U.O. Epatologia-Azienda Ospedaliero Universitaria Pisana, Pisa, Italy. Electronic address: firstname.lastname@example.org.
BACKGROUND & AIMS:
We investigated whether HBV genotype influences on-treatment HBsAg kinetics and/or the end-of-treatment HBsAg levels associated with long-term virological response in HBeAg-negative chronic hepatitis B patients treated with peginterferon alfa-2a ± lamivudine in the Phase III trial.
All patients (n = 230) who participated in long-term follow-up were included according to the availability of HBsAg levels measurements. Long-term virological response was defined as HBV DNA ⩽10,000 cp/mL (1786 IU/mL) at 5 years post-treatment. Genotype-specific end-of-treatment HBsAg levels associated with long-term virological response (identified by ROC analysis) were assessed in 199 patients with HBsAg measurements available at baseline and end-of-treatment. HBsAg kinetics according to genotype and long-term virological response were investigated in the 117 patients with additional samples available at weeks 12, 24 and 72.
Baseline HBsAg levels were significantly higher for A than B, C and D genotypes (p<0.05). On-treatment HBsAg kinetics varied according to HBV genotype. The difference between responders and non-responders was greatest for genotype A from weeks 12 to 24; for genotypes B and D from baseline to week 12; there was no significant difference over any timeframe for genotype C. High positive predictive values for long-term virological response could be obtained by applying end-of-treatment genotype-specific cut-offs: 75%, 47%, 71% and 75% for genotypes A (<400 IU/mL), B (<50 IU/mL), C (<75 IU/mL) and D (<1000 IU/mL), respectively.
On-treatment HBsAg kinetics vary between HBV genotypes. Genotype-specific monitoring timeframes and end-of-treatment thresholds could ameliorate response-guided treatment of HBeAg-negative chronic hepatitis B.