Appearance of nephrotic syndrome following interferon-alpha therapy in a patient with hepatitis B virus and hepatitis C virus coinfection.

A 59-year-old woman with hepatitis B surface antigen (HBsAg) and hepatitis C viral (HCV) antibody presented with proteinuria and hematuria. The patient was treated with interferon-alpha (INF-alpha) because plasma aminotransferase levels had been elevated and a liver biopsy had showed chronic active hepatitis. Her urinary protein excretion decreased as liver function normalized and her serum HCV-RNA was negative during treatment. Eleven weeks after completion of INF-alpha treatment, she suddenly presented with nephrotic-range proteinuria, although an improvement in the hepatic function was maintained. Renal pathologic findings were consistent with membranous glomerulonephritis (MGN), and HBsAg was detected in the glomeruli but not HCV. After treatment with prednisolone, her 24-hour protein excretion was below 0.7 g/day. To our knowledge this is the first report on hepatitis B virus MGN with nephrotic syndrome following IFN-alpha therapy for HCV. This suggests that treatment with INF-alpha might affect the immune processes and may be associated with the pathogenic mechanism in this patient.