26 consecutive patients chronically infected with HBV were enrolled in the study (13 carriers of the adw subtype and 13 with ayw).
|HBV subtype adw is associated with high risk of lamivudine resistance|
Patients received 100mg lamivudine daily for the study period (range 3-31 months). The median duration of lamivudine intake was 12 months for adw carriers and 11 months for ayw carriers. Consecutive blood samples were taken from patients every 3 months and HBV DNA was analyzed.
The researchers found that lamivudine resistance developed in seven adw carriers and one ayw carrier after a median of 12 months. Risk of lamivudine resistance was shown to be significantly higher for adw carriers than for ayw carriers (a twenty-fold increase).
Investigator Bernhard Zöllner, of the Institute for Medical Microbiology and Immunology at the university, concluded, "We believe that the adw subtype of HBV is associated with a high risk of lamivudine resistance, which might be linked to simultaneous changes of the HBsAg that occurs with the emergence of resistance."