Epidemiology of acute liver failure

Interplay Between Inflammatory-immune and Interleukin-17 Signalings Plays a Cardinal Role on Liver Ischemia-reperfusion Injury-Synergic Effect of IL-17Ab, Tacrolimus and ADMSCs on Rescuing the Liver Damage

BACKGROUND

This study tested the hypothesis that inflammatory and interleukin (IL)-17 signalings were essential for acute liver ischemia (1 h)-reperfusion (72 h) injury (IRI) that was effectively ameliorated by adipose-derived mesenchymal stem cells (ADMSCs) and tacrolimus.

METHODS

Adult-male SD rats (n = 50) were equally categorized into groups 1 (sham-operated-control), 2 (IRI), 3 [IRI + IL-17-monoclonic antibody (Ab)], 4 (IRI + tacrolimus), 5 (IRI + ADMSCs) and 6 (IRI + tacrolimus-ADMSCs) and liver was harvested at 72 h.

RESULTS

The main findings included: (1) circulatory levels: inflammatory cells, immune cells, and proinflammatory cytokines as well as liver-damage enzyme at the time point of 72 h were highest in group 2, lowest in group 1 and significantly lower in group 6 than in groups 3 to 5 (all p < 0.0001), but they did not differ among these three latter groups; (2) histopathology: the liver injury score, fibrosis, inflammatory and immune cell infiltration in liver immunity displayed an identical pattern of inflammatory cells among the groups (all p < 0.0001); and (3) protein levels: upstream and downstream inflammatory signalings, oxidative-stress, apoptotic and mitochondrial-damaged biomarkers exhibited an identical pattern of inflammatory cells among the groups (all p < 0.0001).

CONCLUSION

Our results obtained from circulatory, pathology and molecular-cellular levels delineated that acute IRI was an intricate syndrome that elicited complex upstream and downstream inflammatory and immune signalings to damage liver parenchyma that greatly suppressed by combined tacrolimus and ADMSCs therapy.

Liver Transplantation for Acute Liver Failure- Indication, Prioritization, Timing, and Referral

Acute liver failure (ALF) is a major success story in gastroenterology, with improvements in critical care and liver transplant resulting in significant improvements in patient outcomes in the current era compared to the dismal survival rates in the pretransplant era. However, the ever-increasing list of transplant candidates and limited organ pool makes judicious patient selection and organ use mandatory to achieve good patient outcomes and prevent organ wastage. Several scoring systems exist to facilitate the identification of patients who need a liver transplant and would therefore need an early referral to a specialized liver unit. The timing of the liver transplant is also crucial as transplanting a patient too early would lead to those who would recover spontaneously receiving an organ (wastage), and a late decision might result in the patient becoming unfit for transplant (delisted) or have an advanced disease which would result in poor post-transplant outcomes. The current article reviews the indications and contraindications of liver transplant in ALF patients, the various prognostic scoring systems, etiology-specific outcomes, prioritization and timing of referral.

Extracorporeal blood purification in patients with liver failure: Considerations for the low-and-middle income countries of Latin America

Severe liver failure is common in Low-and-Medium Income Countries (LMIC) and is associated with a high morbidity, mortality and represents an important burden to the healthcare system. In its most severe state, liver failure is a medical emergency, that requires supportive care until either the liver recovers or a liver transplant is performed. Frequently the patient requires intensive support until their liver recovers or they receive a liver transplant. Extracorporeal blood purification techniques can be employed as a strategy for bridging to transplantation or recovery. The most common type of extracorporeal support provided to these patients is kidney replacement therapy (KRT), as acute kidney injury is very common in these patients and KRT devices more readily available. However, because most of the substances that the liver clears are lipophilic and albumin-bound, they are not cleared effectively by KRT. Hence, there has been much effort in developing devices that more closely resemble the clearance function of the liver. This article provides a review of various non-biologic extracorporeal liver support devices that can be used to support these patients, and our perspective keeping in mind the needs and unique challenges present in the LMIC of Latin America.

Model of Acute Liver Failure in an Isolated Perfused Porcine Liver-Challenges and Lessons Learned

Acute liver failure (ALF) is a rare but devastating disease associated with substantial morbidity and a mortality rate of almost 45%. Medical treatments, apart from supportive care, are limited and liver transplantation may be the only rescue option. Large animal models, which most closely represent human disease, can be logistically and technically cumbersome, expensive and pose ethical challenges. The development of isolated organ perfusion technologies, originally intended for preservation before transplantation, offers a new platform for experimental models of liver disease, such as ALF. In this study, female domestic swine underwent hepatectomy, followed by perfusion of the isolated liver on a normothermic machine perfusion device. Five control livers were perfused for 24 h at 37 °C, while receiving supplemental oxygen and nutrition. Six livers received toxic doses of acetaminophen given over 12 h, titrated to methemoglobin levels. Perfusate was sampled every 4 h for measurement of biochemical markers of injury (e.g., aspartate aminotransferase [AST], alanine aminotransferase [ALT]). Liver biopsies were taken at the beginning, middle, and end of perfusion for histological assessment. Acetaminophen-treated livers received a median dose of 8.93 g (8.21–9.75 g) of acetaminophen, achieving a peak acetaminophen level of 3780 µmol/L (3189–3913 µmol/L). Peak values of ALT (76 vs. 105 U/L; p = 0.429) and AST (3576 vs. 4712 U/L; p = 0.429) were not significantly different between groups. However, by the end of perfusion, histology scores were significantly worse in the acetaminophen treated group (p = 0.016). All acetaminophen treated livers developed significant methemoglobinemia, with a peak methemoglobin level of 19.3%, compared to 2.0% for control livers (p = 0.004). The development of a model of ALF in the ex vivo setting was confounded by the development of toxic methemoglobinemia. Further attempts using alternative agents or dosing strategies may be warranted to explore this setting as a model of liver disease.

The molecular mechanism of acute liver injury and inflammatory response induced by Concanavalin A

Acute liver injury is a common but urgent clinical condition, and its underlying mechanism remains to be further elucidated. Concanavalin A (ConA)-induced liver injury was investigated in the study. Different from the caspase-dependent cell apoptosis in lipopolysaccharide/D-aminogalactose (LPS/D-GalN) induced liver injury, ConA-induced hepatocyte death was independent on caspase. Increased hepatocytic expressions of mixed lineage kinase domain like (MLKL) and receptor-interacting protein kinase 1 (RIPK1), and higher serum concentration of tumor necrosis factor-α (TNF-α) were noticed in mice with ConA-induced liver injury. Inhibition of RIPK1 protein or deletion of MLKL gene could significantly attenuate the acute liver injury and improve mice survival. Besides, the ConA treatment induced severe hepatic inflammation in wide type (WT) mice in comparison with Mlkl-/- mice, suggesting the RIPK1-MLKL-mediated hepatocellular necroptosis might participate in the process of liver injury. Moreover, mitochondrial damage associated molecular patterns (DAMPs) were subsequently released after the hepatocyte death, and further activated the p38 mitogen-activated protein kinase (MAPK) pathway, which could be reduced by deletion or inhibition of Toll-like receptor 9 (TLR9). Taken together, our research revealed that ConA-induced acute liver injury was closely related to TNF-α-mediated cell necroptosis, and inhibiting RIPK1 or deleting MLKL gene could alleviate liver injury in mice. The mitochondrial DNA released by dead hepatocytes further activated neutrophils through TLR9, thus resulting in the exacerbation of liver injury.

