This study aims to investigate the methylomic features of patients with hepatitis B-related acute-on-chronic liver failure and establish and validate a prognostic risk prediction classification model. The findings are of significant importance for guiding clinical practice and improving patient prognosis. Additionally, a methylomics-based classifier model for liver failure will be developed for disease prognosis analysis and clinical assessment, with the potential to enhance the diagnostic efficiency of liver failure.

Inclusion Criteria:

• Chronic hepatitis B was persistent hepatitis B surface antigen (HBsAg) seropositivity for more than six months.

Hepatitis B-related liver cirrhosis was diagnosed based on histological examination, typical features on ultrasound or radiological imaging, endoscopic findings of portal hypertension, and clinical history.

Hepatitis B-related acute-on-chronic liver failure meets the diagnostic criteria of the 2018 Asia-Pacific guidelines for the diagnosis and treatment of liver failure.Laboratory tests:Jaundice: Serum total bilirubin ≥ 85 µmol/L and coagulopathy [International Normalized Ratio (INR) ≥ 1.5 or Prothrombin Activity (PTA) < 40%].

Exclusion Criteria:

• co-infection with other hepatitis viruses; history of hepatocellular carcinoma or other malignancies; concomitant autoimmune liver disease; or insufficient clinical data.

The study population consists of patients with chronic hepatitis B, Hepatitis B-related liver cirrhosis, and Hepatitis B-related acute-on-chronic liver failure