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Luyendyk JP, Morozova E, Copple BL. Good Cells Go Bad: Immune Dysregulation in the Transition from Acute Liver Injury to Liver Failure After Acetaminophen Overdose. Drug Metab Dispos 2024; 52:722-728. [PMID: 38050055 PMCID: PMC11257689 DOI: 10.1124/dmd.123.001280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 11/12/2023] [Accepted: 11/27/2023] [Indexed: 12/06/2023] Open
Abstract
The role of inflammatory cells and other components of the immune system in acetaminophen (APAP)-induced liver injury and repair has been extensively investigated. Although this has resulted in a wealth of information regarding the function and regulation of immune cells in the liver after injury, apparent contradictions have fueled controversy around the central question of whether the immune system is beneficial or detrimental after APAP overdose. Ultimately, this may not be a simple assignment of "good" or "bad." Clinical studies have clearly demonstrated an association between immune dysregulation and a poor outcome in patients with severe liver damage/liver failure induced by APAP overdose. To date, studies in mice have not uniformly replicated this connection. The apparent disconnect between clinical and experimental studies has perhaps stymied progress and further complicated investigation of the immune system in APAP-induced liver injury. Mouse models are often dismissed as not recapitulating the clinical scenario. Moreover, clinical investigation is most often focused on the most severe APAP overdose patients, those with liver failure. Notably, recent studies have made it apparent that the functional role of the immune system in the pathogenesis of APAP-induced liver injury is highly context dependent and greatly influenced by the experimental conditions. In this review, we highlight some of these recent findings and suggest strategies seeking to resolve and build on existing disconnects in the literature. SIGNIFICANCE STATEMENT: Acetaminophen overdose is the most frequent cause of acute liver failure in the United States. Studies indicate that dysregulated innate immunity contributes to the transition from acute liver injury to acute liver failure. In this review, we discuss the evidence for this and the potential underlying causes.
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Affiliation(s)
- James P Luyendyk
- Departments of Pathobiology and Diagnostic Investigation (J.P.L., E.M.) and Pharmacology and Toxicology (B.L.C.), Michigan State University, East Lansing, Michigan
| | - Elena Morozova
- Departments of Pathobiology and Diagnostic Investigation (J.P.L., E.M.) and Pharmacology and Toxicology (B.L.C.), Michigan State University, East Lansing, Michigan
| | - Bryan L Copple
- Departments of Pathobiology and Diagnostic Investigation (J.P.L., E.M.) and Pharmacology and Toxicology (B.L.C.), Michigan State University, East Lansing, Michigan
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2
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Reutemann B, Gordon FD. Evaluation of the Patient with Markedly Abnormal Liver Enzymes. Clin Liver Dis 2023; 27:1-16. [PMID: 36400459 DOI: 10.1016/j.cld.2022.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Liver enzyme tests are very commonly ordered by physicians, and when they return as abnormal, they can pose a clinical challenge to the provider. Markedly abnormal liver enzymes indicate severe hepatic injury and require immediate evaluation. There are various causes for abnormal liver tests, including infectious, autoimmune, genetic, metabolic, drug, and vascular causes. An understanding of the patterns of aminotransferase and alkaline phosphatase elevations is useful in narrowing the differential diagnosis. A thorough history and physical examination, appropriate blood testing, and imaging are typically key to evaluating the patient with abnormal liver enzymes.
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Affiliation(s)
- Bethany Reutemann
- Dartmouth Hitchock Medical Center, 100 Hitchcock Way, Manchester, NH 03104, USA.
