Evidence of hepatitis C virus antibodies in the cryoprecipitate of patients with mixed cryoglobulinemia.

OBJECTIVE To describe the clinical features of 8 patients with mixed cryoglobulinemia and hepatitis C virus (HCV) infection. METHODS A clinical study of the patients was performed. Anti-HCV antibodies were determined by ELISA and confirmed by immunoblot (RIBA) in the sera and in the cryoprecipitate. RESULTS All patients had liver dysfunction, while most had arthralgias and/or arthritis, purpura, peripheral nervous system involvement and renal disorders. Cryocrits ranged from 1 to 6%. Six patients had type III mixed cryoglobulinemia and the remaining 2 had type II. History of blood transfusion was recorded in 2 patients. Hepatitis B virus (HBV) markers were negative in all sera samples. The cryoprecipitate of 7 patients was negative for HBV markers, but anti-HCV antibodies were positive by both ELISA and RIBA. CONCLUSION After reviewing published reports and discussing the possible role that hepatitis C virus plays in the pathogenesis of mixed cryoglobulinemia, we conclude that HCV may stimulate immune complex formation and produce cryoglobulinemia. Therefore its investigation is recommended before the diagnosis of "essential" mixed cryoglobulinemia is established.