Rapid rebound in hepatitis B DNA in previously undetectable hepatitis B/HIV co-infected patients switching from tenofovir to entecavir therapy

Abstract

of results Six patients switched from tenofovir to entecavir in 2007. All patients were male with a median age of 49 yrs (IQR 46–58 yrs) and a median CD4 count of 500 cells/mm3 (IQR 253–658 cells/mm3). All patients were hepatitis Be antigen positive, and had undetectable HBV viral loads while on tenofovir therapy prior to initiation of entecavir. 5/6 patients had prior HBV DNA samples available for genotypic testing; 100% revealed evidence of baseline lamivudine resistance (presence of L180 M + M204 V) but no evidence of entecavir-associated resistance mutations. Patients were treated with entecavir 1 mg daily or renallyadjusted equivalent. Lamivudine was maintained within the antiretroviral regimen of 5/6 patients. All patients experienced HBV rebound on entecavir. Median time to HBV virologic rebound was 2 months (range 1–11 months), and the median HBV DNA viral load at rebound was 226,012 copies/mL (IQR 6,771–492,237 copies/mL). Only one patient experienced a rise in ALT (to 143 IU/mL) at the time of initial HBV rebound. All patients maintained HIV virologic suppression during the substitution period and at the time of HBV rebound.