To the Editor.
—An intriguing association between hepatitis C virus (HCV) infection and membranoproliferative glomerulonephritis has been described in patients with clinical and histological evidence of chronic liver disease1 (either chronic active hepatitis or cirrhosis). In some of these patients an improvement in liver and kidney disease was obtained by means of antiviral treatment with interferon alfa. To date, there is no report of membranoproliferative glomerulonephritis associated with HCV infection in the absence of liver disease.We identified a 63-year-old man with vasculitis, hypertension, heavy proteinuria, red blood cell casts, increased serum creatinine level, cryoglobulinemia, hypocomplementemia, positivity for rheumatoid factor and circulating immune complexes, and negativity for antinuclear, antineutrophil cytoplasmic, anti-smooth muscle, and antimitochondrial antibodies. Results of renal biopsy showed type I membranoproliferative glomerulonephritis with increased mesangial matrix and cellularity in a lobular pattern, tubular atrophy, and mononuclear cells in the interstitium. Immunofluorescence showed granular staining of the glomerular