Model for end-stage liver disease-sodium underestimates 90-day mortality risk in patients with acute-on-chronic liver failure

Acute-on-chronic liver failure: clinical course and liver transplantation

INTRODUCTION

Acute-on-chronic liver failure (ACLF) is a clinical syndrome characterized by intense systemic inflammatory response, multiple-organ failures, and high short-term mortality in patients with chronic liver disease. ACLF is dynamic and heterogeneous, and the prognosis is closely related to the clinical course. Currently, liver transplantation (LT) remains the only potential curative treatment that improves survival of ACLF patients.

AREAS COVERED

In this review, we summarize the dynamic clinical course of ACLF and the relationship between the clinical course and the post-LT prognosis, especially the factors affecting the mortality after LT in severe ACLF patients and explore the optimal choice of LT therapy for ACLF patients, both to benefit patients the most and to avoid futile therapy.

EXPERT OPINION

ACLF is a dynamic disease with varying clinical phenotypes, and the global burden is high. Early identification of the clinical course is important to assess the prognosis and guide the treatment. The contradiction between shortage of liver donors and the large number of recipients makes it necessary for us to strictly screen out the recipients and identify patients who really need LT to save liver sources.

Impact of cirrhosis-related complications on posttransplant survival in patients with acute-on-chronic liver failure

BACKGROUND

Acute-on-chronic liver failure (ACLF) is a life-threatening syndrome defined as acute decompensation in patients with chronic liver disease. Liver transplantation (LT) is the most effective treatment. We aimed to assess the impact of cirrhosis-related complications pre-LT on the posttransplant prognosis of patients with ACLF.

METHODS

This was an observational cohort study conducted between January 2018 and December 2020. Clinical characteristics, cirrhosis-related complications at LT and patient survival post-LT were collected. All liver recipients with ACLF were followed for 1 year post-LT.

RESULTS

A total of 212 LT recipients with ACLF were enrolled, including 75 (35.4%) patients with ACLF-1, 64 (30.2%) with ACLF-2, and 73 (34.4%) with ACLF-3. The median waiting time for LT was 11 (4-24) days. The most prevalent cirrhosis-related complication was ascites (78.8%), followed by hepatic encephalopathy (57.1%), bacterial infections (48.1%), hepatorenal syndrome (22.2%) and gastrointestinal bleeding (11.3%). Survival analyses showed that patients with complications at LT had a significantly lower survival probability at both 3 months and 1 year after LT than those without complications (all P < 0.05). A simplified model was developed by assigning one point to each complication: transplantation for ACLF with cirrhosis-related complication (TACC) model. Risk stratification of TACC model identified 3 strata (≥ 4, = 3, and ≤ 2) with high, median and low risk of death after LT (P < 0.001). Moreover, the TACC model showed a comparable ability for predicting the outcome post-LT to the other four prognostic models (chronic liver failure-consortium ACLF score, Chinese Group on the Study of Severe Hepatitis B-ACLF score, model for end-stage liver disease score and Child-Turcotte-Pugh score).

CONCLUSIONS

The presence of cirrhosis-related complications pre-LT increases the risk of death post-LT in patients with ACLF. The TACC model based on the number of cirrhosis-related complications pre-LT could stratify posttransplant survival, which might help to determine transplant timing for ACLF.

Mortality scoring systems for liver transplant recipients: before and after model for end-stage liver disease score

The mortality scoring systems for patients with end-stage liver disease have evolved from the Child-Turcotte-Pugh score to the model for end-stage liver disease (MELD) score, affecting the wait list for liver allocation. There are inherent weaknesses in the MELD score, with the gradual decline in its accuracy owing to changes in patient demographics or treatment options. Continuous refinement of the MELD score is in progress; however, both advantages and disadvantages exist. Recently, attempts have been made to introduce artificial intelligence into mortality prediction; however, many challenges must still be overcome. More research is needed to improve the accuracy of mortality prediction in liver transplant recipients.

Portal vein thrombosis compromises the performance of MELD and MELD-Na scores in patients with cirrhosis

BACKGROUND AND AIMS

The accuracy of model for end-stage liver disease (MELD) and MELD with sodium (MELD-Na) scores in reflecting the clinical outcomes of patients with cirrhosis and portal vein thrombosis (PVT) remains unclear. This study aimed to evaluate the performance of scores in predicting 90-day mortality in patients with cirrhosis and PVT.

METHODS

Post hoc analysis was performed in two prospective cohorts (NCT02457637 and NCT03641872). The correlation between the MELD/MELD-Na score and 90-day liver transplantation (LT)-free mortality was investigated in patients with cirrhosis with and without PVT.

RESULTS

In this study, 2826 patients with cirrhosis were included, and 255 (9.02%) had PVT. The cumulative incidence of 90-day LT-free mortality did not significantly differ between patients with and without PVT (log-rank P = 0.0854). MELD [area under the receiver operating curve (AUROC), 0.649 vs. 0.842; P = 0.0036] and MELD-Na scores (AUROC, 0.691 vs. 0.851; P = 0.0108) were compared in patients with and without PVT, regarding the prediction of 90-day LT-free mortality. In MELD < 15 and MELD-Na < 20 subgroups, patients with PVT had a higher 90-day LT-free mortality than those without PVT (7.91% vs. 2.64%, log-rank P = 0.0011; 7.14% vs. 3.43%, log-rank P = 0.0223), whereas in MELD ≥ 15 and MELD-Na ≥ 20 subgroups, no significant difference was observed between patients with and without PVT.

CONCLUSIONS

The performance of MELD and MELD-Na scores in predicting 90-day LT-free mortality of patients with cirrhosis was compromised by PVT. MELD < 15 or MELD-Na < 20 may underestimate the 90-day LT-free mortality in patients with PVT.

Liver volume based prediction model for patients with hepatitis B virus-related acute-on-chronic liver failure

BACKGROUND

Hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) is a life-threatening disease with high short-term mortality. Early and accurate prognosis is significant for clinical decisions, in which liver volume (LV) imparts important information. However, LV has not been considered in current prognostic models for HBV-ACLF.

METHODS

Three hundred and twenty-three patients were recruited to the deriving cohort, while 163 were enrolled to validation cohort. The primary end-point was death within 28 days since admission. Estimated liver volume (ELV) was calculated by the formula based on healthy population. Logistic regression was used to develop a prediction model. Accuracy of models were evaluated by receiver operating characteristic (ROC) curves.

