Background: Liver injury is the most common severe adverse effect of first-line anti-tuberculosis therapy (ATT). Nacetylcysteine (NAC) has efficacy in patients with paracetamol toxicity, and may be of benefit in liver injury due to other causes, such as ATT-induced liver injury (AT-DILI). Rechallenge of first line ATT after liver injury is usually attempted and may result in recurrence of liver injury. Alanine transaminase (ALT) is the biomarker currently used in AT-DILI diagnosis. MicroRNA-122 (miR-122) is a sensitive biomarker for liver injury due to paracetamol, but data on utility as a biomarker for ATDILI are limited. Methods: We conducted a randomized double-blind placebo-controlled trial of intravenous NAC in adult hospitalized participants with AT-DILI. Primary endpoint was time to ALT < 100 U/L; secondary endpoints included length of hospital stay and 8-week mortality. We described outcomes of ATT rechallenge following AT-DILI. We quantified miR-122 and ALT concentrations before and after infusion of NAC/placebo, and explored the effect of NAC on miR-122. Results We enrolled 102 participants with AT-DILI, 53 randomized to NAC and 49 to placebo. Mean age was 38 (SD±10) years, 58 (57%) were female and 89 (87%) were HIV positive. Median time to ALT

Thesis (Ph. D.)--Case Western Reserve University, 2010. / [School of Medicine] Department of Nutrition. Includes bibliographical references.

Perinatal omphalocele rupture is a rare occurrence. We present a case of a baby delivered at 35 weeks with a known giant omphalocele, transverse lie, and the omphalocele downward in the birth canal who suffered rupture of the omphalocele and liver injury around the time of delivery. The pregnancy was complicated by one day of preterm labor, preterm premature rupture of the membranes, and the omphalocele was the presenting part. Despite pulmonary hypertension, rupture of the omphalocele, and a significant liver injury, individualized management with decompression of the liver hematoma allowed successful early closure with mesh followed by delayed reconstruction. (C) 2016 The Authors. Published by Elsevier Inc.

Wong Suk-kwan, Amy. / Thesis (M.Ph.)--Chinese University of Hong Kong, 1988. / Bibliography: leaves 184-206.

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Pneumonia and sepsis are distinct but linked public health concerns. Each condition is the leading cause of the other; however, the responses controlling the susceptibility between the two disease processes remain speculative. The acute phase response (APR) is an important component of the host immune response during pneumonia and sepsis, and primarily driven by the activation of hepatocyte transcription factors NF-κB RelA and STAT3. While the NF-κB pathway is essential for inflammation and hepatocyte function, its inactivation has been associated with hepatotoxicity. Liver injury is an independent risk factor for sepsis morbidity and mortality, suggesting that pathways promoting liver homeostasis may limit the systemic consequences of pneumonia. To identify conditions in which NF-κB RelA is required for liver resilience, we challenged mice lacking hepatocyte RelA (hepRelAΔ/Δ) and wildtype (WT) controls with E. coli, K. pneumoniae, S. pneumoniae, LPS, or αGalCer to induce pneumonia, sepsis, and/or NKT cell activation. Severe hepatotoxicity was observed in hepRelAΔ/Δ mice in all conditions examined in association with apoptosis, which could be prevented by neutralization of TNFα. Lastly, these changes were associated with remodeling of the hepatic transcriptome, likely reflecting both the cause and consequence of hepatoxicity. We have previously shown that activation of STAT3 in hepatocytes limits pneumonia susceptibility during endotoxemia, but the mechanisms whereby this liver APR provides protection are unknown. Iron sequestration is a defense mechanism against bacterial infections, which require iron for growth. Based on previous observations that alveolar lining fluid is favorable for bacteria in the absence of liver STAT3, we investigated whether liver APR limits pneumonia susceptibility during sepsis by withholding iron to prevent bacterial outgrowth. WT mice or mice lacking hepatocyte STAT3 (hepSTAT3Δ/Δ) mice were challenged with endotoxemia followed by E. coli pneumonia, or cecal ligation and puncture (CLP). Induction of mRNA encoding several essential iron-regulating factors was ablated in hepSTAT3Δ/Δ mice after endotoxemia and pneumonia, and post CLP. Additionally, liver STAT3 activation significantly remodeled the pulmonary transcriptome during endotoxemia, which potentially represents other protective mechanisms. Taken together, these results suggest that hepatic APR is an important immunological interface modulating pneumonia and sepsis interaction and susceptibility.

The liver is a multi-functional and highly regenerative organ. While resilient, the liver is susceptible to organ damage and failure. In both the acute and chronic settings liver disease has dire consequences for health. A common cause of liver damage is adverse reactions to drugs which can lead to drug induced liver injury (DILI). This creates major problems for patients, clinicians, the pharmaceutical industry and regulatory authorities. In the context of drug overdose or serious adverse reactions, liver failure can be acute and life threatening, and in some cases require orthotopic liver transplantation. While transplantation is highly successful, such an approach has limitations and justifies basic science attempts to develop better human models to study liver injury and to develop scalable intervention strategies. With this in mind, we have studied the importance of microRNAs (miRs) in regulating human drug metabolism in pluripotent stem cell – derived hepatocytes and their potential to reduce liver toxicity in response to toxic levels of paracetamol. miRs are small non-coding RNAs that are approximately 20 - 24 nucleotides long and their major function is to fine tune gene expression of their target genes. Recently, it has been demonstrated that microRNAs play a role in regulating the first phase of drug metabolism however the second phase of drug metabolism, drug conjugation, has not been studied in detail. Drug conjugation is a crucial stage in human drug metabolism, and any alterations in this process can lead to changes in compound pharmacology, including therapeutic dose and clearance from the body. To test the importance of miRs in regulating phase II drug metabolism we opted to study the metabolism of a common used analgesic, paracetamol. When taken in the appropriate amounts paracetamol is modified by sulfotransferases (SULTs) and UDP - glucuronosyltransferases (UGTs) and removed from the body without organ damage. However, when paracetamol is taken above the recommended dose it is metabolised by phase I enzymes to generate a toxic intermediate N-acetyl-p-benzoquinone imine (NAPQI), which if untreated can lead to massive hepatocyte cell death and liver failure, placing the patient in a life threatening situation. In order to promote non-toxic drug metabolism, in the context of drug overdose, we employed candidate miRs to regulate different parts of the paracetamol metabolism pathway. In summary, we have focused on studying human drug metabolism in the major metabolic cell type of the liver, the hepatocyte. We have identified a novel microRNA (called miR-324-5p) which regulates phase II drug metabolism and reduces cell cytotoxicity. Additionally, a supportive role of anti-microRNA- 324 in response to fulminant plasma collected from paracetamol overdose patients is also observed. The findings of this project are novel, provide proof of concept and exemplify the power of stem cell based models to identify new approaches to treating human liver damage.

