Association of angiotensin I-converting enzyme gene insertion/deletion polymorphism and IgA nephropathy: a meta-analysis

BACKGROUND/AIMS

The angiotensin I-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism has been extensively examined for the association with immunoglobulin A (IgA) nephropathy (IgAN), however, conflicting results have occurred. We performed a meta-analysis to evaluate the association of ACE I/D polymorphism with IgAN in different ethnic groups.

METHODS

11 studies testing the association between ACE I/D polymorphism and IgAN susceptibility, and 9 studies testing the association of ACE I/D with IgAN progression were used in this analysis. The overall odds ratio (OR) was estimated by a fixed or random effect model.

RESULTS

The overall OR for the risk of susceptibility and progression of IgAN in Asians for the DD genotype is 2.37 (95% CI 1.04-5.41) and 1.75 (95% CI 1.24-2.56). The overall OR for the D allele in Asians also showed a similar magnitude, though without statistical significance (p = 0.09, p = 0.13, respectively). In Caucasians, both the DD genotype and D allele were associated with IgAN progression (OR 1.90, 1.61, respectively), but not IgAN susceptibility (p = 0.30, p = 0.41, respectively).

CONCLUSION

Our findings support the notion that ACE I/D polymorphism is associated with IgAN. Meanwhile, the role of ACE I/D polymorphism in Asians is different from that of Caucasians.

Association of Uteroglobin G38A Polymorphism With IgA Nephropathy: A Meta-Analysis

Both uteroglobin knockout and antisense transgenic mice develop pathological and clinical features similar to immunoglobulin A (IgA) nephropathy. However, several association studies of uteroglobin G38A polymorphism and IgA nephropathy showed controversial findings. We used meta-analysis to assess the impact of the uteroglobin G38A polymorphism on susceptibility to and progression of IgA nephropathy. Six studies involving uteroglobin G38A genotyping of 930 patients with IgA nephropathy and 768 healthy controls were included. No significant publication bias was found (Egger's linear regression, P = 0.763; 95% confidence interval [CI], -0.610 to 0.476). All control samples were in Hardy-Weinberg proportion. No association between the AA genotype and risk for IgA nephropathy relative to both other genotypes (odds ratio [OR], 1.05; 95% CI, 0.71 to 1.54) or A allele and risk for IgA nephropathy (OR, 0.96; 95% CI, 0.84 to 1.11) were shown in the total meta-analysis. In both Asian and European subgroups, the overall effect of the AA genotype and A allele also showed no significant difference. There also was no significant association between uteroglobin AA genotype or A allele and IgA nephropathy progression (OR, 3.62; 95% CI, 0.59 to 22.34; OR, 2.19, 95% CI, 0.37 to 13.14, respectively). We suggest that uteroglobin G38A polymorphism is not related to the development and progression of IgA nephropathy.