Acute liver failure and liver transplantation

Low liver reserve is a risk factor for acute pancreatitis in patients with acute liver failure

AIM

Acute pancreatitis is a complication of acute liver failure (ALF). This study aimed to investigate the prevalence of and clinical features associated with acute pancreatitis in patients with ALF.

METHODS

We retrospectively analyzed a cohort of ALF patients without hepatic encephalopathy diagnosed during a period 2011-2018, and compared clinical features between patients with acute pancreatitis and those without. Acute pancreatitis was diagnosed according to the Acute Pancreatitis Clinical Practice Guidelines 2021. A multivariate analysis was carried out to identify factors associated with acute pancreatitis.

RESULTS

There were 83 ALF patients without hepatic encephalopathy (34 men; 11 deaths; 6 liver transplants; median age, 63 years). Acute pancreatitis occurred in nine patients (10.8%). The median time duration from ALF to the onset of acute pancreatitis was 8 days. The survival rate was lower in patients with than those without acute pancreatitis (22% vs. 86%). The model for end-stage liver disease score (hazard ratio 1.10, 95% confidence interval 1.03-1.18) was found to be a significant factor associated with acute pancreatitis, whereas triglyceride, age, and sex were not.

CONCLUSIONS

A high model for end-stage liver disease score may be a marker to stratify patients with ALF at a risk of acute pancreatitis.

Single-center experience in 127 adult patients, mono or dual artificial liver support therapy, in patients with acute liver failure

Background

Acute liver failure (ALF) is a serious condition characterized by sudden liver dysfunction, jaundice and hepatic encephalopathy. Its mortality rate of approximately 80% underscores the urgent need for effective treatments. Supportive extracorporeal therapies (SET), which temporarily support liver function and remove toxins, have shown promise in improving outcomes in acute liver failure (ALF). The aim of this study was to compare the outcomes of dual supportive extracorporeal therapy (SET) and mono supportive extracorporeal therapy in patients with acute liver failure.

Methods

A total of 127 patients with acute liver failure were included in this retrospective, single-center study. Of these, 62 patients received dual supportive extracorporeal therapy and 65 patients received mono supportive extracorporeal therapy. Primary endpoints were survival without the need for liver transplantation and mortality. Secondary endpoints included resolution of encephalopathy and normalization of International Normalized Ratio (INR).

Results

In the dual supportive extracorporeal therapy group, 59.6% of patients survived without the need for liver transplantation, while 27.4% achieved recovery with liver transplantation. The mortality rate in this group was 12.9%. Significant regression of encephalopathy grade was observed in 87% of patients, and the 1 year mortality rate for liver transplant recipients was 10.7%. In the mono supportive extracorporeal therapy group, 61.5% of patients experienced a successful recovery without the need for liver transplantation, with a mortality rate of 29.2%. Significant improvement in the grade of encephalopathy was observed in 70.7% of patients.

Conclusion

Both dual supportive extracorporeal therapy (CVVHDF and PE) and mono supportive extracorporeal therapy (PE) were associated with significant improvements in renal and hepatic biochemical parameters, blood ammonia levels, and neurological status in patients with acute liver failure associated with grade III-IV hepatic encephalopathy. In particular, dual support was associated with improved hemodynamic stability, lactic acidosis and acid-base balance. Survival in acute liver failure in our retrospective cohort using a protocolized approach to extracorporeal therapies is higher compared to previously published large ALF studies. This protocolized approach warrants further prospective studies.

Etiology of viral induced acute liver failure and defensins as potential therapeutic agents in ALF treatment

Acute liver failure (ALF) is a rare and severe disease, which, despite continuous advances in medicine, is still characterized by high mortality (65-85%). Very often, a liver transplant is the only effective treatment for ALF. Despite the implementation of prophylactic vaccinations in the world, the viral background of ALF is still a problem and leads to many deaths. Depending on the cause of ALF, it is sometimes possible to reverse this condition with appropriate therapies, which is why the search for effective antiviral agents seems to be a very desirable direction of research. Defensins, which are our natural antimicrobial peptides, have a very high potential to be used as therapeutic agents for infectious liver diseases. Previous studies on the expression of human defensins have shown that increased expression of human α and β-defensins in HCV and HBV infections is associated with a better response to treatment. Unfortunately, conducting clinical trials for ALF is very difficult due to the severity of the disease and the low incidence, therefore animal models are important for the development of new therapeutic strategies. One of the best animal models that has real reference to research on acute liver failure (ALF) is rabbit hemorrhagic disease in rabbits caused by the Lagovirus europaeus virus. So far, there have been no studies on the potential of defensins in rabbits infected with Lagovirus europaeus virus.

