Severe cryoglobulinemia in a patient with asymptomatic hepatitis C virus infection

A patient with severe type II cryoglobulinemia after ten years of asymptomatic hepatitis C virus (HCV) infection is reported. Laboratory data showed hypergammaglobulinemia with polyclonal IgG and monoclonal IgM, blood hyperviscosity, high level of cryocrit (60%), HCV viremia, and normal levels of serum transaminases. Due to cold exposure, acrocyanosis and cardiac ischemic attack occurred; he recovered after being artificially warmed. Administration of prednisolone and natural interferon-alpha for three months resulted in significant decreases in the levels of serum IgM and cryocrit.