RESULTS

The ratio of LV to ELV (LV/ELV%) was significantly lower in non-survivors, and LV/ELV% ≤82% indicated poor prognosis. LV/ELV%, Age, prothrombin time (PT), the grade of hepatic encephalopathy (HE), ln-transformed total bilirubin (lnTBil), and log-transformed HBV DNA (Log₁₀ HBV DNA) were identified as independent predictors to develop an LV-based model, LEAP-HBV. The mean area under the ROC (AUC) of LEAP-HBV was 0.906 (95% CI, 0.904-0.908), higher than other non-LV-based models.

CONCLUSION

Liver volume was an independent predictor, and LEAP-HBV, a prediction model based on LV, was developed for the short-term mortality in HBV-ACLF. This study was registered on ClinicalTrails (NCT03977857).

Galectin-3 critically mediates the hepatoprotection conferred by M2-like macrophages in ACLF by inhibiting pyroptosis but not necroptosis signalling

We previously documented that M2-like macrophages exert a hepatoprotective effect in acute-on-chronic liver failure (ACLF) by inhibiting necroptosis signalling. Nevertheless, the molecular mechanism behind this hepatoprotection still needs to be further dissected. Galectin-3 (GAL3) has been reported to be critically involved in the pathogenesis of multiple liver diseases, whereas the potential role of GAL3 in ACLF remains to be explored. Herein, we hypothesised that GAL3 plays a pivotal role in the hepatoprotection conferred by M2-like macrophages in ACLF by inhibiting necroptosis. To test this hypothesis, we first assessed the expression of GAL3 in control and fibrotic mice with or without acute insult. Second, loss- and gain-of-function experiments of GAL3 were performed. Third, the correlation between GAL3 and M2-like macrophage activation was analysed, and the potential role of GAL3 in M2-like macrophage-conferred hepatoprotection was confirmed. Finally, the molecular mechanism underlying GAL3-mediated hepatoprotection was dissected. GAL3 was found to be obviously upregulated in fibrotic mice with or without acute insult but not in acutely injured mice. Depletion of GAL3 aggravated hepatic damage in fibrotic mice upon insult. Conversely, adoptive transfer of GAL3 provided normal mice enhanced resistance against acute insult. The expression of GAL3 is closely correlated with M2-like macrophage activation. Through adoptive transfer and depletion experiments, M2-like macrophages were verified to act as a major source of GAL3. Importantly, GAL3 was confirmed to hold a pivotal place in the hepatoprotection conferred by M2-like macrophages through loss- and gain-of-function experiments. Unexpectedly, the depletion and adoptive transfer of GAL3 resulted in significant differences in the expression levels of pyroptosis but not necroptosis signalling molecules. Taken together, GAL3 plays a pivotal role in the hepatoprotection conferred by M2-like macrophages in ACLF by inhibiting pyroptosis but not necroptosis signalling. Our findings provide novel insights into the pathogenesis and therapy of ACLF.

Liver Transplantation in Acute-on-Chronic Liver Failure: Excellent Outcome and Difficult Posttransplant Course

Background

Acute-on-chronic liver failure (ACLF) patients have high mortality in a short period of time. This study aimed to compare the prognosis of transplanted ACLF patients to that of nontransplanted ACLF patients and decompensated cirrhosis recipients.

Methods

Clinical data of 29 transplanted ACLF patients, 312 nontransplanted ACLF patients, and 60 transplanted decompensated cirrhosis patients were retrospectively collected. Propensity score matching (PSM) analysis was used to match patients between different groups.

Results

After PSM, the 90-day and 1-year survival of transplanted ACLF patients was significantly longer than that of nontransplant controls. Although the 90-day survival and 1-year survival of ACLF recipients was similar to that of decompensated cirrhosis controls, ACLF recipients were found to have longer mechanical ventilation, longer intensive care unit (ICU) stay, longer hospital stay, higher incidence of tracheotomy, higher expense, and higher morbidity of complication than matched decompensated cirrhosis controls. The 90-day and 1-year survival of transplanted ACLF grade 2–3 patients was also significantly longer than that of nontransplanted controls.

Conclusions

Liver transplantation can strongly improve the prognosis of ACLF patients. Despite having more burdens (including longer mechanical ventilation, longer ICU stay, higher incidence of tracheotomy, longer hospital stay, higher hospitalization expense, and higher complication morbidity), ACLF recipients can obtain similar short-term and long-term survival to decompensated cirrhosis recipients. For severe ACLF patients, liver transplantation can also significantly improve their short-term and long-term survival.

Rising Trend in Waitlisting for Alcoholic Hepatitis With More Favorable Outcomes Than Other High Model for End-stage Liver Disease in the Current Era

BACKGROUND

In the appropriate candidate, liver transplantation (LT) is a viable treatment for alcoholic hepatitis (AH). We compared the waitlisting trends and outcomes of AH patients in the context of others with high Model for End-stage Liver Disease (MELD) score.

METHODS

LT listings for AH between January 1, 2008, and June 12, 2020 were identified in the United Network for Organ Sharing database. Temporal trends in listings for AH were assessed. Covariate adjusted competing risks models evaluated waitlist mortality and LT rates between AH candidates and others with listing native MELD ≥30.

RESULTS

Between 2008 and 2019, waitlist additions for AH increased 6.5-fold. Waiting time for AH candidates was short (median 10 d). Delisting for clinical improvement was infrequent in AH, albeit higher than MELD ≥30 patients (3.3% versus 0.8%; P < 0.001). Among 99 centers with ≥1 AH listing, AH patients accounted for 0.2%-18.2% of all alcohol-related listings and 0.6%-25.0% of those with native listing MELD ≥30. Overall listing volume was larger at these 99 centers than the 40 with no AH listings (P < 0.001). AH candidates in 2014-2020 experienced improved waitlist survival (adjusted subhazard ratio, 0.67; 95% confidence interval, 0.52-0.86; P = 0.002) and higher transplant rates (adjusted subhazard ratio, 1.14; 95% confidence interval, 1.04-1.25; P = 0.006) versus other MELD ≥30 candidates.

CONCLUSIONS

There has been a rising trend in waitlisting patients with AH and high MELD score. Liver disease causes influence waitlist outcomes and those of AH candidates are more favorable. Further research and allocation adjustments may be needed to ensure equitable organ allocation, based on liver disease cause, for those on the LT waitlist.

