Insertion/deletion polymorphism of the angiotensin-converting enzyme gene in lupus nephritis among Mexicans

The angiotensin (Ang)-converting enzyme (ACE) insertion/deletion (I/D) polymorphism determines Ang II levels, but its relationship with lupus nephritis (LN) in different populations is controversial. Objective: To describe the allelic and genotypic distribution of the I/D polymorphism in Mexican mestizos with LN and assess an association with histological classes. Methods: We included 24 patients with systemic lupus erythematosus (SLE) without nephropathy, 41 with LN, 144 healthy subjects, and 36 with primary glomerulonephritis (GMN). Three ACE I/D polymorphism genotypes-ID, DD, and II-were detected by PCR using peripheral blood genomic DNA. Results: Frequencies for II, ID, and DD were 0.29, 0.46, and 0.25 in the SLE group; 0.17, 0.63, and 0.20 in the LN group; 0.14, 0.5, and 0.36 in the GMN group; and 0.26, 0.52, and 0.22 among healthy subjects. The I/D polymorphism distribution according to histological class was class II: 1 II, 3 ID, and 1 DD; class III: 2 II, 10 ID, and 1 DD; class IV: 2 II, 9 ID, and 2 DD; class V: 2 II, 3 ID, and 4 DD; and class VI, 1 II. The histological classes with at least three patients had ID genotype as the most frequent except for class V. Conclusion: No association was identified between I/D polymorphisms of ACE and SLE, LN, or GMN in a Mexican population.