Etiologies of acute liver failure: location, location, location!

Complications and Long-Term Outcomes in Adult Patients Undergoing Living Donor Liver Transplantation Because of Fulminant Hepatitis

BACKGROUND

The present study investigates the complications that may occur during long-term follow-up in patients aged 18 years and older undergoing living donor liver transplantation (LDLT) in our clinic because of fulminant hepatitis.

METHODS

The study included patients aged 18 years and older with a minimum survival of 6 months who underwent an LDLT between June 2000 and June 2017. The demographic data of the patients were evaluated in terms of late-term complications.

RESULTS

Of the 240 patients who met the study criteria, 8 (3.3%) underwent LDLT for fulminant hepatitis. The indication for transplantation in patients with fulminant hepatitis was cryptogenic liver hepatitis in 4 patients, acute hepatitis B infection in 2 patients, hemochromatosis in 1 patient, and toxic hepatitis in 1 patient. Of the 240 patients, 65 (27%) undergoing LDLT underwent a liver biopsy for suspected rejection because of an elevation in liver function test results during follow-up. Histopathologic scoring was carried out according to the Banff scoring system. A diagnosis of late acute rejection was made in only 1 of the 8 patients (12.5%) who underwent LDLT for fulminant hepatitis.

CONCLUSION

Patients with fulminant hepatitis must be prepared for an LDLT, if available, while waiting for a cadaveric donor. The results of the present study suggest that LDLTs in patients with fulminant hepatitis are safe, and the outcomes are acceptable in terms of survival and complications.

Classification and Epidemiologic Aspects of Acute Liver Failure

Acute liver failure is a rare condition with high short-term morbidity and mortality. The most widely accepted definition is an abnormality in coagulation with any degree of encephalopathy in a patient without cirrhosis and an illness duration of less than 26 weeks. Multiple classifications systems are currently in use to help categorize the condition. This article reviews the most commonly used systems. The epidemiologic aspects of the disease are also reviewed, including incidence, prevalence, demographics, geographic distribution, and racial and cultural factors and are discussed for the various subtypes of acute liver failure.

Liver cell therapy: is this the end of the beginning?

The prevalence of liver diseases is increasing globally. Orthotopic liver transplantation is widely used to treat liver disease upon organ failure. The complexity of this procedure and finite numbers of healthy organ donors have prompted research into alternative therapeutic options to treat liver disease. This includes the transplantation of liver cells to promote regeneration. While successful, the routine supply of good quality human liver cells is limited. Therefore, renewable and scalable sources of these cells are sought. Liver progenitor and pluripotent stem cells offer potential cell sources that could be used clinically. This review discusses recent approaches in liver cell transplantation and requirements to improve the process, with the ultimate goal being efficient organ regeneration. We also discuss the potential off-target effects of cell-based therapies, and the advantages and drawbacks of current pre-clinical animal models used to study organ senescence, repopulation and regeneration.

Right-lobe living-donor liver transplantation in adult patients with acute liver failure

BACKGROUND

Right-lobe living-donor liver transplantation (RLDLT) is an excellent option to reduce donor shortages for adult patients with acute liver failure (ALF). The aim of this study was to evaluate the etiologies and outcomes of 30 consecutive adult patients who underwent emergency RLDLT for ALF.

METHODS

Between January 2007 and September 2011, we examined data from medical records of patients with ALF who underwent RLDLT.

RESULTS

Their mean age was 32.2 ± 13.05 years. The etiologies of ALF were acute hepatitis B (n = 11; 36.6%), hepatitis A (n = 4; 13.3%), drug intoxication (n = 4; 13.3%), pregnancy (n = 2; 6.7%), hepatitis B with pregnancy (n = 1; 3.3%), mushroom intoxication (n = 1; 3.3%), and unknown (n = 7; 23.3%). The mean hepatic coma grade (Model for End-Stage Liver Disease score) was 34.13 ± 8.72. The 43 (48.7%) postoperative complications were minor (grades I-II) and 44 (51.3%) were major (grades III-V). Reoperation was required in 14 of 30 (47%) recipients (grades IIIb-IVa). Deaths occurred owing to pulmonary (n = 2), cardiac (n = 1), septic (n = 2), or encephalopathic (n = 4) complications. The mean durations of intensive care unit stay and postoperative hospitalization were 3.2 ± 2.3 and 29.5 ± 23 days, respectively. The survival rate was 70%. The mean follow-up duration was 305 days (range, 1-1582).