Downregulation of augmenter of liver regeneration impairs the therapeutic efficacy of liver epithelial progenitor cells against acute liver injury by enhancing mitochondrial fission

Cell-based therapeutic approaches have been proven to be effective strategies for the treatment of acute liver injury (ALI). However, widespread application of these procedures is limited by several key issues, including rapid loss of stemness in vitro, aberrant differentiation into undesirable cell types, and low engraftment in vivo. In this study, liver epithelial progenitor cells (LEPCs) were characterized and transfected with augmenter of liver regeneration (ALR). The results revealed that in ALI mice with CCl₄ , the transplantation of ALR-bearing LEPCs into the liver markedly protected mice against ALI by decreasing the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), thus relieving hepatic tissue injury and attenuating inflammatory infiltration. Mechanistically, the knockdown of ALR in LEPCs activated the phosphorylation of dynamin-related protein 1 (Drp1) at the S616 site and thereby enhanced mitochondrial fission. In contrast, the transfection of ALR into LEPCs significantly inhibited Drp1 phosphorylation, thereby favoring the maintenance of mitochondrial integrity and the preservation of adenosine triphosphate contents in LEPCs. Consequently, the ALR-bearing LEPCs transplanted into ALI mice exhibited substantially greater homing ability to the injured liver via the SDF-1/CXCR4 axis than that of LEPCs-lacking ALR. In conclusion, we demonstrated that the transplantation of ALR-transfected LEPCs protected mice against CCl₄ -induced ALI, thus offering immense curative potential in the clinic.

Administration of glycyrrhetinic acid reinforces therapeutic effects of mesenchymal stem cell-derived exosome against acute liver ischemia-reperfusion injury

Recent studies have shown that mesenchymal stem cell‐derived exosome could attenuate ischaemia‐reperfusion (I/R) injury by suppressing inflammatory response in the liver. Glycyrrhetinic acid was also shown to be capable of repressing the TLR4 signalling pathway. However, it remains to be explored as whether the combined administration of mesenchyma stem cell (MSC)‐derived exosome and glycyrrhetinic acid (GA) could increase their therapeutic effects on I/R injury. Western blot was performed to evaluate the expression of proteins associated with inflammatory response in THP‐1 cells and I/R rat models treated under different conditions. Flow cytometry was carried out to analyse the proportions of different subtypes of peripheral blood cells in I/R rats. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured to assess the liver injury in I/R rats. Combined treatment with MSC‐derived exosome and GA effectively maintained the expression of key proteins involved in inflammatory response in LPS stimulated THP‐1 cells and THP‐1 cells treated under hypoxia conditions. In the established of I/R rat models, GA administration reinforced the therapeutic efficiency of MSC‐derived exosomes by maintaining the proportion of different subgroups of peripheral blood cells, decreasing the concentration of ALT and AST, and restoring the expression of dysregulated proteins associated with inflammation. Our results demonstrated that treatment with exosomes derived from mesenchymal stem cells (MSCs) attenuated liver I/R injury, while the pre‐treatment with GA may further promote the therapeutic effect of mesenchymal stem cell‐derived exosome against acute liver ischaemia‐reperfusion injury.

Hepatic 31 P-magnetic resonance spectroscopy identified the impact of melatonin-pretreated mitochondria in acute liver ischaemia-reperfusion injury

Acute liver ischaemia-reperfusion injury (IRI), commonly encountered during liver resection and transplantation surgery, is strongly associated with unfavourable clinical outcome. However, a prompt and accurate diagnosis and the treatment of this entity remain formidable challenges. This study tested the hypothesis that ³¹ P-magnetic resonance spectroscopy (³¹ P-MRS) findings could provide reliable living images to accurately identify the degree of acute liver IRI and melatonin-pretreated mitochondria was an innovative treatment for protecting the liver from IRI in rat. Adult male SD rats were categorized into group 1 (sham-operated control), group 2 (IRI only) and group 3 (IRI + melatonin [ie mitochondrial donor rat received intraperitoneal administration of melatonin] pretreated mitochondria [10 mg/per rat by portal vein]). By the end of study period at 72 hours, ³¹ P-MRS showed that, as compared with group 1, the hepatic levels of ATP and NADH were significantly lower in group 2 than in groups 1 and 3, and significantly lower in group 3 than in group 1. The liver protein expressions of mitochondrial-electron-transport-chain complexes and mitochondrial integrity exhibited an identical pattern to ³¹ P-MRS finding. The protein expressions of oxidative stress, inflammatory, cellular stress signalling and mitochondrial-damaged biomarkers displayed an opposite finding of ³¹ P-MRS, whereas the protein expressions of antioxidants were significantly progressively increased from groups 1 to 3. Microscopic findings showed that the fibrotic area/liver injury score and inflammatory and DNA-damaged biomarkers exhibited an identical pattern of cellular stress signalling. Melatonin-pretreated mitochondria effectively protected liver against IRI and ³¹ P-MRS was a reliable tool for measuring the mitochondrial/ATP consumption in living animals.

Abdominal Compartment Syndrome After Liver Transplant in Drug-Induced Acute Liver Failure: A Case Report

The incidence of drug-induced acute liver failure (ALF) has been increasing in recent years. Despite the complex intensive treatment, liver transplant should be performed in progressive cases. A systemic inflammatory response syndrome and the burden of surgical intervention promote abdominal compartment syndrome (ACS); observed preoperatively, they are significant negative prognostic factors. THE CASE: We demonstrate a young woman with liver transplant after ALF and a consecutive ACS. We presumed drug toxicity in the background of the rapidly progressive ALF, based on the preoperative hematologic examination and the histology of the removed liver. An ACS has occurred in the postoperative period that must have been resolved with mesh, and later, anatomic segment 2-3 resection had to be performed to further decrease the pressure. The patient left the hospital after 62 days with good graft function. DISCUSSION: A complex intensive care is mandatory in the case of orthotopic liver transplant for ALF. Outcomes are good after orthotopic liver transplant. An ACS might occur after surgery. In these rare cases a delayed abdominal closure or even a liver resection can be the only solution and sometimes an urgent need to resolve the life-threatening problem.

