Reviewing the diagnostic criteria for acute-on-chronic liver failure.

For over 20 years, acute-on-chronic liver failure (ACLF) has taken multiple definitions and/or classifications. The definition outlines the acute and chronic insults to include a homogenous patient group with liver failure and an expected outcome in a specific time frame. Early and accurate diagnosis is essential as this inflammation of the liver may tilt the balance of liver destruction and regeneration adversely. Various factors such as superadded systemic sepsis, liver reserve, cause of primary chronic liver disease, state of immune system or the state of gut microbial flora might determine the ultimate prognosis. Areas covered: To date, there has been no universally accepted definition of ACLF. In this review, we discuss the strengths and weaknesses, controversies and basis for early identification and accurate diagnosis of ACLF. PubMed and Google scholar database searches were conducted, search terms included 'acute on chronic liver failure,' 'ACLF,' and 'diagnostic criteria.' Expert commentary: With recent advances in the management of advanced cirrhosis, research will gradually shift towards ACLF in the near future, focusing on the pathogenesis, new treatment options and improving survival. Once we improve understanding of this syndrome, newer definitions will evolve, thereby enabling earlier diagnosis and novel therapeutic avenues.