Angiotensin-converting enzyme gene polymorphism in Kuwaiti patients with systemic lupus erythematosus

Objective: To investigate the frequency of angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism genotypes in patients with systemic lupus erythematosus (SLE), and to study the correlation between I/D polymorphism of the ACE gene and the clinical manifestations of SLE, especially vascular involvement, lupus nephritis and disease severity. Methods: The frequency of ACE gene I/D polymorphism genotypes was determined in 92 patients with SLE from Kuwait, and compared to that in 100 ethnically matched healthy controls using the polymerase chain reaction. Results: The distribution of ACE I/D polymorphism and allele frequencies in SLE patients was not significantly different from controls. Further analyses of SLE patients showed that there was a significant association between DD genotype and Raynaud's phenomenon (p = 0.008, odd ratio = 5.4, 95% confidence interval: 1.6-18.6). However, there was no significant association between the ACE genotype and lupus nephritis or disease severity. Conclusion: No difference was found between the distribution of the ACE genotype in SLE patients and the general population in Kuwait. However, the presence of the DD genotype may confer susceptibility to the development of vascular morbidity.