Whole Exome Sequencing Reveals Genetic Variants in HLA Class II Genes Associated With Transplant-free Survival of Indeterminate Acute Liver Failure

INTRODUCTION

Indeterminate acute liver failure (IND-ALF) is a rare clinical syndrome with a high mortality rate. Lacking a known etiology makes rapid evaluation and treatment difficult, with liver transplantation often considered as the only therapeutic option. Our aim was to identify genetic variants from whole exome sequencing data that might be associated with IND-ALF clinical outcomes.

METHODS

Bioinformatics analysis was performed on whole exome sequencing data for 22 patients with IND-ALF. A 2-tier approach was used to identify significant single-nucleotide polymorphisms (SNPs) associated with IND-ALF clinical outcomes. Tier 1 identified the SNPs with a higher relative risk in the IND-ALF population compared with those identified in control populations. Tier 2 determined the SNPs connected to transplant-free survival and associated with model for end-stage liver disease serum sodium and Acute Liver Failure Study Group prognostic scores.

RESULTS

Thirty-one SNPs were found associated with a higher relative risk in the IND-ALF population compared with those in controls, of which 11 belong to the human leukocyte antigen (HLA) class II genes but none for the class I. Further analysis showed that 5 SNPs: rs796202376, rs139189937, and rs113473719 of HLA-DRB5; rs9272712 of HLA-DQA1; and rs747397929 of IDO1 were associated with a higher probability of IND-ALF transplant-free survival. Using 3 selected SNPs, a model for the polygenic risk score was developed to predict IND-ALF prognoses, which are comparable with those by model for end-stage liver disease serum sodium and Acute Liver Failure Study Group prognostic scores.

DISCUSSION

Certain gene variants in HLA-DRB5, HLA-DQA1, and IDO1 were found associated with IND-ALF transplant-free survival. Once validated, these identified SNPs may help elucidate the mechanism of IND-ALF and assist in its diagnosis and management.

Exacerbated LPS/GalN-Induced Liver Injury in the Stress-Sensitive Wistar Kyoto Rat Is Associated with Changes in the Endocannabinoid System

Acute liver injury (ALI) is a highly destructive and potentially life-threatening condition, exacerbated by physical and psychological stress. The endocannabinoid system plays a key role in modulating stress and hepatic function. The aim of this study was to examine the development of acute liver injury in the genetically susceptible stress-sensitive Wistar-Kyoto (WKY) rat compared with normo-stress-sensitive Sprague Dawley (SD) rats, and associated changes in the endocannabinoid system. Administration of the hepatotoxin lipopolysaccharide/D-Galactosamine (LPS/GalN) resulted in marked liver injury in WKY, but not SD rats, with increased alanine aminotransferase (ALT), aspartate aminotransferase (AST) and glutamate dehydrogenase (GLDH) plasma levels, significant histopathological changes, increased hepatic pro-inflammatory cytokine expression and caspase-3 activity and expression and reduced Glutathione (GSH) activity. Furthermore, compared to SD controls, WKY rats display increased anandamide and 2-Arachidonoylglycerol levels concurrent with decreased expression of their metabolic enzymes and a decrease in cannabinoid (CB)₁ receptor expression following LPS/GalN. CB₁ antagonism with AM6545 or CB₂ agonism with JWH133 did not alter LPS/GalN-induced liver injury in SD or WKY rats. These findings demonstrate exacerbation of acute liver injury induced by LPS/GalN in a stress-sensitive rat strain, with effects associated with alterations in the hepatic endocannabinoid system. Further studies are required to determine if the endocannabinoid system mediates or modulates the exacerbation of liver injury in this stress-sensitive rat strain.

