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Saeidinejad M, Elshabrawi A, Sriphoosanaphan S, Andreola F, Mehta G, Agarwal B, Jalan R. Novel Therapeutic Approaches in Treatment of Acute-on-Chronic Liver Failure. Semin Liver Dis 2023; 43:429-445. [PMID: 38101419 PMCID: PMC10723941 DOI: 10.1055/s-0043-1776773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2023]
Abstract
Acute-on-chronic liver failure (ACLF), a clinical syndrome that can develop at any stage in the progression of cirrhotic liver disease, is characterized by an acute decompensation in liver function with associated multiorgan failure and high short-term mortality. Current evidence points to ACLF being reversible, particularly in those at the lower end of the severity spectrum. However, there are no specific treatments for ACLF, and overall outcomes remain poor. Expedited liver transplantation as a treatment option is limited by organ shortage and a lack of priority allocation for this indication. Other options are therefore urgently needed, and our improved understanding of the condition has led to significant efforts to develop novel therapies. In conclusion, this review aims to summarize the current understanding of the pathophysiological processes involved in the onset, progression, and recovery of ACLF and discuss novel therapies under development.
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Affiliation(s)
- MohammadMahdi Saeidinejad
- Liver Failure Group, Department of Medicine, Institute for Liver and Digestive Health, University College London, London, United Kingdom
| | - Ahmed Elshabrawi
- Liver Failure Group, Department of Medicine, Institute for Liver and Digestive Health, University College London, London, United Kingdom
- Intensive Care Unit, Endemic Hepatology and Gastroenterology Department, Mansoura University, Mansoura, Egypt
| | - Supachaya Sriphoosanaphan
- Liver Failure Group, Department of Medicine, Institute for Liver and Digestive Health, University College London, London, United Kingdom
- Division of Gastroenterology, Department of Medicine, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Thai Red Cross Society, Bangkok
| | - Fausto Andreola
- Liver Failure Group, Department of Medicine, Institute for Liver and Digestive Health, University College London, London, United Kingdom
| | - Gautam Mehta
- Liver Failure Group, Department of Medicine, Institute for Liver and Digestive Health, University College London, London, United Kingdom
| | - Banwari Agarwal
- Liver Failure Group, Department of Medicine, Institute for Liver and Digestive Health, University College London, London, United Kingdom
- Intensive Care Unit, Royal Free Hospital, London, United Kingdom
| | - Rajiv Jalan
- Liver Failure Group, Department of Medicine, Institute for Liver and Digestive Health, University College London, London, United Kingdom
- Hepatology Department, Royal Free Hospital, London, United Kingdom
- European Foundation for the Study of Chronic Liver Failure, Barcelona, Spain
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DeMorrow S, Cudalbu C, Davies N, Jayakumar AR, Rose CF. 2021 ISHEN guidelines on animal models of hepatic encephalopathy. Liver Int 2021; 41:1474-1488. [PMID: 33900013 PMCID: PMC9812338 DOI: 10.1111/liv.14911] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 03/05/2021] [Accepted: 04/01/2021] [Indexed: 02/07/2023]
Abstract
This working group of the International Society of Hepatic Encephalopathy and Nitrogen Metabolism (ISHEN) was commissioned to summarize and update current efforts in the development and characterization of animal models of hepatic encephalopathy (HE). As defined in humans, HE in animal models is based on the underlying degree and severity of liver pathology. Although hyperammonemia remains the key focus in the pathogenesis of HE, other factors associated with HE have been identified, together with recommended animal models, to help explore the pathogenesis and pathophysiological mechanisms of HE. While numerous methods to induce liver failure and disease exist, less have been characterized with neurological and neurobehavioural impairments. Moreover, there still remains a paucity of adequate animal models of Type C HE induced by alcohol, viruses and non-alcoholic fatty liver disease; the most common etiologies of chronic liver disease.
