The burden and predictors of 30-day unplanned readmission in patients with acute liver failure: a national representative database study.

BACKGROUND: Liver diseases were significant source of early readmission burden. This study aimed to evaluate the 30-day unplanned readmission rates, causes of readmissions, readmission costs, and predictors of readmission in patients with acute liver failure (ALF). METHODS: Patients admitted for ALF from 2019 National Readmission Database were enrolled. Weighted multivariable logistic regression models were applied and based on Directed Acyclic Graphs. Incidence, causes, cost, and predictors of 30-day unplanned readmissions were identified. RESULTS: A total of 3,281 patients with ALF were enrolled, of whom 600 (18.3%) were readmitted within 30 days. The mean time from discharge to early readmission was 12.6 days. The average hospital cost and charge of readmission were $19,629 and $86,228, respectively. The readmissions were mainly due to liver-related events (26.6%), followed by infection (20.9%). The predictive factors independently associated with readmissions were age, male sex (OR 1.227, 95% CI 1.023-1.472; P = 0.028), renal failure (OR 1.401, 95% CI 1.139-1.723; P = 0.001), diabetes with chronic complications (OR 1.327, 95% CI 1.053-1.672; P = 0.017), complicated hypertension (OR 1.436, 95% CI 1.111-1.857; P = 0.006), peritoneal drainage (OR 1.600, 95% CI 1.092-2.345; P = 0.016), etc. CONCLUSIONS: Patients with ALF are at relatively high risk of early readmission, which imposes a heavy medical and economic burden on society. We need to increase the emphasis placed on early readmission of patients with ALF and establish clinical strategies for their management.

Selecting serum-free hepatocyte cryopreservation stage and storage temperature for the application of an "off-the-shelf" bioartificial liver system.

The bioartificial liver (BAL) system can potentially rescue acute liver failure (ALF) patients by providing partial liver function until a suitable donor liver can be found or the native liver has self-regenerated. In this study, we established a suitable cryopreservation process for the development of an off-the-shelf BAL system. The viability of hepatocyte spheroids cryopreserved in liquid nitrogen was comparable to that of fresh primary hepatocyte spheroids. When hepatocyte spheroids were subjected to cryopreservation in a deep freezer, no statistically significant differences were observed in ammonia removal rate or urea secretion rate based on the cryopreservation period. However, the functional activity of the liver post-cryopreservation in a deep freezer was significantly lower than that observed following liquid nitrogen cryopreservation. Moreover, cryopreserving spheroid hydrogel beads in a deep freezer resulted in a significant decrease (approximately 30%) in both ammonia removal and urea secretion rates compared to the group cryopreserved in liquid nitrogen. The viabilities of spheroid hydrogel beads filled into the bioreactor of a BAL system were similar across all four groups. However, upon operating the BAL system for 24 h, the liver function activity was significantly higher in the group comprising hydrogel beads generated after thawing hepatocyte spheroids cryopreserved in liquid nitrogen. Consequently, the manufacturing of beads after the cryopreservation of hepatocyte spheroids is deemed the most suitable method, considering efficiency, economic feasibility, and liver function activity, for producing a BAL system.

Management of pediatric liver failure with therapeutic plasma exchange and continuous renal replacement therapy: A retrospective observational study.

