Acute-on-chronic liver failure (ACLF) is a condition associated with high mortality in the absence of liver transplantation. There have been various definitions proposed worldwide. The first consensus report of the working party of the Asian Pacific Association for the Study of the Liver (APASL) set in 2004 on ACLF was published in 2009, and the "APASL ACLF Research Consortium (AARC)" was formed in 2012. The AARC database has prospectively collected nearly 10,500 cases of ACLF from various countries in the Asia-Pacific region. This database has been instrumental in developing the AARC score and grade of ACLF, the concept of the 'Golden Therapeutic Window', the 'transplant window', and plasmapheresis as a treatment modality. Also, the data has been key to identifying pediatric ACLF. The European Association for the Study of Liver-Chronic Liver Failure (EASL CLIF) and the North American Association for the Study of the End Stage Liver Disease (NACSELD) from the West added the concepts of organ failure and infection as precipitants for the development of ACLF and CLIF-Sequential Organ Failure Assessment (SOFA) and NACSELD scores for prognostication. The Chinese Group on the Study of Severe Hepatitis B (COSSH) added COSSH-ACLF criteria to manage hepatitis b virus-ACLF with and without cirrhosis. The literature supports these definitions to be equally effective in their respective cohorts in identifying patients with high mortality. To overcome the differences and to develop a global consensus, APASL took the initiative and invited the global stakeholders, including opinion leaders from Asia, EASL and AASLD, and other researchers in the field of ACLF to identify the key issues and develop an evidence-based consensus document. The consensus document was presented in a hybrid format at the APASL annual meeting in Kyoto in March 2024. The 'Kyoto APASL Consensus' presented below carries the final recommendations along with the relevant background information and areas requiring future studies.

Acute-on-chronic liver failure (ACLF) is characterized by an acute hepatic insult happening in a patient with underlying cirrhosis with compromised hepatic reserve leading to development of systemic inflammation, sepsis, and organ failure resulting in poor outcome in majority. While Asia Pacific Association for Study of Liver Diseases (APASL) emphasizes on early diagnosis before development of organ failure, European Association for Study of Liver Diseases (EASL) mandates the presence of organ failures to define ACLF. There is a lack of consensus definition of pediatric ACLF although recent APASL guidelines have tried to address the issue. While Wilson disease (WD) and autoimmune hepatitis (AIH) are the most common cause of underlying cirrhosis in children, acute viral hepatitis and flares of WD and AIH are the commonest acute precipitating events. Poor outcomes [death and liver transplantation (LT)] ranging from 19 to 59% have been reported. Prognosis in pediatric ACLF is usually better than that in adults due to greater proportion of treatable etiologies, lesser organ failures, comorbidities and better hepatic reserves. APASL ACLF Research Consortium (AARC) score more than or equal to 11 is predictive of poor 28-90 d mortality. Treatment of pediatric ACLF relies mainly on prompt diagnosis and medical management of a potentially treatable etiology of underlying cirrhosis. Bridging therapies, especially high volume plasma exchange can be initiated early as a bridge to LT or native liver recovery. Those with no improvement in 4-7 d should undergo LT before development of sepsis or multi-organ failure.

Acute-on chronic liver failure (ACLF) has been an intensively debated topic mainly due to the lack of a unified definition and diagnostic criteria. The growing number of publications describing the mechanisms of ACLF development, the progression of the disease, outcomes and treatment has contributed to a better understanding of the disease, however, it has also sparked the debate about this condition. As an attempt to provide medical professionals with a more uniform definition that could be applied to our population, the first Mexican consensus was performed by a panel of experts in the area of hepatology in Mexico. We used the most relevant and impactful publications along with the clinical and research experience of the consensus participants. The consensus was led by 4 coordinators who provided the most relevant bibliography by doing an exhaustive search on the topic. The entire bibliography was made available to the members of the consensus for consultation at any time during the process and six working groups were formed to develop the following sections: 1.- Generalities, definitions, and criteria, 2.- Pathophysiology of cirrhosis, 3.- Genetics in ACLF, 4.- Clinical manifestations, 5.- Liver transplantation in ACLF, 6.- Other treatments.

Liver failure is a group of clinical syndromes with a mortality rate of >50%. The accurate evaluation of severity in patients with liver failure has been a meaningful and hot topic in clinical research and an important guide for liver transplantation. Numerous prognosis studies have emerged in recent years with high accuracy and adequate validity. Nonetheless, different models utilize distinct parameters and have unequal efficiencies, leading to a specific value and unique application situations for each model. This review focused on the progress in recent prognostic studies including the model for end-stage liver disease, sequential organ failure assessment and its derivative models, the Chinese Group on the Study of Severe Hepatitis B Acute-on-Chronic Liver Failure, the Tongji prognostic predictor model, and other emerging prognostic models and predictors. This review aims to assist clinicians understand the framework of recent models and choose the appropriate model and treatment.