A prognostic model of acute-on-chronic liver failure based on sarcopenia

BACKGROUND

Acute-on-chronic liver failure (ACLF) is characterized by the development of a syndrome associated with a high risk of short-term death in patients with acute decompensated cirrhosis, and better indicators are needed to predict such outcomes. Sarcopenia, a common complication of cirrhosis, is closely associated with poor prognosis and increased mortality. In this study, the skeletal muscle index of ACLF patients was measured to determine whether sarcopenia combined with clinical parameters can aid in identifying those at high risk of progression.

METHODS

A total of 433 hospitalized patients with ACLF according to the APASL criteria were included and allocated into two groups: transplantation-free survival (n = 293) or progression (n = 140, 107 died; 33 underwent liver transplantation) within 90 days. Muscle mass was assessed based on the skeletal muscle index. The optimal cut-off value of the AMPAS1 model (age, MELD score, platelet count, alpha-fetoprotein level, sarcopenia, and more than one complication combination) for progression prediction was identified using receiver-operating characteristic (ROC) analysis.

RESULTS

Sarcopenia was an independent risk factor for progression in the ACLF population (HR 3.771 95% CI 2.114-6.727, p < 0.001). AMPAS1 was a good predictor, with an area under the ROC curve of 0.865, and the cut-off value for poor outcome prediction was 0.31 (sensitivity 79.4%, specificity 76.4%).

CONCLUSION

We demonstrate that sarcopenia is a simple and objective indicator for predicting short-term prognosis in patients with ACLF. Moreover, compared to conventional prognostic scores, AMPAS1 is a better model for predicting 90 day adverse outcomes in ACLF patients.

"Beyond MELD" - Emerging strategies and technologies for improving mortality prediction, organ allocation and outcomes in liver transplantation

In this review article, we discuss the model for end-stage liver disease (MELD) score and its dual purpose in general and transplant hepatology. As the landscape of liver disease and transplantation has evolved considerably since the advent of the MELD score, we summarise emerging concepts, methodologies, and technologies that may improve mortality prognostication in the future. Finally, we explore how these novel concepts and technologies may be incorporated into clinical practice.

Model for end-stage liver disease underestimates mortality of patients with acute-on-chronic liver failure waiting for liver transplantation

BACKGROUND AND AIMS

Patients with acute-on-chronic liver failure (ACLF) show excess mortality in MELD-Na based organ allocation for liver transplantation (LT). Whether MELD-based allocation in the Eurotransplant region similarly underprioritizes ACLF patients is unknown.

METHODS

428 patients listed for LT from 01/2010 to 02/2021 at a tertiary center in Germany were screened and 209 patients included as derivation (n = 123) and validation cohort (n = 86). Competing risk analysis for waitlist mortality and LT as competing events was performed.

RESULTS

90-day waitlist mortality for patients with MELD < and ≥ 25 at baseline was 9% vs. 33%, respectively (p = 0.009). Competing risk analysis shows significantly higher 90-day waitlist mortality in patients listed with ACLF compared to those without ACLF (p = 0.021) in the low MELD stratum. Probability of LT was similar between the two groups (p = 0.91). In the high MELD group, 90-day waitlist mortality and rates of LT were not significantly different between patients with and without ACLF (31% vs. 20%, p = 0.55 and 59% vs. 60%, p = 0.72, respectively). Post-transplant survival was similar between patients with and without ACLF. This result was confirmed in the validation cohort.

CONCLUSION

MELD-based organ allocation in the Eurotransplant region underestimates waitlist mortality in patients with ACLF in lower MELD ranges.

Definition and classification of acute-on-chronic liver diseases

Patients with chronic liver diseases (CLDs) develop acute liver injury and/or acute decompensation under the attack of various precipitants and present with significantly elevated alanine aminotransferase and/or total bilirubin levels, liver failure, or acute decompensation of liver cirrhosis, which is called acute-on-CLD (AoCLD). AoCLD accounts for the majority of patients hospitalized in the Department of Hepatology or Infectious Diseases. AoCLD is complicated by various clinical types, the severity of the disease, and may pose a high risk of death. To date, the definition of AoCLD is still vague, and a consensus concept of the clinical classification is lacking. This review aimed to define the concept and clinical types of AoCLD based on related studies and the literature.

Severe Alcohol-Associated Hepatitis Is Associated With Worse Survival in Critically Ill Patients With Acute on Chronic Liver Failure

Differences in mortality between critically ill patients with severe alcohol-associated hepatitis (sAH) and acute-on-chronic liver failure (ACLF) and non-sAH ACLF (i.e., ACLF not precipitated by sAH) are unknown. Such differences are important, as they may inform on prognosis and optimal timing of liver transplantation (LT). Thus, we aimed to compare short-term and longer-term mortality between patients with sAH ACLF and patients with non-sAH ACLF who were admitted to the intensive care unit. Patients with ACLF admitted from 2016-2018 at two tertiary care intensive care units were analyzed. SAH was defined by the National Institute on Alcohol Abuse and Alcoholism's Alcoholic Hepatitis Consortium and Model for End-Stage Liver Disease score >20. Mortality without LT was compared between sAH ACLF and non-sAH ACLF using Fine and Gray's competing-risks regression. A total of 463 patients with ACLF (18% sAH and 82% non-sAH) were included. Compared to patients with non-sAH ACLF, patients with sAH ACLF were younger (49 vs. 56 years; P < 0.001) and had higher admission Model for End-Stage Liver Disease (MELD) (35 vs. 25; P < 0.001) and Chronic Liver Failure Consortium (CLIF-C) scores (61 vs. 57; P = 0.002). There were no significant differences between the two groups for vasopressor, mechanical ventilation, and hemodialysis use. The cumulative incidence of death was significantly higher in patients with sAH ACLF compared to patients with non-sAH ACLF: 30-day 74.7% versus 45.3%; 90-day 81.9% versus 57.4%; 180-day 83.2% versus 63.0% (unadjusted subdistribution hazard ratio [sHR] 1.88 [95% confidence interval (CI) 1.44-2.46]; P < 0.001). After adjusting for CLIF-C score and infection in a multivariable competing-risk model, patients with sAH ACLF had significantly higher risk of death (sHR 1.57 [95% CI 1.20-2.06]; P = 0.001) compared to patients with non-sAH ACLF. Conclusion: Critically ill patients with sAH ACLF have worse mortality compared to patients with non-sAH ACLF. These data may inform prognosis in patients with sAH and ACLF, and early LT referral in potentially eligible patients.