Liver Transplantation for Acute Liver Failure in Presence of Acute Kidney Injury

Acute liver failure (ALF) is a catastrophic illness, which is associated with high mortality in absence of liver transplantation. ALF is associated with multisystem involvement including acute kidney injury (AKI). AKI worsens the already poor prognosis of ALF. There is limited literature on impact of AKI on outcomes of liver transplantation (LT). The use of continuous renal replacement therapy (CRRT) may have a role in transplant-free survival or bridging to LT. Although results suggest a somewhat lower survival in patients with ALF and AKI, LT is a life-saving option and should not be deferred in absence of other contraindications. In the current review, we discuss impact of AKI on transplant-free survival, possible role of CRRT, and role of LT in patients with ALF associated with AKI.

[Multiple organ manifestations of liver failure in acute small bowel obstruction]

Modern surgical and intensive care achievements did not result decrease of mortality in patients with acute small bowel obstruction (ASBO). Direct cause of mortality in ASBO patients is peritonitis followed by multiple organ failure syndrome including acute failure of liver, kidneys, lungs and other organs. Publications devoted to the problem of acute liver failure and its complicationsare reviewed in the article. Mechanisms of pathogenesis and clinical manifestations of multiple organ failure syndrome in patients with acute small bowel obstruction are analyzed.

Liver Fibrosis Markers Improve Prediction of Outcome in Non-Acetaminophen-Associated Acute Liver Failure

A prognostic system for acute liver failure (ALF) with a higher predictive value is urgently needed. The role of extracellular matrix (ECM) remodeling in ALF has not been fully elucidated. We hypothesized that serologic fibrosis markers, which reflect ECM remodeling, are predictive of ALF outcome at first presentation. This observational study included 110 patients with acute liver dysfunction, of which 73 had non-acetaminophen-associated ALF (NAA-ALF). We evaluated serum levels of hyaluronic acid, 7S domain of type IV collagen (4COL7S), and Wisteria floribunda agglutinin-positive Mac-2-binding protein at first presentation to a tertiary center. Serologic fibrosis markers were significantly higher in NAA-ALF compared with acute hepatitis. Elevated hyaluronic acid and 4COL7S levels at first presentation correlated significantly with worse clinical outcomes. 4COL7S, along with age, ammonia, and the Model for End-Stage Liver Disease (MELD) score, was a significant prognostic factor in multivariate analysis; 4COL7S correlated significantly with coagulopathy, decreased hepatic synthetic functions, advanced hepatic encephalopathy, and liver atrophy and also predicted 180-day transplant-free survival. Cox regression models incorporating 4COL7S with the MELD system had profoundly improved predictive values that significantly surpassed the MELD system alone. Conclusion: Elevation of serologic fibrosis markers reflecting ECM remodeling in NAA-ALF predicted a worse clinical outcome. Incorporation of 4COL7S at first presentation to a transplant center improves the specificity while retaining the sensitivity of the MELD system. External validation of a fibrosis marker as part of a clinical prediction tool in ALF warrants further investigation.

Intravital Microscopic Evaluation of the Effects of a CXCR2 Antagonist in a Model of Liver Ischemia Reperfusion Injury in Mice

Background

Ischemia-reperfusion (IR) is a major contributor to graft rejection after liver transplantation. During IR injury, an intense inflammatory process occurs in the liver. Neutrophils are considered central players in the events that lead to liver injury. CXC chemokines mediate hepatic inflammation following reperfusion. However, few studies have demonstrated in real-time the behavior of recruited neutrophils. We used confocal intravital microscopy (IVM) to image neutrophil migration in the liver and to analyze in real-time parameters of neutrophil recruitment in the inflamed tissue in animals treated or not with reparixin, an allosteric antagonist of CXCR1/2 receptors.

Materials and methods

WT and LysM-eGFP mice treated with reparixin or saline were subjected to 60 min of ischemia followed by different times of reperfusion. Mice received Sytox orange intravenously to show necrotic DNA in IVM. The effect of reparixin on parameters of local and systemic reperfusion-induced injury was also investigated.

