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Yuming Z, Ruqi T, Gershwin ME, Xiong M. Autoimmune Hepatitis: Pathophysiology. Clin Liver Dis 2024; 28:15-35. [PMID: 37945156 DOI: 10.1016/j.cld.2023.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
Genome-wide association analyses suggest that HLA genes including HLA-DRB*0301, HLA-DRB*0401, and HLA-B*3501 as well as non-HLA genes including CD28/CTLA4/ICOS and SYNPR increased AIH susceptibility. The destruction of hepatocytes is the result of the imbalance between proinflammatory cells and immunosuppressive cells, especially the imbalance between Tregs and Th17 cells. The microbiome in patients with AIH is decreased in diversity with a specific decline in Bifidobacterium and enrichment in Veillonella and Faecalibacterium. Recent evidence has demonstrated the pathogenic role of E. gallinarum and L.reuteri in inducing autoimmunity in the liver.
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Affiliation(s)
- Zhou Yuming
- Division of Gastroenterology and Hepatology, Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, NHC Key Laboratory of Digestive Diseases, State Key Laboratory for Oncogenes and Related Genes, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Institute of Digestive Disease, 145 Middle Shandong Road, Shanghai, China
| | - Tang Ruqi
- Division of Gastroenterology and Hepatology, Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, NHC Key Laboratory of Digestive Diseases, State Key Laboratory for Oncogenes and Related Genes, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Institute of Digestive Disease, 145 Middle Shandong Road, Shanghai, China
| | - Merrill Eric Gershwin
- Division of Rheumatology, Department of Medicine, Allergy and Clinical Immunology, University of California at Davis, 451 Health Sciences Drive, Suite 6510, Davis, CA 95616, USA.
| | - Ma Xiong
- Division of Gastroenterology and Hepatology, Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, NHC Key Laboratory of Digestive Diseases, State Key Laboratory for Oncogenes and Related Genes, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai Institute of Digestive Disease, 145 Middle Shandong Road, Shanghai, China; Institute of Aging & Tissue Regeneration, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
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Poddighe D, Maulenkul T, Zhubanova G, Akhmaldtinova L, Dossybayeva K. Natural Killer T (NKT) Cells in Autoimmune Hepatitis: Current Evidence from Basic and Clinical Research. Cells 2023; 12:2854. [PMID: 38132174 PMCID: PMC10742140 DOI: 10.3390/cells12242854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Revised: 12/05/2023] [Accepted: 12/05/2023] [Indexed: 12/23/2023] Open
Abstract
Natural killer T (NKT) cells are unconventional T cells that are activated by glycolipid antigens. They can produce a variety of inflammatory and regulatory cytokines and, therefore, modulate multiple aspects of the immune response in different pathological settings, including autoimmunity. NKT cells have also been implicated in the immunopathogenesis of autoimmune hepatitis, and in this review we summarize and analyze the main studies investigating the involvement and/or homeostasis of NKT cells in this disease. In detail, the evidence from both basic and clinical research has been specifically analyzed. Even though the experimental murine models supported a relevant role of NKT cells in immune-mediated hepatic injury, very few studies specifically investigated NKT cell homeostasis in patients with autoimmune hepatitis; however, these initial studies reported some alterations of NKT cells in these patients, which may also correlate with the disease activity to some extent. Further clinical studies are needed to investigate the potential role and use of NKT cell analysis as a disease marker of clinical relevance, and to better understand the precise cellular and molecular mechanisms by which NKT cells contribute to the pathogenesis of autoimmune hepatitis.
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Affiliation(s)
- Dimitri Poddighe
- School of Medicine, Nazarbayev University, Kerei-Zhanibek Str. 5/1, Astana 010000, Kazakhstan
- Clinical Academic Department of Pediatrics, National Research Center for Maternal and Child Health, University Medical Center, Astana 010000, Kazakhstan
| | - Tilektes Maulenkul
- School of Medicine, Nazarbayev University, Kerei-Zhanibek Str. 5/1, Astana 010000, Kazakhstan
- Clinical Academic Department of Pediatrics, National Research Center for Maternal and Child Health, University Medical Center, Astana 010000, Kazakhstan
| | - Gulsamal Zhubanova
- School of Medicine, Nazarbayev University, Kerei-Zhanibek Str. 5/1, Astana 010000, Kazakhstan
| | - Lyudmila Akhmaldtinova
- School of Medicine, Nazarbayev University, Kerei-Zhanibek Str. 5/1, Astana 010000, Kazakhstan
| | - Kuanysh Dossybayeva
- School of Medicine, Nazarbayev University, Kerei-Zhanibek Str. 5/1, Astana 010000, Kazakhstan
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Zhou H, Ye Q. Clinical Features of COVID-19 Vaccine-Associated Autoimmune Hepatitis: A Systematic Review. Diseases 2023; 11:80. [PMID: 37366868 DOI: 10.3390/diseases11020080] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/17/2023] [Accepted: 05/24/2023] [Indexed: 06/28/2023] Open
Abstract
Autoimmune hepatitis (AIH) is an inflammatory liver disease wherein the body's immune system instigates an attack on the liver, causing inflammation and hepatic impairment. This disease usually manifests in genetically predisposed individuals and is triggered by stimuli or environments such as viral infections, environmental toxins, and drugs. The causal role of COVID-19 vaccination in AIH remains uncertain. This review of 39 cases of vaccine-related AIH indicates that female patients above the age of 50 years or those with potential AIH risk factors may be susceptible to vaccine-related AIH, and the clinical features of vaccine-associated AIH are similar to those of idiopathic AIH. These features commonly manifest in patients after the first dose of vaccination, with symptom onset typically delayed by 10-14 days. The incidence of underlying liver disease in patients with potential health conditions associated to liver disease is similar to that of patients without preexisting illnesses. Steroid administration is effective in treating vaccine-related AIH-susceptible patients, with most patients experiencing improvement in their clinical symptoms. However, care should be taken to prevent bacterial infections during drug administration. Furthermore, the possible pathogenic mechanisms of vaccine-associated AIH are discussed to offer potential ideas for vaccine development and enhancement. Although the incidence of vaccine-related AIH is rare, individuals should not be deterred from receiving the COVID-19 vaccine, as the benefits of vaccination significantly outweigh the risks.
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Affiliation(s)
- Hao Zhou
- Department of Laboratory Medicine, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, National Children's Regional Medical Center, Hangzhou 310000, China
| | - Qing Ye
- Department of Laboratory Medicine, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, National Children's Regional Medical Center, Hangzhou 310000, China
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Czaja AJ. Incorporating the Molecular Mimicry of Environmental Antigens into the Causality of Autoimmune Hepatitis. Dig Dis Sci 2023:10.1007/s10620-023-07967-5. [PMID: 37160542 PMCID: PMC10169207 DOI: 10.1007/s10620-023-07967-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 05/01/2023] [Indexed: 05/11/2023]
Abstract
Molecular mimicry between foreign and self-antigens has been implicated as a cause of autoimmune hepatitis in experimental models and cross-reacting antibodies in patients. This review describes the experimental and clinical evidence for molecular mimicry as a cause of autoimmune hepatitis, indicates the limitations and uncertainties of this premise, and encourages investigations that assess diverse environmental antigens as sources of disease-relevant molecular mimics. Pertinent articles were identified in PubMed using multiple search phrases. Several pathogens have linear or conformational epitopes that mimic the self-antigens of autoimmune hepatitis. The occurrence of an acute immune-mediated hepatitis after vaccination for severe acute respiratory syndrome (SARS)-associated coronavirus 2 (SARS-CoV-2) has suggested that vaccine-induced peptides may mimic disease-relevant tissue antigens. The intestinal microbiome is an under-evaluated source of gut-derived antigens that could also engage in molecular mimicry. Chaperone molecules may enhance the pathogenicity of molecular mimics, and they warrant investigation. Molecular mimics of immune dominant epitopes within cytochrome P450 IID6, the autoantigen most closely associated with autoimmune hepatitis, should be sought in diverse environmental antigens and assessed for pathogenicity. Avoidance strategies, dietary adjustments, vaccine improvement, and targeted manipulation of the intestinal microbiota may emerge as therapeutic possibilities. In conclusion, molecular mimicry may be a missing causality of autoimmune hepatitis. Molecular mimics of key immune dominant epitopes of disease-specific antigens must be sought in diverse environmental antigens. The ubiquity of molecular mimicry compels rigorous assessments of peptide mimics for immunogenicity and pathogenicity in experimental models. Molecular mimicry may complement epigenetic modifications as causative mechanisms of autoimmune hepatitis.