CONCLUSION

Liver transplantation is potentially the only curative modality, markedly improving the prognosis of patients with ALF. The interval between ALF onset and death is short and crucial because of the rapid, progressive multiorgan failure. Thus, RLDLT should be considered to be a life-saving procedure for adult patients with ALF, requiring quicker access to a deceased-donor liver graft and a short ischemia time.

Association of a single-nucleotide polymorphism within the miR-146a gene with susceptibility for acute-on-chronic hepatitis B liver failure

Excessive activation of innate immune response contributes to the pathogenesis of acute-on-chronic hepatitis B liver failure (ACLF-HBV). miR-146a was recently found to be implicated in the regulation of innate immunity. In this study, we explored the biological significance of a single-nucleotide polymorphism (rs2910164) within the miR-146a gene in the risk of acquiring ACLF-HBV. We completed a hospital-based case-control study including 717 cases of HBV-infected patients--251 cases of ACLF-HBV and 466 cases of chronic hepatitis B. Whole blood samples were collected for isolation of DNA and peripheral blood mononuclear cells (PBMCs). The association between genotypes and risk of ACLF-HBV was analyzed by multivariate unconditional logistic regression, with adjustment for sex and age. Our results showed that the GG homozygote was a protective genotype in terms of susceptibility to ACLF-HBV, with odds ratio = 0.496, 95 % confidence interval = 0.309-0.797, P = 0.004 compared with CC+GC genotypes. The amount of mature miR-146a in PBMCs was significantly higher in the GG homozygote group than those in the CC and CG genotype groups of ACLF-HBV patients. The GG genotype group also represented lower serum level of TNF-α and higher survival rate (follow-up period = 4 months). In conclusion, The GG genotype within the pre-miR-146a is reversely associated with susceptibility of ACLF-HBV in the studied Chinese population. This may be partially explained by the relatively higher amount of mature miR-146a and the lower serum level of TNF-α in this genotype group.

Etiologies and outcomes of acute liver failure in a spanish community

Previous retrospective study (1992 to 2000) performed in Spain showed that drug toxicity, viral hepatitis, and indeterminate etiology were the most prevalent causes of acute liver failure (ALF). In the last decade, there is no information about ALF in our country. For these reasons we analyze retrospectively, in a ten-year period (2000 to 2010), the presumed causes, clinical characteristics, course, and outcome of ALF in a Spanish community. Causes of ALF were indeterminate in 4 patients (24%), acute hepatitis B infection in 4 patients (24%), drug or toxic reactions in 4 patients (24%), including one case of acetaminophen overdose, followed by miscellaneous causes. The overall short-term survival (6 weeks after admission) was 65%. Liver transplantation was performed in 11 patients with a survival of 82%. Despite fulfilling criteria, 2 patients were not transplanted because of contraindications; they both died. In summary, acute hepatitis B and indeterminate cause are still being the most frequent causes of ALF in our region, and patients with ALF have an excellent chance of survival after emergency liver transplantation. Acetaminophen overdose still represents a very rare cause of ALF in our community.

Acute liver failure and liver assist devices

Survival of patients presenting with acute liver failure (ALF) has improved over the past decades due to earlier disease recognition, advances in supportive measures, intensive care, and liver transplantation. Liver assist devices may have a role in future care of patients with ALF, bridging them to recovery or to transplantation. A multidisciplinary team approach to the care of patients with ALF is critical for achieving good patient outcomes.

Drugs associated with hepatotoxicity and their reporting frequency of liver adverse events in VigiBase: unified list based on international collaborative work

BACKGROUND

Challenges exist in the clinical diagnosis of drug-induced liver injury (DILI) and in obtaining information on hepatotoxicity in humans.