Con: Patients With Acute-on-Chronic Liver Failure Should Not Receive Priority on the Waiting List

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Discordance in categorization of acute-on-chronic liver failure in the United Network for Organ Sharing database

BACKGROUND & AIMS

Studies regarding acute-on-chronic liver failure (ACLF) among liver transplant (LT) candidates from the United Network for Organ Sharing (UNOS) database are being used to inform LT policy changes worldwide. We assessed the validity of identifying ACLF in UNOS.

METHODS

We performed stratified random sampling among 3 US LT centers between 2013-2019 to obtain a representative patient sample across ACLF grades. We compared the concordance of ACLF classification by UNOS vs. blinded manual chart review, according to EASL-CLIF.

RESULTS

Among 481 sampled LT registrants, 250 (52%) had no ACLF, 75 (16%) had ACLF grade 1, 79 (16%) had ACLF grade 2, and 77 (16%) had ACLF grade 3 per UNOS categorization. Concordance of ACLF grade by UNOS vs. chart review was: 72%, 64%, 56%, and 64% for no ACLF, grade 1, grade 2, and grade 3, respectively, with an overall Cohen's kappa coefficient of 0.48 (95% CI 0.42-0.54). Absence of acute decompensation was the most common reason for overestimation, and discordant brain and respiratory failure categorization were the most common reasons for underestimation of ACLF by UNOS.

CONCLUSIONS

In this retrospective multi-center study, ACLF categorization by UNOS showed weak agreement with manual chart review. These findings are informative for ongoing allocation policy discussions, highlight the importance of prospective studies regarding ACLF in LT, and should encourage UNOS reform.

LAY SUMMARY

Acute-on-chronic-liver-failure (ACLF) is a specific and common form of liver failure associated with high death rates. Studies have been published using the United States transplant registry (UNOS) to identify and describe outcomes of transplant candidates and recipients with ACLF, and these data are driving policy changes for transplant allocation around the world, but nobody has shown whether these data are reliable. We found that UNOS was not categorizing ACLF in concordance or accurately when compared to chart review, which shows the need for UNOS reform and non-UNOS studies to appropriately inform policies regarding the transplantation of patients with ACLF.

Liver Transplantation as a Cornerstone Treatment for Acute-On-Chronic Liver Failure

Acute-on-chronic liver failure (ACLF) is a distinct clinical syndrome, characterized by acute decompensation (AD) of liver cirrhosis, severe systemic inflammation, intra- and extrahepatic organ failures, and a high short-term mortality. Liver transplantation (LT) is a potentially life-saving treatment for patients with decompensated liver cirrhosis and, due to the high mortality rates, particularly for ACLF patients. In the last decade, a plethora of studies has produced compelling evidence in favor of LT in ACLF, demonstrating high post-LT survival rates and excessive waitlist mortality. The importance of LT in these patients is underscored by the fact that no specific therapy for ACLF is available yet, rendering expeditious life-saving LT to be the only feasible treatment option for some ACLF patients. This review aims to provide an overview on pathophysiology, clinical trajectory, and clinical management of ACLF and to delineate the current literature regarding perspectives and limitations of LT as a life-saving treatment option for ACLF patients.

Acute-on-Chronic Liver Failure Clinical Guidelines

In patients with cirrhosis and chronic liver disease, acute-on-chronic liver failure is emerging as a major cause of mortality. These guidelines indicate the preferred approach to the management of patients with acute-on-chronic liver failure and represent the official practice recommendations of the American College of Gastroenterology. The scientific evidence for these guidelines was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluation process. In instances where the evidence was not appropriate for Grading of Recommendations, Assessment, Development, and Evaluation, but there was consensus of significant clinical merit, key concept statements were developed using expert consensus. These guidelines are meant to be broadly applicable and should be viewed as the preferred, but not only, approach to clinical scenarios.

Introduction: The Role of Liver Transplantation in Acute‐on‐Chronic Liver Failure

The article (CLD1189/CLD‐21‐0084.R1) “Surgical considerations regarding transplantation for the patient with acute on chronic liver failure” was published outside of this series issue “The Role of Liver Transplantation in Acute on Chronic Liver Failure”. Please click here to access the article, https://aasldpubs.onlinelibrary.wiley.com/doi/full/10.1002/cld.1189

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Novel drug discovery strategies for the treatment of decompensated cirrhosis

INTRODUCTION

Disease progression in cirrhosis leads to decompensation and acute-on-chronic liver failure (ACLF), which is characterized by organ failure and high mortality. Portal hypertension and cardiovascular dysfunction trigger the development of cirrhosis-related complications whilst tissue injury and cellular metabolic dysfunction lead to organ failure. System inflammation is the overarching mechanism mediating both the transition from compensation to decompensation as well as progression to ACLF. Treatment of precipitating events and intensive organ support is the only established therapeutic strategies. Liver transplantationrepresents the only curative therapy but contraindications and organ scarcity limit its availability to only a minority of patients with end-stage liver disease. Therefore, the discovery and development of novel interventions modifying the disease course and improving patients' outcome are of utmost importance.

AREAS COVERED

This review highlights and discusses therapeutic novelties in the field of end-stage liver disease.

EXPERT OPINION

Despite decades of research, there are still no established therapies to improve the devastating prognosis of patients with end-stage liver disease. The clinical heterogeneity and complex pathogenesis will put high demands on drug discovery. Combinatorial therapies tailored to the patients' individual pattern of pathomechanisms may be the most efficient way to modify disease course.

Clinical Prediction Models for Hepatitis B Virus-related Acute-on-chronic Liver Failure: A Technical Report

BACKGROUND AND AIMS

It is critical but challenging to predict the prognosis of hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF). This study systematically summarized and evaluated the quality and performance of available clinical prediction models (CPMs).

METHODS

A keyword search of articles on HBV-ACLF CPMs published in PubMed from January 1995 to April 2020 was performed. Both the quality and performance of the CPMs were assessed.