Results

IR induced liver injury and inflammation, as evidenced by high levels of alanine aminotransferase and myeloperoxidase activity, chemokine and cytokine production, and histological outcome. Treatment with reparixin significantly decreased neutrophil influx. Moreover, reparixin effectively suppressed the increase in serum concentrations of TNF-α, IL-6, and CCL3, and the reperfusion-associated tissue damage. The number of neutrophils in the liver increased between 6 and 24 h of reperfusion, whereas the distance traveled, velocity, neutrophil size and shape, and cluster formation reached a maximum 6 h after reperfusion and then decreased gradually. In vivo imaging revealed that reparixin significantly decreased neutrophil infiltration and movement and displacement of recruited cells. Moreover, neutrophils had a smaller size and less elongated shape in treated mice.

Conclusion

Imaging of the liver by confocal IVM was successfully implemented to describe neutrophil behavior in vivo during liver injury by IR. Treatment with reparixin decreased not only the recruitment of neutrophils in tissues but also their activation state and capacity to migrate within the liver. CXCR1/2 antagonists may be a promising therapy for patients undergoing liver transplantation.

The role of extracellular histone in organ injury

Histones are intra-nuclear cationic proteins that are present in all eukaryotic cells and are highly conserved across species. Within the nucleus, they provide structural stability to chromatin and regulate gene expression. Histone may be released into the extracellular space in three forms: freely, as a DNA-bound nucleosome or as part of neutrophil extracellular traps, and all three can be detected in serum after significant cellular death such as sepsis, trauma, ischaemia/reperfusion injury and autoimmune disease. Once in the extracellular space, histones act as damage-associated molecular pattern proteins, activating the immune system and causing further cytotoxicity. They interact with Toll-like receptors (TLRs), complement and the phospholipids of cell membranes inducing endothelial and epithelial cytotoxicity, TLR2/TLR4/TLR9 activation and pro-inflammatory cytokine/chemokine release via MyD88, NFκB and NLRP3 inflammasome-dependent pathways. Drugs that block the release of histone, neutralise circulating histone or block histone signal transduction provide significant protection from mortality in animal models of acute organ injury but warrant further research to inform future clinical applications.

Establishment of a Novel Simplified Surgical Model of Acute Liver Failure in the Cynomolgus Monkey

Models using large animals that are suitable for studying artificial liver support system (ALSS) are urgently needed. Presently available acute liver failure (ALF) models mainly involve pigs or dogs. Establishment of current surgical ALF models (hepatectomy/devascularization) requires either very good surgical skills or multistep processes—even multiple stages of surgery. Therefore, it is necessary to develop a simplified surgical method. Here we report a novel simplified surgical ALF model using cynomolgus monkeys. Six monkeys underwent portal-right renal venous shunt combined with common bile duct ligation and transection (PRRS + CBDLT). Postoperatively, the monkeys had progressively increased listlessness, loss of appetite, and obvious jaundice. Blood biochemistry levels (Amm, ALT, AST, TBiL, DBiL, ALP, LDH, CK, and Cr) and prothrombin time (PT) were significantly increased (all P < 0.01) and albumin (ALB) was markedly reduced (P < 0.01) compared with baseline values. Histological examination of liver specimens on postoperative day 10 revealed cholestasis and inflammation. PRRS + CBDLT produced ALF that closely correlated with clinical situations. Compared with other surgical or drug ALF models, ours was simplified and animals were hemodynamically stable. This model could provide a good platform for further research on ALSS, especially regarding their detoxification functions.

Post-operative hypertension, a surrogate marker of the graft function and predictor of survival in living donor liver transplant recipients: A retrospective study

BACKGROUND AND AIMS

De novo hypertension (HTN) in liver transplantation recipients is a known entity. We investigated haemodynamic behaviour after a liver transplant to see if it can predict survival to discharge from the hospital.

METHODS

electronic records of Haemodynamic parameters and laboratory investigations of 95 patients of living donor liver transplant (LDLT) were retrospectively analysed.

