Background: Mixed cryoglobulinemia (MC) is a systemic disorder, characterized by a typical clinical triad: purpura, weakness, and arthralgias, with visceral complications such as liver and renal involvement. The objective was to study the association between hepatitis C virus (HCV) infection and essential mixed cryoglobulinemia (EMC).
Patients and methods: Markers of HCV infection in 11 patients with cryoglobulinemia were examined and hepatitis C virus (HCV) was detected in eight of them. These patients were included in a clinical and histologic study. Anti-HCV antibodies were determined by a second-generation enzyme-linked immunosorbent assay (ELISA-2) in sera and cryoprecipitates. Studies on HCV-RNA were performed by a two-stage polymerase chain reaction (PCR) in the serum. A control group, consisting of 28 patients with other cutaneous disorders, was studied for HCV infection using ELISA-2 and PCR.
Results: All patients had liver dysfunction, arthralgias, and purpura. Three patients had involvement of the peripheral nervous system, two had renal involvement, and one patient had Sjögren's syndrome. Cryocrits ranged from 3% to 20%. Six patients had type III cryoglobulinemia and the remaining two had type II. Markers for hepatitis B virus (HBV) were negative in all serum samples. Anti-HCV antibodies and HCV-RNA were positive in the serum of all the cases with MC. Anti-HCV antibodies were positive in all cases except for one of the cryoprecipitates tested. Four patients received recombinant interferon alfa. In two of them, serum aminotransferases became normal and cryoglobulins disappeared.
Conclusions: The results strongly suggest that HCV infection is responsible for the cryoglobulinemia and vasculitis in patients with MC and that treatment with interferon alfa is presently the treatment of choice for such patients.