Liver failure represents a critical medical condition, marked by the rapid decline of hepatic functions. Emerging therapies, notably therapeutic plasma exchange (TPE) and continuous venovenous hemodiafiltration (CVVHDF), have demonstrated potential in mitigating these conditions through their roles in detoxification and hepatic support. The utility of these treatments, whether applied individually or in tandem, constitutes a significant area of research concerning the management of liver failure in pediatric patients. This study aims to evaluate the role and efficacy of TPE or TPE combined with CVVHDF in the treatment of liver failure among children. This retrospective study was conducted in a LTICU by reviewing the medical history of pediatric patients aged 1 month to 18 years. Patients were admitted between January 1, 2021 and December 1, 2023 due to acute liver failure or acute-chronic liver failure. The study evaluated those who received TPE or continuous renal replacement therapy combined with TPE. In statistical analyses, a P-value of <.05 was considered statistically significant. The study involved 24 patients with liver failure, comprising 13 males and 11 females. Sixteen patients (66.6%) received only TPE, while 8 patients (33.4%) were treated with TPE and CVVHDF. For patients treated only with TPE, the median INR reduced from 3.1 to 1.26, alanine aminotransferase from 1255 to 148, and aspartate aminotransferase from 2189 to 62. Similar significant reductions were observed in the TPE and CVVHDF group: INR from 3.9 to 1.26, alanine aminotransferase from 1749 to 1148, and aspartate aminotransferase from 1489 to 62. These changes were statistically significant with P-values of .01 for each parameter in both groups. Overall, 14 patients survived without requiring a liver transplant, while 4 patients underwent liver transplantation. Our study on pediatric liver failure treatment shows that both standalone TPE and its combination with CVVHDF are effective, especially as a bridge to transplantation. With 58% transplant-free survival, these therapies demonstrate significant clinical improvements. Future multicentric studies are needed for broader validation of these findings in liver failure management.

Clinical presentation and outcomes of patients with rhabdomyolysis: A tertiary care center experience.

OBJECTIVES: To evaluate the clinical and laboratory features, complications, and outcomes of patients with rhabdomyolysis in the Saudi population. METHODS: Retrospectives descriptive study of adult patients who presented to King Abdulaziz Medical City (KAMC) withrhabdomyolysis between January 2016 and December 2022. RESULTS: Most of the participants (84.5%) were male, with a median age of 41 years and a body mass index of 26.5 kg/m2. Medications, mainly statins (22.4%) and illicit drugs (15.5%), constituted the root causes of rhabdomyolysis in the cohort (44.8%). The most common presenting complaints were myalgia (63.8%) and fatigue (37.9%). More than one-third of the participants (32.8%) developed AKI, with 3 patients requiring temporary hemodialysis, and only 8.6% developed acute liver failure (ALF). Intensive care unit (ICU) admission was required for 10 patients (17.2%), and the overall mortality rate was 8.6%. Patients who developed complications (composite outcomes of AKI, ALF, multiorgan failure, or death) had significantly reduced kidney function and higher levels of blood urea nitrogen, anion gap, and uric acid upon admission than those who did not. CONCLUSION: This study offers a thorough understanding of clinical and laboratory features, causes, complications, and outcomes of rhabdomyolysis among Saudi patients. The insights gained enhance our understanding of rhabdomyolysis within this population, providing a foundation for future research and improvements in clinical management.

Plasma exchange improves survival in acute liver failure - An updated systematic review and meta-analysis focussed on comparing within single etiology.

BACKGROUND AND OBJECTIVE: Therapeutic plasma exchange (PLEX) is increasingly used in patients with acute liver failure (ALF) as either stand-alone therapy or bridge to liver transplantation. Etiology plays a major role in prognosis of these patients and benefit of PLEX may consequently differ across etiologies. This systematic review and meta-analysis aims to evaluate the efficacy of PLEX in treating ALF, focussing on studies with single etiology. METHODS: We conducted a systematic literature search and identified studies comparing PLEX vs. standard medical therapy (SMT) for patients with ALF across all age groups. The protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42023442383). Pooled risk-ratios were determined by Mantel-Haenszel method within a random effect model. Primary outcome was mortality at ≤ 60-days and 90 days. Secondary outcome was adverse events attributable to PLEX. RESULTS: Eight studies (pooled sample size in PLEX arm: 284; randomized trials: 2; Comparative cohorts: 6) with retrievable data on ALF were included in this systematic review. Analysis showed that PLEX was associated with significant reduction in mortality at ≤ 60-days (RR 0.64; CI, 0.51-0.80; P < 0.001) and at 90-days (RR 0.67; CI, 0.50-0.90; P = 0.008) as compared to SMT. On sub-group analysis, the survival benefit was noted irrespective of the volume of plasma exchanged during PLEX. Three studies (pooled sample size in PLEX arm: 110; all comparative cohorts) were identified, which included patients with a single etiology for ALF. These studies included patients with Wilson's disease, rodenticidal hepatotoxicity and acute fatty liver of pregnancy. Pooled analysis of studies with single etiology ALF showed better reduction in ≤ 90-day mortality with PLEX (RR 0.53; CI, 0.37-0.74; P < 0.001). Studies reported no major side-effects attributable to PLEX. CONCLUSION: PLEX is safe and improves survival, independent of the volumes utilized, in patients with ALF as compared to standard medical treatment. The survival benefit is especially pronounced in studies restricted to single etiology.