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Affiliation(s)
- Albert J Czaja
- Professor Emeritus of Medicine, Mayo Clinic College of Medicine and Science, 200 First Street SW, Rochester, MN, 55905, USA.
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Christen U, Hintermann E. Animal Models for Autoimmune Hepatitis: Are Current Models Good Enough? Front Immunol 2022; 13:898615. [PMID: 35903109 PMCID: PMC9315390 DOI: 10.3389/fimmu.2022.898615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 06/22/2022] [Indexed: 11/13/2022] Open
Abstract
Autoimmune liver diseases like autoimmune hepatitis, primary biliary cholangitis, primary sclerosing cholangitis, and IgG4-related cholangitis are chronic inflammatory diseases of the liver with an autoimmune background. The therapy of autoimmune hepatitis targets the autoreactive immune system and is largely dependent on the use of glucocorticoids and cytostatic drugs. In contrast, the treatment of cholestatic autoimmune liver diseases is restricted to the use of secondary or semi-synthetic bile acids, like ursodeoxycholic acid or obeticholic acid. Although the management of the disease using such drugs works well for the majority of patients, many individuals do not respond to standard therapy. In addition, chronic treatment with glucocorticoids results in well-known side effects. Further, the use of bile acids is a symptomatic therapy that has no direct immunomodulatory effect. Thus, there is still a lot of room for improvement. The use of animal models has facilitated to elucidate the pathogenesis of autoimmune liver diseases and many potential target structures for immunomodulatory therapies have been identified. In this review, we will focus on autoimmune hepatitis for which the first animal models have been established five decades ago, but still a precise treatment for autoimmune hepatitis, as obtainable for other autoimmune diseases such as rheumatoid arthritis or multiple sclerosis has yet to be introduced. Thus, the question arises if our animal models are too far from the patient reality and thus findings from the models cannot be reliably translated to the patient. Several factors might be involved in this discrepancy. There is first and foremost the genetic background and the inbred status of the animals that is different from human patients. Here the use of humanized animals, such as transgenic mice, might reduce some of the differences. However, there are other factors, such as housing conditions, nutrition, and the microbiome that might also play an important role. This review will predominantly focus on the current status of animal models for autoimmune hepatitis and the possible ways to overcome discrepancies between model and patient.
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Poyatos E, Morandeira F, Climent J, Mas V, Castellote J, Bas J. Detection of anti-mitochondrial 2-oxoacid dehydrogenase complex subunit's antibodies for the diagnosis of primary biliary cholangitis. Clin Immunol 2021:108749. [PMID: 33945872 DOI: 10.1016/j.clim.2021.108749] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 04/13/2021] [Accepted: 04/27/2021] [Indexed: 12/12/2022]
Abstract
Anti-mitochondrial antibodies (AMA), directed against the E2 subunits of the 2-oxo acid dehydrogenase complexes, are markers of Primary Biliary Cholangitis (PBC), a chronic autoimmune liver disease. However, the clinical significance of subunits-specific AMA type PDC-E2 -E2 subunit of the pyruvate dehydrogenase complex-, BCOADC-E2 -E2 subunit of the branched-chain 2-oxo acid dehydrogenase complex-, OGDC-E2 -E2 subunit of the 2-oxo-glutarate dehydrogenase complex- and nPDC -native pyruvate dehydrogenase complex (M2-AMA) . Is not well known, and not all AMA specificities are associated with PBC. The aim of the study was to show the usefulness of the number and combination of subunits-specific AMA positive for the diagnosis of PBC. We detected AMA by indirect immunofluorescence (IIF-AMA) and M2-AMA by dot-blot. We studied the relationship of AMA with some clinical and laboratory variables in 307 patients (37% PBC) with positive dot-blot for M2-AMA. In PBC patients, we detected different E2 subunits of the 2-oxo acid dehydrogenase complexes antibodies (M2-AMA): 82.9% were specific for nPDC, 64.5% for PDC-E2, 44.4% for BCOADC-E2, and 9.6% for OGDC-E2. IIF and dot-blot tests achieved a Area Under the Receiver Operating Characteristic Curve (ROC AUC) of 0.674 (1: 320 cut-off titer, Sensibility (Se) 64.7%, Specificity (Sp) 63.4%) and 0.663 (three specificities M2-AMA, Se 43%, Sp 81.2%), respectively. The detection of different E2 subunits of the 2-oxo acid dehydrogenase complexes antibodies (M2-AMA) by dot-blot showed different ROC AUC: anti-PDC-E2 showed an AUC of 0.610, a Se of 43.7%, and a Sp of 76.4%. Finally, the combined detection of nPDC/BCOADC-E2/PDC-E2 reached an AUC of 0.6095, a Se of 59.6%, and a Sp of 70.2%.The identification of two M2-AMA specificities through dot-blot increased PBC odds ratio (OR) by 2.05 (p:0.031), as compared to the identification of one specificity. Moreover, the identification of three and four specificities increased OR by 4.63 (p:0.000) and by 21.53 (p:0.006), respectively. nPDC/OGDC-E2/PDC-E2 and nPDC/OGDC-E2/BCOADC-E2/PDC-E2 combinations increased PBC OR by 10.04 (p:0.034), as compared to any other combination. 1:320 and 1:640 IIF-AMA increased PBC OR by 4.93 (p:0.009) and 7.67 (p:0.001), respectively, as compared to IIF-AMA titers equal to or less than 1:160. M2-AMA dot-blot was less sensitive but more specific than IIF-AMA, with similar predictive capacity for PBC. Increased numbers of M2-AMA specificities clearly increased the risk of PBC. Some combinations were strongly related to PBC (nPDC/BCOADC-E2/PDC-E2), but others were not (one single M2-AMA, and nPDC plus PDC-E2). M2-AMA dot-blot was less sensitive but more specific than IIF-AMA, with similar predictive capacity for PBC. Increased numbers of M2-AMA specificities clearly increased the risk of PBC, being some combinations, such as nPDC/BCOADC-E2/PDC-E2, more related to PBC than others. Finally, the determination of the number of M2-AMA specificities was more useful than the particular subunit target for PBC diagnosis. In conclusion, the study of the number of M2-AMA specificities by dot-blot should definitely be considered for PBC diagnosis.