Acute liver failure: A review for emergency physicians

INTRODUCTION

Acute liver failure (ALF) remains a high-risk clinical presentation, and many patients require emergency department (ED) management for complications and stabilization.

OBJECTIVE

This narrative review provides an evidence-based summary of the current data for the emergency medicine evaluation and management of ALF.

DISCUSSION

While ALF remains a rare clinical presentation, surveillance data suggest an overall incidence between 1 and 6 cases per million people every year, accounting for 6% of liver-related deaths and 7% of orthotopic liver transplants (OLT) in the U.S. The definition of ALF includes neurologic dysfunction, an international normalized ratio ≥ 1.5, no prior evidence of liver disease, and a disease course of ≤26 weeks, and can be further divided into hyperacute, acute, and subacute presentations. There are many underlying etiologies, including acetaminophen toxicity, drug induced liver injury, and hepatitis. Emergency physicians will be faced with several complications, including encephalopathy, coagulopathy, infectious processes, renal injury, and hemodynamic instability. Critical patients should be evaluated in the resuscitation bay, and consultation with the transplant team for appropriate patients improves patient outcomes. This review provides several guiding principles for management of acute complications. Using a pathophysiological-guided approach to the management of ALF associated complications is essential to optimizing patient care.

CONCLUSIONS

ALF remains a rare clinical presentation, but has significant morbidity and mortality. Physicians must rapidly diagnose these patients while evaluating for other diseases and complications. Early consultation with a transplantation center is imperative, as is identifying the underlying etiology and initiating symptomatic care.

Liver maximum capacity (LiMAx) test as a helpful prognostic tool in acute liver failure with sepsis: a case report

Background

Acute liver failure (ALF) is a life-threatening entity particularly when infectious complications worsen the clinical course. Urgent liver transplantation (LT) is frequently the only curative treatment. However, in some cases, recovery is observed under conservative treatment. Therefore, prognostic tools for estimating course of the disease are of great clinical interest. Since laboratory parameters sometimes lack sensitivity and specificity, enzymatic liver function measured by liver maximum capacity (LiMAx) test may offer novel and valuable additional information in this setting.

Case presentation

We here report the case of a formerly healthy 20-year old male caucasian patient who was admitted to our clinic for ALF of unknown origin in December 2017. Laboratory parameters confirmed the diagnosis with an initial MELD score of 28 points. Likewise, enzymatic liver function was significantly impaired with a value of 147 [> 315] μg/h/kg. Clinical and biochemical analyses for viral-, autoimmune-, or drug-induced hepatitis were negative. Liver synthesis parameters further deteriorated reaching a MELD score of 40 points whilst clinical course was complicated by septic pneumonia leading to severe hepatic encephalopathy grade III-IV, finally resulting in mechanical ventilation of the patient. Interestingly, although clinical course and laboratory data suggested poor outcome, serial LiMAx test revealed improvement of the enzymatic liver function at this time point increasing to 169 μg/h/kg. Clinical condition and laboratory data slowly improved likewise, however with significant time delay of 11 days. Finally, the patient could be dismissed from our clinic after 37 days.

Conclusion

Estimating prognosis in patients with ALF is challenging by use of the established scores. In our case, improvement of enzymatic liver function measured by the LiMAx test was the first parameter predicting beneficial outcome in a patient with ALF complicated by sepsis.

The Clinical Spectrum and Manifestations of Acute Liver Failure

Acute liver failure (ALF) is a rare life-threatening condition characterized by rapid progression and death. Causes vary according to geographic region, with acetaminophen and drug-induced ALF being the most common causes in the United States. Determining the cause aids in predicting the prognosis and the presentation of manifestations and guides providers to perform cause-specific management. At initial presentation, nonspecific symptoms are present but may progress to complications, including cerebral edema, infection, coagulopathy, renal failure, cardiopulmonary failure, and acid-base and/or metabolic disturbances. Although some cases of ALF resolve with conservative measures, liver transplantation is the ultimate treatment in many cases.

Pre- vs. post-treatment with melatonin in CCl4-induced liver damage: Oxidative stress inferred from biochemical and pathohistological studies

AIMS

The present study was designed to compare the ameliorating potential of pre- and post-treatments with melatonin, a potent natural antioxidant, in the carbon tetrachloride-induced rat liver damage model by tracking changes in enzymatic and non-enzymatic liver tissue defense parameters, as well as in the occurring pathohistological changes.

MAIN METHODS

Rats from two experimental groups were treated with melatonin before and after CCl₄ administration, while the controls, negative and positive, received vehicle/melatonin and CCl₄, respectively. Serum levels of transaminases, alkaline phosphates, γ-GT, bilirubin, and albumin, as well as a wide panel of oxidative stress-related parameters in liver tissue, were determined in all experimental animals. Liver tissue specimens were stained with hematoxylin and eosin and further evaluated for morphological changes.

KEY FINDINGS

Both pre- and post-treatment with melatonin prevented a CCl₄-induced increase in serum (ALT, AST, and γ-GT) and tissue (MDA and XO) liver damage markers and a decrease in the tissue total antioxidant capacity, in both enzymatic and non-enzymatic systems. The intensity of pathological changes, hepatocyte vacuolar degeneration, necrosis and inflammatory cell infiltration, was suppressed by the treatment with melatonin.

SIGNIFICANCE

In conclusion, melatonin, especially as a post-intoxication treatment, attenuated CCl₄-induced liver oxidative damage, increased liver antioxidant capacities and improved liver microscopic appearance. The results are of interest due to the great protective potential of melatonin that was even demonstrated to be stronger if applied after the tissue damage.

Mortality Analysis of Acute Liver Failure in Uruguay

BACKGROUND

Acute liver failure (ALF) is a syndrome with high mortality.

OBJECTIVE

Describe characteristics and outcomes of patients with ALF in Uruguay, and identify factors associated with mortality.

METHODS

A retrospective analysis of 33 patients with ALF was performed between 2009 and 2017.