Acute liver failure in pregnancy.

Liver function abnormalities are noted in a minority of pregnancies with multiple causes for the same. A small proportion of these develop severe liver injury and progress to acute liver failure (ALF). There is a discrete set of etiology for ALF in pregnancy and comprehensive understanding will help in urgent evaluation. Certain diseases such as acute fatty liver of pregnancy, hemolysis, elevated liver enzyme, low platelet (HELLP) syndrome and pre-eclampsia are secondary to pregnant state and can present as ALF. Quick and targeted evaluation with urgent institution of etiology-specific management, especially urgent delivery in patients with pregnancy-associated liver diseases, is the key to avoiding maternal deaths. Pregnancy, as also the fetal life, imparts a further layer of complication in assessment, prognosis and management of these sick patients with ALF. Optimal management often requires a multidisciplinary approach in a well-equipped centre. In this review, we discuss evaluation, assessment and management of pregnant patients with ALF, focussing on approach to pregnancy-associated liver diseases.

Overview of acute liver failure in India.

Acute liver failure (ALF) is an infrequent, but serious complication subsequent to severe acute liver injury (sALI) due to various hepatotoxic agents such as hepatotropic virus(es) and drugs such as anti-tubercular medications, paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs), antibiotics and anti-cancer and anti-epileptic therapy and due to metabolic and autoimmune disease flares. ALF after sALI presents with encephalopathy associated with prolonged international normalized ratio (INR). Mortality in ALF is high and ranges between 50% and 80%. Due to severe liver damage, multiple sequels consequent to hepatic dysfunction result in complications such as hyperammonemia that culminates in encephalopathy associated with cerebral edema; innate immune paralysis resulting in increased frequency of infections and endotoxemia causing decrease in systemic vascular resistance (SVR) and tissue hypoperfusion and damage-associated molecular patterns (DAMPs) released from damaged hepatic parenchyma inducing pro-inflammatory cytokine storm, which may cause other organ dysfunctions. Certain etiologies such as hepatitis E virus and hepatitis A virus-related ALF or paracetamol-ALF (hyper-acute presentation) have better survival than remaining causes. In addition, if etiology-specific treatment (antivirals for ALF related to hepatitis B virus (HBV) or Herpes simplex virus (HSV) or N-acetylcysteine for paracetamol) is available, then the outcome with treatment is better. About half of the patients can be salvaged with medical therapy. All patients need intensive care and organ support to provide time for the liver to regenerate. Various prognostic models to predict high probability of mortality have been described, which should be used to select patient early during the disease for liver transplantation, which is associated with high long-term survival in these sick patients. The Indian National Association for Study of the Liver (INASL) recommends the ALF-Early Dynamic (ALFED) model as a preferred prognostic model in the Indian scenario, where hepatitis viruses are a dominant etiology of ALF and occur on a naïve liver with good regenerative capacity.

Perioperative care in acute liver failure: An anaesthesiologist perspective in the operating theatre.