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Affiliation(s)
- Elisabet Poyatos
- Department of Immunology, Hospital Universitari de Bellvitge, Catalonia, Spain.
| | | | - Joan Climent
- Department of Immunology, Hospital Universitari de Bellvitge, Catalonia, Spain
| | - Virginia Mas
- Department of Immunology, Hospital Universitari de Bellvitge, Catalonia, Spain
| | - José Castellote
- Department of Gastroenterology, Hospital Universitari de Bellvitge, Catalonia, Spain
| | - Jordi Bas
- Department of Immunology, Hospital Universitari de Bellvitge, Catalonia, Spain
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Czaja AJ. Examining pathogenic concepts of autoimmune hepatitis for cues to future investigations and interventions. World J Gastroenterol 2019; 25:6579-6606. [PMID: 31832000 PMCID: PMC6906207 DOI: 10.3748/wjg.v25.i45.6579] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 11/25/2019] [Accepted: 11/29/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Multiple pathogenic mechanisms have been implicated in autoimmune hepatitis, but they have not fully explained susceptibility, triggering events, and maintenance or escalation of the disease. Furthermore, they have not identified a critical defect that can be targeted. The goals of this review are to examine the diverse pathogenic mechanisms that have been considered in autoimmune hepatitis, indicate investigational opportunities to validate their contribution, and suggest interventions that might evolve to modify their impact. English abstracts were identified in PubMed by multiple search terms. Full length articles were selected for review, and secondary and tertiary bibliographies were developed. Genetic and epigenetic factors can affect susceptibility by influencing the expression of immune regulatory genes. Thymic dysfunction, possibly related to deficient production of programmed cell death protein-1, can allow autoreactive T cells to escape deletion, and alterations in the intestinal microbiome may help overcome immune tolerance and affect gender bias. Environmental factors may trigger the disease or induce epigenetic changes in gene function. Molecular mimicry, epitope spread, bystander activation, neo-antigen production, lymphocytic polyspecificity, and disturbances in immune inhibitory mechanisms may maintain or escalate the disease. Interventions that modify epigenetic effects on gene expression, alter intestinal dysbiosis, eliminate deleterious environmental factors, and target critical pathogenic mechanisms are therapeutic possibilities that might reduce risk, individualize management, and improve outcome. In conclusion, diverse pathogenic mechanisms have been implicated in autoimmune hepatitis, and they may identify a critical factor or sequence that can be validated and used to direct future management and preventive strategies.
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Affiliation(s)
- Albert J Czaja
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine and Science, Rochester, MN 55905, United States
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Czaja AJ. Immune inhibitory proteins and their pathogenic and therapeutic implications in autoimmunity and autoimmune hepatitis. Autoimmunity 2019; 52:144-160. [PMID: 31298041 DOI: 10.1080/08916934.2019.1641200] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Key inhibitory proteins can blunt immune responses to self-antigens, and deficiencies in this repertoire may promote autoimmunity. The goals of this review are to describe the key immune inhibitory proteins, indicate their possible impact on the development of autoimmune disease, especially autoimmune hepatitis, and encourage studies to clarify their pathogenic role and candidacy as therapeutic targets. English abstracts were identified in PubMed by multiple search terms. Full length articles were selected for review, and secondary and tertiary bibliographies were developed. Cytotoxic T lymphocyte antigen-4 impairs ligation of CD28 to B7 ligands on antigen presenting cells and inhibits the adaptive immune response by increasing anti-inflammatory cytokines, generating regulatory T cells, and reducing T cell activation and proliferation. Programed cell death antigen-1 inhibits T cell selection, activation, and proliferation by binding with two ligands at different phases and locations of the immune response. A soluble alternatively spliced variant of this protein can dampen the inhibitory signal. Autoimmune hepatitis has been associated with polymorphisms of the cytotoxic T lymphocyte antigen-4 gene, reduced hepatic expression of a ligand of programed cell death antigen-1, an interfering soluble variant of this key inhibitory protein, and antibodies against it. Findings have been associated with laboratory indices of liver injury and suboptimal treatment response. Abatacept, belatacept, CD28 blockade, and induction of T cell exhaustion are management considerations that require scrutiny. In conclusion, deficiencies in key immune inhibitory proteins may promote the occurrence of autoimmune diseases, such as autoimmune hepatitis, and emerging interventions may overcome these deficiencies. Investigations should define the nature, impact and management of these inhibitory disturbances in autoimmune hepatitis.
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Affiliation(s)
- Albert J Czaja
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine and Science , Rochester , MN , USA
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Ebadi M, Bhanji RA, Mazurak VC, Lytvyak E, Mason A, Czaja AJ, Montano-Loza AJ. Severe vitamin D deficiency is a prognostic biomarker in autoimmune hepatitis. Aliment Pharmacol Ther 2019; 49:173-182. [PMID: 30484857 DOI: 10.1111/apt.15029] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 07/30/2018] [Accepted: 09/30/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND Vitamin D deficiency has been implicated in the outcome of chronic liver disease. AIM To determine the frequency of severe vitamin D deficiency in autoimmune hepatitis (AIH), assess its association with treatment non-response, and evaluate the relationship between vitamin D status and liver-related mortality and need for transplantation. METHODS Two hundred and nine patients were evaluated by liver tissue examination at presentation. Serum vitamin D levels were determined, and serum levels <25 nmol/L (10 ng/mL) were considered severely deficient. Treatment non-response was defined as non-normalised aspartate aminotransferase/alanine aminotransferase and immunoglobulin G levels during conventional immunosuppressive therapy. Univariate and multivariate analyses were performed using binary logistic regression and Cox proportional hazards model. RESULTS The mean vitamin D level was 60 ± 38 nmol/L (range, 3-263 nmol/L), and 42 patients (20%) had severe vitamin D deficiency. Treatment non-response was more common in patients with severe vitamin D deficiency than in patients without (59% vs 41%, P = 0.04). Severe vitamin D deficiency was also independently associated with a higher risk of developing cirrhosis (HR 3.40; 95% CI 1.30-8.87, P = 0.01) and liver-related mortality or requirement for liver transplantation (LT; HR 5.26, 95% CI, 1.54-18.0, P = 0.008). Patients with persistent severe deficiency following vitamin D supplementation continued to have poor outcomes. CONCLUSIONS Severe vitamin D deficiency is associated with treatment non-response, progression to cirrhosis, and liver-related death or need for LT. Severe vitamin D deficiency is a prognostic biomarker in AIH.
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Affiliation(s)
- Maryam Ebadi
- Division of Gastroenterology & Liver Unit, University of Alberta Hospital, Edmonton, AB, Canada
| | - Rahima A Bhanji
- Division of Gastroenterology & Liver Unit, University of Alberta Hospital, Edmonton, AB, Canada
| | - Vera C Mazurak
- Division of Human Nutrition, University of Alberta, Edmonton, AB, Canada
| | - Ellina Lytvyak
- Division of Gastroenterology & Liver Unit, University of Alberta Hospital, Edmonton, AB, Canada
| | - Andrew Mason
- Division of Gastroenterology & Liver Unit, University of Alberta Hospital, Edmonton, AB, Canada
| | - Albert J Czaja
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine and Science, Rochester, Minnesota
| | - Aldo J Montano-Loza
- Division of Gastroenterology & Liver Unit, University of Alberta Hospital, Edmonton, AB, Canada
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Stirnimann G, Ebadi M, Czaja AJ, Montano-Loza AJ. Recurrent and De Novo Autoimmune Hepatitis. Liver Transpl 2019; 25:152-166. [PMID: 30375180 DOI: 10.1002/lt.25375] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 10/23/2018] [Indexed: 02/07/2023]
Abstract
Clinical indications for liver transplantation (LT) in patients with autoimmune hepatitis (AIH) are identical to those of patients with other chronic liver diseases that end in acute or semiacute liver failure, decompensated cirrhosis, or hepatocellular carcinoma. Recurrent disease after LT has been reported in 10%-50% of patients with AIH, and the frequency of detection is influenced in part by the use of protocol or clinically indicated liver biopsy. De novo AIH connotes the development of AIH in patients transplanted for liver diseases other than AIH, and it has been reported in 5%-10% of pediatric and 1%-2% of adult recipients. Recurrent disease can negatively impact on graft and patient survival, and retransplantation has been required in 8%-23%. De novo AIH is within the spectrum of graft dysfunction that includes plasma cell-rich rejection, and it can also progress to cirrhosis and graft failure. Treatment for recurrent or de novo disease is based on the conventional regimens for AIH, and corticosteroid therapy alone or combined with azathioprine is standard. Better control of disease activity prior to LT has been associated with less recurrence, and maintenance corticosteroid treatment after LT can reduce its frequency. In conclusion, recurrent AIH is far more frequent than de novo AIH. Both may have negative impacts on graft and patient survival, and early detection and treatment are key objectives. Future investigations must codify the diagnostic criteria for each graft dysfunction, seek diagnostic biomarkers, and evaluate treatments that improve outcomes without increasing the risk of pre- and post-LT infections.
