The Association of IL-12b Polymorphisms with Systemic Lupus Erythematosus in Chinese Han Population.

Background. Systemic lupus erythematosus (SLE) is a complex immune disease. The genetic variation in the IL-12b gene was found to associate with SLE in Caucasian population. In this study, we examined this association in Chinese Han population by a recently developed method, unlabeled probe-based high resolution melting analysis. Methods. A total of 297 SLE patients and 351 controls were recruited. Unlabeled probe-based high resolution melting analysis (HRMA) was used in genotyping. Results. Statistically significant differences were observed in both genotype and allele frequencies for rs6887695 in the SLE patients as compared with the controls. Minor allele (C) of rs6887695 (P = 0.031, OR 0.78, [95% CI 0.63-0.98]) was found to be protective against SLE. The association of SNP rs6887695 with the diagnostic criteria of SLE was also examined. Minor allele (C) exerts protective effect on the incidence of arthritis (P = 0.013, OR = 0.65, 95% CI = 0.47-0.92) and abnormalities of antinuclear antibody (P = 0.022, OR = 0.68, 95% CI = 0.49-0.95). IL-12b SNPs were irrelevant to other diagnostic criteria of SLE. Summary. Polymorphisms of rs6887695 in IL-12b gene were associated with disease risk, as well as arthritis and antinuclear antibody synthesis, of systemic lupus erythematosus in Chinese population.