20-fold increase in risk of lamivudine resistance in hepatitis B virus subtype adw

We investigated subtype-dependent development of lamivudine resistance In h epatitis B virus (HBV) longitudinally In 26 consecutive patients (13 adw an d 13 ayw carriers) during antiviral treatment of chronic hepatitis B, Lamiv udine resistance developed in seven adw carriers and one ayw carrier. Risk of lamivudine resistance was significantly higher for adw carriers than for ayw carriers (p=0.03). We believe that the adw subtype of HBV Is associate d with a high risk of lamivudine resistance, which might be linked to simul taneous changes of the HBsAg that occurs with the emergence of resistance.