| | - Fredric D Gordon
- Tufts Medical Center, 800 Washington St. #40, South Building, 4th floor, Boston, MA 02111, USA
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Zaghmi A, Pérez-Mato M, Dopico-López A, Candamo-Lourido M, Campos F, Gauthier MA. New Perspectives for Developing Therapeutic Bioconjugates of Metabolite-Depleting Enzymes: Lessons Learned Combating Glutamate Excitotoxicity. Biomacromolecules 2022; 23:1864-1872. [PMID: 35394759 DOI: 10.1021/acs.biomac.2c00117] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Glutamate, the main excitatory neurotransmitter in the central nervous system, plays an essential role in several cognitive activities such as memorizing and learning. Excessive glutamate release and disturbance of glutamate homeostasis participates in multiple neuronal pathologies including cerebral ischemia (inadequate blood supply), traumatic brain injury (e.g., from a fall or an accident), multiple sclerosis, epilepsy, migraine, fetal hypoxia, or Alzheimer's disease. Attenuating excitotoxicity by, for example, targeting glutamate receptors has proved to be beneficial in animal models but has largely failed in clinical trials because of toxic side effects. New therapeutic concepts have been explored to reduce the excitotoxic effect caused by the excessive glutamate release by using or stimulating glutamate-depleting enzymes in the bloodstream. These enzymes indirectly act upon the brain by depleting glutamate in the bloodstream, which is believed to siphon it out of the brain. Recent studies have shown that bioconjugate approaches applied to such enzymes exacerbate this therapeutic effect but raise additional questions for future research. This Perspective provides an overview of lessons learned by our group when exploring bioconjugate approaches for combatting glutamate excitotoxicity as an illustration of how research on therapeutic bioconjugates is evolving.
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Affiliation(s)
- Ahlem Zaghmi
- Institut National de la Recherche Scientifique, EMT Research Center, Varennes J3X 1S2, Canada
| | - María Pérez-Mato
- Neuroscience and Cerebrovascular Research Laboratory, Department of Neurology and Stroke Center, La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Universidad Autónoma de Madrid, Madrid 28049, Spain
| | - Antonio Dopico-López
- Clinical Neuroscience Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela 15782, Spain
| | - María Candamo-Lourido
- Clinical Neuroscience Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela 15782, Spain
| | - Francisco Campos
- Clinical Neuroscience Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela 15782, Spain
| | - Marc A Gauthier
- Institut National de la Recherche Scientifique, EMT Research Center, Varennes J3X 1S2, Canada
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4
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Liver enzyme delayed clearance in rat treated by CSF1 receptor specific antagonist Sotuletinib. Curr Res Toxicol 2022; 3:100091. [DOI: 10.1016/j.crtox.2022.100091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 10/25/2022] [Accepted: 10/26/2022] [Indexed: 11/06/2022] Open
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Åberg F, Danford CJ, Thiele M, Talbäck M, Rasmussen DN, Jiang ZG, Hammar N, Nasr P, Ekstedt M, But A, Puukka P, Krag A, Sundvall J, Erlund I, Salomaa V, Stål P, Kechagias S, Hultcrantz R, Lai M, Afdhal N, Jula A, Männistö S, Lundqvist A, Perola M, Färkkilä M, Hagström H. A Dynamic Aspartate-to-Alanine Aminotransferase Ratio Provides Valid Predictions of Incident Severe Liver Disease. Hepatol Commun 2021; 5:1021-1035. [PMID: 34141987 PMCID: PMC8183175 DOI: 10.1002/hep4.1700] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/14/2021] [Accepted: 02/01/2021] [Indexed: 12/15/2022] Open
Abstract
The aspartate-to-alanine aminotransferase ratio (AAR) is associated with liver fibrosis, but its predictive performance is suboptimal. We hypothesized that the association between AAR and liver disease depends on absolute transaminase levels and developed and validated a model to predict liver-related outcomes in the general population. A Cox regression model based on age, AAR, and alanine aminotransferase (ALT) level (dynamic AAR [dAAR]) using restricted cubic splines was developed in Finnish population-based health-examination surveys (FINRISK, 2002-2012; n = 18,067) with linked registry data for incident liver-related hospitalizations, hepatocellular carcinoma, or liver death. The model was externally validated for liver-related outcomes in a Swedish population cohort (Swedish Apolipoprotein Mortality Risk [AMORIS] subcohort; n = 126,941) and for predicting outcomes and/or prevalent fibrosis/cirrhosis in biopsied patients with nonalcoholic fatty liver disease (NAFLD), chronic hepatitis C, or alcohol-related liver disease (ALD). The dynamic AAR model predicted liver-related outcomes both overall (optimism-corrected C-statistic, 0.81) and in subgroup analyses of the FINRISK cohort and identified persons with >10% risk for liver-related outcomes within 10 years. In independent cohorts, the C-statistic for predicting liver-related outcomes up to a 10-year follow-up was 0.72 in the AMORIS cohort, 0.81 in NAFLD, and 0.75 in ALD. Area-under-the-curve (AUC) for detecting prevalent cirrhosis was 0.80-0.83 in NAFLD, 0.80 in hepatitis C, but only 0.71 in ALD. In ALD, model performance improved when using aspartate aminotransferase instead of ALT in the model (C-statistic, 0.84 for outcome; AUC, 0.82 for prevalent cirrhosis). Conclusion: A dAAR score provides prospective predictions for the risk of incident severe liver outcomes in the general population and helps detect advanced liver fibrosis/cirrhosis. The dAAR score could potentially be used for screening the unselected general population and as a trigger for further liver evaluations.