RESULTS

Fifty-two CPMs were identified, of which 31 were HBV-ACLF specific. The modeling data were mostly derived from retrospective (83.87%) and single-center (96.77%) cohorts, with sample sizes ranging from 46 to 1,202. Three-month mortality was the most common endpoint. The Asian Pacific Association for the Study of the Liver consensus (51.92%) and Chinese Medical Association liver failure guidelines (40.38%) were commonly used for HBV-ACLF diagnosis. Serum bilirubin (67.74%), the international normalized ratio (54.84%), and hepatic encephalopathy (51.61%) were the most frequent variables used in models. Model discrimination was commonly evaluated (88.46%), but model calibration was seldom performed. The model for end-stage liver disease score was the most widely used (84.62%); however, varying performance was reported among the studies.

CONCLUSIONS

Substantial limitations lie in the quality of HBV-ACLF-specific CPMs. Disease severity of study populations may impact model performance. The clinical utility of CPMs in predicting short-term prognosis of HBV-ACLF remains to be undefined.

Development and validation of the nomogram based on INR and eGFR for estimation of mortality in patients with acute-on-chronic hepatitis B liver failure

AIMS AND OBJECTIVES

Acute-on-chronic hepatitis B liver failure (ACHBLF) is a critical clinical syndrome with a high short-term mortality evolved from chronic hepatitis B (CHB)-related liver disease. Prediction of mortality risk and early intervention can improve the prognosis of patients. This study aimed to develop and validate the nomogram for short-time mortality estimation in ACHBLF patients defined according to Asian Pacific Association for the Study of the Liver (APASL).

METHODS

A study of 105 ACHBLF patients with 90-day follow up was performed to develop the nomogram. Patients were randomly assigned to derivation cohort (n = 75) and validation cohort (n = 35) according to 7:3. Concordance index (C-index), calibration curve and decision curve analysis (DCA) were used to evaluate the nomogram. We also compared the nomogram with APASL ACLF research consortium (AARC) score, model for end-stage liver disease (MELD) score, MELD with serum sodium (MELD-Na) score and albumin-bilirubin (ALBI) score. The nomogram was validated using an external cohort including 40 patients.

RESULTS

The 28-day and 90-day mortality of 105 patients were respectively 49.52% and 55.24%. Albumin (ALB), international normalized ratio (INR) and estimated glomerular filtration rate (eGFR) were independent predictors for 28-day mortality; INR and eGFR were independent predictors for 90-day mortality. C-index of Nomogram-1 for 28-day mortality and Nomogram-2 for 90-day mortality were respectively 0.82 and 0.81. Calibration curve and Hosmer-Lemeshow test (Nomogram-1, 0.323; Nomogram-2, 0.231) showed optimal agreement between observed and predicted death. Areas under receiver operator characteristic curve(AUROC) of Nomogram-1(0.772) and Nomogram-2(0.771) were larger compared with AARC, MELD, MELD-Na and ALBI score. The results were well estimated in the external validation cohort.

CONCLUSIONS

This study highlighted the predictive value of eGFR, and the nomogram based on INR and eGFR could effectively estimate individualized risk for short-term mortality of ACHBLF patients defined according to APASL.

Targeted NMR-based serum metabolic profiling of serine, glycine and methionine in acute-on-chronic liver failure patients: Possible insights into mitochondrial dysfunction

Background

A recent study based on blood metabolomics analysis revealed inflammation-associated mitochondrial dysfunction as a potential mechanism underlying acute-on-chronic liver failure (ACLF) in cirrhotic patients. Serine, glycine, and methionine serve to maintain a healthy immune system and adequately sustain mitochondrial functionality in hepatocytes for regulating redox homeostasis through the production of antioxidant glutathione (GSH). Based on this, we hypothesized that the circulatory levels of serine, glycine and methionine will be altered in ACLF patients due to acute worsening of hepatic function and may provide novel insights into the mitochondrial dysfunction as well.

Methods

The circulatory concentrations of serine, glycine, and methionine were estimated in the sera of 40 ACLF patients and 49 normal controls (NC) subject using 1D 1H-CPMG NMR spectra recorded at 800 MHz NMR spectrometer. The resulting metabolite concentrations were compared using unpaired Student t-test and p-value < 0.05 was considered as the criterion of statistical significance. The diagnostic potential and statistical correlations were established using receiver-operating-characteristic (ROC) curve analysis and Pearson-r method, respectively.

Results

Circulating levels of serine and glycine were significantly decreased in ACLF patients (Ser = 23.06 ± 1.67 µM and Gly = 83.11±7.52 µM) compared to NC subjects (Ser = 55.61 ± 2.28 µM and Gly = 156.9±7.16 µM) with p-value < 0.0001, whereas those of methionine were significantly increased in ACLF (22.60 ± 2.49 µM) compared to NC subjects (=14.63 ± 0.85 µM) with p-value < 0.0015. Further, the ROC analysis yielded satisfactory sensitivity and specificity for serine, glycine, and methionine-to-glycine ratio (MGR) with area under ROC (AUROC) curve values equal to: 0.95 [95%CI = 0.91-0.99] for Ser; 0.87 [95%CI = 0.79-0.95] for Gly; and 0.90 [95%CI = 0.83-0.97] for MGR.

Conclusion

Compared to NC subjects, the sera of ACLF patients were characterized by hypermethioninemia and aberrantly decreased levels of serine and glycine suggesting mitochondrial dysfunction as the possible mechanism for disturbed redox homeostasis and therefore depressed immune system in ACLF.

Early transplantation maximizes survival in severe acute-on-chronic liver failure: Results of a Markov decision process model

Background & Aims

Uncertainties exist surrounding the timing of liver transplantation (LT) among patients with acute-on-chronic liver failure grade 3 (ACLF-3), regarding whether to accept a marginal quality donor organ to allow for earlier LT or wait for either an optimal organ offer or improvement in the number of organ failures, in order to increase post-LT survival.

Methods

We created a Markov decision process model to determine the optimal timing of LT among patients with ACLF-3 within 7 days of listing, to maximize overall 1-year survival probability.

Results

We analyzed 6 groups of candidates with ACLF-3: patients age ≤60 or >60 years, patients with 3 organ failures alone or 4-6 organ failures, and hepatic or extrahepatic ACLF-3. Among all groups, LT yielded significantly greater overall survival probability vs. remaining on the waiting list for even 1 additional day (p <0.001), regardless of organ quality. Creation of 2-way sensitivity analyses, with variation in the probability of receiving an optimal organ and expected post-transplant mortality, indicated that overall survival is maximized by earlier LT, particularly among candidates >60 years old or with 4-6 organ failures. The probability of improvement from ACLF-3 to ACLF-2 does not influence these recommendations, as the likelihood of organ recovery was less than 10%.

