HEPATITIS-C VIRUS-INFECTION AND MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS IN JAPAN

The prevalence of hepatitis C virus (HCV) infection was determined in 146 adult patients with various types of glomerulonephritis and renal diseases monitored between 1990 and 1993. Serum HCV antibody (HCV Ab) was evaluated, and positive cases were tested for HCV RNA by polymeras e chain reaction. HCV infection was present in 1 (1.7%) of 58 cases of immunoglobulin A nephropathy, 0 (0%) of 14 cases of lupus nephritis, 0 (0%) of 12 cases of minimal change nephrosis, and 0 (0%) of 28 cases of other renal diseases, which is similar to the 2% prevalence observ ed in healthy blood donors in Japan. in contrast, HCV Ab was observed in 2 (8.3%) of 24 cases of membranous nephropathy and 6 (60%) of 10 ca ses of membranoproliferative glomerulonephritis (MPGN) Type I. The pre valence of HCV infection in MPGN patients was significantly higher tha n the frequency of HCV infection observed in the other patients with r enal diseases (P < 0.001), HCV RNA was present in all cases in which H CV Ab was present. The six patients with HCV-MPGN were similar to the four patients with idiopathic MPGN with respect to age, presence of ne phrotic syndrome, and renal dysfunction, but had a higher incidence of liver dysfunction, cryoglobulinemia, rheumatoid factor, and hypocompl ementemia (low C3). HCV infection is present in a large percentage of patients with MPGN in Japan and clinically may differ slightly from ot her cases of MPGN.