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Affiliation(s)
- Guido Stirnimann
- Department of Visceral Surgery and Medicine, Inselspital Bern, Bern University Hospital and University of Bern, Bern, Switzerland.,Division of Gastroenterology and Liver Unit, University of Alberta Hospital, Edmonton, Alberta, Canada
| | - Maryam Ebadi
- Division of Gastroenterology and Liver Unit, University of Alberta Hospital, Edmonton, Alberta, Canada
| | - Albert J Czaja
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine and Science, Rochester, MN
| | - Aldo J Montano-Loza
- Division of Gastroenterology and Liver Unit, University of Alberta Hospital, Edmonton, Alberta, Canada
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11
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Christen U, Hintermann E. Pathogens and autoimmune hepatitis. Clin Exp Immunol 2018; 195:35-51. [PMID: 30113082 DOI: 10.1111/cei.13203] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Revised: 07/30/2018] [Accepted: 08/06/2018] [Indexed: 12/12/2022] Open
Abstract
Autoimmune hepatitis (AIH) is a severe form of hepatitis resulting in the autoimmune-mediated destruction of the liver parenchyma. Whereas many of the immunopathogenic events have been elucidated and some of the drivers of the disease have been identified, little is known about the aetiology of the disease. There are certain risk factors, such as particular human leucocyte antigen (HLA) haplotypes, that enhance the susceptibility for AIH or influence the severity of the disease. However, as for many other autoimmune diseases, the mere presence of such risk factors does not warrant the occurrence of the disease. Not all individuals carrying risk factors develop AIH, and not all patients with AIH are carriers of high-risk alleles. Thus, additional environmental factors need to be considered as triggers for AIH. Environmental factors include diet, sunlight exposure, stress, medication and hygiene, as well as pathogen infections and vaccinations. This review discusses if pathogens should be considered as triggers for the initiation and/or propagation of AIH.
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Affiliation(s)
- U Christen
- Pharmazentrum Frankfurt / ZAFES, Goethe University Hospital, Frankfurt am Main, Germany
| | - E Hintermann
- Pharmazentrum Frankfurt / ZAFES, Goethe University Hospital, Frankfurt am Main, Germany
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12
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Woolbright BL, Jaeschke H. Mechanisms of Inflammatory Liver Injury and Drug-Induced Hepatotoxicity. CURRENT PHARMACOLOGY REPORTS 2018; 4:346-357. [PMID: 30560047 PMCID: PMC6294466 DOI: 10.1007/s40495-018-0147-0] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PURPOSE OF REVIEW This article provides a brief overview of mechanisms of inflammatory liver injury and how this applies to drug hepatotoxicity with a particular emphasis on the role of inflammation in acetaminophen-induced liver injury. RECENT FINDINGS Significant progress has been made in the last decade in our understanding of the initiation of sterile inflammation after necrotic cell death by the release of damage-associated molecular patterns and their recognition by toll-like receptors and others on macrophages. These events trigger the formation of cytokines and chemokines directly or with assistance of inflammasome activation thereby activating and recruiting leukocytes including neutrophils and monocyte-derived macrophages into the necrotic areas. Although this sterile inflammatory response is mainly geared towards the removal of necrotic cell debris and preparation of regeneration, there are conditions where these innate immune cells can aggravate the initial injury. The mechanisms and controversial findings of the innate immunity are being discussed in detail. In contrast, drug metabolism and formation of a reactive metabolite that binds to proteins in the absence of extensive cell death, can induce an adaptive immune response, which eventually also results in severe liver injury. However, the initiating event appears to be the formation of protein adducts, which act as haptens to activate an adaptive immune response. Overall, these mechanisms are less well understood. SUMMARY The past decade has revolutionized our understanding of the mechanisms that control the interplay between cell death and innate or adaptive immune responses. This report provides an update on these mechanisms.
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Affiliation(s)
| | - Hartmut Jaeschke
- Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, KS, USA
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Satta A, Mezzanzanica D, Caroli F, Frigerio B, Di Nicola M, Kontermann RE, Iacovelli F, Desideri A, Anichini A, Canevari S, Gianni AM, Figini M. Design, selection and optimization of an anti-TRAIL-R2/anti-CD3 bispecific antibody able to educate T cells to recognize and destroy cancer cells. MAbs 2018; 10:1084-1097. [PMID: 29993310 DOI: 10.1080/19420862.2018.1494105] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Recombinant human tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) or TRAIL-receptor agonistic monoclonal antibodies promote apoptosis in most cancer cells, and the differential expression of TRAIL-R2 between tumor and normal tissues allows its exploitation as a tumor-associated antigen. The use of these antibodies as anticancer agents has been extensively studied, but the results of clinical trials were disappointing. The observed lack of anticancer activity could be attributed to intrinsic or acquired resistance of tumor cells to this type of treatment. A possible strategy to circumvent drug resistance would be to strike tumor cells with a second modality based on a different mechanism of action. We therefore set out to generate and optimize a bispecific antibody targeting TRAIL-R2 and CD3. After the construction of different bispecific antibodies in tandem-scFv or single-chain diabody formats to reduce possible immunogenicity, we selected a humanized bispecific antibody with very low aggregates and long-term high stability and functionality. This antibody triggered TRAIL-R2 in an agonistic manner and its anticancer activity proved dramatically potentiated by the redirection of cytotoxic T cells against both sensitive and resistant melanoma cells. The results of our study show that combining the TRAIL-based antitumor strategy with an immunotherapeutic approach in a single molecule could be an effective addition to the anticancer armamentarium.