Acute liver failure (ALF) is a life-threatening condition characterized by rapid liver function deterioration, necessitating a multidisciplinary approach for optimal perioperative care. This comprehensive review focuses on the critical role of the anaesthesiologist throughout the preoperative, intraoperative, and postoperative phases, addressing the unique challenges posed by ALF. The article begins with an exploration of ALF, underlining the urgency of timely referral to specialized hepatology centres. Liver transplantation emerges as a life-saving intervention, and the complex decision-making process is discussed, emphasizing the need for a multidisciplinary team to assess transplantation candidacy based on established prognostic criteria. In the preoperative phase, the review stresses the importance of early engagement with tertiary liver centres for timely referrals and identifies patients suitable for transplantation. Safe transport protocols are detailed, highlighting the meticulous planning required for the secure transfer of ALF patients between healthcare facilities. The intraoperative management section delves into the anaesthesiologist's key concerns, including neurological status, sepsis, acute kidney injury, body mass index, and preoperative fasting. Hemodynamic stability, fluid management, and coagulation balance during surgery are emphasized, with insights into anaesthesia techniques, vascular access, monitoring, and hemodynamic management tailored to the challenges posed by ALF patients. The postoperative care is thoroughly examined covering neurological, hemodynamic, metabolic, renal, and nutritional aspects. Management of ALF involves multidisciplinary team, including nephrology for continuous renal replacement therapy, transfusion medicine for plasma exchange, critical care for overall patient care, nutritionists for ensuring adequate nutrition, and hepatologists as the primary guides. In conclusion, the review recognizes the anaesthesiologist as a linchpin in the perioperative care of ALF patients. The integration of safe transport protocols and multidisciplinary approach is deemed crucial for navigating complexities of ALF, contributing to improved patient outcomes. This article serves as an invaluable resource for gastroenterologist and intensivists, enhancing their understanding of the anaesthesiologist's indispensable role in the holistic care of ALF patients in an ever-evolving healthcare landscape.

[Extracorporeal Support Strategies in Liver Failure - Focus on Albumin Dialysis and Therapeutic Plasma Exchange]. / Extrakorporale Unterstützungsstrategien beim Leberversagen.

Combining albumin dialysis for the removal of hydrophobic substances with classical haemodialysis in the treatment of acute liver failure (ALF) and acute-on-chronic liver failure (ACLF) has a strong theoretical rational and clinical data showed a positive effect on laboratory and partly clinical characteristics of ALF and ACLF. However, neither the MARS nor the Prometheus System has so far been able to demonstrate a mortality benefit in ALF or ACLF patients. To date, only the use of therapeutic plasma exchange (TPE) has demonstrated significant removal of pathogen-associated (PAMPs), damage-associated molecular patterns (DAMPs) and pro-inflammatory cytokines. In addition, TPE also acts simultaneously by replacing protective but depleted mediators, thus improving multiple key pathophysiological principles of both ALF and ACLF. In ALF, both high-volume and standard-volume TPE showed a significant improvement in survival. The data on the use of TPE in ACLF is still sparse, with only two Chinese monocentric studies in patients with exclusively hepatitis B-associated ACLF suggesting potentially improved survival with TPE. The currently recruiting APACHE study will include patients with the modern EASL-CLIF definition of ACLF.

Toxin-Induced Liver Injury and Extracorporeal Treatment of Liver Failure.

Poisoning with a large variety of drugs and naturally occurring toxins may result in acute liver injury and failure. Drug-induced liver injury is a major cause of liver failure nationwide, and it is likely that nephrologists will be involved in treating patients with these conditions. A number of xenobiotics resulting in liver toxicity may cause acute kidney injury or other organ injury as well. Most agents causing drug- or toxin-induced liver failure lack specific therapies, although a few xenobiotics such as acetaminophen have effective antidotal therapies if administered prior to development of hepatotoxicity. The nephrologist should be aware that extracorporeal treatment of liver failure associated with drugs and toxins may be indicated, including therapies conventionally performed by nephrologists (hemodialysis, continuous kidney replacement therapy), therapies occasionally performed by nephrologists and other specialists (plasma exchange, albumin dialysis, hemadsorption), and therapies performed by other specialists (extracorporeal membrane oxygenation). An overview of the role of these therapies in liver failure is provided, as well as a review of their limitations and potential complications.

Dengue-related acute liver failure-A scoping review.

