Hepatitis C and kidney disease.

Hepatitis C virus (HCV) infection is often associated with kidney diseases such as membranoproliferative glomerulonephritis (MPGN), with and without cryoglobulinemia, membranous glomerulonephritis (MGN) or glomerulosclerosis (FSGN). The aim of our study was to determine the frequency of HCV with or without hypertransaminasemia in patients with chronic nephropathy in the predialytic phase. We tested 340 subjects with chronic renal insufficiency (CRI) from our hospital's nephrology outpatient clinic for anti-HCV antibodies. In positive subjects we tested for HCV RNA by PCR method, monitoring, for at least 4 months, common biohumoral parameters including transaminases (AST, ALT). Of the 340 subjects, 46 (13.5%) were positive for HCV RNA, and 8 of these (17%) showed constant alteration of transaminases. HBsAg was found in 8 of the total study population (2.3%), and none of these showed altered transaminases. Type II diabetes mellitus was found in 26% (12/46) of the HCV-RNA positive patients, and in only 12.5% (37/294) of the negative ones. The kidney diseases we found in the 46 HCV-RNA positive patients were: diabetic nephropathy in 11 (23.9%), MPGN in 7 (15.2%), MPGN + cryoglobulinemia in 2 (4.3%), interstitial nephropathy in 4 (8.7%), IgA mesangial GN in 3 (6.5%), hypertensive nephropathy in 2 (4.3%), focal and segmental GN in 1 (2.2%), urologic disease in 4 (8.7%), other (hematological, genetic, iatrogenic) in 3 (6.6%), unknown in 9 (19.6%). Our data show that the most frequent kidney diseases associated with HCV infection were diabetic related nephropathy and MPGN with and without cryoglobulinemia. HCV infection had a positive association with diabetes. It is interesting to note that in this study population the hepatitis C concomitant to kidney disease was unusually mild: only 4 of the 46 subjects (9%) showed clinical, biohumoral and ultrasound evidence of cirrhosis.