Macroglobulinemia and membranoproliferative glomerulonephritis in a hepatitis C virus-positive patient.

A 72-year-old female was admitted to our hospital for massive proteinuria. She had previously been diagnosed with hepatitis C virus (HCV) infection and macroglobulinemia. Renal histological examination demonstrated membranoproliferative glomerulonephritis (MPGN), and type 2 cryoglobulinemia was positive in her serum. It is generally recognized that MPGN is the most common nephritis associated with HCV infection and cryoglobulinemia, but this is the first report of an HCV-infected patient with macroglobulinemia associated with MPGN. After treatment with prednisolone and melphalan, proteinuria disappeared, but macroglobulinemia and cryoglobulinemia were not improved.