Background: Hepatic ischemia reperfusion injury (IRI) results from the interruption and then reinstatement of the liver’s blood supply. IRI involves both an ischemic and an immune-mediated reperfusion phase of tissue injury; similar inflammatory events are seen in other forms of acute (sterile) liver injury (ALI), including paracetamol toxicity. Hypothesis Irrespective of the primary insult, common pathways exist in the pathophysiology of the lymphocyte-mediated secondary liver injury. Natural mechanisms exist to limit lymphocyte function and these pathways can be targeted therapeutically by immunomodulatory agents. Aims: 1. To assess the relative importance of different lymphocyte subsets in IRI. 2. To correlate observations in IRI with other models of ALI. 3. To identify possible pharmacological targets. Materials and Methods Three experimental murine models of acute liver injury were utilised to test this hypothesis: murine model of warm hepatic IRI, concanavalin A (con A) hepatitis and paracetamol-induced liver injury. These models were interrogated with a combination of (transgenic and knockout) mouse lines, in vivo antibody depletion and small molecule inhibition. Injury was evaluated primarily in terms of the biochemical marker of liver injury alanine aminotransferase (ALT). Data were correlated with human tissue where possible. Results: T cells (CD3εKO vs WT p=0.010), but not other lymphocyte populations (B cells, NK cells, or other innate lymphoid cells), play a central role in warm hepatic IRI. Programmed Death Receptor-1 (PD-1) is a negative regulator of pro-inflammatory cytokine production by T cells and the absence of PD-1 was associated with significantly worse hepatic IRI (p=0.034), con A hepatitis (p=0.00020) and paracetamol-induced liver injury (p=0.0050). Interferon-γ (IFNγ) and T-box expressed in T cells (T-bet) are important mediators of hepatic IRI (p=0.017) and paracetamol induced liver injury (p=0.0007). The absence of IL-6 was associated with significant protection in paracetamol induced liver injury (p=0.006). The infiltrates within the recipient liver of patients transplanted following paracetamol overdose stain positively for PD-1, IFNγ and T-bet. The Janus family of kinases (JAK) play an important role in the common pathways of cytokine signal transduction. In vivo use of a selective JAK1/JAK2 inhibitor is protective in hepatic IRI (p=0.0014), con A hepatitis (p=0.019) and paracetamol-induced liver injury (p=0.0045). Conclusions: Common pathways appear to exist in the immune-mediated secondary phase of injury in ALI. Targeting these pathways will complement existing (cytoprotective) treatment strategies.

The mechanisms of idiosyncratic drug reactions (IDRs) are unknown; however, most appear to be immune-mediated. Their idiosyncratic nature and the paucity of animal models make mechanistic studies very difficult. One of the few animal models is penicillamine-induced autoimmunity in Brown Norway rats. The major focus of this thesis was the use of this model to study the interaction between penicillamine and macrophages, the involvement of Th17 cells, and extension of this model to idiosyncratic drug-induced liver injury. One of the costimulatory signals leading to T cell activation appears to be reversible Schiff-base formation between an amine on T cells and an aldehyde on macrophages. We hypothesized that penicillamine binds to these aldehydes leading to macrophage activation and autoimmunity. By using biotinylated aldehyde-reactive agents such as ARP, we demonstrated the existence of aldehydes on the surface of macrophages. We synthesized biotinylated-penicillamine and it also binds to macrophages. Several proteins to which ARP binds were identified providing clues to the signal transduction pathways leading to macrophage activation. Biological consequences of this binding were investigated with a microarray study. ARP binding was also observed in the macrophage cell line, RAW264.7, and incubation with penicillamine stimulated the production of TNF-α, IL-6, and IL-23. Hydralazine and isoniazid, which are known to cause a lupus-like syndrome in humans and irreversibly bind to aldehyde groups, were also found to activate RAW264.7 cells. Th17 cells are prominent in autoimmune syndromes and Th17-associated cytokines such as IL-17 were elevated in the penicillamine-treated animals that developed autoimmunity. We have hypothesized that some drug-induced liver injury has an autoimmune component. A pilot study quantified serum concentrations of 26 cytokines/chemokines in patients with various forms of acute liver failure (ALF): idiosyncratic drug-induced ALF, acetaminophen-induced ALF, and viral hepatitis. IL-17 was elevated in 60% of patients with idiosyncratic drug-induced ALF, which supports an autoimmune component in these patients; however, it was also elevated in many cases of acetaminophen-induced ALF, presumably released by the innate immune system. These studies provide important insights into the mechanism of penicillamine-, hydralazine-, and isoniazid-induced autoimmunity and also provide clues to other IDRs that may have an autoimmune component.