Therapy of hepatitis C: other options

Abstract

Because current standard therapy of chronic hepatitis C with alpha interferon is less than ideal, numerous other approaches have been studied. Iron in the liver, particularly that found in vascular endothelial cells of portal tracts, has been associated with decreased responsiveness to alpha interferon therapy. Iron reduction alone, generally achieved by therapeutic phlebotomy, regularly has been associated with biochemical improvement (decrease in serum alanine aminotransferase), but not with virological improvement. Iron reduction has been reported to increase the therapeutic response to alpha interferon. Most studies of this combination have been conducted in patients who had not responded to interferon alone; in these patients, improved responsiveness has been observed in some, but not all studies. In patients not previously treated, iron reduction was found in a recent trial to improve the sustained biochemical and virological response rate from 5% to 29%. Hepatic iron and chronic hepatitis C increase oxidative stress in the liver and are associated with decreases in hepatic glutathione levels. In one report, administration of N-acetyl cysteine, a sulfhydryl donor, led to improved response to interferon in chronic hepatitis C. Several cytokines and immunomodulators have undergone limited study; perhaps the most promising of these is thymosin alpha-1. In one small study, amantadine was found to produce some response in patients who previously had failed to respond to interferon. Ursodiol improves serum aminotransferase levels in chronic hepatitis C but has no antiviral effect, nor has it been found to improve histologic abnormalities. The future of therapy of chronic hepatitis C will likely include measures to decrease oxidative stress and injury and multidrug combinations, including inhibitors of the hepatitis C viral protease and RNA polymerase.