Objective: To evaluate the efficacy of a long-term course of alpha-interferon (alpha-IFN) in the treatment of HCV-related mixed cryoglobulinaemia and to determine the impact of cryoglobulinaemia on therapeutic response to IFN in chronic hepatitis C (CHC) patients.
Design: Prospective controlled study.
Setting: University Medical Centre.
Participants: Ninety consecutive CHC patients, 50 with cryoglobulinaemia (25 symptomatic and 25 asymptomatic; median cryocrit, 8%; chronic persistent hepatitis (CPH) 7, chronic active hepatitis (CAH) 27, cirrhosis 16) and 40 without cryoglobulinaemia (CPH 6, CAH 20, cirrhosis 14). HCV genotypes in the cryoglobulinaemic and non-cryoglobulinaemic groups were: 1b 40% and 45%; 2a 40% and 30%; others 20% and 25%, respectively.
Interventions: Twelve-month course of alpha-IFN 2a, 3 MU, three times weekly.
Main outcome measures: Disappearance of cryoglobulinaemia and related syndrome, clearance of serum HCV RNA and normalization serum transaminase levels at the end of treatment (response) and after 12 months follow-up (sustained response).
Results: Overall, cryoglobulinaemic patients showed a similar response to IFN to those without cryoglobulinaemia (44% vs. 42.5%, respectively). In the cryoglobulinaemic group, symptomatic patients showed a lower response rate than asymptomatic patients (28% vs. 60%, respectively; P<0.05). HCV genotype 2a/c, absence of cirrhosis and a low cryocrit (<9%) were predictive factors of high response rate to IFN. Sustained response in non-cryoglobulinaemic patients (22.5%) tended to be higher than in patients with symptomatic cryoglobulinaemia (4%), as well as among patients carrying genotype 2a/c (67% vs. 10%, respectively; P<0.02). IFN was effective in controlling purpura (80%) but was moderately effective on severe haematuria/proteinuria, renal insufficiency and neuropathy.
Conclusions: A 12-month course of alpha-IFN is effective treatment for HCV-related cryoglobulinaemia. However, patients with CHC associated to symptomatic cryoglobulinaemia have a lower response rate to IFN.