This is a multi-center, nested cohort study intended to investigate the prevalence, risk factors, and outcomes of complications in patients with acutely decompensated cirrhosis, especially focused on Cytomegalovirus (CMV) reactivation, bacterial infections, hepatic encephalopathy, and Hepatorenal syndrome. Patients diagnosed with acutely decompensated cirrhosis were enrolled. Upon enrollment, detailed baseline data were collected and samples were harvested. Complications were assessed during hospitalization. Post-discharge follow-up was conducted through telephonic interviews at Day 30 and Day 90.

This is a multi-center, nested cohort study intended to investigate the prevalence, risk factors, and outcomes of complications in patients with acutely decompensated cirrhosis, especially focused on CMV reactivation, bacterial infections, hepatic encephalopathy, and Hepatorenal syndrome. Patients diagnosed with acute decompensated cirrhosis were enrolled. Upon enrollment, detailed baseline data were collected and samples including ascites, feces, plasma, urine and PBMC were harvested. Following enrollment, patients were subjected to a rigorous follow-up regimen extending over a period of 90 days. Complications were assessed every 3-4 days during hospitalization through a combination of laboratory and clinical evaluations. Post-discharge follow-up was conducted through telephonic interviews at Day 30 and Day 90. Upon the emergence of new complications, such as infections (viral, bacterial or fungal) or hepatic encephalopathy, a detailed, complication-specific protocol was activated (Per complications protocols as follows).

Special complications protocols:

Hepatic encephalopathy:

1. The feces, plasma, and urine were collected at hepatic encephalopathy diagnosis before treatment and at Day 4, 7, 14 since hepatic encephalopathy treatment. If patients were discharged before14 days post-hepatic encephalopathy, the sample at discharge were collocated;
2. The treatment strategy for HE is recorded;
3. The HE severity assessments were carried out daily.

CMV reactivation:

1. The patients' plasma were collected twice a week for the assessment of CMV reactivation; The patients' peripheral blood mononuclear cells (PBMC) samples were collected at baseline and at the time of diagnosis of CMV reactivation;
2. The treatment strategy for CMV is recorded.

Inclusion Criteria:

• Informed written consent
• Age between 18 years and 80 years
• Cirrhosis based on liver histology or a combination of characteristic clinical, biochemical, and imaging features
• Complications of decompensated cirrhosis (ascites, gastrointestinal bleeding and hepatic encephalopathy)

Exclusion Criteria:

• Malignancy
• Acquired immune deficiency syndrome
• Received immunosuppressive drugs for non-hepatic reasons
• Received organ transplantations

All patients with liver cirrhosis, irrespective of time and circumstances of diagnosis, comorbidities and severity of disease will be offered inclusion in the cohort.