Renal involvement in patients with hepatitis C virus infection.

INTRODUCTION Hepatitis C virus (HCV) infection is a hepatotropic virus causing a variety of extrahepatic immunological manifestations and is a risk factor of a variety of extrahepatic diseases, such as mixed cryoglobulinemia and membranoproliferative glomerulonephritis (MPGN), which is the most common glomerulonephritis. The aim of this study was to evaluate renal involvement in HCV-infected patients. MATERIALS AND METHODS A total of 300 randomly-selected HCV antibody-positive outpatients at the HCV clinic of Shariati hospital were enrolled. Serum creatinine was measured and glomerular filtration rate was estimated accordingly. Urine proteinuria was measured in 24-hour urine samples. RESULTS The patients were 249 men (83.2%) and 51 women (16.8%) with a mean age of 37.8 +/- 11.7 years (range, 18 to 70 years). Proteinuria was found in 12 HCV antibody-positive adults (4%), 1 of whom underwent biopsy. He was a 55- year-old man with a 4-month history of facial and lower extremities edema and 3-g proteinuria with a normal kidney function (glomerular filtration rate, 85 mL/min) and normocomplementemia. Kidney biopsy specimens showed MPGN. The frequency of low glomerular filtration rate was 0.7% (2 patients) in the HCV antibody-positive adults. There was no significant relationship between HCV seropositivity and low glomerular filtration rate. CONCLUSIONS Our observations showed renal involvement in HCV antibody-positive patients. Among immune complex glomerular kidney diseases, MPGN without cryoglobulins is thought to be the most common in these patients.