RESULTS

Twenty-three patients were operated for acute liver failure (ALF) and 72 patients for chronic liver disease (CLD). Eight patients of CLD and four of ALF did not survive. CLD patients had statistically significant rise in systolic blood pressure from the post-operative day (POD) 1 to POD 4 and diastolic blood pressure (DBP) from POD 3 to POD 6. Heart rate (HR) significantly decreased from POD 3 to POD 5. Haemodynamic parameters returned to baseline values within 20 days. Diastolic HTN had a positive predictive value of 100% for survival with 100% sensitivity and specificity. Systolic HTN had a positive predictive value of 100% for survival (sensitivity-89%, specificity-100%). ALF patients had a significant decrease in HR from POD 2 to POD 10. Bradycardia (HR ≤60/min) had a positive predictive value of 100% for survival with a sensitivity of 45% and 58% in CLD and ALF, respectively, with a specificity of 100% in both the groups. Non-survivors had no significant change in haemodynamics. In CLD group, International Normalised Ratio had statistically significant, strong negative correlation with DBP.

CONCLUSION

Haemodynamic pattern of recovery may be used for predicting survival to discharge after LDLT.

An updated systematic review of the evolution of ALPPS and evaluation of its advantages and disadvantages in accordance with current evidence

The main obstacle to achieving an R0 resection after a major hepatectomy is inability to preserve an adequate future liver remnant (FLR) to avoid postoperative liver failure (PLF). Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) is a novel technique for resecting tumors that were previously considered unresectable, and this technique results in a vast increase in the volume of the FLR in a short period of time. However, this technique continues to provoke heated debate because of its high mortality and morbidity.The evolution of ALPPS and its advantages and disadvantages have been systematically reviewed and evaluated in accordance with current evidence. Electronic databases (PubMed and Medline) were searched for potentially relevant articles from January 2007 to January 2016.ALPPS has evolved into various modified forms. Some of these modified techniques have reduced the difficulty of the procedure and enhanced its safety. Current evidence indicates that the advantages of ALPPS are rapid hypertrophy of the FLR, the feasibility of the procedure, and a higher rate of R0 resection in comparison to other techniques. However, ALPPS is associated with worse major complications, more deaths, and early tumor recurrence.Hepatobiliary surgeons should carefully consider whether to perform ALPPS. Some modified forms of ALPPS have reduced the mortality and morbidity of the procedure, but they cannot be recommended over the original procedure currently. Portal vein embolization (PVE) is still the procedure of choice for patients with a tumor-free FLR, and ALPPS could be used as a salvage procedure when PVE fails. More persuasive evidence needs to be assembled to determine whether ALPPS or two-stage hepatectomy (TSH) is better for patients with a tumor involving the FLR. Evidence with regard to long-term oncological outcomes is still limited. More meticulous comparative studies and studies of the 5-year survival rate of ALPPS could ultimately help to determine the usefulness of ALPPS. Indications and patient selection for the procedure need to be determined.

High Levels of Gamma-Glutamyl Transferase and Indocyanine Green Retention Rate at 15 min as Preoperative Predictors of Tumor Recurrence in Patients With Hepatocellular Carcinoma

This study investigated the preoperative independent risk factors associated with survival and recurrence for patients with hepatocellular carcinoma (HCC) who underwent hepatic resection. In total, 384 consecutive patients who underwent curative hepatic resection for single primary HCC were studied. Predictive factors associated with 1-, 3-, and 5-year survival and recurrence-free survival (RFS) were assessed using a univariate log-rank test and multivariate Cox proportional hazards regression model. Gamma-glutamyl transferase (GGT) > 100 U/L was identified as a preoperative independent risk factor affecting 1-, 3-, and 5-year survival whereas GGT > 50 U/L and indocyanine green retention 15 min (ICG-R15) > 10% were identified as preoperative independent risk factors affecting 1-, 3-, and 5-year RFS. The 384 patients studied had a 1-, 3-, and 5-year RFS rate of 72.8%, 43.3%, and 27%, respectively. Patients with GGT > 50 U/L had a 1-, 3-, and 5-year RFS rate of 64.5%, 36.0%, and 21.7%. These patients had lower survival rates than did patients with GGT ≤ 50 U/L (P < 0.05). Patients with GGT > 50 U/L and ICG-R15 > 10% had a 1-, 3-, and 5-year RFS rate of 62.4%, 29.5%, and 14.1%, respectively. These patients had lower survival rates than did patients in the other 2 groups with different levels of GGT and ICG (P < 0.05, respectively). The same was also true for patients with a tumor < 5 cm in size. Combined information in the form of high levels of GGT and ICG-R15 is a preoperative predictor that warrants full attention when evaluating tumor recurrence postoperatively.