Virologic response and breakthrough in chronic hepatitis B Egyptian patients receiving lamivudine therapy

BACKGROUND Lamivudine monotherapy is effective in suppressing hepatitis B virus (HBV) replication to undetectable levels by PCR, in ameliorating liver disease and to some extent in achieving HBsAg seroconversion. This study aimed at assessing the virological and biochemical responses as well as breakthrough in HBeAg-negative chronic HBV (CHB) Egyptian patients receiving lamivudine therapy. METHODS This retrospective study included 140 CHB patients with positive serum HBV-DNA by quantitative PCR assays and negative HBeAg who had never received prior anti-viral therapy for HBV. According to duration of lamivudine therapy (100 mg/day) patients were grouped into: group I (n=59) who received lamivudine for 1 year, group II (n=50) who received lamivudine for 2 years, and group III (n=31) who received lamivudine for 3 years. RESULTS In group I, 76.3% patients had virologic response but this was reduced in group II and group III to 72% and 67.7% respectively. None of the patients in group I developed virologic breakthrough, whereas 12% and 25.8% in groups II and III respectively developed breakthrough. In group I, 25% of patients having high pre-treatment viremia showed virologic response compared to 84.6% and 83.3% having mild and moderate viremia respectively (P<0.01). However, in groups II and III, there was no significant relationship between pre-treatment viremia and virologic response. No significant relationship was found between pre-treatment viral load and incidence of breakthrough within each group. CONCLUSION Lamivudine remains one of the antiviral therapies for HBeAg negative CHB patients. The rates of maintained virologic and biochemical responses to lamivudine decrease in time due to selection of drug-resistant mutants and, hence, breakthrough.