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Affiliation(s)
- Fredrik Åberg
- Transplantation and Liver Surgery ClinicHelsinki University HospitalHelsinki UniversityHelsinkiFinland
- The Transplant InstituteSahlgrenska University HospitalGothenburgSweden
| | - Christopher J. Danford
- Division of Gastroenterology and HepatologyBeth Israel Deaconess Medical CenterBostonMAUSA
| | - Maja Thiele
- Department of Gastroenterology and HepatologyOdense University HospitalOdenseDenmark
- Department for Clinical ResearchUniversity of Southern DenmarkOdenseDenmark
| | - Mats Talbäck
- Unit of EpidemiologyInstitute of Environmental MedicineKarolinska InstitutetStockholmSweden
| | | | - Z. Gordon Jiang
- Division of Gastroenterology and HepatologyBeth Israel Deaconess Medical CenterBostonMAUSA
| | - Niklas Hammar
- Unit of EpidemiologyInstitute of Environmental MedicineKarolinska InstitutetStockholmSweden
| | - Patrik Nasr
- Department of Health, Medicine, and Caring SciencesLinköping UniversityLinköpingSweden
| | - Mattias Ekstedt
- Department of Health, Medicine, and Caring SciencesLinköping UniversityLinköpingSweden
| | - Anna But
- Biostatistics ConsultingDepartment of Public HealthUniversity of Helsinki and Helsinki University HospitalHelsinkiFinland
| | | | - Aleksander Krag
- Department of Gastroenterology and HepatologyOdense University HospitalOdenseDenmark
- Department for Clinical ResearchUniversity of Southern DenmarkOdenseDenmark
| | - Jouko Sundvall
- Department of Government ServicesFinnish Institute for Health and WelfareHelsinkiFinland
| | - Iris Erlund
- Department of Government ServicesFinnish Institute for Health and WelfareHelsinkiFinland
| | | | - Per Stål
- Unit of HepatologyDivision of Upper Gastrointestinal DiseasesKarolinska University HospitalStockholmSweden
- Department of MedicineHuddingeKarolinska InstitutetStockholmSweden
| | - Stergios Kechagias
- Department of Health, Medicine, and Caring SciencesLinköping UniversityLinköpingSweden
| | - Rolf Hultcrantz
- Department of MedicineSolnaKarolinska InstitutetStockholmSweden
| | - Michelle Lai
- Division of Gastroenterology and HepatologyBeth Israel Deaconess Medical CenterBostonMAUSA
| | - Nezam Afdhal
- Division of Gastroenterology and HepatologyBeth Israel Deaconess Medical CenterBostonMAUSA
| | - Antti Jula
- Finnish Institute for Health and WelfareHelsinkiFinland
| | - Satu Männistö
- Finnish Institute for Health and WelfareHelsinkiFinland
| | | | - Markus Perola
- Finnish Institute for Health and WelfareHelsinkiFinland
| | - Martti Färkkilä
- Clinic of GastroenterologyHelsinki University and Helsinki University HospitalHelsinkiFinland
| | - Hannes Hagström
- Unit of HepatologyDivision of Upper Gastrointestinal DiseasesKarolinska University HospitalStockholmSweden
- Department of MedicineHuddingeKarolinska InstitutetStockholmSweden
- Unit of EpidemiologyDepartment of Medicine SolnaKarolinska InstitutetStockholmSweden
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Schadt HS, Wolf A, Mahl JA, Wuersch K, Couttet P, Schwald M, Fischer A, Lienard M, Emotte C, Teng CH, Skuba E, Richardson TA, Manenti L, Weiss A, Graus Porta D, Fairhurst RA, Kullak-Ublick GA, Chibout SD, Pognan F, Kluwe W, Kinyamu-Akunda J. Bile Acid Sequestration by Cholestyramine Mitigates FGFR4 Inhibition-Induced ALT Elevation. Toxicol Sci 2019; 163:265-278. [PMID: 29432567 DOI: 10.1093/toxsci/kfy031] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The FGF19- fibroblast growth factor receptor (FGFR4)-βKlotho (KLB) pathway plays an important role in the regulation of bile acid (BA) homeostasis. Aberrant activation of this pathway has been described in the development and progression of a subset of liver cancers including hepatocellular carcinoma, establishing FGFR4 as an attractive therapeutic target for such solid tumors. FGF401 is a highly selective FGFR4 kinase inhibitor being developed for hepatocellular carcinoma, currently in phase I/II clinical studies. In preclinical studies in mice and dogs, oral administration of FGF401 led to induction of Cyp7a1, elevation of its peripheral marker 7alpha-hydroxy-4-cholesten-3-one, increased BA pool size, decreased serum cholesterol and diarrhea in dogs. FGF401 was