Acute-on-chronic liver failure—old concepts made clearer

Acute-on-chronic liver failure (ACLF) is not a new disease. Instead, it refers to extremely severe forms of acute decompensation of chronic liver diseases, which lead to high short-term mortality. What changed in the past few years is that the old concepts regarding ACLF have been made clearer through the proposition of objective definitions for this condition. With clear definitions of ACLF, medical knowledge concerning it is rapidly growing, so that now we can begin to understand its epidemiology, its pathophysiology, its natural course and prognosis, as well as we can start working on treatments for it. Recently, Hernaez et al . have published a very interesting update on ACLF (1). Nevertheless, as this is one of the most promising areas of research in hepatology, new information is already available, and we intend to discuss it.