Role of HBV genotype in predicting response to lamivudine therapy in patients with chronic hepatitis B.

Background: Predictors of response of chronic hepatitis B (CHB) to lamivudine therapy need better definition. Whether hepatitis B virus (HBV) genotypes could serve as such a predictor has not been well studied.
Aim: To study the association of HBV genotypes with the outcome of lamivudine treatment in patients with CHB.
Methods: Seventy-six patients with CHB (45 HBeAg +ve) received lamivudine 100 mg/day, orally for 12 mo. Infecting HBV genotypes were determined in pre-treatment specimens using restriction fragment length polymorphism. End-of-treatment response (ETR) and sustained viral response (SVR) were defined as undetectable HBV DNA (< 0.5 pg/mL) at 12 and 18 months, respectively.
Results: ETR was observed in 26 (34%) and SVR in 11 (14%) patients receiving lamivudine. The pre-treatment characteristics of the responders and non-responders were comparable. Genotypes A and D were observed in 28 (37%) and 48 (63%) patients, respectively. The frequency of genotypes A and D was comparable between responders (28.6% vs. 37.5%) and non-responders (71.4% vs. 62.5%), respectively (p=ns). Of the 26 responders, SVR could be evaluated in 20 subjects; 9 (45%) relapsed and 11 achieved SVR. Patients with genotype D achieved higher SVR rate than genotype A (10 of 48, 28.8% vs. 1 of 28, 3.5% p =0.0359).
Conclusions: Forty-five percent of Indian patients with CHB who achieve ETR relapse, and SVR to lamivudine therapy is achieved in 14%. Patients with genotype D achieve higher SVR rate than with genotype A.