Association between the angiotensin-converting enzyme insertion/deletion polymorphism and susceptibility to systemic lupus erythematosus: a meta-analysis

OBJECTIVE: The aim of this study was to determine whether the insertion (I) /deletion (D) polymorphism within intron 16 of angiotensin-converting enzyme (ACE) confers susceptibility to systemic lupus erythematosus (SLE) and lupus nephritis (LN). METHODS: A meta-analysis was conducted on the associations between the ACE I/D polymorphism and SLE and LN. RESULTS: A total of 1907 patients with SLE and 1842 controls in 18 comparative studies were included in this meta-analysis. The analysis showed a significant association between SLE and the DD genotype (recessive effect) of the ACE polymorphism (odds ratio [OR] 1.383, 95% confidence interval [CI] 1.065-1.797, p = 0.015). Stratification by ethnicity indicated a marginal association between the DD genotype and SLE in Europeans (OR 1.210, 95% CI 0.964-1.519, p = 0.099; I(2) = 0%). Meta-analysis also revealed a trend toward to an association between SLE and the ACE polymorphism using the allelic or additive models in Europeans. Furthermore, meta-analysis of the DD+ID genotype showed a significant association with LN (OR 0.582, 95% CI 0.425-0.797, p = 0.001; I(2) = 0%). CONCLUSION: This meta-analysis demonstrates a strong association between DD genotype and SLE in overall study and a marginal association between SLE and the ACE D/I polymorphism in Europeans, and suggests that this polymorphism might confer susceptibility to LN.