[New German and American guidelines for therapy of hepatitis B. Discrepancies and similarities].

The new German and American guidelines on hepatitis B show similarities but also some discrepancies. In general, indication for therapy depends more on hepatitis B virus-(HBV-)DNA than alanine aminotransferase (ALT) values. Antivirals are recommended by German guidelines when HBV-DNA exceeds 10,000 copies/ml and ALT is increased more than twice the upper normal limit or when liver biopsy shows significant inflammation and fibrosis. By contrast, American guidelines recommend therapy only when HBV-DNA exceeds 100,000 copies/ml. American guidelines do not recommend lamivudine or telbivudine as initial monotherapy because of risk for resistance, but adefovir or entecavir. By contrast, according to German guidelines monotherapy with lamivudine, telbivudine, adefovir or entecavir may be initiated, if HBV-DNA is < 1 million copies/ml and cirrhosis is absent. Both guidelines recommend to monitor HBV-DNA even in the absence of therapy. Under antiviral therapy HBV-DNA should be measured more often than previously recommended to early identify lack of response and upcoming resistance. When resistance occurs, combination therapy is indicated. Risk for resistance is low as long as viral suppression is effective. In both guidelines liver biopsy should be considered when there are doubts on indication of therapy or selection of antiviral substances. In the presence of severe fibrosis and high HBV-DNA, antiviral substances should have high potency and low risk for resistance.