Infection by dengue virus is common in tropical countries. Hepatic involvement in dengue can range from asymptomatic elevation of transaminases to life-threatening acute liver failure (ALF). Dengue-related ALF (DALF) is responsible for significant morbidity and mortality, especially in Southeast Asia. However, there is a scarcity of literature on DALF, necessitating a thorough examination of its clinical determinants and management strategies. All relevant studies related to DALF were reviewed until December 2023. Case reports, case series and studies reporting ALF in dengue infection were included. Demographics, clinical profiles, management and outcomes of DALF cases were analyzed, which revealed a predominance of DALF incidence in pediatric patients (1.1% to 15.8%) and an upward trend over the years, particularly in India. The proportion of ALF cases attributable to dengue was also higher among pediatric ALF patients (6.7% to 34.3%). Age ≤ 40 years, persistent nausea, vomiting and elevated serum bilirubin and alkaline phosphatase (ALP) with aspartate aminotransferase (AST) > 1000 IU/mL within the first five days of illness, more than 10% of atypical lymphocytes in peripheral blood, platelet count of < 50,000/cu·mm, severe hepatitis at presentation and baseline model for end-stage liver disease (MELD) > 15 were the risk factors for the development of DALF. Histopathological features of DALF included multi-lobular hepatic necrosis, steatosis and occasional cholestasis. Mortality in DALF ranged from 0% to 80%; admission pH and lactate strongly predicted mortality, while mortality was found to be significantly higher in patients with cirrhosis. N-Acetyl cysteine (NAC) has been used as a treatment modality with varying results. There is limited evidence regarding the use of extra-corporeal support systems, while candidate selection for liver transplantation (LT) in DALF remains poorly defined.

Acute kidney injury in acute liver failure: A narrative review.

Acute kidney injury (AKI) is a frequent complication of acute liver failure (ALF) and it worsens the already worse prognoses of ALF. ALF is an uncommon disease, with varying etiologies and varying definitions in different parts of the world. There is limited literature on the impact of AKI on the outcome of ALF with or without transplantation. The multifaceted etiology of AKI in ALF encompasses factors such as hemodynamic instability, systemic inflammation, sepsis and direct nephrotoxicity. Indications of renal replacement therapy (RRT) for AKI in ALF patients extend beyond the conventional criteria for dialysis and continuous renal replacement therapy (CRRT) may have a role in transplant-free survival or bridge to liver transplantation (LT). LT is a life-saving option for ALF, so despite somewhat lower survival rates of LT in ALF patients with AKI, LT is not usually deferred. In this review, we will discuss the guidelines' recommended definition and classification of AKI in ALF, the impact of AKI in ALF, the pathophysiology of AKI and the role of CRRT and LT in ALF patients with AKI.

Critical care management of acute liver failure.

The management of acute liver failure (ALF) in modern hepatology intensive care units (ICU) has improved patient outcomes. Critical care management of hepatic encephalopathy, cerebral edema, fluid and electrolytes; prevention of infections and organ support are central to improved outcomes of ALF. In particular, the pathogenesis of encephalopathy is multifactorial, with ammonia, elevated intra-cranial pressure and systemic inflammation playing a central role. Although ALF remains associated with high mortality, the availability of supportive care, including organ failure support such as plasma exchange, timely mechanical ventilation or continuous renal replacement therapy, either conservatively manages patients with ALF or offers bridging therapy until liver transplantation. Thus, appropriate critical care management has improved the likelihood of patient recovery in ALF. ICU care interventions such as monitoring of cerebral edema, fluid status assessment and interventions for sepsis prevention, nutritional support and management of electrolytes can salvage a substantial proportion of patients. In this review, we discuss the key aspects of critical care management of ALF.

Acute liver failure.

ABSTRACT: Acute liver failure, commonly caused by acetaminophen overdose, is associated with numerous systemic complications including cerebral edema, hypotension, acute kidney injury, and infection. Management is primarily supportive, with an emphasis on excellent neurocritical care. Although some antidotes and targeted treatments exist, the only definitive treatment remains orthotopic liver transplant.

Assessing the clinical efficacy of low-volume therapeutic plasma exchange in achieving recovery from acute liver failure induced by yellow phosphorous poisoning.