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Affiliation(s)
- S DeMorrow
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Texas, USA; Department of Internal Medicine, Dell Medical School, The University of Texas at Austin, Texas, USA; Research division, Central Texas Veterans Healthcare System, Temple Texas USA.,Correspondance: Sharon DeMorrow, PhD, ; tel: +1-512-495-5779
| | - C Cudalbu
- Center for Biomedical Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - N Davies
- Institute for Liver and Digestive Health, University College London, Royal Free Campus, London, United Kingdom
| | - AR Jayakumar
- General Medical Research, Neuropathology Section, R&D Service and South Florida VA Foundation for Research and Education Inc; Obstetrics, Gynecology and Reproductive Sciences, University of Miami School of Medicine, Miami FL, USA
| | - CF Rose
- Hepato-Neuro Laboratory, CRCHUM, Université de Montréal, Montreal, Canada
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3
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Hu C, Huang K, Zhao L, Zhang F, Wu Z, Li L. Serum ammonia is a strong prognostic factor for patients with acute-on-chronic liver failure. Sci Rep 2020; 10:16970. [PMID: 33046732 PMCID: PMC7550336 DOI: 10.1038/s41598-020-73603-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 09/10/2020] [Indexed: 02/07/2023] Open
Abstract
Ammonia is thought to be central to the pathogenesis of hepatic encephalopathy (HE), but its prognostic role in acute-on-chronic liver failure (ACLF) is still unknown. We aimed to determine the association between serum ammonia level and short-term prognosis in ACLF. Furthermore, we performed an in-depth evaluation of the independent effect of serum ammonia level on the short-term prognosis of hepatitis B virus (HBV) reactivation-induced ACLF patients. We identified 174 patients as part of prospective observational studies in patients with ACLF. Plasma ammonia levels were measured on admission, and several prognostic scores were used to determine the prognostic effect of ammonia. The 28-day patient survival was determined. Receiver operating characteristic analysis was used to identify the cut-off points for ammonia values, and multivariable analysis was performed using the Cox proportional hazard regression model. Plasma ammonia was significantly higher in nonsurvivors (83.53 ± 43.78 versus 67.13 ± 41.77 µmol/L, P = 0.013), and ACLF patients with hyperammonemia had significantly higher 28-day mortality than those without hyperammonemia. Ammonia was also closely related to ACLF grade (P < 0.001) and organ failure, including liver (P = 0.048), coagulation (P < 0.001) and brain (P < 0.001). HBV reactivation serves as the main precipitating factor in the ACLF population. Subgroup analysis showed that ammonia is also a strong prognostic factor in the HBV reactivation-induced ACLF population. Ammonia level is closely correlated with failure of other organs and is an independent risk factor for mortality in ACLF and the special population defined as HBV reactivation-related ACLF. Based on the results from our study, we measured serum ammonia in the population with ACLF, which strongly indicates their prognosis. It serves as an important biomarker and a therapeutic target.
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Affiliation(s)
- Chenxia Hu
- Collaborative Innovation Center for the Diagnosis and Treatment of Infectious Diseases, State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China.,National Clinical Research Center for Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
| | - Kaizhou Huang
- Shantou Central Hospital, Affiliated Shantou Hospital of Sun Yat-Sen University, Shantou, 515041, Guangdong, People's Republic of China
| | - Lingfei Zhao
- Key Laboratory of Kidney Disease Prevention and Control Technology, Kidney Disease Center, Institute of Nephrology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
| | - Fen Zhang
- Collaborative Innovation Center for the Diagnosis and Treatment of Infectious Diseases, State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China.,National Clinical Research Center for Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
| | - Zhongwen Wu
- Collaborative Innovation Center for the Diagnosis and Treatment of Infectious Diseases, State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China.,National Clinical Research Center for Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
| | - Lanjuan Li
- Collaborative Innovation Center for the Diagnosis and Treatment of Infectious Diseases, State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China. .,National Clinical Research Center for Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China.