Conclusion

During the first week after listing for patients with ACLF-3, earlier LT in general is favored over waiting for an optimal quality donor organ or for recovery of organ failures, with the understanding that the analysis is limited to consideration of only these 3 variables.

Lay summary

In the setting of grade 3 acute-on-chronic liver failure (ACLF-3), questions remain regarding the timing of transplantation in terms of whether to proceed with liver transplantation with a marginal donor organ or to wait for an optimal liver, and whether to transplant a patient with ACLF-3 or wait until improvement to ACLF-2. In this study, we used a Markov decision process model to demonstrate that earlier transplantation of patients listed with ACLF-3 maximizes overall survival, as opposed to waiting for an optimal donor organ or for improvement in the number of organ failures.

Development and validation of a dynamic survival prediction model for patients with acute-on-chronic liver failure

Background & Aims

Acute-on-chronic liver failure (ACLF) is usually associated with a precipitating event and results in the failure of other organ systems and high short-term mortality. Current prediction models fail to adequately estimate prognosis and need for liver transplantation (LT) in ACLF. This study develops and validates a dynamic prediction model for patients with ACLF that uses both longitudinal and survival data.

Methods

Adult patients on the UNOS waitlist for LT between 11.01.2016-31.12.2019 were included. Repeated model for end-stage liver disease-sodium (MELD-Na) measurements were jointly modelled with Cox survival analysis to develop the ACLF joint model (ACLF-JM). Model validation was carried out using separate testing data with area under curve (AUC) and prediction errors. An online ACLF-JM tool was created for clinical application.

Results

In total, 30,533 patients were included. ACLF grade 1 to 3 was present in 16.4%, 10.4% and 6.2% of patients, respectively. The ACLF-JM predicted survival significantly (p <0.001) better than the MELD-Na score, both at baseline and during follow-up. For 28- and 90-day predictions, ACLF-JM AUCs ranged between 0.840-0.871 and 0.833-875, respectively. Compared to MELD-Na, AUCs and prediction errors were improved by 23.1%-62.0% and 5%-37.6% respectively. Also, the ACLF-JM could have prioritized patients with relatively low MELD-Na scores but with a 4-fold higher rate of waiting list mortality.

Conclusions

The ACLF-JM dynamically predicts outcome based on current and past disease severity. Prediction performance is excellent over time, even in patients with ACLF-3. Therefore, the ACLF-JM could be used as a clinical tool in the evaluation of prognosis and treatment in patients with ACLF.

Lay summary

Acute-on-chronic liver failure (ACLF) progresses rapidly and often leads to death. Liver transplantation is used as a treatment and the sickest patients are treated first. In this study, we develop a model that predicts survival in ACLF and we show that the newly developed model performs better than the currently used model for ranking patients on the liver transplant waiting list.

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ACLF is a dynamic disease that can rapidly change over time, which greatly influences patient survival without LT.

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Currently, the MELD-Na score is used to prioritize patients for LT, but MELD-Na underestimates ACLF disease severity.

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The ACLF joint model (ACLF-JM) was developed to dynamically predict survival.

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The ACLF-JM significantly outperformed the MELD-Na score for the prediction of mortality on the LT waiting list.

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The ACLF-JM can be used online to predict survival in individual patients.

Joint modeling of liver transplant candidates outperforms the model for end-stage liver disease: The effect of disease development over time on patient outcome

Liver function is measured regularly in liver transplantation (LT) candidates. Currently, these previous disease development data are not used for survival prediction. By constructing and validating joint models (JMs), we aimed to predict the outcome based on all available data, using both disease severity and its rate of change over time. Adult LT candidates listed in Eurotransplant between 2007 and 2018 (n = 16 283) and UNOS between 2016 and 2019 (n = 30 533) were included. Patients with acute liver failure, exception points, or priority status were excluded. Longitudinal MELD(-Na) data were modeled using spline-based mixed effects. Waiting list survival was modeled with Cox proportional hazards models. The JMs combined the longitudinal and survival analysis. JM 90-day mortality prediction performance was compared to MELD(-Na) in the validation cohorts. MELD(-Na) score and its rate of change over time significantly influenced patient survival. The JMs significantly outperformed the MELD(-Na) score at baseline and during follow-up. At baseline, MELD-JM AUC and MELD AUC were 0.94 (0.92-0.95) and 0.87 (0.85-0.89), respectively. MELDNa-JM AUC was 0.91 (0.89-0.93) and MELD-Na AUC was 0.84 (0.81-0.87). The JMs were significantly (p < .001) more accurate than MELD(-Na). After 90 days, we ranked patients for LT based on their MELD-Na and MELDNa-JM survival rates, showing that MELDNa-JM-prioritized patients had three times higher waiting list mortality.

'Equity' and 'Justice' for patients with acute-on chronic liver failure: A call to action

Acute-on-chronic liver failure (ACLF) occurs in hospitalised patients with cirrhosis and is characterised by multiorgan failures and high rates of short-term mortality. Without liver transplantation (LT), the 28-day mortality rate of patients with ACLF ranges from 18-25% in those with ACLF grade 1 to 68-89% in those with ACLF grade 3. It has become clear that patients with ACLF do not have equitable access to LT because of current allocation policies, which are based on prognostic scores that underestimate their risk of death and a lack of appreciation of the clear evidence of transplant benefit in carefully selected patients (who can have excellent post-LT outcomes). In this expert opinion, we provide evidence supporting the argument that patients with ACLF should be given priority for LT based on prognostic models that define the risk of death for these patients. We also pinpoint risk factors for poor post-LT outcomes, identify unanswered questions and describe the design of a global study, the CHANCE study, which will provide answers to the outstanding issues. We also propose the worldwide adoption of new organ allocation policies for patients with ACLF, as have been initiated in the UK and recommended in Spain.

