Update on acute-on-chronic liver failure.

Acute-on-chronic liver failure (ACLF) is a recently defined syndrome characterised by acute decompensation of chronic liver disease, associated with organ failures and high mortality. ACLF is a common condition and may affect up to 30% of patients admitted to hospital for cirrhosis complications. Bacterial infections, alcoholism and reactivation of viral hepatitis are the most common precipitating factors in ACLF, although in up to 40% of patients no precipitating factor can be identified. Although the pathophysiology of ACLF is not completely understood, the presence of an excessive inflammatory response appears to play a key role. There is no specific treatment for patients with ACLF and management is based on organ support and liver transplantation. New treatment strategies based on liver support systems and immunomodulatory treatments are being evaluated but existing data are still limited.