OBJECTIVE

(i) To develop a unified list that combines drugs incriminated in well vetted or adjudicated DILI cases from many recognized sources and drugs that have been subjected to serious regulatory actions due to hepatotoxicity; and (ii) to supplement the drug list with data on reporting frequencies of liver events in the WHO individual case safety report database (VigiBase).

DATA SOURCES AND EXTRACTION

(i) Drugs identified as causes of DILI at three major DILI registries; (ii) drugs identified as causes of drug-induced acute liver failure (ALF) in six different data sources, including major ALF registries and previously published ALF studies; and (iii) drugs identified as being subjected to serious governmental regulatory actions due to their hepatotoxicity in Europe or the US were collected. The reporting frequency of adverse events was determined using VigiBase, computed as Empirical Bayes Geometric Mean (EBGM) with 90% confidence interval for two customized terms, 'overall liver injury' and 'ALF'. EBGM of >or=2 was considered a disproportional increase in reporting frequency. The identified drugs were then characterized in terms of regional divergence, published case reports, serious regulatory actions, and reporting frequency of 'overall liver injury' and 'ALF' calculated from VigiBase.

DATA SYNTHESIS

After excluding herbs, supplements and alternative medicines, a total of 385 individual drugs were identified; 319 drugs were identified in the three DILI registries, 107 from the six ALF registries (or studies) and 47 drugs that were subjected to suspension or withdrawal in the US or Europe due to their hepatotoxicity. The identified drugs varied significantly between Spain, the US and Sweden. Of the 319 drugs identified in the DILI registries of adjudicated cases, 93.4% were found in published case reports, 1.9% were suspended or withdrawn due to hepatotoxicity and 25.7% were also identified in the ALF registries/studies. In VigiBase, 30.4% of the 319 drugs were associated with disproportionally higher reporting frequency of 'overall liver injury' and 83.1% were associated with at least one reported case of ALF.

CONCLUSIONS

This newly developed list of drugs associated with hepatotoxicity and the multifaceted analysis on hepatotoxicity will aid in causality assessment and clinical diagnosis of DILI and will provide a basis for further characterization of hepatotoxicity.

Emergency adult-to-adult living-donor liver transplantation for acute liver failure in a hepatitis B virus endemic area

The outcomes of patients with acute liver failure (ALF) vary greatly according to etiology. Emergency adult-to-adult living-donor liver transplantation (adult LDLT) would help address the shortage of available organs for patients with ALF, especially in hepatitis B virus (HBV)-endemic areas. We analyzed a prospective database of 110 consecutive adult patients with ALF. ALF was defined as sudden development of severe coagulopathy and encephalopathy within 26 weeks of onset of symptoms. In about 90% of patients, ALF was caused by etiologies that usually result in poor outcomes, including HBV infection (37%). Three cases (3%) were associated with acetaminophen overdose. Of the 99 patients listed for emergency liver transplantation, four (4%) underwent deceased-donor liver transplantation (DDLT), and 40 (40%) underwent adult LDLT. The 1-year survival rate of adult LDLT patients was 85%. Of the 55 patients listed but not transplanted, 45 (82%) died within a median of 7 days (range, 1-90 days). Multivariate analysis showed that adult LDLT (hazard ratio [HR] 0.10, P < 0.01) and DDLT (HR 0.12, P = 0.04) were associated with decreased mortality, whereas older age (HR 1.03, P = 0.01) and higher Model for End-stage Liver Disease (MELD) (HR 1.03, P = 0.04) was associated with increased mortality of patients. There was no living donor mortality. Eight (17.8%) and three (6.7%) living donors experienced grade 1 and 2 complications, respectively.

CONCLUSION

Emergency adult LDLT can be performed expeditiously and safely for patients with ALF, and greatly improves the survival rate. As the window during which transplantation is possible is limited, emergency adult LDLT should be considered one of the first-line treatment options in patients with ALF, especially in regions in which ALFs are caused by etiologies associated with poor outcome and the supply of organs is severely limited.