also associated with increases of serum aminotransferases, primarily alanine aminotransferase (ALT), in the absence of any observable adverse histopathological findings in the liver, or in any other organs. We hypothesized that the increase in ALT could be secondary to increased BAs and conducted an investigative study in dogs with FGF401 and coadministration of the BA sequestrant cholestyramine (CHO). CHO prevented and reversed FGF401-related increases in ALT in dogs in parallel to its ability to reduce BAs in the circulation. Correlation analysis showed that FGF401-mediated increases in ALT strongly correlated with increases in taurolithocholic acid and taurodeoxycholic acid, the major secondary BAs in dog plasma, indicating a mechanistic link between ALT elevation and changes in BA pool hydrophobicity. Thus, CHO may offer the potential to mitigate elevations in serum aminotransferases in human subjects that are caused by targeted FGFR4 inhibition and elevated intracellular BA levels.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Corinne Emotte
- PK Sciences, Novartis Institutes for Biomedical Research, 4002 Basel, Switzerland
| | - Chi-Hse Teng
- Biostatistics and Pharmacometrics, Novartis Institutes for Biomedical Research, Cambridge, Massachusetts 02139
| | | | | | - Luigi Manenti
- Oncology, Novartis Institutes for Biomedical Research, East Hanover, New Jersey 07936
| | | | | | - Robin A Fairhurst
- Global Discovery Chemistry, Novartis Institutes for Biomedical Research, 4002 Basel, Switzerland
| | - Gerd A Kullak-Ublick
- Mechanistic Safety, Novartis Global Drug Development, 4002 Basel, Switzerland.,Department of Clinical Pharmacology and Toxicology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland
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7
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Pognan F, Couttet P, Demin I, Jaitner B, Pang Y, Roubenoff R, Sutter E, Timsit Y, Valentin MA, Vogel B, Woerly G, Wolf A, Schramm U. Colony-Stimulating Factor-1 Antibody Lacnotuzumab in a Phase 1 Healthy Volunteer Study and Mechanistic Investigation of Safety Outcomes. J Pharmacol Exp Ther 2019; 369:428-442. [DOI: 10.1124/jpet.118.254128] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 03/18/2019] [Indexed: 01/09/2023] Open
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8
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Zoppini G, Cacciatori V, Negri C, Stoico V, Lippi G, Targher G, Bonora E. The aspartate aminotransferase-to-alanine aminotransferase ratio predicts all-cause and cardiovascular mortality in patients with type 2 diabetes. Medicine (Baltimore) 2016; 95:e4821. [PMID: 27787357 PMCID: PMC5089086 DOI: 10.1097/md.0000000000004821] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
An increased aspartate aminotransferase-to-alanine aminotransferase ratio (AAR) has been widely used as a marker of advanced hepatic fibrosis. Increased AAR was also shown to be significantly associated with the risk of developing cardiovascular (CV) disease. The aim of this study was to assess the relationship between the AAR and mortality risk in a well-characterized cohort of patients with type 2 diabetes.A cohort of 2529 type 2 diabetic outpatients was followed-up for 6 years to collect cause-specific mortality. Cox regression analyses were modeled to estimate the independent association between AAR and the risk of all-cause and CV mortality.Over the 6-year follow-up period, 12.1% of patients died, 47.5% of whom from CV causes. An increased AAR, but not its individual components, was significantly associated with an increased risk of all-cause (adjusted-hazard risk 1.83, confidence interval [CI] 95% 1.14-2.93, P = 0.012) and CV (adjusted-hazard risk 2.60, CI 95% 1.38-4.90, P < 0.003) mortality after adjustment for multiple clinical risk factors and potential confounding variables.The AAR was independently associated with an increased risk of both all-cause and CV mortality in patients with type 2 diabetes. These findings suggest that an increased AAR may reflect more systemic derangements that are not simply limited to liver damage. Further studies are needed to elucidate the pathophysiological implications of an increased AAR.