RESULTS

The patients' median age was 43 years, and 64% were women. Average Model for End-Stage Liver Disease (MELD) score at admission was 33. The median referral time to the liver transplant (LT) center was 7 days. The most common etiologies were viral hepatitis (27%), indeterminate (21%), autoimmune (18%), and Wilson disease (15%). Overall mortality was 52% (71% of transplanted and 46% of nontransplanted patients). Dead patients had higher referral time (10 vs 4 days, P = .008), higher MELD scores at admission (37 vs 28) and highest achieved MELD scores (42 vs 29; P < .001), and higher encephalopathy grade III to IV (94% vs 25%, P < .001) than survivors. Patients without LT criteria (n = 4) had lower MELD score at admission (25 vs 34, P = .001) and highest achieved MELD score (27 vs 37, P = .008) compared with the others. Patients with LT criteria but contraindications (n = 7) had higher MELD scores at admission (38 vs 31, P = .02), highest achieved MELD scores (41 vs 34, P = .03), and longer referral time (10 days) than those without contraindications (3.5 days) or those without LT criteria (7.5 days, P = .02). Twenty-two patients were listed; LT was performed in 7, with a median time on waiting list of 6 days.

CONCLUSIONS

ALF in Uruguay has high mortality associated with delayed referral to the LT center, MELD score, and encephalopathy. The long waiting times to transplantation might influence mortality.

Methane Medicine: A Rising Star Gas with Powerful Anti-Inflammation, Antioxidant, and Antiapoptosis Properties

Methane, the simplest organic compound, was deemed to have little physiological action for decades. However, recently, many basic studies have discovered that methane has several important biological effects that can protect cells and organs from inflammation, oxidant, and apoptosis. Heretofore, there are two delivery methods that have been applied to researches and have been proved to be feasible, including the inhalation of methane gas and injection with the methane-rich saline. This review studies on the clinical development of methane and discusses about the mechanism behind these protective effects. As a new field in gas medicine, this study also comes up with some problems and prospects on methane and further studies.

Indoline derivatives mitigate liver damage in a mouse model of acute liver injury

BACKGROUND

Exposure of mice to D-galactosamine (GalN) and lipopolysaccharide (LPS) induces acute liver failure through elevation of TNF-α, which causes liver damage resembling that in humans. The current study evaluated in this model the effect of two indoline derivatives, which have anti-inflammatory activity in macrophages.

METHODS

AN1297 and AN1284 (0.025-0.75mg/kg) or dexamethasone (3mg/kg), were injected subcutaneously, 15min before intraperitoneal injection of GalN (800mg) plus LPS (50μg) in male Balb/C mice. After 6h, their livers were evaluated histologically by staining with hematoxylin and eosin for tissue damage and by cleaved caspase 3 for apoptosis. Activity of liver enzymes, alanine transaminase (ALT) and aspartate aminotransferase (AST) and levels of TNF-α and IL-6 were measured in plasma, and those of TNF-α and IL-6, in the liver.

RESULTS

AN1297 (0.075-0.75mg/kg) and AN1284 (0.25-0.75mg/kg) maximally reduced ALT by 51% and 80%, respectively. Only AN1284 (0.25 and 0.75mg/kg) reduced AST by 41% and 48%. AN1297 and AN1284 (0.25mg/kg) decreased activation of caspase 3 (a sign of apoptosis) by 80% and plasma TNF-α by 75%. AN1297 and AN1284 (0.075mg/kg) prevented the rise in TNF-α and IL-6 in the liver. AN1284 (0.25mg/kg) reduced mortality from 90% to 20% (p<0.01) and AN1297, to 60% (p=0.121). Both indoline derivatives inhibited the phosphorylation of MAPK p38 and DNA binding of the transcription factor, AP-1.

CONCLUSION

While both compounds are highly potent anti-inflammatory agents, AN1284 is more effective in mitigating the underlying causes of GalN/LPS-induced acute liver failure in mice.

[Prescription of acetaminophen in five French hospitals: What are the practices?]

AIM

Acetaminophen is widely used in hospital settings and often considered as nontoxic. We conducted a multicentric study in order to evaluate its proper use.

METHOD

Prescriptions from five general hospitals were analyzed, according to dose adjustments required in renal or liver failure, weight or chronic alcoholism, determined using a literature review. Other criteria have been assessed: indication for parenteral access, accuracy of administration time and pain assessment.

RESULTS

Among the 1256 analyzed prescriptions, 21% are non-compliants. The main causes of non-compliance (NC) are adjustments to weight and renal failure. Higher NC rates concern chronic alcoholism and liver failure.

CONCLUSION

Misuse of acetaminophen seems related to a lack of official recommendations concerning dose adjustments. Hospital pharmacists have an important role to play in the promotion of proper use of acetaminophen. Therefore we established a prescribing aid.

Antioxidant and Hepatoprotective Efficiency of Selenium Nanoparticles Against Acetaminophen-Induced Hepatic Damage

Overdoses of acetaminophen (APAP), a famous and widely used drug, may have hepatotoxic effects. Nanoscience is a novel scientific discipline that provides specific tools for medical science problems including using nano trace elements in hepatic diseases. Our study aimed to assess the hepatoprotective role of selenium nanoparticles (Nano-Se) against APAP-induced hepatic injury. Twenty-four male rats were classified into three equal groups: a control group that received 0.9 % NaCl, an APAP-treated group (oral administration), and a group treated with Nano-Se (10-20 nm, intraperitoneal (i.p.) injection) and APAP (oral administration). APAP overdose induced significant elevations in liver function biomarkers, hepatic lipid peroxidation, hepatic catalase, and superoxide dismutase (SOD), decreased the reduced glutathione (GSH) content and glutathione reductase (GR) activity, and stimulated significant DNA damage in hepatocytes, compared to control rats. Nano-Se administration improved the hepatic antioxidant protection mechanism and decreased cellular sensitivity to DNA fragmentation. Nano-Se exhibits a protective effect against APAP-induced hepatotoxicity through improved liver function and oxidative stress mediated by catalase, SOD, and GSH and decreases hepatic DNA fragmentation, a hepatic biomarker of cell death. Nano-Se could be a novel hepatoprotective strategy to inhibit oxidative stress.

The Diagnosis and Manifestations of Liver Injury Secondary to Off-Label Androgenic Anabolic Steroid Use

Drug-induced liver injury (DILI) presents as a broad spectrum of adverse drug reactions which can range from a mild elevation in liver enzymes to fulminant liver failure. The primary goal is to identify DILI early when the patient's liver enzymes are elevated and to discontinue the offending agent as soon as possible to prevent further injury. Herbal, dietary supplements and anabolic steroids represent a significant component of the drugs thought to cause DILI in the United States. Unlike all other drugs known to cause DILI, these drugs fall into a category of injury that is neither intrinsic nor idiosyncratic due to overlapping characteristics between the two. Here, we present a case of the off-label use of androgenic anabolic steroids inducing liver injury. A combination of clinical, laboratory, and histologic workup eventually led to the diagnosis of DILI. This can be a diagnostic challenge for practitioners. The American College of Gastroenterology (ACG) published guidelines to aid the clinician in diagnosing DILI. Proving that an episode of liver injury is caused by a drug is difficult in many cases as it requires the exclusion of alternative etiologies. Some of the variables include temporal association, clinical-biochemical features, type of injury (hepatocellular and/or cholestatic), extrahepatic features, and the likelihood that a given agent is the culprit based on its known manifestations with prior cases. This case illustrates the utility of the diagnostic tools used for DILI as recommended by the ACG, along with a supplemental histopathologic diagnosis.

