The Influence of ACE Insertion/Deletion Gene Polymorphism on the Risk of IgA Nephropathy: A Debatable Topic.

Background: The connection between angiotensin-converting enzyme insertion/deletion (ACE I/) gene polymorphisms and IgA nephropathy (IgAN) was conflicting. This pooled analysis was performed to explore this issue.

Methods: All eligible investigations were identified from various electronic databases, and the pooled analysis was evaluated using Stata software.

Results: 27 studies with 2538 IgAN cases and 3592 controls were included. In overall subjects, ACE allele, DD, and II genotype were associated with IgAN susceptibility (D vs. I: OR = 1.21, 95% CI: 1.10-1.32, < 0.001; DD vs. ID + II: OR = 1.38, 95% CI: 1.20-1.60, < 0.001; and II vs. DD + ID: OR = 0.83, 95% CI: 0.73-0.95, =0.007). In Asian and Chinese patients, ACE I/ gene polymorphism was also correlated with IgAN vulnerability. Moreover, ACE allele, DD, and II genotype were correlated with the progression of IgAN (D vs. I: OR = 1.37, 95% CI: 1.09-1.73, =0.008; DD vs. ID + II: OR = 1.57, 95% CI: 1.06-2.31, =0.024; and II vs. DD + ID: OR = 0.69, 95% CI: 0.49-0.99, =0.045). Conversely, in Caucasian subjects, there was no link between ACE I/ gene polymorphism and the risk of IgAN.

Conclusion: ACE I/ gene polymorphism was correlated with the vulnerability and progression of IgAN in Asian and Chinese patients, and ACE allele and DD homozygote genotype could be adverse factors for IgAN, while the II homozygote genotype could be an advantage factor. But, no significant association was found between ACE I/ gene polymorphism and IgAN in Caucasians.