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Affiliation(s)
- Alessandro Satta
- a Molecular Therapies Unit, Department of Experimental Oncology and Molecular Medicine , Fondazione IRCCS Istituto Nazionale dei Tumori , Milan , Italy
| | - Delia Mezzanzanica
- a Molecular Therapies Unit, Department of Experimental Oncology and Molecular Medicine , Fondazione IRCCS Istituto Nazionale dei Tumori , Milan , Italy
| | - Francesco Caroli
- a Molecular Therapies Unit, Department of Experimental Oncology and Molecular Medicine , Fondazione IRCCS Istituto Nazionale dei Tumori , Milan , Italy
| | - Barbara Frigerio
- a Molecular Therapies Unit, Department of Experimental Oncology and Molecular Medicine , Fondazione IRCCS Istituto Nazionale dei Tumori , Milan , Italy
| | - Massimo Di Nicola
- b Medical Oncology C Unit, Department of Medical Oncology and Hematology , Fondazione IRCCS Istituto Nazionale dei Tumori , Milan , Italy
| | - Roland E Kontermann
- c Institut for Zellbiologie und Immunologie, Universität Stuttgart , Stuttgart , Germany
| | | | | | - Andrea Anichini
- e Human Tumor Immunobiology Unit, Department of Experimental Oncology and Molecular Medicine , Fondazione IRCCS Istituto Nazionale dei Tumori , Milan , Italy
| | - Silvana Canevari
- a Molecular Therapies Unit, Department of Experimental Oncology and Molecular Medicine , Fondazione IRCCS Istituto Nazionale dei Tumori , Milan , Italy
| | - Alessandro Massimo Gianni
- b Medical Oncology C Unit, Department of Medical Oncology and Hematology , Fondazione IRCCS Istituto Nazionale dei Tumori , Milan , Italy.,f Department of Pathophysiology and Transplantation , University of Milan , Milan , Italy
| | - Mariangela Figini
- a Molecular Therapies Unit, Department of Experimental Oncology and Molecular Medicine , Fondazione IRCCS Istituto Nazionale dei Tumori , Milan , Italy
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Czaja AJ. Under-Evaluated or Unassessed Pathogenic Pathways in Autoimmune Hepatitis and Implications for Future Management. Dig Dis Sci 2018; 63:1706-1725. [PMID: 29671161 DOI: 10.1007/s10620-018-5072-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 04/12/2018] [Indexed: 12/11/2022]
Abstract
Autoimmune hepatitis is a consequence of perturbations in homeostatic mechanisms that maintain self-tolerance but are incompletely understood. The goals of this review are to describe key pathogenic pathways that have been under-evaluated or unassessed in autoimmune hepatitis, describe insights that may shape future therapies, and encourage investigational efforts. The T cell immunoglobulin mucin proteins constitute a family that modulates immune tolerance by limiting the survival of immune effector cells, clearing apoptotic bodies, and expanding the population of granulocytic myeloid-derived suppressor cells. Galectins influence immune cell migration, activation, proliferation, and survival, and T cell exhaustion can be induced and exploited as a possible management strategy. The programmed cell death-1 protein and its ligands comprise an antigen-independent inhibitory axis that can limit the performance of activated T cells by altering their metabolism, and epigenetic changes can silence pro-inflammatory genes or de-repress anti-inflammatory genes that affect disease severity. Changes in the intestinal microbiota and permeability of the intestinal mucosal barrier can be causative or consequential events that affect the occurrence and phenotype of immune-mediated disease, and they may help explain the female propensity for autoimmune hepatitis. Perturbations within these homeostatic mechanisms have been implicated in experimental models and limited clinical experiences, and they have been favorably manipulated by monoclonal antibodies, recombinant molecules, pharmacological agents or dietary supplements. In conclusion, pathogenic mechanisms that have been implicated in other systemic immune-mediated and liver diseases but under-evaluated or unassessed in autoimmune hepatitis warrant consideration and rigorous evaluation.
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Affiliation(s)
- Albert J Czaja
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine and Science, 200 First Street S.W., Rochester, MN, 55905, USA.
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15
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Christen U. Animal models of autoimmune hepatitis. Biochim Biophys Acta Mol Basis Dis 2018; 1865:970-981. [PMID: 29857050 DOI: 10.1016/j.bbadis.2018.05.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 05/14/2018] [Accepted: 05/22/2018] [Indexed: 02/06/2023]
Abstract
Many animal models for autoimmune hepatitis (AIH) have been described in the past. Most models had to deal with the relative immunosuppressive environment of the liver. Therefore, some models used a combination of several triggering factors often on a susceptible background to generate an aggressive immune response that targets the liver. In addition, in order to be able to track the immune response the models used specific model autoantigens as targets that are either not present or have not been identified as a natural autoantigen in AIH patients. Thereby the feasibility of such models is somewhat questionable. Although many historic approaches included challenges of experimental animals with liver homogenates it was only in the last decade that natural occurring liver autoantigens have been used in animal models. This article reflects on the requirements for breaking liver tolerance and on how an ideal experimental model for AIH would look like. In addition, it discusses historic as well as recent animal models in the context of feasibility of induction, similarity of the clinical outcome to human AIH, and gain of knowledge for possible future therapies.
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Affiliation(s)
- Urs Christen
- Pharmazentrum Frankfurt/ZAFES, Goethe University Hospital, Frankfurt am Main, Germany.
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16
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Hintermann E, Bayer M, Conti CB, Fuchs S, Fausther M, Leung PS, Aurrand-Lions M, Taubert R, Pfeilschifter JM, Friedrich-Rust M, Schuppan D, Dranoff JA, Gershwin ME, Manns MP, Imhof BA, Christen U. Junctional adhesion molecules JAM-B and JAM-C promote autoimmune-mediated liver fibrosis in mice. J Autoimmun 2018; 91:83-96. [PMID: 29753567 DOI: 10.1016/j.jaut.2018.05.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 04/26/2018] [Accepted: 05/02/2018] [Indexed: 12/17/2022]
Abstract
Fibrosis remains a serious health concern in patients with chronic liver disease. We recently reported that chemically induced chronic murine liver injury triggers increased expression of junctional adhesion molecules (JAMs) JAM-B and JAM-C by endothelial cells and de novo synthesis of JAM-C by hepatic stellate cells (HSCs). Here, we demonstrate that biopsies of patients suffering from primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC) or autoimmune hepatitis (AIH) display elevated levels of JAM-C on portal fibroblasts (PFs), HSCs, endothelial cells and cholangiocytes, whereas smooth muscle cells expressed JAM-C constitutively. Therefore, localization and function of JAM-B and JAM-C were investigated in three mouse models of autoimmune-driven liver inflammation. A PBC-like disease was induced by immunization with 2-octynoic acid-BSA conjugate, which resulted in the upregulation of both JAMs in fibrotic portal triads. Analysis of a murine model of PSC revealed a role of JAM-C in PF cell-cell adhesion and contractility. In mice suffering from AIH, endothelial cells increased JAM-B level and HSCs and capsular fibroblasts became JAM-C-positive. Most importantly, AIH-mediated liver fibrosis was reduced in JAM-B-/- mice or when JAM-C was blocked by soluble recombinant JAM-C. Interestingly, loss of JAM-B/JAM-C function had no effect on leukocyte infiltration, suggesting that the well-documented function of JAMs in leukocyte recruitment to inflamed tissue was not effective in the tested chronic models. This might be different in patients and may even be complicated by the fact that human leukocytes express JAM-C. Our findings delineate JAM-C as a mediator of myofibroblast-operated contraction of the liver capsule, intrahepatic vasoconstriction and bile duct stricture. Due to its potential to interact heterophilically with endothelial JAM-B, JAM-C supports also HSC/PF mural cell function. Together, these properties allow JAM-B and JAM-C to actively participate in vascular remodeling associated with liver/biliary fibrosis and suggest them as valuable targets for anti-fibrosis therapies.
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Affiliation(s)
- Edith Hintermann
- Pharmazentrum Frankfurt, ZAFES, Goethe University Hospital Frankfurt, Frankfurt am Main, Germany.
| | - Monika Bayer
- Pharmazentrum Frankfurt, ZAFES, Goethe University Hospital Frankfurt, Frankfurt am Main, Germany.
| | - Clara Benedetta Conti
- Department of Internal Medicine 1, Goethe University Hospital Frankfurt, Frankfurt am Main, Germany; Fondazione IRCCS Cà, Granda Ospedale Maggiore Policlinico, Department of Pathophysiology and Organ Transplantation, Milan, Italy.
| | - Sina Fuchs
- Pharmazentrum Frankfurt, ZAFES, Goethe University Hospital Frankfurt, Frankfurt am Main, Germany.
| | - Michel Fausther
- Division of Gastroenterology and Hepatology, University of Arkansas, Little Rock, AR, USA.
| | - Patrick S Leung
- Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis, Davis, CA, USA.
| | - Michel Aurrand-Lions
- Aix Marseille Univ, CNRS, INSERM, Institut Paoli-Calmettes, CRCM, Marseille, France.
| | - Richard Taubert
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, Germany.
| | - Josef M Pfeilschifter
- Pharmazentrum Frankfurt, ZAFES, Goethe University Hospital Frankfurt, Frankfurt am Main, Germany.
| | - Mireen Friedrich-Rust
- Department of Internal Medicine 1, Goethe University Hospital Frankfurt, Frankfurt am Main, Germany.
| | - Detlef Schuppan
- Institute of Translational Immunology and Research Center for Immune Therapy, University Medical Center, Johannes Gutenberg University, Mainz, Germany.
| | - Jonathan A Dranoff
- Division of Gastroenterology and Hepatology, University of Arkansas, Little Rock, AR, USA.
| | - M Eric Gershwin
- Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis, Davis, CA, USA.
| | - Michael P Manns
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, Germany.
| | - Beat A Imhof
- Department of Pathology and Immunology, Centre Médical Universitaire, University of Geneva, Geneva, Switzerland.
| | - Urs Christen
- Pharmazentrum Frankfurt, ZAFES, Goethe University Hospital Frankfurt, Frankfurt am Main, Germany.
