Biclonal gammopathy and platelet antibodies in a patient with chronic hepatitis C virus infection and mixed cryoglobulinemia.

The presence of biclonal gammopathy [immunoglobulin (Ig)Mk + IgAlambda] and platelet antibodies in a patient with chronic hepatitis C virus (HCV) infection is reported. A type-II cryoglobulinemia (IgMk and polyclonal IgG) has also been detected. The IgAlambda monoclonal component still persists after removal of the cryoprecipitate. Two populations of atypical lymphoid cells with plasmocytoid features in bone marrow have been detected. They express IgM with k restriction and IgA with lambda restriction, respectively. These cells are CD19+, CD5+, bc12+, and Ki67-. Liver biopsy shows lymphoid infiltrates with features of B follicles. Thrombocytopenia with platelet antibodies but without splenomegaly is also present. This case is interesting because two hematologic extrahepatic manifestations simultaneously occur in a patient with HCV infection. Moreover the association between HCV and biclonal gammopathies has never been reported.