Response to interferon alfa is hepatitis B virus genotype dependent: genotype A is more sensitive to interferon than genotype D.

BACKGROUND AND AIMS Current interferon alfa (IFN) treatment of chronic hepatitis B has limited efficacy. The role of hepatitis B virus (HBV) genotypes for response to IFN was investigated. PATIENTS AND METHODS HBV genotype was determined by direct sequencing of the HBV X gene in 165 consecutive patients with chronic replicative hepatitis B treated with standard IFN. HBV genotype A or D was found in 144 cases. RESULTS Sustained response (six months after treatment) to standard IFN therapy was higher in HBV genotype A compared with HBV genotype D infected patients (49% v 26%; p<0.005). Sustained response to IFN was 46% versus 24% (p<0.03) in hepatitis B e antigen (HBeAg) positive hepatitis (n = 99) and 59% versus 29% (p<0.05) in HBeAg negative hepatitis (n = 45) for HBV genotype A compared with HBV genotype D. HBeAg status had no negative impact on IFN response. Multivariate logistic regression identified HBV genotype A and high pretreatment alanine aminotransferase levels (>2 x upper limit of normal) as independent positive predictive parameters of IFN response. CONCLUSIONS The present study indicates that HBV genotypes A and D are important and independent predictors of IFN responsiveness in chronic hepatitis B. HBV genotype adapted treatment regimens may further improve treatment efficacy in chronic hepatitis B.