IL-10 Gene Polymorphisms and Susceptibility to Systemic Lupus Erythematosus: A Meta-Analysis

BACKGROUND: A number of observational studies have been conducted to investigate the association of the IL-10 gene polymorphisms with systemic lupus erythematosus (SLE) susceptibility. However, their results are conflicting. METHOD: We searched published case-control studies on the IL-10 polymorphisms and SLE in PubMed, EMBASE and Chinese Biomedical Literature Database. A meta-analysis was conducted using a fixed-effect or random-effect model based on between-study heterogeneity. RESULTS: A total of 42 studies with 7948 cases and 11866 controls were included in this meta-analysis. Among Caucasians, the CA27 allele of the IL10.G microsatellites (OR 2.38, 95% CI 1.01-5.62), the G allele of the IL-10 -1082G/A polymorphism (G vs. A: OR 1.21, 95% CI 1.02-1.44; GG vs. AA: OR 1.45, 95% CI 1.16-1.82; GG+GA vs. AA: OR 1.16, 95% CI 1.03-1.29) and its associated haplotype -1082G/-819C/-592C (OR 1.25, 95% CI 1.10-1.42) were associated with increased SLE susceptibility without or with unimportant between-study heterogeneity. Removing studies deviating from Hardy-Weinberg equilibrium (HWE) hardly changed these results. Among Asians, the CA21 allele of the IL-10.G microsatellites (OR 1.28, 95% CI 1.02-1.60) and the -1082G/-819C/-592C haplotype (OR 1.24, 95% CI 1.00-1.53) were associated with increased SLE susceptibility, but with substantial between-study heterogeneity or sensitive to HWE status. Removing studies deviating from HWE also produced statistically significant associations of the IL-10 -1082G/A (GG vs. AA: OR 3.21, 95% CI 1.24-8.28; GG vs. AA+GA: OR 2.85, 95% CI 1.19-6.79) and -592C/A polymorphisms (CC+CA vs. AA: OR 0.69, 95% CI 0.51-0.94) with SLE among Asians. CONCLUSION: This meta-analysis showed that the IL10.G microsatellites, the IL-10 -1082G/A and -592C/A polymorphisms and the haplotype -1082G/-819C/-592C are associated with SLE susceptibility. Besides, this is the first time to report an association between the CA27 allele of the IL-10.G microsatellites and SLE among Caucasians. Further studies are needed to confirm these findings.