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4
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De Chiara F, Thomsen KL, Habtesion A, Jones H, Davies N, Gracia-Sancho J, Manicardi N, Hall A, Andreola F, Paish HL, Reed LH, Watson AA, Leslie J, Oakley F, Rombouts K, Mookerjee RP, Mann J, Jalan R. Ammonia Scavenging Prevents Progression of Fibrosis in Experimental Nonalcoholic Fatty Liver Disease. Hepatology 2020; 71:874-892. [PMID: 31378982 DOI: 10.1002/hep.30890] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Accepted: 07/07/2019] [Indexed: 01/10/2023]
Abstract
BACKGROUND AND AIMS In nonalcoholic fatty liver disease (NAFLD), fibrosis is the most important factor contributing to NAFLD-associated morbidity and mortality. Prevention of progression and reduction in fibrosis are the main aims of treatment. Even in early stages of NAFLD, hepatic and systemic hyperammonemia is evident. This is due to reduced urea synthesis; and as ammonia is known to activate hepatic stellate cells, we hypothesized that ammonia may be involved in the progression of fibrosis in NAFLD. APPROACH AND RESULTS In a high-fat, high-cholesterol diet-induced rodent model of NAFLD, we observed a progressive stepwise reduction in the expression and activity of urea cycle enzymes resulting in hyperammonemia, evidence of hepatic stellate cell activation, and progressive fibrosis. In primary, cultured hepatocytes and precision-cut liver slices we demonstrated increased gene expression of profibrogenic markers after lipid and/or ammonia exposure. Lowering of ammonia with the ammonia scavenger ornithine phenylacetate prevented hepatocyte cell death and significantly reduced the development of fibrosis both in vitro in the liver slices and in vivo in a rodent model. The prevention of fibrosis in the rodent model was associated with restoration of urea cycle enzyme activity and function, reduced hepatic ammonia, and markers of inflammation. CONCLUSIONS The results of this study suggest that hepatic steatosis results in hyperammonemia, which is associated with progression of hepatic fibrosis. Reduction of ammonia levels prevented progression of fibrosis, providing a potential treatment for NAFLD.
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Affiliation(s)
- Francesco De Chiara
- UCL Institute of Liver and Digestive Health, University College London, London, UK
| | - Karen Louise Thomsen
- UCL Institute of Liver and Digestive Health, University College London, London, UK.,Department of Hepatology & Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Abeba Habtesion
- UCL Institute of Liver and Digestive Health, University College London, London, UK
| | - Helen Jones
- UCL Institute of Liver and Digestive Health, University College London, London, UK
| | - Nathan Davies
- UCL Institute of Liver and Digestive Health, University College London, London, UK
| | - Jordi Gracia-Sancho
- Liver Vascular Biology Research Group, IDIBAPS Biomedical Research Institute & CIBEREHD, Barcelona, Spain
| | - Nicolò Manicardi
- Liver Vascular Biology Research Group, IDIBAPS Biomedical Research Institute & CIBEREHD, Barcelona, Spain
| | - Andrew Hall
- UCL Institute of Liver and Digestive Health, University College London, London, UK
| | - Fausto Andreola
- UCL Institute of Liver and Digestive Health, University College London, London, UK
| | - Hannah L Paish
- Newcastle Fibrosis Research Group, Institute of Cellular Medicine, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Lee H Reed
- Newcastle Fibrosis Research Group, Institute of Cellular Medicine, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Abigail A Watson
- Newcastle Fibrosis Research Group, Institute of Cellular Medicine, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Jack Leslie
- Newcastle Fibrosis Research Group, Institute of Cellular Medicine, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Fiona Oakley
- Newcastle Fibrosis Research Group, Institute of Cellular Medicine, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Krista Rombouts
- UCL Institute of Liver and Digestive Health, University College London, London, UK
| | | | - Jelena Mann
- Newcastle Fibrosis Research Group, Institute of Cellular Medicine, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Rajiv Jalan
- UCL Institute of Liver and Digestive Health, University College London, London, UK
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5
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Gutiérrez-de-Juan V, López de Davalillo S, Fernández-Ramos D, Barbier-Torres L, Zubiete-Franco I, Fernández-Tussy P, Simon J, Lopitz-Otsoa F, de las Heras J, Iruzubieta P, Arias-Loste MT, Villa E, Crespo J, Andrade R, Lucena MI, Varela-Rey M, Lu SC, Mato JM, Delgado TC, Martínez-Chantar ML. A morphological method for ammonia detection in liver. PLoS One 2017; 12:e0173914. [PMID: 28319158 PMCID: PMC5358814 DOI: 10.1371/journal.pone.0173914] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 02/28/2017] [Indexed: 12/27/2022] Open
Abstract
Hyperammonemia is a metabolic condition characterized by elevated levels of ammonia and a common event in acute liver injury/failure and chronic liver disease. Even though hepatic ammonia levels are potential predictive factors of patient outcome, easy and inexpensive methods aiming at the detection of liver ammonia accumulation in the clinical setting remain unavailable. Thus, herein we have developed a morphological method, based on the utilization of Nessler´s reagent, to accurately and precisely detect the accumulation of ammonia in biological tissue. We have validated our method against a commercially available kit in mouse tissue samples and, by using this modified method, we have confirmed the hepatic accumulation of ammonia in clinical and animal models of acute and chronic advanced liver injury as well as in the progression of fatty liver disease. Overall, we propose a morphological method for ammonia detection in liver that correlates well with the degree of liver disease severity and therefore can be potentially used to predict patient outcome.
