Angiotensin I converting enzyme gene polymorphism in glomerulonephritis

ABSTRACT

Since an insertion / deletion [I/D] polymorphism of the angiotensin converting enzyme [ACE] gene significantly influences circulating ACE levels, we examined the role of this polymorphism in glomerulonephritis. ACE genotypes were retrospectively analyzed in 39 patients with clinical and biopsy proven glomerulonephritis [27 with idiopathic and 12 with lupus nephritis] and compared with ACE genotypes of 36 age and sex matched healthy control subjects. The ACE variants were determined by PCR and the genotypes were classified as DD, ID and II. Patients with glomerulonephritis had significantly higher frequency of DD genotype when compared to the control [DD ID+II 61.5% 38.5% vs 25% 75%, p = 0.001]. Still, patients with lupus nephritis had a higher frequency of DD genotype than those with idiopathic glomerulonephritis [although non-significantly [75% vs 55.6%, p > 0.05]]. The risk of presence of DD genotype was 5 times greater in patients with glomerulonephritis than the control [Odds ratio 4.8, 95% CI - 1.6 - 14.75]. Patients with glomerulonephritis had significantly lower frequency of I allele compared to the control [38.5% vs 75%, p = 0.001]. Patients with DD genotype were significantly younger and belong to the male gender compared to patients having ID+II genotypes [p < 0.05, p < 0.01 respectively]. Taken together, these findings suggest a strong association between the DD genotype and histopathologic proven glomerulonephritis and that it may be a genetic marker identifying patients at risk of developing such disease. Moreover, it may identify patients with systemic lupus erythematosus at risk of developing lupus nephritis. The presence of I allele may be protective against development of glomerulonephritis