Liver transplantation for fulminant hepatic failure in infancy: a single center experience

FHF is characterized by a high percentage of unknown causes leading to acute liver failure and furthermore by an increased morbidity and mortality prior to and post-Ltx. In different transplant centers, the reasons leading to FHF differ significantly as well as outcome. We report our single center experience with 30 pediatric patients receiving a liver transplant for FHF, out of a total of 83 children presenting with FHF. The time to transfer patients to the transplant center after the diagnosis of FHF was long, with a median of 14 days (Ltx group) and 12 days (controls), respectively. In nearly half of the patients (n = 14) in the Ltx group, we were not able to establish an exact diagnosis prior to Ltx: 50% suffered from encephalopathy, and 13 patients were treated in the intensive care unit prior to transplant. Because of the availability of different surgical techniques, all children received a timely transplant [split (n = 18), living donor (n = 9), whole organ (n = 2), and reduced liver (n = 1)]. Patient survival was 93.4%, and graft survival was 83.4% for at least one yr follow-up. Severe complications following Ltx included three cases with aplastic anemia and one child suffering from systemic mitochondrial depletion syndrome. The survival of patients treated medically was 83%. We conclude that a strong focus should be made on early referral to a specialized center and on improvement of diagnostic tools to timely detect the underlying reason for FHF. Results following Ltx for FHF are good.

ICU management of acute liver failure

Survival of patients presenting with acute liver failure (ALF) has improved because of earlier disease recognition, better understanding of pathophysiology of various insults leading to ALF, and advances in supportive measures including a team approach, better ICU care, and liver transplantation. This article focuses on patient management and evaluation that takes place in the ICU for patients who have acute liver injury. An organized team approach to decision making about critical care delivered during this period of time is important for achieving a good patient outcome.

Transport advances in disposable bioreactors for liver tissue engineering

Acute liver failure (ALF) is a devastating diagnosis with an overall survival of approximately 60%. Liver transplantation is the therapy of choice for ALF patients but is limited by the scarce availability of donor organs. The prognosis of ALF patients may improve if essential liver functions are restored during liver failure by means of auxiliary methods because liver tissue has the capability to regenerate and heal. Bioartificial liver (BAL) approaches use liver tissue or cells to provide ALF patients with liver-specific metabolism and synthesis products necessary to relieve some of the symptoms and to promote liver tissue regeneration. The most promising BAL treatments are based on the culture of tissue engineered (TE) liver constructs, with mature liver cells or cells that may differentiate into hepatocytes to perform liver-specific functions, in disposable continuous-flow bioreactors. In fact, adult hepatocytes perform all essential liver functions. Clinical evaluations of the proposed BALs show that they are safe but have not clearly proven the efficacy of treatment as compared to standard supportive treatments. Ambiguous clinical results, the time loss of cellular activity during treatment, and the presence of a necrotic core in the cell compartment of many bioreactors suggest that improvement of transport of nutrients, and metabolic wastes and products to or from the cells in the bioreactor is critical for the development of therapeutically effective BALs. In this chapter, advanced strategies that have been proposed over to improve mass transport in the bioreactors at the core of a BAL for the treatment of ALF patients are reviewed.

Etiologies of acute liver failure

PURPOSE OF REVIEW

Acute liver failure remains a unique syndrome that results from massive loss of hepatocytes or hepatocyte function due to a variety of etiologies: viruses, drugs, toxins and other genetic and autoimmune conditions. The resulting clinical picture is remarkably similar across the different etiologies, reflecting common patterns of response of the innate immune system and the resulting inflammatory response. This review highlights developments in the delineation of etiologies of this relatively rare condition.

RECENT FINDINGS

The contribution of different etiologies to the overall picture varies by country. Europe and North America demonstrate a large proportion of cases due to acetaminophen and to idiosyncratic drug reactions, whereas reports from emerging countries in Asia and Africa are more likely to feature viral illnesses, particularly hepatitis B and E. Recent studies have suggested ever more exotic etiologies, new drugs and viruses.

SUMMARY

A careful search for the cause of acute liver failure in each case is of value in determining whether there are specific antidotes available and what the prognosis might be.