Mutations in the NS5A gene predict response to interferon therapy in Japanese patients with chronic hepatitis C and cirrhosis

The virus genotype, serum HCV-RNA level and liver histology are reported to be important factors in the response to interferon therapy. Recent studies have revealed that HCV NS5A 2209-2248 amino acid changes affect the respon se to interferon therapy of genotype Ib chronic hepatitis C. In contrast, s ome studies done in western countries have reported no such correlation. In the present study, interferon therapy was given to 58 Japanese patients, i ncluding 15 liver cirrhosis patients. NS5A 2209-2248 changes, the serum HCV level, ALT level, age and histology were examined in relation to the inter feron effect. Twenty-four of the 58 patients (41%) showed a sustained virol ogical response to the therapy. The responses to interferon therapy were si gnificantly correlated with NS5A 2209-2248 changes (p < 0.0001), the HCV-RN A level (p < 0.0001) and histology (p < 0.0060). Among 15 liver cirrhosis p atients, 3 of 6 mutant type patients showed a sustained virological respons e; 5 intermediate and 4 with wild type virus infected patients showed no re sponses. In conclusion, NS5A 2209-2248 changes may be a useful predictive m arker of response to interferon therapy in addition to the serum HCV RNA le vel even in histologically advanced patients.