Mincle Signaling Promotes Con A Hepatitis

Con A hepatitis is regarded as a T cell-mediated model of acute liver injury. Mincle is a C-type lectin receptor that is critical in the immune response to mycobacteria and fungi but does not have a well-defined role in preclinical models of non-pathogen-mediated inflammation. Because Mincle can ligate the cell death ligand SAP130, we postulated that Mincle signaling drives intrahepatic inflammation and liver injury in Con A hepatitis. Acute liver injury was assessed in the murine Con A hepatitis model using C57BL/6, Mincle(-/-), and Dectin-1(-/-) mice. The role of C/EBPβ and hypoxia-inducible factor-1α (HIF-1α) signaling was assessed using selective inhibitors. We found that Mincle was highly expressed in hepatic innate inflammatory cells and endothelial cells in both mice and humans. Furthermore, sterile Mincle ligands and Mincle signaling intermediates were increased in the murine liver in Con A hepatitis. Most significantly, Mincle deletion or blockade protected against Con A hepatitis, whereas Mincle ligation exacerbated disease. Bone marrow chimeric and adoptive transfer experiments suggested that Mincle signaling in infiltrating myeloid cells dictates disease phenotype. Conversely, signaling via other C-type lectin receptors did not alter disease course. Mechanistically, we found that Mincle blockade decreased the NF-κβ-related signaling intermediates C/EBPβ and HIF-1α, both of which are necessary in macrophage-mediated inflammatory responses. Accordingly, Mincle deletion lowered production of nitrites in Con A hepatitis and inhibition of both C/EBPβ and HIF-1α reduced the severity of liver disease. Our work implicates a novel innate immune driver of Con A hepatitis and, more broadly, suggests a potential role for Mincle in diseases governed by sterile inflammation.

Hepatic Failure

The progression of liver disease can cause several physiologic derangements that may precipitate hepatic failure and require admission to an intensive care unit. The underlying pathology may be acute, acute-on chronic, or chronic in nature. Liver failure may manifest with a variety of clinical signs and symptoms that need prompt attention. The compromised synthetic and metabolic activity of the failing liver affects all organ systems, from neurologic to integumentary. Supportive care and specific therapies should be instituted in order to improve outcome and minimize time of recovery.

In this chapter we will discuss the definition, clinical manifestations, workup, and management of acute and chronic liver failure and the general principles of treatment of these patients. Management of liver failure secondary to certain common etiologies will also be presented. Finally, liver transplantation and alternative therapies will also be discussed.

Cardiohepatic syndrome

Accumulating evidence shows that acute as well as chronic heart disease can directly contribute to an acute or chronic worsening of liver function and vice versa. Description and definition of cardiohepatic syndrome (CHS) in this review are based on the cardiorenal syndrome (CRS) concept. The eye-catching analogy between CHS and CRS is applied to facilitate an understanding of the pathophysiology and overall burden of disease for each of the proposed CHS subtypes, their natural course, and associated morbidity and mortality.

Acute liver failure and liver transplantation in a patient with multiple sclerosis treated with interferon beta

In the treatment of multiple sclerosis (MS), interferon beta (IFNβ) applies. It rarely can lead to acute liver failure (ALF). A 42-year-old female with MS was admitted to the Department because of jaundice, general weakness, drowsiness and nausea. Four weeks earlier, she had started therapy with IFNβ-1a. Liver tests made prior to initiation of IFNβ-1a were normal but on admission to the Department exceed several times the upper limit. ALF was recognized and IFNβ-1a was immediately stopped. In the fourth day of hospitalization, symptoms of hepatic encephalopathy have progressed. The patient was transferred to the Department of Transplantation, where hepatic coma developed and three days later the orthotopic liver transplantation was performed. In histopathological picture of the removed liver extensive necrosis and fibrosis dominated. Immunosuppressive therapy consisted of tacrolimus, mycophenolate mofetil and tapering prednisone. Within five years after surgery, there was no recurrence of symptoms of MS and the transplanted organ is functioning properly. ALF is a rare complication of IFNβ therapy but it can occur. The appearance of symptoms suggestive of liver injury should prompt extension of diagnosis and, if necessary, discontinuation of therapy.

A Cytochrome P450-Independent Mechanism of Acetaminophen-Induced Injury in Cultured Mouse Hepatocytes

Mouse hepatic parenchymal cells (HPCs) have become the most frequently used in vitro model to study mechanisms of acetaminophen (APAP)-induced hepatotoxicity. It is universally accepted that APAP hepatocellular injury requires bioactivation by cytochromes P450 (P450s), but this remains unproven in primary mouse HPCs in vitro, especially over the wide range of concentrations that have been employed in published reports. The aim of this work was to test the hypothesis that APAP-induced hepatocellular death in vitro depends solely on P450s. We evaluated APAP cytotoxicity and APAP-protein adducts (a biomarker of metabolic bioactivation by P450) using primary mouse HPCs in the presence and absence of a broad-spectrum inhibitor of P450s, 1-aminobenzotriazole (1-ABT). 1-ABT abolished formation of APAP-protein adducts at all concentrations of APAP (0-14 mM), but eliminated cytotoxicity only at small concentrations (≦5 mM), indicating the presence of a P450-independent mechanism at larger APAP concentrations. P450-independent cell death was delayed in onset relative to toxicity observed at smaller concentrations. p-Aminophenol was detected in primary mouse HPCs exposed to large concentrations of APAP, and a deacetylase inhibitor [bis (4-nitrophenyl) phosphate (BNPP)] significantly reduced cytotoxicity. In conclusion, APAP hepatocellular injury in vitro occurs by at least two mechanisms, a P450-dependent mechanism that operates at concentrations of APAP ≦ 5 mM and a P450-independent mechanism that predominates at larger concentrations and is slower in onset. p-Aminophenol most likely contributes to the latter mechanism. These findings should be considered in interpreting results from APAP cytotoxicity studies in vitro and in selecting APAP concentrations for use in such studies.

