Hepatitis B virus genotype and basal core promoter/precore mutations are associated with hepatitis B‐related acute‐on‐chronic liver failure without pre‐existing liver cirrhosis

Summary. The study was undertaken to investigate the features and clinical implications of hepatitis B virus (HBV) genotypes, basal core promoter (BCP) and precore (PC) mutations in hepatitis B‐related acute‐on‐chronic liver failure (HB‐ACLF). Samples from 75 patients with HB‐ACLF and without pre‐existing liver cirrhosis and 328 age‐matched patients with chronic hepatitis B (CHB) were analyzed. HBV genotype and BCP/PC mutations were determined by direct sequencing. Mutations at 8 sites of the BCP/PC region were compared between the two groups of patients. A significantly higher ratio of genotype B to C was found in patients with HB‐ACLF than in patients with CHB (30.7–69.3%vs16.5–82.6%, P < 0.01). Single mutations including T1753V (C/A/G), A1762T, G1764A, G1896A and G1899A and triple mutations T1753V/A1762T/G1764A and A1762T/G1764A/C1766T (or T1768A) were more frequently detected in patients with HB‐ACLF than in patients with CHB. Correspondingly, BCP/PC wild‐type sequences were absent in patients with HB‐ACLF in contrast to 27.1% in patients with CHB. The BCP/PC mutations were found to be associated with increased HBeAg negativity, higher alanine aminotransferase level and lower viral load. Patients with HB‐ACLF infected with the PC mutant virus had a higher mortality. The findings suggest that patients with CHB infected with genotype B with BCP/PC mutations were more likely to develop HB‐ACLF than those with genotype C with wild‐type BCP/PC regions, and patients with HB‐ACLF with the PC mutation had increased risk of a fatal outcome.