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17
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Mieli-Vergani G, Vergani D, Czaja AJ, Manns MP, Krawitt EL, Vierling JM, Lohse AW, Montano-Loza AJ. Autoimmune hepatitis. Nat Rev Dis Primers 2018; 4:18017. [PMID: 29644994 DOI: 10.1038/nrdp.2018.17] [Citation(s) in RCA: 230] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Autoimmune hepatitis (AIH) is a severe liver disease that affects children and adults worldwide. The diagnosis of AIH relies on increased serum transaminase and immunoglobulin G levels, presence of autoantibodies and interface hepatitis on liver histology. AIH arises in genetically predisposed individuals when a trigger, such as exposure to a virus, leads to a T cell-mediated autoimmune response directed against liver autoantigens; this immune response is permitted by inadequate regulatory immune control leading to a loss of tolerance. AIH responds favourably to immunosuppressive treatment, which should be started as soon as the diagnosis is made. Standard regimens include fairly high initial doses of corticosteroids (prednisone or prednisolone), which are tapered gradually as azathioprine is introduced. For those patients who do not respond to standard treatment, second-line drugs should be considered, including mycophenolate mofetil, calcineurin inhibitors, mechanistic target of rapamycin (mTOR) inhibitors and biologic agents, which should be administered only in specialized hepatology centres. Liver transplantation is a life-saving option for those who progress to end-stage liver disease, although AIH can recur or develop de novo after transplantation. In-depth investigation of immune pathways and analysis of changes to the intestinal microbiota should advance our knowledge of the pathogenesis of AIH and lead to novel, tailored and better tolerated therapies.
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Affiliation(s)
- Giorgina Mieli-Vergani
- Paediatric Liver, GI and Nutrition Centre, MowatLabs, King's College Hospital, Denmark Hill, SE5 9RS London, UK
| | - Diego Vergani
- Institute of Liver Studies, MowatLabs, King's College Hospital, Denmark Hill, SE5 9RS London, UK
| | - Albert J Czaja
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Michael P Manns
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, Germany.,Helmholtz Centre for Infection Research (HZI), Braunschweig, Germany
| | - Edward L Krawitt
- Department of Medicine, University of Vermont, Burlington, VT, USA.,Department of Medicine, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - John M Vierling
- Division of Abdominal Transplantation and Section of Gastroenterology and Hepatology, Departments of Medicine and Surgery, Baylor College of Medicine, Houston, TX, USA
| | - Ansgar W Lohse
- Department of Medicine, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Aldo J Montano-Loza
- Division of Gastroenterology and Liver Unit, University of Alberta, Edmonton, Alberta, Canada
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18
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Christen U, Hintermann E. Autoantibodies in Autoimmune Hepatitis: Can Epitopes Tell Us about the Etiology of the Disease? Front Immunol 2018; 9:163. [PMID: 29503645 PMCID: PMC5820307 DOI: 10.3389/fimmu.2018.00163] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 01/18/2018] [Indexed: 12/12/2022] Open
Abstract
Autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC) are serious autoimmune liver diseases that are characterized by a progressive destruction of the liver parenchyma and/or the hepatic bile ducts and the development of chronic fibrosis. Left untreated autoimmune liver diseases are often life-threatening, and patients require a liver transplantation to survive. Thus, an early and reliable diagnosis is paramount for the initiation of a proper therapy with immunosuppressive and/or anticholelithic drugs. Besides the analysis of liver biopsies and serum markers indicating liver damage, the screening for specific autoantibodies is an indispensable tool for the diagnosis of autoimmune liver diseases. Such liver autoantigen-specific antibodies might be involved in the disease pathogenesis, and their epitope specificity may give some insight into the etiology of the disease. Here, we will mainly focus on the generation and specificity of autoantibodies in AIH patients. In addition, we will review data from animal models that aim toward a better understanding of the origins and pathogenicity of such autoantibodies.
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Affiliation(s)
- Urs Christen
- Pharmazentrum Frankfurt/ZAFES, Goethe University Hospital, Frankfurt am Main, Germany
| | - Edith Hintermann
- Pharmazentrum Frankfurt/ZAFES, Goethe University Hospital, Frankfurt am Main, Germany
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19
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Barteneva NS, Baiken Y, Fasler-Kan E, Alibek K, Wang S, Maltsev N, Ponomarev ED, Sautbayeva Z, Kauanova S, Moore A, Beglinger C, Vorobjev IA. Extracellular vesicles in gastrointestinal cancer in conjunction with microbiota: On the border of Kingdoms. Biochim Biophys Acta Rev Cancer 2017; 1868:372-393. [DOI: 10.1016/j.bbcan.2017.06.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 06/26/2017] [Accepted: 06/26/2017] [Indexed: 12/16/2022]
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20
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Czaja AJ. Review article: next-generation transformative advances in the pathogenesis and management of autoimmune hepatitis. Aliment Pharmacol Ther 2017; 46:920-937. [PMID: 28901565 DOI: 10.1111/apt.14324] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 08/01/2017] [Accepted: 08/25/2017] [Indexed: 12/15/2022]
Abstract
BACKGROUND Advances in autoimmune hepatitis that transform current concepts of pathogenesis and management can be anticipated as products of ongoing investigations driven by unmet clinical needs and an evolving biotechnology. AIM To describe the advances that are likely to become transformative in autoimmune hepatitis, based on the direction of current investigations. METHODS Pertinent abstracts were identified in PubMed by multiple search terms. Full-length articles were selected for review, and a secondary bibliography was developed. The discovery process was repeated, and a tertiary bibliography was identified. The number of abstracts reviewed was 2830, and the number of full-length articles reviewed exceeded 150. RESULTS Risk-laden allelic variants outside the major histocompatibility complex (rs3184504, r36000782) are being identified by genome-wide association studies, and their gene products are potential therapeutic targets. Epigenetic changes associated with environmental cues can enhance the transcriptional activity of genes, and chromatin re-structuring and antagonists of noncoding molecules of ribonucleic acid are feasible interventions. The intestinal microbiome is a discovery field for microbial products and activated immune cells that may translocate to the periphery and respond to manipulation. Epidemiological studies and controlled interview-based surveys may implicate environmental and xenobiotic factors that warrant evidence-based changes in lifestyle, and site-directed molecular and cellular interventions promise to change the paradigm of treatment from one of blanket immunosuppression. CONCLUSIONS Advances in genetics, epigenetics, pathophysiology, epidemiology, and site-directed molecular and cellular interventions constitute the next generation of transformative advances in autoimmune hepatitis.