Platelets and protease-activated receptor-4 contribute to acetaminophen-induced liver injury in mice

Acetaminophen (APAP)-induced liver injury in humans is associated with robust coagulation cascade activation and thrombocytopenia. However, it is not known whether coagulation-driven platelet activation participates in APAP hepatotoxicity. Here, we found that APAP overdose in mice caused liver damage accompanied by significant thrombocytopenia and accumulation of platelets in the liver. These changes were attenuated by administration of the direct thrombin inhibitor lepirudin. Platelet depletion with an anti-CD41 antibody also significantly reduced APAP-mediated liver injury and thrombin generation, indicated by the concentration of thrombin-antithrombin (TAT) complexes in plasma. Compared with APAP-treated wild-type mice, biomarkers of hepatocellular and endothelial damage, plasma TAT concentration, and hepatic platelet accumulation were reduced in mice lacking protease-activated receptor (PAR)-4, which mediates thrombin signaling in mouse platelets. However, selective hematopoietic cell PAR-4 deficiency did not affect APAP-induced liver injury or plasma TAT levels. These results suggest that interconnections between coagulation and hepatic platelet accumulation promote APAP-induced liver injury, independent of platelet PAR-4 signaling. Moreover, the results highlight a potential contribution of nonhematopoietic cell PAR-4 signaling to APAP hepatotoxicity.

Sphingolipids in liver injury, repair and regeneration

Sphingolipids are not only essential components of cellular membranes but also function as intracellular and extracellular mediators that regulate important physiological cellular processes including cell survival, proliferation, apoptosis, differentiation, migration and immune responses. The liver possesses the unique ability to regenerate after injury in a complex manner that involves numerous mediators, including sphingolipids such as ceramide and sphingosine 1-phosphate. Here we present the current understanding of the involvement of the sphingolipid pathway and the role this pathway plays in regulating liver injury, repair and regeneration. The regulation of sphingolipids and their enzymes may have a great impact in the development of novel therapeutic modalities for a variety of liver injuries and diseases.

Protective effects of Iranian Achillea wilhelmsii essential oil on acetaminophen-induced oxidative stress in rat liver

CONTEXT

Achillea wilhelmsii C. Koch (Asteraceae) is widely used in Iranian traditional medicine.

OBJECTIVE

This in vivo study evaluates the hepatoprotective role of Iranian A. wilhelmsii oils against acetaminophen-induced oxidative damages in rats.

MATERIALS AND METHODS

The animals were divided into five groups: in negative control and control groups, the DMSO and 500 mg/kg acetaminophen were i.p. injected, respectively. In treatment groups, 100 and 200 mg/kg oils and 10 mg/kg BHT were given i.p. immediately after acetaminophen administration. Then, the hepatic oxidative/antioxidant parameters such as lipid peroxidation (LP), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), and ferric reducing ability of plasma (FRAP) were measured in time intervals (2, 4, 8, 16, and 24 h) after administrations confirmed by histophatological consideration at 24 h.

RESULTS

The results indicated that acetaminophen caused a significant elevation in SOD activity (8-24 h) and LP and FRAP levels (4 h) paralleled with significant decline in GSH level (4 and 8 h). The apparent oxidative injury was associated with evident hepatic necrosis confirmed in histological examination. The presences of A. wilhelmsii oils (100 and 200 mg/kg) with acetaminophen mitigated significantly the rise in SOD, LP, and FRAP levels and restored the GSH compared with the group treated with acetaminophen. These were confirmed by histological examination indicating the hepatic necrosis reversal by the oils.

DISCUSSION AND CONCLUSION

It can be concluded that concomitant administration of A. wilhelmsii oils with acetaminophen may be useful in reversing the drug hepatotoxicity.

Potential preventive role of Iranian Achillea wilhelmsii C. Koch essential oils in acetaminophen-induced hepatotoxicity

BACKGROUND

The essential oil of Achillea wilhelmsii C. Koch (100 & 200 mg/kg b.w, i.p) was evaluated against acetaminophen induced hepatic injuries in rats. For this purpose, the activities of cytochrome P450 (CYP450), glutathione s-transferase (GST) and markers of liver injuries (ALT, AST, ALP) together with level of GSH measured analytically in time intervals (2, 4, 8, 16 & 24 h) after treatments confirmed by histophatological consideration in rat livers.

RESULTS

Administration of acetaminophen (500 mg/kg bw, i.p) significantly increased the activity of CYP450 concomitant with increasing the release of ALT and AST. Whereas, GSH level and GST activity were decreased significantly after acetaminophen treatment. Treatment of rats with Achillea wilhelmsii essential oils significantly modulate these parameters to normal values. Also, histophatological analysis of liver biopsies was consistent with the biochemical findings.

CONCLUSION

The data led us to conclude the curative potential of Achillea wilhelmsii essential oils against APAP induced hepatic injuries.

Preparation, spectroscopic, thermal, antihepatotoxicity, hematological parameters and liver antioxidant capacity characterizations of Cd(II), Hg(II), and Pb(II) mononuclear complexes of paracetamol anti-inflammatory drug

Keeping in view that some metal complexes are found to be more potent than their parent drugs, therefore, our present paper aimed to synthesized Cd(II), Hg(II) and Pb(II) complexes of paracetamol (Para) anti-inflammatory drug. Paracetamol complexes with general formula [M(Para)2(H2O)2]·nH2O have been synthesized and characterized on the basis of elemental analysis, conductivity, IR and thermal (TG/DTG), (1)H NMR, electronic spectral studies. The conductivity data of these complexes have non-electrolytic nature. Comparative antimicrobial (bacteria and fungi) behaviors and molecular weights of paracetamol with their complexes have been studied. In vivo the antihepatotoxicity effect and some liver function parameters levels (serum total protein, ALT, AST, and LDH) were measured. Hematological parameters and liver antioxidant capacities of both Para and their complexes were performed. The Cd(2+)+Para complex was recorded amelioration of antioxidant capacities in liver homogenates compared to other Para complexes treated groups.

Cell-based therapy for acute and chronic liver failures: distinct diseases, different choices

Cell-based therapies (CBTs) are considered the effective approaches to treat liver failure. However, which cell type is the most suitable source of CBTs for acute liver failure (ALF) or chronic liver failure (CLF) remains unclear. To investigate this, mature hepatocytes in adult liver (adult HCs), fetal liver cells (FLCs), induced hepatic stem cells (iHepSCs) and bone marrow derived mesenchymal stromal cells (BMSCs) were used to CBTs for ConA-induced ALF and Fah-deficient induced CLF in mice. The results showed that only BMSCs remitted liver damage and rescued ALF in ConA-treated mice. In this process, BMSCs inhibited ConA-induced inflammatory response by decreasing the mRNA expressions of TNF-α, IFN-γ and FasL and increasing IL-10 mRNA expression. However, in the CLF model, not BMSCs but adult HCs transplantation lessened liver injury, recovered liver function and rescued the life of Fah-/- mice after NTBC withdrawal. Further study showed that adult HCs offered more effective liver regeneration compared to other cells in Fah-/- mice without NTBC. These results demonstrated that BMSCs and adult HCs are the optimal sources of CBTs for ConA-induced ALF and Fah-deficient induced CLF in mice, respectively. This finding deepens our understanding about how to select a proper CBT for different liver failure.

