Association of angiotensin‐converting enzyme insertion/deletion polymorphism with susceptibility to systemic lupus erythematosus: a meta‐analysis

Background The aim of this study was to determine whether the angiotensin‐converting enzyme ( ACE ) insertion/deletion (I/D) gene polymorphism confers susceptibility to systemic lupus erythematosus ( SLE )/lupus nephritis ( LN ). Methods A meta‐analysis was conducted on the association between the ACE I/D polymorphism and SLE / LN (when available) using: (i) the allelic contrast; (ii) the recessive; (iii) the dominant; and (iv) the additive models. Results A total of 27 relevant comparisons meeting the inclusion criteria were identified, involving 2718 SLE patients and 3655 controls. Meta‐analysis showed a significant association between SLE and the allele D in overall populations (odds ratio [ OR ] = 1.25, 95% CI : 1.07–1.48, P = 0.004). Stratification by ethnicity indicated a strong association between the allele D and SLE in Asians ( OR = 1.36, 95% CI : 1.05–1.75, P = 0.019). Meta‐analysis also showed a significant association between SLE and the DD genotype in overall populations (additive model) ( OR = 1.38, 95% CI : 1.05–1.83, P = 0.022). In addition, we found significant associations between the recessive model and SLE in overall populations, Asians and Europeans ( OR = 1.44, 95% CI : 1.11–1.88, P = 0.007; OR = 1.69, 95% CI : 1.07–2.68, P = 0.024; and OR = 1.31, 95% CI : 1.06–1.62, P = 0.013, respectively). With respect to the association between ACE I/D gene polymorphism and LN risk, there was no significant association in either the overall populations or subpopulations. Conclusion The present study might suggest that ACE I/D polymorphism may be a genetic molecular marker to predict SLE , while this polymorphism may not correlate with LN susceptibility.