Acute on chronic liver failure what is it?? is liver transplantation needed for it ??

Acute-on-chronic liver failure (ACLF) is an increasingly recognized entity encompassing an acute deterioration of liver function in patients with cirrhosis, either secondary to superimposed liver injury or due to extrahepatic precipitating factors such as infection

culminating in the end-organ dysfunction. Occasionally, no specific precipitating event can be found. Although the exact pathophysiology of the development of ACLF remains to be elucidated, unregulated inflammation is thought to be a major contributing factor. A characteristic feature of ACLF is its rapid progression, the requirement for multiple organ supports and a high incidence of short and medium term mortality of 50–90%.

The condition remains undefined but two consensus working definitions for this syndrome exist. The first was put forward by the Asia–Pacific association for the study of liver disease :Acute hepatic insult manifesting as jaundice and coagulopathy, complicated within 4 weeks by ascites and/or encephalopathy in a patient with previously diagnosed or undiagnosed chronic liver disease’; and a second at a EASL-AASLD single topic symposium : ‘Acute deterioration of pre-existing, chronic liver disease, usually related to a precipitating event and associated with increased mortality at 3 months due to multi-system organ failure’. These definitions are too imprecise to allow homogeneous diagnostic criteria and clinical studies are currently underway to reach an evidence-based definition. The latter definition implies that organ failure is a central component of this syndrome and leads to the hypothesis that the organs may behave

differently to chronic decompensated liver disease..

The prognostic factors determining the outcome of patients with cirrhosis and multiorgan failure are currently under evaluation, but it seems that the scoring systems addressing the severity of liver disease, such as Child-Pugh score [6] or Model of End Stage Liver Disease (MELD) perform less well than the scoring systems addressing organ dysfunction such as the Sequential Organ Failure Assessment (SOFA) or the Acute Physiology, Age and Chronic Health Evaluation (APACHE)

There is some role of liver supporting system like MARS but not proven completly

Liver transplantation in patients with ACLF has not been systematically analyzed but a recent retrospective study was performed in 332 patients of whom 157 patients had ACLF and 175 patients had no ACLF pre-transplant . Thirty-four patients received a liver-kidney transplant, of whom 10 (29.4%) had ACLF. The definition was based on a rapid increase in MELD by >5 points. The results showed that the group with ACLF had a  26% mortality compared with a mortality of 17% in the non-ACLF group. The difference was statistically different in univariate analysis, but when only single organ transplants were analyzed, the results were not statistically different. On multivariate analysis, ACLF was not an independent predictor of post-transplant mortality, arguing strongly that this is a good indication for transplantation . The timing of transplantation is crucial as patients with ACLF may provide a window of opportunity. Therefore, living-donor transplantation is an attractive option, the experience of which has been reported extensively from South-East Asia, mainly in patients with ACLF resulting from re-activation of hepatitis B virus infection. The data from Hong Kong suggests that although the patients with ACLF and HRS had stormier post-operative course, living donor transplantation could be performed safely and overall there were no significant differences in survival with 5-year survivals of about 80% . Similar observations have been made regarding the safety and feasibility of living donor transplantation from the Chinese groups . Currently, in most countries there is no priority for ACLF patients who have significantly higher short-term mortality. A better understanding of the natural history and prognostic criteria will allow ACLF to be incorporated as a possible new indication for high urgency allocation.

Following figures shows mechanism of acute on chronic liver failure.