Nationwide longitudinal analysis of acute liver failure in taiwan

Acute liver failure (ALF) is uncommon but fatal. Current management is based mostly on clinical experience. We aimed to investigate the incidence, etiology, outcomes, and prognostic factors of ALF in Taiwan. Patients with the admission diagnosis of ALF between January 2005 and September 2007 were identified from the Longitudinal Health Insurance Database of Taiwan. ALF was further confirmed by disease severity based on laboratory orders, prescriptions, and duration of hospital stay, and acute onset without prior liver disease. Prognostic factors were identified using Cox regression analysis. During the study period, 218 eligible cases were identified from 28,078 potential eligible ALF patients. The incidence was 80.2 per million person-years in average and increased with age. The mean age was 57.9 ± 17.1 years and median survival was 171 days. The most common etiologies were viral (45.4%, mainly hepatitis B virus) and followed by alcohol/toxin (33.0%). Independent prognostic factors included alcohol consumption (hazard ratio, HR, 1.67 [1.01-2.77]), malignancy (HR 2.90 [1.92-4.37]), frequency of checkups per week for total bilirubin (HR 1.57 [1.40-1.76]), sepsis (HR 1.85 [1.20-2.85]), and the use of hemodialysis/hemofiltration (HR 2.12 [1.15-3.9]) and proton pump inhibitor (HR 0.94 [0.90-0.98]). Among the 130 patients who survived ≥90 days, 66 (50.8%) were complicated by liver cirrhosis. Eight (3.7%) were referred for liver transplantation evaluation, but only 1 received transplantation and survived. ALF in Taiwan is mainly due to viral infection. Patients with malignancy and alcohol exposure have worst prognosis. The use of proton pump inhibitor is associated with improved survival. Half of the ALF survivors have liver cirrhosis.

Neurologic manifestations of acute liver failure

Fulminant hepatic failure presents with a hepatic encephalopathy and may progress to coma and often brain death from cerebral edema. This natural progression in severe cases contributes to early mortality, but outcome can be good if liver transplantation is appropriately timed and increased intracranial pressure (ICP) is managed. Neurologists and neurosurgeons have become more involved in these very challenging patients and are often asked to rapidly identify patients who are at risk of cerebral edema, to carefully select the patient population who will benefit from invasive ICP monitoring, to judge the correct time to start monitoring, to participate in treatment of cerebral edema, and to manage complications such as intracranial hemorrhage or seizures. This chapter summarizes the current multidisciplinary approach to fulminant hepatic failure and how to best bridge patients to emergency liver transplantation.

The PanAM study: a multi-center, double-blinded, randomized, non-inferiority study of paracetamol versus non-steroidal anti-inflammatory drugs in treating acute musculoskeletal trauma

BACKGROUND

Acute musculoskeletal trauma, including strains, sprains or contusions, occur frequently. Pain management is a crucial component of treatment. However, there is no convincing evidence which drug is superior in managing pain in these patients. The aim of the PanAM Study is to compare analgesic efficacy of three strategies of pain management: paracetamol, diclofenac, or a combination of both in patients with acute musculoskeletal trauma.

METHODS/DESIGN

The PanAM Study is a multi-center, double blind randomized controlled trial with non-inferiority design. Included are adult patients presenting to an academic, urban Emergency Department or to a General Practice with acute, blunt, traumatic limb injury. In total, 547 patients will be included using a predefined list of exclusion criteria, to be allocated by randomization to treatment with paracetamol + placebo diclofenac, diclofenac + placebo paracetamol or paracetamol + diclofenac. The hypothesis is that paracetamol will not be inferior to treatment with diclofenac, or the combination of both. Primary outcome will be between-group differences in decrease in pain, measured with Numerical Rating Scales at baseline and at 90 minutes after study drug administration. Secondary outcomes are Numerical Rating Scales at 30 and 60 minutes and measured frequently during three consecutive days after discharge; occurrence of adverse effects; patient satisfaction and an analysis of quality of life and cost-effectiveness. Recruitment started July 2013 and is expected to last a year.

DISCUSSION

With this multi-center randomized clinical trial we will investigate whether treatment with paracetamol alone is not inferior to diclofenac alone or a combination of both drugs in adult patients with acute musculoskeletal trauma. The main relevance of the trial is to demonstrate the benefits and risks of three commonly used treatment regimens for musculoskeletal trauma. Data that lead to the prevention of severe Non-Steroidal Anti-Inflammatory Drugs-related adverse effects might be gathered.

TRIAL REGISTRATION

Dutch Trial Register (http://www.trialregister.nl): NTR3982.EudraCT database (http://www.clinicaltrialsregister.eu): 201300038111.

Acute hepatitis in a young woman with systemic lupus erythematosus: a diagnostic challenge

A 48-year-old woman with systemic lupus erythematosus diagnosis was on naproxen, hidroxichloroquine and acetylsalicylic acid. She had self-suspended all medication and resumed 1 year later. Five days after the medication was resumed, she developed acute hepatitis, with biochemical hepatic cytolysis, hypergamaglobulinaemia and a serum antinuclear antibody titre of 1/2560. Idiopathic autoimmune hepatitis was considered, but drug-induced liver injury could not definitely be ruled out. Patient declined liver biopsy. Oral prednisolone was started. Within 3 months with prednisolone being tapered to 10 mg/day, a new flare occurred. Liver biopsy was performed and it favoured autoimmune hepatitis diagnosis. We discuss the diagnostic options and treatment approach in a patient with autoimmune disease and possible drug-induced liver injury who initially declined liver biopsy.

Perioperative liver protection

PURPOSE OF REVIEW

This review presents important pathophysiological alterations associated with impaired liver function and discusses protective perioperative strategies and the various anaesthetic agents recommended.

RECENT FINDINGS

Perioperative liver impairment is a serious complication of anaesthesia and surgery. Unfortunately, clinicians are provided with only crude macrohaemodynamic monitoring devices to optimize their therapy. Technical improvements have revealed some complex mysteries of perioperative microcirculatory alterations and have disclosed a large heterogeneity between different vascular beds. The present review will critically discuss current clinical concepts of optimizing global haemodynamic variables and the often contrasting effects of vasoactive agents on the microcirculatory nutritional blood flow. Finally, promising protective experimental interventions of pharmacological or ischaemic preconditioning are presented and their often disillusioning transition into recent clinical trials is highlighted.

