CT or PTPN22*TT, n (%) PTPN22*CC, n (%) PTPN22*CT or PTPN22*TT, n (%) 65 (26.0) 123 (21.8) 50 (31.5) 109 (21.9) E x t e n d e d r e p o r t 53 (25.5) 60 (20.6) 45 (30.6) 45 (17.9) REFERENCES 1. MacGregor AJ, Snieder H, Rigby AS, Koskenvuo M, Kaprio J, Aho K, et al. Characterizing the quantitative genetic contribution to rheumatoid arthritis using data from twins. 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