Objectives: Hepatitis C virus (HCV)-associated mixed cryoglobulins appear to be detected often in hepatitis C-related chronic liver disease. The association of the two phenomenon among Japanese patients is the subject of the present study.
Methods: Serum levels of total hemolytic complement (CH50) and anti-C3d-binding immune complex, as well as the prevalence of cryoglobulins, were studied in 213 patients with chronic liver disease (hepatitis C, 155; hepatitis B, 58). Cryoprecipitates were tested for anti-HCV Ab and HCV RNA.
Results: CH50 activity was significantly lower in patients with hepatitis C than in those with hepatitis B except in responders to interferon who showed a sustained loss of HCV RNA. Cryoglobulins were detected in 24 (37%) of 65 patients with hepatitis C; they generally consisted of polyclonal immunoglobulins but one case. Cryoglobulins were more frequently observed in cirrhotic patients and in those with a longer duration of disease. Cryoglobulinemia-related clinical signs such as vasculitis occurred in only three cases. Patients with cryoglobulins had lower CH50 activity and higher immune complex values than those without cryoglobulins. Anti-HCV Ab and HCV RNA were detected in all cryoprecipitates tested.
Conclusions: These findings suggest that HCV is a major cause of cryoglobulins and advanced liver damage. However, serum cryoglobulins with polyclonal immunoglobulins appear to be less frequent among Japanese patients than among those studied in Western countries.