Ribavirin in the Treatment of Hepatitis C

Abstract

The hepatitis C virus (HCV) is a major cause of chronic liver disease worldwide, with approximately 170-200 million people infected. The HCV virus is transmitted by blood and blood products and such transmission occurs primarily through drug use by injection, sex with an infected partner and occupational exposure. The severity of the disease varies widely from mild chronic hepatitis to cirrhosis and hepatocellular carcinoma (HCC). Nowadays, the reference treatment is combination therapy of pegylated interferon and ribavirin, which is an inosine monophosphate dehydrogenase inhibitor and immunomodulator. Efficacy of treatment in our clinical trials is 87% in patients infected by HCV genotypes 2 or 3, whereas in patients infected by HCV genotype 1 response to treatment is 66%. The current combination treatment has significant side-effects and sometimes is poorly tolerated. HCV genotypes 2 or 3 can be treated with a lower dose of ribavirin and a shorter course of therapy, 24 weeks vs 48 weeks for patients with genotype 1. There is a growing consensus that acute control of HCV infection is associated with a vigorous intrahepatic antiviral CD4+ and CD8+ T-cell response, enhanced Th1 and natural killer activity. Pretreatment genotype and response to therapy measured at weeks 12 and 24 of treatment have been identified as key determinants in decisions about continuing treatment. Elevated serum ferritin levels and hepatic iron deposition as well as hepatic steatosis and high ALT levels with chronic hepatitis C are risk factors for HCC development. Heterozygosity for the C282Y mutation in HFE contributes to iron accumulation and fibrosis progression in chronic hepatitis C. Ribavirin could cause dose-dependent reversible haemolytic anaemia, which can be managed with dose reductions or with administration of epoetin alpha at 40,000 IU once weekly without sacrificing the optimal dosing of ribavarin. Among patients who received ribavirin alone, serum ALT levels and necroinflammatory features of liver histology were improved, whereas symptoms, HCV RNA levels and hepatic fibrosis scores were not changed significantly from baseline. For HCV-HIV co-infected patients, treatment is given when blood CD4 counts are above 350/ml and before antiretroviral (ART) treatment is needed.