Cryoglobulinemia in hepatitis C virus chronic active hepatitis: effects of interferon-alpha therapy.

We investigated the prevalence of mixed cryoglobulinemia (MC) in 100 cases of chronic hepatitis C virus (HCV) infection and the effect of a 6-month treatment with interferon-alpha (IFN-alpha). Cryoglobulins were detected on admission in 36 of 100 patients and appeared during observation in a further 18 cases. Cryocrit ranged from 0.5% to 20%. Patients with MC were older and had a higher incidence of cirrhosis than those without MC. Immunologic characterization of the cryoprecipitate showed the presence of type II in 84% of cases and type III in 16%. The patients received IFN-alpha (6 MU three times per week) for 6 months. Fifty-seven were responders (i.e., reached normal aminotransferase levels), 26 of these relapsed within 2 months after IFN withdrawal, and 30 did not relapse. After IFN-alpha treatment, cryoglobulinemia disappeared in 11 of the 21 evaluable responders, but in none of the 15 nonresponder patients (p < 0.003). The clearance of MC was associated in all cases with clearance of HCV RNA. The delayed appearance of cryoglobulinemia in responders seems to be associated with a higher probability of relapse.