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Affiliation(s)
- A J Czaja
- Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, Rochester, MN, USA
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21
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Gilbert KM, Bai S, Barnette D, Blossom SJ. Exposure Cessation During Adulthood Did Not Prevent Immunotoxicity Caused by Developmental Exposure to Low-Level Trichloroethylene in Drinking Water. Toxicol Sci 2017; 157:429-437. [PMID: 28369519 PMCID: PMC6075179 DOI: 10.1093/toxsci/kfx061] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Exposure to the water pollutant trichloroethylene (TCE) can promote autoimmunity in both humans and rodents. Using a mouse model we have shown that chronic adult exposure to TCE at 500 μg/ml in drinking water generates autoimmune hepatitis in female MRL+/+ mice. There is increasing evidence that developmental exposure to certain chemicals can be more toxic than adult exposure. This study was designed to test whether exposure to a much lower level of TCE (0.05 μg/ml) during gestation, lactation, and early life generated autoimmunity similar to that found following adult exposure to higher concentrations of TCE. When female MRL+/+ mice were examined at postnatal day (PND) 259 we found that developmental/early life exposure [gestational day 0 to PND 154] to TCE at a concentration 10 000 fold lower than that shown to be effective for adult exposure triggered autoimmune hepatitis. This effect was observed despite exposure cessation at PND 154. In concordance with the liver pathology, female MRL+/+ exposed during development and early life to TCE (0.05 or 500 μg/ml) generated a range of antiliver antibodies detected by Western blotting. Expression of proinflammatory cytokines by CD4+ T cells was also similarly observed at PND 259 in the TCE-exposed mice regardless of concentration. Thus, exposure to TCE at approximately environmental levels from gestational day 0 to PND 154 generated tissue pathology and CD4+ T cell alterations that required higher concentrations if exposure was limited to adulthood. TCE exposure cessation at PND 154 did not prevent the immunotoxicity.
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Affiliation(s)
- Kathleen M. Gilbert
- *Department of Microbiology and Immunology; Department of Biochemistry and Molecular Biology; and Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children’s Research Institute, Little Rock, Arkansas 72202
| | - Shasha Bai
- *Department of Microbiology and Immunology; Department of Biochemistry and Molecular Biology; and Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children’s Research Institute, Little Rock, Arkansas 72202
| | - Dustyn Barnette
- *Department of Microbiology and Immunology; Department of Biochemistry and Molecular Biology; and Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children’s Research Institute, Little Rock, Arkansas 72202
| | - Sarah J. Blossom
- *Department of Microbiology and Immunology; Department of Biochemistry and Molecular Biology; and Department of Pediatrics, University of Arkansas for Medical Sciences, Arkansas Children’s Research Institute, Little Rock, Arkansas 72202
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22
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Affiliation(s)
- Albert J. Czaja
- Professor Emeritus of Medicine, Mayo Clinic College of Medicine, Rochester, MN, USA
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23
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Abstract
Despite the central role of the liver in drug metabolism, surprisingly there is lack of certainty in anticipating the extent of modification of the clearance of a given drug in a given patient. The intent of this review is to provide a conceptual framework in considering the impact of liver disease on drug disposition and reciprocally the impact of drug disposition on liver disease. It is proposed that improved understanding of the situation is gained by considering the issue as a special example of a drug-gene-environment interaction. This requires an integration of knowledge of the drug's properties, knowledge of the gene products involved in its metabolism, and knowledge of the pathophysiology of its disposition. This will enhance the level of predictability of drug disposition and toxicity for a drug of interest in an individual patient. It is our contention that advances in pharmacology, pharmacogenomics, and hepatology, together with concerted interests in the academic, regulatory, and pharmaceutical industry communities provide an ideal immediate environment to move from a qualitative reactive approach to quantitative proactive approach in individualizing patient therapy in liver disease.
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Affiliation(s)
- Nathalie K Zgheib
- a Department of Pharmacology and Toxicology , American University of Beirut Faculty of Medicine , Beirut , Lebanon
| | - Robert A Branch
- b Department of Medicine, School of Medicine , University of Pittsburgh , Pittsburgh , PA , USA
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24
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Christen U, Hintermann E. Immunopathogenic Mechanisms of Autoimmune Hepatitis: How Much Do We Know from Animal Models? Int J Mol Sci 2016; 17:ijms17122007. [PMID: 27916939 PMCID: PMC5187807 DOI: 10.3390/ijms17122007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 11/22/2016] [Accepted: 11/23/2016] [Indexed: 12/14/2022] Open
Abstract
Autoimmune hepatitis (AIH) is characterized by a progressive destruction of the liver parenchyma and a chronic fibrosis. The current treatment of autoimmune hepatitis is still largely dependent on the administration of corticosteroids and cytostatic drugs. For a long time the development of novel therapeutic strategies has been hampered by a lack of understanding the basic immunopathogenic mechanisms of AIH and the absence of valid animal models. However, in the past decade, knowledge from clinical observations in AIH patients and the development of innovative animal models have led to a situation where critical factors driving the disease have been identified and alternative treatments are being evaluated. Here we will review the insight on the immunopathogenesis of AIH as gained from clinical observation and from animal models.
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Affiliation(s)
- Urs Christen
- Pharmazentrum Frankfurt/ZAFES, Goethe University Hospital, Theodor-Stern Kai 7, 60590 Frankfurt am Main, Germany.
| | - Edith Hintermann
- Pharmazentrum Frankfurt/ZAFES, Goethe University Hospital, Theodor-Stern Kai 7, 60590 Frankfurt am Main, Germany.
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25
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Czaja AJ. Factoring the intestinal microbiome into the pathogenesis of autoimmune hepatitis. World J Gastroenterol 2016; 22:9257-9278. [PMID: 27895415 PMCID: PMC5107691 DOI: 10.3748/wjg.v22.i42.9257] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2016] [Revised: 10/07/2016] [Accepted: 10/31/2016] [Indexed: 02/06/2023] Open
Abstract
The intestinal microbiome is a reservoir of microbial antigens and activated immune cells. The aims of this review were to describe the role of the intestinal microbiome in generating innate and adaptive immune responses, indicate how these responses contribute to the development of systemic immune-mediated diseases, and encourage investigations that improve the understanding and management of autoimmune hepatitis. Alterations in the composition of the intestinal microflora (dysbiosis) can disrupt intestinal and systemic immune tolerances for commensal bacteria. Toll-like receptors within the intestine can recognize microbe-associated molecular patterns and shape subsets of T helper lymphocytes that may cross-react with host antigens (molecular mimicry). Activated gut-derived lymphocytes can migrate to lymph nodes, and gut-derived microbial antigens can translocate to extra-intestinal sites. Inflammasomes can form within hepatocytes and hepatic stellate cells, and they can drive the pro-inflammatory, immune-mediated, and fibrotic responses. Diet, designer probiotics, vitamin supplements, re-colonization methods, antibiotics, drugs that decrease intestinal permeability, and molecular interventions that block signaling pathways may emerge as adjunctive regimens that complement conventional immunosuppressive management. In conclusion, investigations of the intestinal microbiome are warranted in autoimmune hepatitis and promise to clarify pathogenic mechanisms and suggest alternative management strategies.
