−1722T/C polymorphism (rs733618) of CTLA-4 significantly associated with systemic lupus erythematosus (SLE): A comprehensive meta-analysis

This study was to determine whether −318C/T (rs5742909), −1722T/C (rs733618) and −1661A/G (rs4553808) of Cytotoxic T-lymphocyte antigen-4 (CTLA-4) are associated with systemic lupus erythematosus (SLE). The meta-analysis for −318C/T (rs5742909) included 1163 cases and 1520 controls, for −1722T/C (rs733618) included 1016 cases and 1078 controls, and for −1661A/G (rs4553808) included 637 cases and 774 controls. For −318C/T (rs5742909), statistically significant differences were not noted between cases and controls {fixed/random: OR: 1.103, 95% CI: (0.907-1.341), p = 0.326}. For −1661A/G (rs4553808), also no significant difference existed {fixed: OR: 1.024, 95% CI: (0.843-1.244), p = 0.812; random: OR: 1.077, 95% CI: (0.780-1.300), p = 0.958}. But −1722T/C (rs733618) was significantly associated with SLE both in allele {fixed: OR: 0.699, 95% CI: (0.602-0.811), p = 0.000; random: OR: 0.748, 95% CI: (0.565-0.990), p = 0.042} and in genotype {CC/(CT + TT)} meta-analysis {OR: 0.422, 95% CI: (0.297-0.598), p = 0.000}. Also, we subdivided the −1722T/C group (rs733618) into Asia and Mixed subgroups, in Asia subgroup, the SNP was significantly associated with SLE {fixed: OR: 0.628, 95% CI: (0.528-0.746), p = 0.000; random: OR: 0.641, 95% CI: (0.470-0.875), p = 0.005}, in the Mixed subgroup, this polymorphism was not associated with SLE {fixed: OR: 0.946, 95% CI: (0.707-1.267), p = 0.711; random: OR: 0.973, 95% CI: (0.606-1.560), p = 0.908}. These results suggest that there is evidence of association between the CLTA-4 and SLE, especially −1722T/C polymorphism (rs733618).