Acute-on-Chronic Liver Failure in Cirrhosis

Acute-on-chronic liver failure (ACLF) is a syndrome that develops in patients with acutely decompensated chronic liver disease. It is characterised by high 28-day mortality, the presence of one or more organ failures (OFs) and a variable but severe grade of systemic inflammation. Despite the peculiarity of each one, every definition proposed for ACLF recognizes it as a proper clinical entity. In this paper, we provide an overview of the diagnostic criteria proposed by the different scientific societies and the clinical characteristics of the syndrome. Established and experimental treatments are also described. Among the former, the most relevant are directed to support organ failures, treat precipitating factors and carry out early assessment for liver transplantation (LT). Further studies are needed to better clarify pathophysiology of the syndrome and discover new therapies.

Liver Transplantation in Patients with Acute-onChronic Liver Failure: Challenging the Limits

Acute-on-chronic liver failure (ACLF) is one of the main causes of death on the waiting list. Liver transplantation (LT) is the only curative treatment for patients with ACLF and therefore it should be considered in all cases. However, the applicability of LT in patients with ACLF is challenging, given the scarcity of donors and the high short-term mortality of these patients. Organ allocation has traditionally been prioritised according to the model for end-stage liver disease (MELD) system. However, the accuracy of MELD score is limited in patients with ACLF. In this article, the authors review the outcomes of patients with ACLF before and after LT, highlighting its clinical course, the feasibility of LT in the sickest patients, the role of the organ allocation system, and possible indicators of futility.

Treatment of Severe Acute on Chronic Liver Failure: Management of Organ Failures, Investigational Therapeutics, and the Role of Liver Transplantation

Acute on chronic liver failure (ACLF) is a unique syndrome that afflicts patients with chronic liver disease and results in high short-term mortality, in the setting of organ system failures. Given this prognosis, there is an urgent need to understand risk factors for this condition, for appropriate medical management of organ failures, and for selection criteria for patients who may benefit from liver transplantation (LT). Although several definitions exist to identify ACLF, all of them are designed to identify patients with uniquely high mortality. Currently, management of severe ACLF relies on best supportive care for specific organ failures. Thromboelastography should guide the evaluation of coagulation pathways and hyperfibrinolysis in ACLF; prophylactic blood product transfusions and thrombopoetin agonists are not recommended. Combination therapy with terlipressin and albumin has been shown to be efficacious in the management of the hepatorenal syndrome but should be administered with caution in patients with ACLF-3. Recent data have characterized the role of beta-blockers and transjugular intrahepatic portosystemic shunt placement in the management of ACLF. Investigational therapies such as extracorporeal liver support and hepatocyte stem cell therapies have shown promise; larger scale studies may better define the subpopulations of patients with ACLF mostly likely to benefit from these evolving therapeutics. Regarding LT in ACLF, data suggest that even patients with 3 or more organ system failures may have a 1-year survival >80%. However, further efforts are needed to understand the predictors of post-LT survival to facilitate LT criteria for this condition.

New Indications for Liver Transplantation

Liver transplantation (LT) is an important therapeutic option for the treatment of several liver diseases. Modern LT is characterized by remarkable improvements in post-transplant patient survival, graft survival, and quality of life. Thanks to these great improvements, indications for LT are expanding. Nowadays, clinical conditions historically considered exclusion criteria for LT, have been considered new indications for LT, showing survival advantages for patients. In this review, we provide an updated overview of the principal newer indications for LT, with particular attention to alcoholic hepatitis, acute-on-chronic liver failure (ACLF), cholangiocarcinoma and colorectal cancer metastases.

Evolution of liver transplant organ allocation policy: Current limitations and future directions

Since the adoption of the model for end-stage liver disease (MELD) score for organ allocation in 2002, numerous changes to the system of liver allocation and distribution have been made with the goal of decreasing waitlist mortality and minimizing geographic variability in median MELD score at time of transplant without worsening post-transplant outcomes. These changes include the creation and adoption of the MELD-Na score for allocation, Regional Share 15, Regional Share for Status 1, Regional Share 35/National Share 15, and, most recently, the Acuity Circles Distribution Model. However, geographic differences in median MELD at time of transplant remain as well as limits to the MELD score for allocation, as etiology of liver disease and need for transplant changes. Acute-on-chronic liver failure (ACLF) is a subset of liver failure where prevalence is rising and has been shown to have an increased mortality rate and need for transplantation that is under-demonstrated by the MELD score. This underscores the limitations of the MELD score and raises the question of whether MELD is the most accurate, objective allocation system. Alternatives to the MELD score have been proposed and studied, however MELD score remains as the current system used for allocation. This review highlights policy changes since the adoption of the MELD score, addresses limitations of the MELD score, reviews proposed alternatives to MELD, and examines the specific implications of these changes and alternatives for ACLF.

Elevated plasma ICAM1 levels predict 28-day mortality in cirrhotic patients with COVID-19 or bacterial sepsis

BACKGROUND & AIMS

Endothelial injury and dysfunction play a detrimental role in the pathogenesis of infections. Endothelium-related molecules have been reported as potential diagnostic and/or prognostic biomarkers of infection. The prognostic value of these biomarkers in patients with cirrhosis and infections remains elusive.

METHODS

In this study, we investigated the performance of key soluble endothelial injury biomarkers, including intercellular adhesion molecule 1 (ICAM1), von Willebrand factor (vWF), vascular endothelial growth factor receptor 1 (VEGFR1), and angiopoietin 1 and 2 (Ang1, 2) as mortality predictors in patients with cirrhosis and severe COVID-19 or bacterial sepsis.

RESULTS

A total of 66 hospitalized patients (admitted to the COVID-19 ward or liver intensive care unit [ICU]) were included. Twenty-two patients had COVID-19 alone, while 20 patients had cirrhosis plus COVID-19. Twenty-four patients had cirrhosis plus bacterial sepsis. Among patients with cirrhosis, the most common aetiology of liver disease was alcohol. ICAM1 was increased (p = 0.003) while VEGFR1 (p <0.0001) and Ang1 (p <0.0001) were reduced in patients with COVID-19 and cirrhosis, compared to patients with COVID-19 alone. Endothelial biomarker levels did not differ significantly between patients with cirrhosis and severe COVID-19 or bacterial sepsis in the ICU. In these patients, ICAM1 levels significantly and independently predicted mortality (hazard ratio 3.24; 95% CI 1.19-8.86) along with model for end-stage liver disease (MELD) score, renal and coagulation failures. The AUC for ICAM1 was 0.74, MELD was 0.60 and combined ICAM1 and MELD was 0.70. ICAM1 also positively correlated with the composite organ failure scores recorded 3-5 days post ICU admission (CLIF-OF and SOFA) in this subgroup of patients.

