Angiotensin I converting enzyme gene polymorphisms in systemic lupus erythematosus: decreased prevalence of DD genotype in African American patients.

The presence of the D (deletion) allele at the angiotensin converting enzyme (ACE) gene has been associated with a) adverse vascular events contributing to early mortality and b) progressive deterioration of renal function in a variety of chronic glomerular diseases. We investigated the potential role of ACE polymorphisms in patients with systemic lupus erythematosus (SLE). Two hundred and sixteen (216) SLE patients (121 Caucasians; 78 African Americans; and 17 other) and 200 normal controls were studied; 134 patients had evidence of renal disease. ACE genotypes were determined by a polymerase chain reaction based assay. The frequency of genotype DD was increased in African American normal controls compared to Caucasians (55% vs. 37%, p = 0.017) and in African American normal controls vs. African American lupus patients (55% vs. 30%, p = 0.008). Trend analysis of the genotype distribution across the three African American groups (renal, non-renal, controls) revealed a trend of increased frequency of I and decreased frequency of D as likelihood of renal disease increases (p = 0.008). No association between any ACE genotype with parameters of renal disease and/or response to therapy was identified. African American patients with lupus have a lower frequency of DD genotype as compared to African American normal controls. Further studies will be necessary to address whether this is due to decreased survival of these patients, a protective effect of DD genotype from developing the disease or a chance sample effect.