Long-term effects of alpha-interferon therapy for type II mixed cryoglobulinemia.

BACKGROUND

Several reports showed that mixed cryoglobulinemia (MC) is closely associated with hepatitis C virus (HCV) infection. Since several authors reported the efficacy of alpha-interferon in the treatment of MC, we investigated the long-term effects of this drug on clinical, hematological and virological parameters in a group of 18 patients (13 women and 5 men, mean age 56 +/- 11 years) affected by MC.

METHODS

A bone marrow biopsy was performed in all patients, and a liver biopsy was obtained in those with biochemical signs of chronic liver disease. The presence of HCV-RNA in serum was assessed by detection of anti-HCV antibodies and by PCR amplification of the 5' untranslated region of HCV. All patients followed the same treatment schedule: three million units of recombinant interferon alpha-2b s.c., three times a week for 1 year.

RESULTS

In 5 cases bone marrow histology showed the presence of a monoclonal lymphocytic infiltrate. Liver biopsies were performed in 13 (72%) of the patients and a chronic liver disease was found in all 13. Anti-HCV antibodies were present in 17 (95%) subjects. HCV-RNA was detected in all cases (100%) before therapy. Five (28%) patients achieved a complete response and 9 (50%) a partial response, while the others (4 cases, 22%) showed minor responses. Four patients cleared the virus and obtained a complete remission of the MC.

CONCLUSIONS

HCV may be a cause of MC. The disease is associated with a high incidence of monoclonal lymphocytic infiltrate of the bone marrow. Alpha-interferon seems to be an effective agent for the treatment of MC.