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Affiliation(s)
- Virginia Gutiérrez-de-Juan
- CIC bioGUNE (Center for Cooperative Research in Biosciences), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Derio, Bizkaia, Spain
| | - Sergio López de Davalillo
- CIC bioGUNE (Center for Cooperative Research in Biosciences), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Derio, Bizkaia, Spain
| | - David Fernández-Ramos
- CIC bioGUNE (Center for Cooperative Research in Biosciences), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Derio, Bizkaia, Spain
| | - Lucía Barbier-Torres
- CIC bioGUNE (Center for Cooperative Research in Biosciences), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Derio, Bizkaia, Spain
| | - Imanol Zubiete-Franco
- CIC bioGUNE (Center for Cooperative Research in Biosciences), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Derio, Bizkaia, Spain
| | - Pablo Fernández-Tussy
- CIC bioGUNE (Center for Cooperative Research in Biosciences), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Derio, Bizkaia, Spain
| | - Jorge Simon
- CIC bioGUNE (Center for Cooperative Research in Biosciences), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Derio, Bizkaia, Spain
| | - Fernando Lopitz-Otsoa
- CIC bioGUNE (Center for Cooperative Research in Biosciences), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Derio, Bizkaia, Spain
| | - Javier de las Heras
- Division of Pediatric Metabolism, University Hospital of Cruces, BioCruces Health Research Institute, University of the Basque Country, UPV/EHU, Barakaldo, Bizkaia, Spain
| | - Paula Iruzubieta
- Gastroenterology and Hepatology Department, Marqués de Valdecilla University Hospital, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Santander, Spain
- Infection, Immunity and Digestive Pathology Group, Research Institute Marqués de Valdecilla (IDIVAL), Santander, Spain
| | - María Teresa Arias-Loste
- Gastroenterology and Hepatology Department, Marqués de Valdecilla University Hospital, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Santander, Spain
- Infection, Immunity and Digestive Pathology Group, Research Institute Marqués de Valdecilla (IDIVAL), Santander, Spain
| | - Erica Villa
- Department of Gastroenterology, Azienda Ospedaliero-Universitaria & University of Modena and Reggio Emilia, Modena, Italy
| | - Javier Crespo
- Division of Pediatric Metabolism, University Hospital of Cruces, BioCruces Health Research Institute, University of the Basque Country, UPV/EHU, Barakaldo, Bizkaia, Spain
- Gastroenterology and Hepatology Department, Marqués de Valdecilla University Hospital, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Santander, Spain
| | - Raúl Andrade
- Unidad de Gestión Clínica de Aparato Digestivo, Servicio de Farmacología Clínica, Instituto de Investigación Biomédica de Málaga-IBIMA, Hospital Universitario Virgen de la Victoria, Universidad de Málaga, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Málaga, Spain
| | - M. Isabel Lucena
- Unidad de Gestión Clínica de Aparato Digestivo, Servicio de Farmacología Clínica, Instituto de Investigación Biomédica de Málaga-IBIMA, Hospital Universitario Virgen de la Victoria, Universidad de Málaga, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Málaga, Spain
| | - Marta Varela-Rey
- CIC bioGUNE (Center for Cooperative Research in Biosciences), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Derio, Bizkaia, Spain
| | - Shelly C. Lu
- Division of Digestive and Liver Disease, Cedars-Sinai Medical Center, Los Angeles, California, United States of America
| | - José M. Mato
- CIC bioGUNE (Center for Cooperative Research in Biosciences), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Derio, Bizkaia, Spain
| | - Teresa Cardoso Delgado
- CIC bioGUNE (Center for Cooperative Research in Biosciences), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Derio, Bizkaia, Spain
- * E-mail: (ML M-C); (TCD)
| | - María-Luz Martínez-Chantar
- CIC bioGUNE (Center for Cooperative Research in Biosciences), Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Derio, Bizkaia, Spain
- * E-mail: (ML M-C); (TCD)
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6
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Kristiansen RG. Current state of knowledge of hepatic encephalopathy (part I): newer treatment strategies for hyperammonemia in liver failure. Metab Brain Dis 2016; 31:1357-1358. [PMID: 27651377 DOI: 10.1007/s11011-016-9908-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Accepted: 09/05/2016] [Indexed: 01/27/2023]
Abstract
Alterations in interorgan metabolism of ammonia play an important role in the onset of hyperammonemia in liver failure. Glutamine synthetase (GS) in muscle is an important target for ammonia removal strategies in hyperammonemia. Ornithine Phenylacetate (OP) is hypothesized to remove ammonia by providing glutamate as a substrate for increased GS activity and hence glutamine production. The newly generated glutamine conjugates with phenylacetate forming phenylacetylglutamine which can be excreted in the urine, providing an excretion pathway for ammonia. We have also shown that OP targets glycine metabolism, providing an additional ammonia reducing effect.