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Affiliation(s)
- Giacomo Zoppini
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine
- Correspondence: Giacomo Zoppini, Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, Azienda Ospedaliera Universitaria Integrata, Piazzale Stefani, 1, 37126 Verona, Italy (e-mail: )
| | | | - Carlo Negri
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine
| | - Vincenzo Stoico
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine
| | - Giuseppe Lippi
- Section of Clinical Biochemistry, Azienda Ospedaliera Universitaria Integrata, University of Verona, Verona, Italy
| | - Giovanni Targher
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine
| | - Enzo Bonora
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine
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9
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Liver. CANINE AND FELINE GASTROENTEROLOGY 2013. [PMCID: PMC7161409 DOI: 10.1016/b978-1-4160-3661-6.00061-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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10
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Calvaruso V, Cammà C, Di Marco V, Maimone S, Bronte F, Enea M, Dardanoni V, Manousou P, Pleguezuelo M, Xirouchakis E, Attanasio M, Dusheiko G, Burroughs AK, Craxì A. Fibrosis staging in chronic hepatitis C: analysis of discordance between transient elastography and liver biopsy. J Viral Hepat 2010; 17:469-74. [PMID: 19780940 DOI: 10.1111/j.1365-2893.2009.01199.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In chronic hepatitis C, transient elastography (TE) accurately identifies cirrhosis, but its ability to assess significant fibrosis (Metavir > or = F2) is variable. Constitutional and liver disease-related factors may influence TE and here we examined the variables associated with differences. Three hundred consecutive hepatitis C virus (HCV)-RNA positive patients had biochemical tests, TE and a biopsy performed on the same day. The Dale model was used to identify the variables associated with discordance between biopsy and elastography results. In 97 patients (34.2%), TE and histological assessment were discordant. Seventy-six of 286 (26.6%) had stage > or =F2 and TE < 7.1 kPa (false negative); 21 of 286 (7.3%) had stage <F2 and TE > or = 7.1 kPa (false positive). No patient with discordant results had cirrhosis. By Dale model, aspartate aminotransferase (AST) was found to be the unique variable significantly related (P = 0.046) with discordance between biopsy and TE. Discordance rate was 43.4% (82 patients) with AST < 1.5 x UNL vs 25.8% (25 patients) with AST > or = 1.5 x UNL (P = 0.004). False negative rate was 43.4 (82 patients) with AST < 1.5 x UNL vs 17.1% (13 patients) with AST > or = 1.5 x UNL (P < 0.001). Areas under the receiver operating characteristic (AUROC) for F > or = 2, according to AST < 1.5 x UNL vs > or = 1.5 x UNL were 0.738 (95% CI: 0.683-0.812) and 0.854(95% CI: 0.754-0.907). Transient elastography is not adequate on its own to rule out or to rule in significant fibrosis, as it is influenced by major variations in biochemical activity of liver disease. Liver stiffness, at low levels of AST, can underestimate fibrosis.
