Few data are available about the predictability of HBsAg quantification to nucleos(t)ide analogues treatment in acute-on-chronic liver failure (ACLF). The aim of this study was to investigate HBsAg level combined with the model for end-stage liver disease (MELD) score for predicting prognosis to lamivudine monotherapy in HBeAg-negative ACLF.

Fifty-seven nucleoside-naïve patients with HBeAg-negative ACLF were treated with 100mg of lamivudine daily. Serum levels of HBsAg, HBV DNA and biochemical items were detected at baseline, before death (patients died within 3months) or month 3 meanwhile MELD score was calculated. Dynamic of these items and 3-month mortality were analyzed.

HBV DNA level significantly decreased while HBsAg level did not after treatment. Twenty-six patients died within 3months and the others survived. Regardless pre- or post-treatment, HBsAg level of survival group was significantly higher than that of dead group meanwhile MELD scores of the former were significantly lower than those of the latter (all P<0.05). Post-treatment MELD scores of 32 patients with pretreatment HBsAg levels above 4000 COI were significantly lower than those of 25 patients below to it (t=−2.116, P=0.044) and the 3-month mortality of the formers was significantly lower than that of the latter (34.3% [11/32] vs 64.0% [16/25], χ²=4.941, P=0.026).

In HBeAg-negative ACLF, patient with higher pretreatment HBsAg levels and early decrease in MELD score has lower 3-month mortality than one without it during lamivudine monotherapy.