BACKGROUND: Acute liver failure (ALF) following yellow phosphorous (YP) ingestion is similar to acetaminophen-induced ALF and it has become a public concern in our region. This study assessed low volume therapeutic plasma exchange (LV-TPE) efficacy in improving the transplant free survival in YP poisoning. METHODS: Adult patients with toxicology reports of YP and ALF requiring critical care were included in the study. LV-TPE was planned for three consecutive days and three more if required. Performed 1.3 to 1.5 plasma volume replacing with 0.9% normal saline, 5% human albumin solution, and fresh frozen plasma based on ASFA 2019 criteria. MELD score, laboratory parameters, LV-TPE details were captured. The study end point was clinical outcome of the patients. RESULTS: Among 36 patients, 19 underwent LV-TPE and 17 opted out of LV-TPE and they were included as a control arm. The MELD score was 32.64 ± 8.05 and 37.83 ± 9.37 in both groups. There were 13 survivors in LV-TPE group leading to a 68.42% reduction in mortality. The coagulation and biochemical parameters showed a significant percentage change after LV-TPE. Refractory shock, delay in initiating procedure and acidosis were independent predictors of mortality. CONCLUSION: A well-timed LV-TPE improves the survival of patients with ALF due to YP poisoning.

Viral hepatitis-induced acute liver failure.

Viral hepatitis-induced acute liver failure (ALF) is a preventable cause for liver-related mortality worldwide. Viruses are the most common cause for ALF in developing nations in contrast to the west, where acetaminophen is largely responsible. Viruses may be hepatotropic or affect the liver secondary to a systemic infection. In tropical countries, infections such as leptospirosis, scrub typhus and malaria can mimic the symptoms of ALF. Differentiating these ALF mimics is crucial because they require etiology-specific therapy. Treatment of viral hepatitis-induced ALF is two-pronged and directed towards providing supportive care to prevent organ failures and antiviral drugs for some viruses. Liver transplantation (LT) is an effective modality for patients deteriorating despite adequate supportive care. Early referral and correct identification of patients who require a transplant are important. Liver support devices and plasma exchange have evolved into "bridging modalities" for LT. Preventive strategies such as hand hygiene, use of clean and potable water and inclusion of vaccines against viral hepatitis in the national program are simple yet very effective methods focusing on the preventive aspect of this disease.

[Advancements in the diagnosis and treatment of pediatric acute liver failure]. / 儿童急性肝衰竭的诊治进展.

Pediatric acute liver failure (PALF) is a rare and rapidly progressive clinical syndrome with a poor prognosis and significant mortality. The etiology of PALF is complex, and it presents with diverse and atypical clinical manifestations. Accurate diagnosis based on age-related factors, early recognition or prevention of hepatic encephalopathy, and precise supportive treatment targeting the underlying cause are crucial for improving outcomes and prognosis. This article provides a comprehensive review of recent research on the diagnosis and treatment of PALF, aiming to offer guidance for clinical practice.

Hypoxia preconditioning of human amniotic mesenchymal stem cells enhances proliferation and migration and promotes their homing via the HGF/C-MET signaling axis to augment the repair of acute liver failure.