SUMMARY

Targeted perioperative liver protection still lacks adequate monitoring tools and is currently based on optimization of global haemodynamic variables. While there is currently no evidence suggesting a positive effect of ischaemic preconditioning, promising experimental results of pharmacological preconditioning and therapeutic hypothermia require further evaluation in larger randomized clinical trials.

Bridging the gap: advances in artificial liver support

1. The goals of liver support therapy include the following: To provide detoxification and synthetic function during liver failure. To remove or reduce the production of proinflammatory cytokines to correct the systemic inflammatory response of liver failure. To stimulate the regeneration of the injured liver and increase the likelihood of spontaneous recovery. 2. There is a large unmet need for a liver support device because of the shortage of organs for liver transplantation and the risks of major surgery. 3. Liver support devices can be divided into 2 groups: purely mechanical artificial devices and cell-based bioartificial devices. Both provide detoxification, but bioartificial liver devices provide the option of synthetic function and biotransformation activities that are not possible with a purely mechanical device. 4. An abundant high-quality supply of human hepatocytes is not currently available for liver cell therapy. However, such a supply is essential for successful bioartificial liver therapy. Novel options are under development for the unlimited production of high-quality human hepatocytes.

A survey of adult awareness and use of medicine containing acetaminophen

PURPOSE

To compare awareness, use of acetaminophen, and preferences for receiving information aimed at reducing acetaminophen overdose.

METHODS

A survey of health plan enrollees identified from automated pharmacy data who were long-term and acute users of opioids with acetaminophen (n = 720 each cohort), and a general population cohort (n = 360) during the 2010-2011 cold/flu season. A 74% response rate was achieved. Differences were tested across the three cohorts, and by level of education, using age-adjusted regression models.

RESULTS

Use of over-the-counter or prescription medicine containing acetaminophen in the prior 2 weeks was reported by 84% in the long-term opioid cohort, 76% in the acute opioid cohort, and 36% in the general population, but use of over-the-counter medicine with acetaminophen did not differ across the cohorts (30-34%). All three cohorts were unlikely to correctly identify drugs containing acetaminophen, but the opioid cohorts performed slightly better than the general population. Those with higher education performed slightly better when asked to identify acetaminophen products than those with no college education. The average usual daily acetaminophen dose (mg/day) reported was highest in the long-term opioid cohort (1185), followed by the acute opioid cohort (1010), and the general population (891)-p < 0.001. Estimated supratherapeutic exposure (>4000 mg/day) was rare but three to five times more common in the opioid cohorts than in the general population.

CONCLUSIONS

Acetaminophen use is common, and supratherapeutic exposure may be of concern in users of opioids. Knowledge of which drugs contain acetaminophen appears inadequate; better labeling and proactive education from professionals may be impactful.

A randomized, double-blind comparison shows the addition of oxygenated glycerol triesters to topical mentholated cream for the treatment of acute musculoskeletal pain demonstrates incremental benefit over time

BACKGROUND

Topical analgesics are important products in the armamentarium for pain relief.

METHODS AND FINDINGS

This study compared a topical analgesic product containing menthol to the same product with the addition of oxygenated glycerol triesters (OGTs) (also called essential oxygen oil) in 66 healthy adult subjects with acute musculoskeletal pain. Patients were randomized in a single-center, double-blind study to receive mentholated cream (MC) only or MC containing OGTs. Patients self-reported their pain intensity, lifestyle limitations, and evaluation of the mobility of the painful joint or muscle at baseline and three times daily over a seven-day course on a 100-mm visual analog scale (VAS). Patients in both groups experienced statistically significant pain relief on Day 8 over baseline, with the MC plus OGT-treated group reporting statistically significantly greater pain relief than the MC group (P = 0.016). In addition, patients treated with the combination product experienced an incremental decrease in pain during each of the 7 days of treatment in addition, and they had lower VAS scores and greater lifestyle and mobility improvements than the MC group. Both products were well tolerated with no serious adverse events reported and no signs of significant skin reactions in either group.

CONCLUSION

Based on this study, a MC containing OGTs is safe, effective, and provided significantly better pain relief than MC alone. The combination of oxygenated glycerol trimesters and MC provided significant pain relief and offered continued improvement in pain relief over time.

Encephalopathy in acute liver failure resulting from acetaminophen intoxication: new observations with potential therapy

OBJECTIVE

Hyperammonemia is a major contributing factor to the encephalopathy associated with liver disease. It is now generally accepted that hyperammonemia leads to toxic levels of glutamine in astrocytes. However, the mechanism by which excessive glutamine is toxic to astrocytes is controversial. Nevertheless, there is strong evidence that glutamine-induced osmotic swelling, especially in acute liver failure, is a contributing factor: the osmotic gliopathy theory. The object of the current communication is to present evidence for the osmotic gliopathy theory in a hyperammonemic patient who overdosed on acetaminophen.

DESIGN

Case report.

SETTING

Johns Hopkins Hospital.

PATIENT

A 22-yr-old woman who, 36 hrs before admission, ingested 15 g acetaminophen was admitted to the Johns Hopkins Hospital. She was treated with N-acetylcysteine. Physical examination was unremarkable; her mental status was within normal limits and remained so until approximately 72 hrs after ingestion when she became confused, irritable, and agitated.

INTERVENTIONS

She was intubated, ventilated, and placed on lactulose. Shortly thereafter, she was noncommunicative, unresponsive to painful stimuli, and exhibited decerebrate posturing. A clinical diagnosis of cerebral edema and increased intracranial pressure was made. She improved very slowly until 180 hrs after ingestion when she moved all extremities. She woke up shortly thereafter.

MEASUREMENTS AND MAIN RESULTS

Despite the fact that hyperammonemia is a major contributing factor to the encephalopathy observed in acute liver failure, the patient's plasma ammonia peaked when she exhibited no obvious neurologic deficit. Thereafter, her plasma ammonia decreased precipitously in parallel with a worsening neurologic status. She was deeply encephalopathic during a period when her liver function and plasma ammonia had normalized. Plasma glutamine levels in this patient were high but began to normalize several hours after plasma ammonia had returned to normal. The patient only started to recover as her plasma glutamine began to return to normal.

CONCLUSIONS

We suggest that the biochemical data are consistent with the osmotic gliopathy theory--high plasma ammonia leads to high plasma glutamine--an indicator of excess glutamine in astrocytes (the site of brain glutamine synthesis). This excess glutamine leads to osmotic stress in these cells. The lag in recovery of brain function presumably reflects time taken for the astrocyte glutamine concentration to return to normal. We hypothesize that an inhibitor of brain glutamine synthesis may be an effective treatment modality for acute liver failure.