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Affiliation(s)
- Rune Gangsoy Kristiansen
- Department of Anesthesiology, Anesthesia and Critical Care Research Group, University Hospital of North Norway, UiT-The Arctic University of Norway, Tromsø, Norway.
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7
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Milewski K, Oria M. What we know: the inflammatory basis of hepatic encephalopathy. Metab Brain Dis 2016; 31:1239-1247. [PMID: 26497651 DOI: 10.1007/s11011-015-9740-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 09/24/2015] [Indexed: 02/07/2023]
Abstract
Central Nervous System (CNS) degeneration appearing in patients with cirrhosis is responsible for cognitive and persistent motor impairments that lead to an important impact on life quality. Brain injury affects certain areas of the CNS that might affect two types of cells: neurons and astrocytes. The process leading to brain injury could be induced by portosystemic shunting accompanied by hyperammonemia and by the activation of peripheral inflammation, manifested as episodic encephalopathy. Hyperammonemia combined with a decrease on the BCA/AAA ratio induces alterations of energetic metabolism and the formation of free radicals in the CNS. This process would be stimulated by the activation of peripheral inflammatory mediators that could act on receptors of the blood brain barrier such as TLR4, activating inflammatory responses in the CNS. As a result, a persistent activation of microglia and an irreversible neuronal and astrocytic injury would be induced. A new knowledge of the mechanisms leading to brain injury in cirrhosis would develop protective strategies to correct changes of nitrogen metabolism and inflammation.
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Affiliation(s)
- K Milewski
- Department of Neurotoxicology, Mossakowski Medical Research Centre, Polish Academy of Sciences, Pawińskiego 5 Str, 02-106, Warsaw, Poland
| | - M Oria
- Translational Research in Fetal Surgery for Congenital Malformations, Center for Fetal, Cellular and Molecular Therapy, Division of Pediatric General and Thoracic Surgery, Cincinnati Children's Hospital Medical Center (CCHMC), 3333 Burnet Avenue, MLC 11020, S 8.400 AT, Cincinnati, OH, 45229-3039, USA.
- Liver Failure Group, UCL Institute for Liver and Digestive Health, Royal Free Hospital, University College London, London, UK.
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8
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Kristiansen RG, Rose CF, Ytrebø LM. Glycine and hyperammonemia: potential target for the treatment of hepatic encephalopathy. Metab Brain Dis 2016; 31:1269-1273. [PMID: 27339764 DOI: 10.1007/s11011-016-9858-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 06/12/2016] [Indexed: 01/10/2023]
Abstract
Hepatic encephalopathy (HE) is a neuropsychiatric disorder caused by hepatic dysfunction. Numerous studies dictate that ammonia plays an important role in the pathogenesis of HE, and hyperammonemia can lead to alterations in amino acid homeostasis. Glutamine and glycine are both ammoniagenic amino acids that are increased in liver failure. Modulating the levels of glutamine and glycine has shown to reduce ammonia concentration in hyperammonemia. Ornithine Phenylacetate (OP) has consistently been shown to reduce arterial ammonia levels in liver failure by modulating glutamine levels. In addition to this, OP has also been found to modulate glycine concentration providing an additional ammonia removing effect. Data support that glycine also serves an important role in N-methyl D-aspartate (NMDA) receptor mediated neurotransmission in HE. This potential important role for glycine in the pathogenesis of HE merits further investigations.