CONCLUSION

The study indicates that in patients with cirrhosis, elevated plasma ICAM1 serves as an independent predictor of severe COVID-19- or sepsis-associated 28-day mortality.

LAY SUMMARY

Bacterial sepsis and COVID-19 lead to increased mortality in patients with cirrhosis. In this study, we demonstrate that high plasma levels of ICAM1, an endothelial injury biomarker, is one of the important factors predicting mortality in critically ill cirrhotic patients with severe COVID-19 or bacterial sepsis.

Liver Transplantation in Acute-on-chronic Liver Failure

Liver transplantation (LT) has revolutionized outcomes for cirrhotic patients. Current liver allocation policies dictate patients with highest short-term mortality receive the highest priority, thus, several patients become increasingly ill on the waitlist. Given cirrhosis is a progressive disease, it can be complicated by the occurrence of acute-on-chronic liver failure (ACLF), a syndrome defined by an acute deterioration of liver function associated with extrahepatic organ failures requiring intensive care support and a high short-term mortality. Successfully bridging to transplant includes accurate prognostication and prioritization of ACLF patients awaiting LT, optimizing intensive care support pre-LT, and tailoring immunosuppressive and anti-infective therapies post-LT. Furthermore, predicting futility (too sick to undergo LT) in ACLF is challenging. In this review, we summarize the role of LT in ACLF specifically highlighting (a) current prognostic scores in ACLF, (b) critical care management of the ACLF patient awaiting LT, (c) donor issues to consider in transplant in ACLF, and (d) exploring of recent post-LT outcomes in ACLF and potential opportunities to improve outcomes including current care gaps and unmet research needs.

Limitations of current liver donor allocation systems and the impact of newer indications for liver transplantation

Liver transplantation represents a life-saving treatment for patients with decompensated cirrhosis, a severe condition associated with a high risk of waiting list mortality. When decompensation occurs rapidly in the presence of extrahepatic organ failures, the condition is called acute-on-chronic liver failure, which is associated with an even higher risk of death, though liver transplantation can also markedly improve survival in affected patients. However, there are still gaps in our understanding of how to optimise prioritisation and organ allocation, as well as survival among patients with acute-on-chronic liver failure (both before and after transplant). Moreover, it is urgent to address inequalities in access to liver transplantation in patients with severe alcoholic hepatitis and non-alcoholic steatohepatitis. Several controversies still exist regarding gender and regional disparities, as well as the use of suboptimal donor grafts. In this review, we aim to provide a critical perspective on the role of liver transplantation in patients with decompensated cirrhosis and address areas of ongoing uncertainty.

Acute-on-chronic liver failure: update on pathogenesis, therapeutic targets, predictive models, and liver transplantation

PURPOSE OF REVIEW

Acute-on-chronic liver failure (ACLF) is a clinical syndrome in patients with chronic liver disease that is associated with multiple organ failures and a high short-term mortality. Systemic inflammation is suggested to play a key role in its pathogenesis, although the precise causative mechanism is unknown. The purpose of this review is to present and discuss new findings related to: mechanisms underlying ACLF, therapeutic targets, risk prediction models for developing ACLF, and liver transplantation for ACLF.

RECENT FINDINGS

Recent studies of ACLF pathophysiology classified the immunosuppressive phenotype in monocytes. Investigation of therapeutic strategies identified inhibition of toll-like receptor-4 (TLR-4) and glutamine synthetase (GLUL) as potential targets. Recent studies identified novel risk prediction models for developing ACLF and enhanced our understanding of liver transplantation for ACLF to guide clinicians in determining that patients will benefit from transplantation.

SUMMARY

Improved knowledge on the pathogenesis of ACLF and identification of TLR-4 and GLUL may lead to clinical trials to study the efficacy of these novel therapeutic targets for patients with ACLF. Liver transplantation is the only current treatment for ACLF. Given the limited availability of donor organs, recent studies have identified ACLF patients who may merit the highest waitlist priority.

Dynamic Prognostication in Transplant Candidates with Acute-on-Chronic Liver Failure

We aimed to extensively investigate clinical markers that are sufficiently dynamic for prognosis of acute-on-chronic liver failure (ACLF). Defined by the Asian Pacific Association for the Study of the Liver (APASL) criteria, patients with ACLF on the liver transplant waitlist in a tertiary center were retrospectively reviewed. Laboratory results and severity scores at three time points (days 1, 7, and 14 after admission) were analyzed. From 2015 to 2019, 64 patients with ACLF were enrolled, of which 24 received a liver transplant from 22 live donors. The hospital mortality rate was 31% (8% for transplant; 45% for nontransplant groups), and the 3-month survival was crucial for determining long-term outcomes. The number of significant variables for mortality, and, specifically, the hazards of international normalized ratio of prothrombin time (INR) and APASL ACLF Research Consortium (AARC) score were increased within two weeks. In multivariable analysis, INR and AARC score (D-14) were associated with poor survival and liver transplant was a protective factor in all patients, while AARC score (D-14) was significant in the nontransplant group. AARC score at day 14 is an independent risk factor for mortality in ACLF. Liver transplant from live donors reversed poor outcomes in patients with ACLF in a timely manner.

Acute-on-chronic liver failure: Definitions, pathophysiology and principles of treatment

The term acute-on-chronic liver failure (ACLF) defines an abrupt and life-threatening worsening of clinical conditions in patients with cirrhosis or chronic liver disease. In recent years, different definitions and diagnostic criteria for the syndrome have been proposed by the major international scientific societies. The main controversies relate to the type of acute insult (specifically hepatic or also extrahepatic), the stage of underlying liver disease (cirrhosis or chronic hepatitis) and the concomitant extrahepatic organ failure(s) that should be considered in the definition of ACLF. Therefore, different severity criteria and prognostic scores have been proposed and validated. Current evidence shows that the pathophysiology of ACLF is closely associated with an intense systemic inflammation sustained by circulating pathogen-associated molecular patterns and damage-associated molecular patterns. The development of organ failures may be a result of a combination of tissue hypoperfusion, direct immune-mediated damage and mitochondrial dysfunction. Management of ACLF is currently based on the supportive treatment of organ failures, mainly in an intensive care setting. For selected patients, liver transplantation is an effective treatment that offers a good long-term prognosis. Future studies on potential mechanistic treatments that improve patient survival are eagerly awaited.