Although various complex definitions of acute-on-chronic liver failure (ACLF) have been suggested in relation to adult patients, there is currently no universal definition of the syndrome in pediatric patients. In simplified terms, ACLF is characterized by the acute deterioration of the liver functions due to the effects of a precipitating factor on the basis of a chronic liver disease. Acute events and underlying liver diseases are very different in children from those seen in adults. Moreover, acute events and underlying chronic liver diseases vary among geographical regions, although it seems that the most common such diseases and acute events are autoimmune hepatitis, Wilson's disease, and their flares. ACLF is associated with a poor prognosis. While no scoring systems have been developed to predict the prognosis for children with ACLF, modified versions of the Asian Pacific Association for the Study of the liver's acute-on-chronic liver failure scoring system and the Chronic Liver Failure-Sequential Organ Failure Assessment criteria can be used in children until specific and validated scoring systems are available. Aside from liver transplantation, there is no proven treatment for ACLF. Thus, the early recognition of ACLF prior to the development of extrahepatic organ failure is important.

Acute-on-chronic liver failure (ACLF) results in very high mortality in children. We aimed to evaluate the role of granulocyte colony-stimulating factor (GCSF) on short-term outcome of children with ACLF in a nontransplant unit.

Children (aged > 1 year) diagnosed with ACLF over a 15 month period were randomised. Group A was given GCSF therapy along with standard medical care (SMC - details in supplementary data) and group B was given only SMC. The outcome was evaluated as survival at 30 and 60 days of therapy.

Thirty-one children with ACLF were enrolled, with a mean age of 6.92 ± 4.3yrs. A total of 15 patients were randomised to group A and 16 to group B. The overall mortality was 54.83%. The intervention group showed survival rates of 80%, 66.67% and 53.3%, whereas the control group had survival rates of 43.75%, 37.5% and 37.5% at 14, 30 and 60 days, respectively. A significant survival benefit was noted on day 14 (p = 0.043) of therapy in group A with significant difference in Child-Turcotte-Pugh (CTP) and pediatric end-stage liver disease (PELD) scores in the two groups. After an initial rise in group A, the granulocyte counts fell to become comparable in the two groups by day 30 and 60, indicating that the effect of GCSF therapy wears off over time. There was no significant difference in the overall survival, median/mean CTP, PELD and MCS (Modified Cliff sequential organ failure assesment (SOFA)) scores on day 30 and 60. Mean (%) CD 34 + cells level showed a rise on day 7 in group A but was statistically insignificant.

The present study shows that GCSF therapy at 5 mcg/kg/day for 5 days seems to be ineffective in improving the survival outcome on day 30 and 60 of therapy. Studies with larger number of children enrolled and longer duration of therapy are required. (CTRI/2017/11/010420).

The first consensus report of the working party of the Asian Pacific Association for the Study of the Liver (APASL) set up in 2004 on acute-on-chronic liver failure (ACLF) was published in 2009. With international groups volunteering to join, the "APASL ACLF Research Consortium (AARC)" was formed in 2012, which continued to collect prospective ACLF patient data. Based on the prospective data analysis of nearly 1400 patients, the AARC consensus was published in 2014. In the past nearly four-and-a-half years, the AARC database has been enriched to about 5200 cases by major hepatology centers across Asia. The data published during the interim period were carefully analyzed and areas of contention and new developments in the field of ACLF were prioritized in a systematic manner. The AARC database was also approached for answering some of the issues where published data were limited, such as liver failure grading, its impact on the 'Golden Therapeutic Window', extrahepatic organ dysfunction and failure, development of sepsis, distinctive features of acute decompensation from ACLF and pediatric ACLF and the issues were analyzed. These initiatives concluded in a two-day meeting in October 2018 at New Delhi with finalization of the new AARC consensus. Only those statements, which were based on evidence using the Grade System and were unanimously recommended, were accepted. Finalized statements were again circulated to all the experts and subsequently presented at the AARC investigators meeting at the AASLD in November 2018. The suggestions from the experts were used to revise and finalize the consensus. After detailed deliberations and data analysis, the original definition of ACLF was found to withstand the test of time and be able to identify a homogenous group of patients presenting with liver failure. New management options including the algorithms for the management of coagulation disorders, renal replacement therapy, sepsis, variceal bleed, antivirals and criteria for liver transplantation for ACLF patients were proposed. The final consensus statements along with the relevant background information and areas requiring future studies are presented here.