VIRUS AND HOST FACTORS ARE BOTH IMPORTANT DETERMINANTS OF RESPONSE TOINTERFERON TREATMENT AMONG PATIENTS WITH CHRONIC HEPATITIS-C

Virus and host factors have both been linked to the response to interf eron treatment among patients with chronic hepatitis C but their relat ive importance and potential interactions are unclear, Hepatitis C vir us genotype and level of viraemia were determined in pretreatment sera from 65 Australian patients treated with interferon-alpha 2b (IFN-alp ha 2b), 3 MU tiw for 6 months. Hepatitis C viraemia was quantitated by a competitive reverse transcription-polymerase chain reaction (RT-PCR ) method and genotype was determined by a line probe assay. By univari ate analysis, there were positive associations between initial (short- term) responses to IFN treatment and younger age (P = 0.004), absence of cirrhosis (P = 0.01), and injecting drug use as risk factor for inf ection (P = 0.05) but not gender, duration of infection, or level of v iraemia, Genotype appeared to be important (P = 0.06) but failed to re ach statistical significance, By multivariate analysis, absence of cir rhosis was the only significant independent predictor of treatment res ponse (P = 0.01), Among initial responders, the factors associated wit h long-term response were the pretreatment HCV RNA titre and the durat ion of infection. There was a close association between viral genotype , but not viral load, and the severity of liver disease, An interplay of factors determines the outcome of a 6-month course of interferon tr eatment for hepatitis C. Severity of liver disease, but not the viral load, is the most crucial determinant of initial response to interfero n, and histological severity appeared to be influenced by the viral ge notype, The level of hepatitis C virus (HCV) viraemia and the duration of infection are independent determinants of long-term response by af fecting the relapse rate after interferon treatment.