BACKGROUND: Transplantation of mesenchymal stem cells (MSCs) is a newly developed strategy for treating acute liver failure (ALF). Nonetheless, the low survival rate of MSCs after transplantation and their poor homing to damaged tissues limit the clinical application of MSCs. The research assessed whether hypoxic preconditioning (HPC) can improve the biological activity of human amniotic mesenchymal stem cells (hA-MSCs), promote their homing ability to the liver of mice with ALF, and influence liver tissue repair. METHODS: Flow cytometry, CCK8, Transwell, and Western blotting assays were conducted to assess the effects of hypoxic preconditioning on the phenotype, proliferation, and migration of hA-MSCs and the changes in the c-Met and CXCR4 gene expression levels were studied. To evaluate the effects of the transplantation of hypoxic preconditioning of hA-MSCs on the homing and repair of D-galactosamine (D-GalN)/LPS-induced ALF, the mechanism was elucidated by adding c-Met, CXCR4-specific blockers (SU11274 and AMD3100). RESULTS: After hypoxia pretreatment (1% oxygen volume fraction), hA-MSCs maintained the morphological characteristics of adherence and vortex colony growth and showed high CD44, CD90, and CD105 and low CD31, CD34, and CD45 expression levels. Hypoxic preconditioning of hA-MSCs significantly increased their proliferation and migration and highly expressed the c-Met and CXCR4 genes. In vivo and in vitro, this migration-promoting effect was suppressed by the c-Met specific blocker SU11274. In the acute liver failure mouse model, the HGF expression level was considerably elevated in the liver than that in the serum, lungs and kidneys. The transplantation of hypoxic preconditioned hA-MSCs introduced a remarkable improvement in the liver function and survival rate of mice with ALF and enhanced the anti-apoptosis ability of liver cells. The anti-apoptotic enhancing effect of hypoxic preconditioning was suppressed by the c-Met specific blocker SU11274. Hypoxic hA-MSCs administration was observed to have considerably increased the fluorescent cells in the liver than that recorded after administering normal oxygen-hA-MSCs. The number of hepatic fluorescent cells decreased remarkably after adding the c-Met inhibitor SU11274, compared to that recorded after hypoxic pretreatment, whereas the effect of c-Met inhibitor SU11274 on normal oxygen-hA-MSCs was not significant. CONCLUSIONS: Hypoxic preconditioning depicted no impact on the morphology and phenotype features of the human amniotic mesenchymal stem cells, but it can promote their proliferation, migration, anti-apoptotic effect, and homing rate and improve the repair of acute liver failure, which might be mediated by the HGF/c-Met signaling axis.

Cryopreserved cGMP-compliant human pluripotent stem cell-derived hepatic progenitors rescue mice from acute liver failure through rapid paracrine effects on liver cells.

BACKGROUND: Liver transplantation remains the only curative treatment for end-stage liver diseases. Unfortunately, there is a drastic organ donor shortage. Hepatocyte transplantation emerged as a viable alternative to liver transplantation. Considering their unique expansion capabilities and their potency to be driven toward a chosen cell fate, pluripotent stem cells are extensively studied as an unlimited cell source of hepatocytes for cell therapy. It has been previously shown that freshly prepared hepatocyte-like cells can cure mice from acute and chronic liver failure and restore liver function. METHODS: Human PSC-derived immature hepatic progenitors (GStemHep) were generated using a new protocol with current good manufacturing practice compliant conditions from PSC amplification and hepatic differentiation to cell cryopreservation. The therapeutic potential of these cryopreserved cells was assessed in two clinically relevant models of acute liver failure, and the mode of action was studied by several analytical methods, including unbiased proteomic analyses. RESULTS: GStemHep cells present an immature hepatic phenotype (alpha-fetoprotein positive, albumin negative), secrete hepatocyte growth factor and do not express major histocompatibility complex. A single dose of thawed GStemHep rescue mice from sudden death caused by acetaminophen and thioacetamide-induced acute liver failure, both in immunodeficient and immunocompetent animals in the absence of immunosuppression. Therapeutic biological effects were observed as soon as 3 h post-cell transplantation with a reduction in serum transaminases and in liver necrosis. The swiftness of the therapeutic effect suggests a paracrine mechanism of action of GStemHep leading to a rapid reduction of inflammation as well as a rapid cytoprotective effect with as a result a proteome reprograming of the host hepatocytes. The mode of action of GStemHep relie on the alleviation of inhibitory factors of liver regeneration, an increase in proliferation-promoting factors and a decrease in liver inflammation. CONCLUSIONS: We generated cryopreserved and current good manufacturing practice-compliant human pluripotent stem cell-derived immature hepatic progenitors that were highly effective in treating acute liver failure through rapid paracrine effects reprogramming endogenous hepatocytes. This is also the first report highlighting that human allogeneic cells could be used as cryopreserved cells and in the absence of immunosuppression for human PSC-based regenerative medicine for acute liver failure.