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Affiliation(s)
- V Calvaruso
- Gastroenterologia & Epatologia, DIBIMIS, Università di Palermo, Palermo, Italy.
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11
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Toniutto P, Fabris C, Bitetto D, Falleti E, Avellini C, Rossi E, Smirne C, Minisini R, Pirisi M. Role of AST to platelet ratio index in the detection of liver fibrosis in patients with recurrent hepatitis C after liver transplantation. J Gastroenterol Hepatol 2007; 22:1904-8. [PMID: 17914968 DOI: 10.1111/j.1440-1746.2006.04628.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
BACKGROUND AND AIM Per protocol annual liver biopsy represents the gold standard in the assessment of graft fibrosis progression due to recurrent hepatitis C after liver transplantation. Non-invasive liver fibrosis tests have been proposed as surrogate markers of liver fibrosis in hepatitis C virus (HCV)-positive immune-competent patients. No data are available in the literature on the usefulness of non-invasive liver fibrosis tests in liver transplanted patients with recurrent HCV infection. METHODS A total of 102 annual per protocol liver biopsies performed in 51 consecutive HCV-positive recipients (31 men), with a follow-up period lasting up to 5 years, were included and evaluated in this study. At each time point, the following non-invasive liver fibrosis tests were calculated: aspartate aminotransferase (AST) to alanine aminotransferase (ALT) ratio, age-platelet index, AST to platelet ratio index (APRI), Forns' fibrosis index and Bonacini's discriminant score. RESULTS In discriminating patients with histological fibrosis score >2, APRI provided the best area under the receiver operating characteristic curves (AUROC) (0.801), in comparison to the other four non-invasive liver fibrosis tests. The AUROC of APRI was better in female (0.871) than in male (0.753) recipients. Among female recipients, an APRI value >1.4 was 91% sensitive and 75% specific in detecting a staging score >2. The corresponding values among male recipients were 60% and 77%, respectively. CONCLUSIONS Among non-invasive liver fibrosis tests, APRI has the highest diagnostic value in discriminating liver transplanted patients with progression to significant liver fibrosis, although its accuracy is influenced by recipient sex.
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Affiliation(s)
- Pierluigi Toniutto
- DPMSC, Medical Liver Transplant Unit, University of Udine, Udine, Italy.
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12
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Abstract
Abnormalities in liver enzymes are commonly encountered in clinical practice. Knowledgeable assessment requires a full understanding of their pathophysiology and provides an important means of detecting the earliest stage of many serious hepatobiliary disorders. The best interpretations are achieved using an integrated approach, combining historical and physical findings with routine and specialized diagnostic procedures and imaging studies. Information in this article provides the foundation, by example, for understanding the reliability of single time point enzyme measurements, the value of sequential measurements, the importance of interpreting the activity of enzymes in light of their half life and tissue of origin, and the influence of the induction phenomenon.
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Affiliation(s)
- Sharon A Center
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
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13
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Pol S, Nalpas B, Vassault A, Bousquet-Lemercier B, Franco D, Lacour B, Berthelot P, Hanoune J, Barouki R. Hepatic activity and mRNA expression of aspartate aminotransferase isoenzymes in alcoholic and nonalcoholic liver disease. Hepatology 1991. [PMID: 1916663 DOI: 10.1002/hep.1840140408] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/14/2023]
Affiliation(s)
- S Pol
- Unité d'Hépatologie, Hôpital Laënnec, Paris, France
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14
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Pappas NJ. Theoretical Aspects of Enzymes in Diagnosis: Why Do Serum Enzymes Change in Hepatic, Myocardial, and Other Diseases? Clin Lab Med 1989. [DOI: 10.1016/s0272-2712(18)30594-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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15
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16
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Smit MJ, Duursma AM, Bouma JM, Gruber M. Receptor-mediated endocytosis of lactate dehydrogenase M4 by liver macrophages: a mechanism for elimination of enzymes from plasma. Evidence for competition by creatine kinase MM, adenylate kinase, malate, and alcohol dehydrogenase. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)45160-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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17
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Fukuda S, Horiuchi S, Tomita K, Murakami M, Morino Y, Takahashi K. Acetylated low-density lipoprotein is endocytosed through coated pits by rat peritoneal macrophages. VIRCHOWS ARCHIV. B, CELL PATHOLOGY INCLUDING MOLECULAR PATHOLOGY 1986; 52:1-13. [PMID: 2881390 DOI: 10.1007/bf02889945] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The surface distribution of the scavenger receptors for acetylated low-density lipoprotein (acetyl-LDL) and their endocytic behavior were studied by the direct immunoperoxidase method using monomeric conjugates of horseradish peroxidase with Fab' antibody raised against LDL. The receptors were demonstrated to be distributed diffusely on the surface membrane of cultured peritoneal macrophages, with preferential localization in coated pit regions. With temperature shift from 4 degrees C to 37 degrees C, acetyl-LDL bound to the surface membrane rapidly disappeared, but became detectable in coated vesicles or lysosomes. Further incubation in the presence of acetyl-LDL revealed lipid vacuoles devoid of a limiting membrane in the cytoplasm, transforming macrophages into typical foam cells. These data suggest that the binding of acetyl-LDL to its receptors triggers the clustering of the receptors into the coated pit regions through which acetyl-LDL is endocytosed by coated vesicles to be degraded in lysosomes with subsequent intracellular accumulation of cholesterol esters.
