Patients with Acute on Chronic Liver Failure (ACLF) have high short-term mortality. The use of a severity score could define the patient's prognosis and would help determine in whom the treatment is effective or futile.

Acute on Chronic Liver Failure (ACLF) is a syndrome characterized by the presence of an acute decompensation of cirrhosis, associated with failure of at least one other organ or extra hepatic system. It is characterized by high mortality in the short term and its prevalence varies between countries and regions.

It is an extraordinarily dynamic entity in which more than 50% of patients with less severe forms improve, while in those with 3 or more organ failures, the transplant rate is low and mortality is 90%. It is important to highlight that those patients with ACLF who manage to be transplanted have the same survival as cirrhotic patients without ACLF. There is no specific treatment, only life support and early determination of the precipitating factor and its eventual resolution.

Having tools that define the short-term prognosis of these patients, especially the variation of the score (CLIF-C ACLF) during the first week, would have an important clinical relevance, because it can help define the patients who benefit from the supportive treatment and in whom the therapeutic effort is futile.

The biomarker Neutrophil Gelatinase-Associated Lipocalin (NGAL) is increased in plasma and urine in patients with ACLF and could help improve the prognostic ability of the CLIF-C ACLF score.

Inclusion Criteria:

• Acute on Chronic Liver Failure

Exclusion Criteria:

• Acute liver failure, terminal disease, pregnancy, previous liver transplant

Patients with liver cirrhosis with ACLF over 18 years.