POLYMORPHISM OF THE ANGIOTENSIN-CONVERTING ENZYME GENE AND CLINICAL ASPECTS OF IGA NEPHROPATHY

To investigate the relationship between the insertion/deletion (I/D) p olymorphism of the angiotensin converting enzyme (ACE) gene and the on set and progression of IgA nephropathy, we studied this polymorphism i n 48 patients (21 males and 27 females) with IEA nephropathy and 104 n ormal controls (51 males and 53 females) using the polymerase chain re action method. There was no difference in either the genotype or allel e frequency of the VD polymorphism between the patients and normal con trols (D allele frequency; 0.303 and 0.325, respectively). But, the me an slope of the reciprocal of the serum creatinine concentration was s ignificantly steeper (p < 0,05) in the patients with the D allele (-0. 0104 +/- 0.007 dl . mg(-1) . month(-1)) than those without the D allel e (-0.0055 +/- 0.008 dl . mg(-1) . month(-1)). The mean percentage of the glomeruli with sclerosis or segmental lesions obtained from each r enal biopsy specimen was significantly larger (p < 0.02) in the patien ts with the D allele (49.5 +/- 17.8%) than in those without (33.3 +/- 22.9%). These results suggest that 1. the ACE gene polymorphism is not related to the onset of IgA nephropathy, but 2. the progression of Ig A nephropathy may be influenced by the polymorphism which may be invol ved in glomerular hypertension.