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18
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Murakami M, Horiuchi S, Takata K, Morino Y. Scavenger receptor for malondialdehyde-modified high density lipoprotein on rat sinusoidal liver cells. Biochem Biophys Res Commun 1986; 137:29-35. [PMID: 3013183 DOI: 10.1016/0006-291x(86)91171-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We report here the presence of a membrane-associated receptor which mediates endocytic uptake of malondialdehyde-modified high density lipoprotein (MDA-HDL) on sinusoidal liver cells. Binding of [125I]MDA-HDL to the cells was followed by internalization and degradation in lysosomes. The binding and lysosomal degradation of [125I]MDA-HDL were effectively inhibited by unlabeled MDA-HDL and acetyl-HDL. However, formaldehyde-treated serum albumin or low density lipoprotein modified either by acetylation or malondialdehyde, ligands known to undergo receptor-mediated endocytosis by sinusoidal liver cells, did not affect the binding of [125I]MDA-HDL to the cells. These results indicate that a receptor for MDA-HDL is described as a distinct member among the scavenger receptors for chemically modified proteins.
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Kamimoto Y, Horiuchi S, Tanase S, Morino Y. Plasma clearance of intravenously injected aspartate aminotransferase isozymes: evidence for preferential uptake by sinusoidal liver cells. Hepatology 1985; 5:367-75. [PMID: 3997068 DOI: 10.1002/hep.1840050305] [Citation(s) in RCA: 128] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Both cytosolic (c-AAT) and mitochondrial (m-AAT) isozymes of aspartate aminotransferase (EC 2.6.1.1) appear in serum in some diseases including hepatobiliary dysfunction. The present study aimed at elucidation of the mechanism by which AAT isozymes are cleared from blood. Intravenous injection into rats of m-AAT and c-AAT purified from rat liver exhibited a biphasic clearance curve with an overall half-life of 42 min and 4.7 hr, respectively. The tissue distribution of the radioactivity following intravenous administration of 125I-labeled isozymes revealed that the liver is a major organ involved in plasma clearance of these isozymes. This conclusion was also supported by the significant retardation in plasma clearance of m-AAT in hepatectomized as well as CCl4-intoxicated rats. Furthermore, clearance rate of each AAT isozyme in an isolated perfused liver exhibited a single exponential process with the uptake rate for m-AAT being much faster than that for c-AAT. Separation of hepatocytes and sinusoidal liver cells from the rat intravenously injected with 125I-labeled AAT isozymes revealed that sinusoidal cells were responsible for the plasma clearances. In vitro uptake study showed that both isozymes were exclusively taken up by sinusoidal liver cells. The uptake rate for m-AAT was considerably greater than that for c-AAT. Endocytotic index for uptake by sinusoidal cells was 16 times with c-AAT and 34 times with m-AAT as compared with that for inulin or dextran which are taken up by fluid-phase endocytosis, suggesting involvement of adsorptive endocytosis in the uptake of the isozymes.
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