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Affiliation(s)
- Rune Gangsøy Kristiansen
- Department of Anesthesiology, Anesthesia and Critical Care Research Group, University Hospital of North Norway and UiT-The Arctic University of Norway, Tromsø, Norway.
- Department of Anesthesiology, Ålesund Hospital, Helse Møre og Romsdal, 6010, Ålesund, Norway.
| | - Christopher F Rose
- Hepato-Neuro Laboratory, CRCHUM, Université de Montréal, Montréal, QC, Canada
| | - Lars Marius Ytrebø
- Department of Anesthesiology, Anesthesia and Critical Care Research Group, University Hospital of North Norway and UiT-The Arctic University of Norway, Tromsø, Norway
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9
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Abstract
OPINION STATEMENT Liver disease, both in its acute and chronic forms, can be associated with a wide spectrum of neurologic manifestations, both central and peripheral, ranging in severity from subclinical changes to neurocritical conditions. Neurologists are frequently consulted to participate in their management. In this review, we present an overview of management strategies for patients with hepatic disease whose clinical course is complicated by neurologic manifestations. Type A hepatic encephalopathy (HE), which occurs in acute liver failure, is a neurologic emergency, and multiple measures should be taken to prevent and treat cerebral edema. In Type C HE, which occurs in chronic liver disease, management should be aimed at correcting precipitant factors and hyperammonemia. There is an increasing spectrum of drug treatments available to minimize ammonia toxicity. Acquired hepatocerebral degeneration is a rare complication of the chronic form of HE, with typical clinical and brain MRI findings, whose most effective treatment is liver transplantation. Epilepsy is frequent and of multifactorial cause in patients with hepatic disease, and careful considerations should be made regarding choice of the appropriate anti-epileptic drugs. Several mechanisms increase the risk of stroke in hepatic disease, but many of the drugs used to treat and prevent stroke are contraindicated in severe hepatic failure. Hepatitis C infection increases the risk of ischemic stroke. Hemorrhagic stroke is more frequent in patients with liver disease of alcoholic etiology. Viral hepatitis is associated with a wide range of immune-mediated complications, mostly in the peripheral nervous system, which respond to different types of immunomodulatory treatment. Several drugs used to treat hepatic disease, such as the classical and the new direct-acting antivirals, may have neurologic complications which in some cases preclude its continued use.
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10
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Vairappan B. Endothelial dysfunction in cirrhosis: Role of inflammation and oxidative stress. World J Hepatol 2015; 7:443-459. [PMID: 25848469 PMCID: PMC4381168 DOI: 10.4254/wjh.v7.i3.443] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 11/08/2014] [Accepted: 12/01/2014] [Indexed: 02/06/2023] Open
Abstract
This review describes the recent developments in the pathobiology of endothelial dysfunction (ED) in the context of cirrhosis with portal hypertension and defines novel strategies and potential targets for therapy. ED has prognostic implications by predicting unfavourable early hepatic events and mortality in patients with portal hypertension and advanced liver diseases. ED characterised by an impaired bioactivity of nitric oxide (NO) within the hepatic circulation and is mainly due to decreased bioavailability of NO and accelerated degradation of NO with reactive oxygen species. Furthermore, elevated inflammatory markers also inhibit NO synthesis and causes ED in cirrhotic liver. Therefore, improvement of NO availability in the hepatic circulation can be beneficial for the improvement of endothelial dysfunction and associated portal hypertension in patients with cirrhosis. Furthermore, therapeutic agents that are identified in increasing NO bioavailability through improvement of hepatic endothelial nitric oxide synthase (eNOS) activity and reduction in hepatic asymmetric dimethylarginine, an endogenous modulator of eNOS and a key mediator of elevated intrahepatic vascular tone in cirrhosis would be interesting therapeutic approaches in patients with endothelial dysfunction and portal hypertension in advanced liver diseases.
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