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26
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Emperipolesis mediated by CD8 T cells is a characteristic histopathologic feature of autoimmune hepatitis. Clin Rev Allergy Immunol 2016; 48:226-35. [PMID: 25051956 DOI: 10.1007/s12016-014-8432-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Emperipolesis has been widely described in patients with autoimmune hepatitis, but the significance and the diagnostic value have not been quantitated. The goal of this study was to define the features and clinical significance of emperipolesis in autoimmune hepatitis (AIH). A retrospective histological evaluation of 101 patients with AIH and 184 controls was performed. Confocal staining for CD4, CD8, CD19, CD56, CD163, and CD11b, CK8/18 and cleaved caspase-3 was performed. Emperipolesis was observed in 65.3 % of the patients with AIH in haematoxylin and eosin (H&E)-stained slides, which was significantly higher than in patients with primary biliary cirrhosis (17.9 %), chronic hepatitis B (14.9 %), and drug-induced liver injury (25.6 %). Among AIH patients, the patients with emperipolesis had significantly higher serum (alanine aminotransferase/aspartate aminotransferase [ALT/AST]) levels. Histologically, emperipolesis was associated with more severe necroinflammatory features and more advanced fibrosis. The lymphocytes in hepatocytes were predominantly as CD8 T cells. Emperipolesis of CD8 T cells induced cleaved caspase-3 expression, and was prominent in areas apoptosis. Emperipolesis is a characteristic feature of AIH which is often seen in conjunction with interface hepatitis, plasmacytic infiltration and hepatocyte rosetting and is associated with more severe necroinflammatory and fibrotic changes. In AIH, emperipolesis is predominantly mediated by CD8 T cells, appears to induce apoptosis and may be another mechanism of autoimmune-mediated hepatocyte injury.
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27
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Debiec H, Ronco P. Immune Response against Autoantigen PLA2R Is not Gambling: Implications for Pathophysiology, Prognosis, and Therapy. J Am Soc Nephrol 2015; 27:1275-7. [PMID: 26657866 DOI: 10.1681/asn.2015101170] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Affiliation(s)
- Hanna Debiec
- Sorbonne Universités, Université Pierre et Marie Curie Université Paris 06, Unité Mixte de Recherche_S 1155, Paris, France; Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche_S 1155, Paris, France; and
| | - Pierre Ronco
- Sorbonne Universités, Université Pierre et Marie Curie Université Paris 06, Unité Mixte de Recherche_S 1155, Paris, France; Institut National de la Santé et de la Recherche Médicale, Unité Mixte de Recherche_S 1155, Paris, France; and Department of Nephrology and Dialysis, Assistance Publique-Hôpitaux de Paris, Hôpital Tenon, Paris, France
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He ZX, Chen XW, Zhou ZW, Zhou SF. Impact of physiological, pathological and environmental factors on the expression and activity of human cytochrome P450 2D6 and implications in precision medicine. Drug Metab Rev 2015; 47:470-519. [PMID: 26574146 DOI: 10.3109/03602532.2015.1101131] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
With only 1.3-4.3% in total hepatic CYP content, human CYP2D6 can metabolize more than 160 drugs. It is a highly polymorphic enzyme and subject to marked inhibition by a number of drugs, causing a large interindividual variability in drug clearance and drug response and drug-drug interactions. The expression and activity of CYP2D6 are regulated by a number of physiological, pathological and environmental factors at transcriptional, post-transcriptional, translational and epigenetic levels. DNA hypermethylation and histone modifications can repress the expression of CYP2D6. Hepatocyte nuclear factor-4α binds to a directly repeated element in the promoter of CYP2D6 and thus regulates the expression of CYP2D6. Small heterodimer partner represses hepatocyte nuclear factor-4α-mediated transactivation of CYP2D6. GW4064, a farnesoid X receptor agonist, decreases hepatic CYP2D6 expression and activity while increasing small heterodimer partner expression and its recruitment to the CYP2D6 promoter. The genotypes are key determinants of interindividual variability in CYP2D6 expression and activity. Recent genome-wide association studies have identified a large number of genes that can regulate CYP2D6. Pregnancy induces CYP2D6 via unknown mechanisms. Renal or liver diseases, smoking and alcohol use have minor to moderate effects only on CYP2D6 activity. Unlike CYP1 and 3 and other CYP2 members, CYP2D6 is resistant to typical inducers such as rifampin, phenobarbital and dexamethasone. Post-translational modifications such as phosphorylation of CYP2D6 Ser135 have been observed, but the functional impact is unknown. Further functional and validation studies are needed to clarify the role of nuclear receptors, epigenetic factors and other factors in the regulation of CYP2D6.
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Affiliation(s)
- Zhi-Xu He
- a Guizhou Provincial Key Laboratory for Regenerative Medicine, Stem Cell and Tissue Engineering Research Center & Sino-US Joint Laboratory for Medical Sciences, Guizhou Medical University , Guiyang , Guizhou , China
| | - Xiao-Wu Chen
- b Department of General Surgery , The First People's Hospital of Shunde, Southern Medical University , Shunde , Foshan , Guangdong , China , and
| | - Zhi-Wei Zhou
- c Department of Pharmaceutical Science , College of Pharmacy, University of South Florida , Tampa , FL , USA
| | - Shu-Feng Zhou
- a Guizhou Provincial Key Laboratory for Regenerative Medicine, Stem Cell and Tissue Engineering Research Center & Sino-US Joint Laboratory for Medical Sciences, Guizhou Medical University , Guiyang , Guizhou , China .,c Department of Pharmaceutical Science , College of Pharmacy, University of South Florida , Tampa , FL , USA
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Abstract
There have been significant advances in our understanding of human autoimmunity that have led to improvements in classification and diagnosis and, most importantly, research advances in new therapies. The importance of autoimmunity and the mechanisms that lead to clinical disease were first recognized about 50 years ago following the pioneering studies of Macfarlane Burnett and his Nobel Prize-winning hypothesis of the 'forbidden clone'. Such pioneering efforts led to a better understanding not only of autoimmunity, but also of lymphoid cell development, thymic education, apoptosis and deletion of autoreactive cells. Contemporary theories suggest that the development of an autoimmune disease requires a genetic predisposition and environmental factors that trigger the immune pathways that lead, ultimately, to tissue destruction. Despite extensive research, there are no genetic tools that can be used clinically to predict the risk of autoimmune disease. Indeed, the concordance of autoimmune disease in identical twins is 12-67%, highlighting not only a role for environmental factors, but also the potential importance of stochastic or epigenetic phenomena. On the other hand, the identification of cytokines and chemokines, and their cognate receptors, has led to novel therapies that block pathological inflammatory responses within the target organ and have greatly improved the therapeutic effect in patients with autoimmune disease, particularly rheumatoid arthritis. Further advances involving the use of multiplex platforms for diagnosis and identification of new therapeutic agents should lead to major breakthroughs within the next decade.
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Affiliation(s)
- Lifeng Wang
- Research Center for Biological Therapy, The Institute of Translational Hepatology, Beijing 302 Hospital, Beijing, China
| | - Fu-Sheng Wang
- Research Center for Biological Therapy, The Institute of Translational Hepatology, Beijing 302 Hospital, Beijing, China
| | - M Eric Gershwin
- Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis School of Medicine, Davis, CA, USA
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Czaja AJ. Transitioning from Idiopathic to Explainable Autoimmune Hepatitis. Dig Dis Sci 2015; 60:2881-900. [PMID: 25999246 DOI: 10.1007/s10620-015-3708-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 05/06/2015] [Indexed: 02/08/2023]
Abstract
Autoimmune hepatitis lacks an identifiable cause, and its diagnosis requires the exclusion of etiologically defined diseases that resemble it. Insights into its pathogenesis are moving autoimmune hepatitis from an idiopathic to explainable disease, and the goal of this review is to describe the insights that are hastening this transition. Two types of autoimmune hepatitis are justified by serological markers, but they also have distinctive genetic associations (DRB1 and DQB1 genes) and autoantigens. DRB1 alleles are the principal susceptibility factors in white adults, and a six amino acid sequence encoded in the antigen-binding groove of class II molecules of the major histocompatibility complex can influence the selection of autoantigens. Polymorphisms, including variants of SH2B3 and CARD10 genes, may affect immune reactivity and disease severity. The cytochrome mono-oxygenase, CYP2D6, is the autoantigen associated with type 2 autoimmune hepatitis, and it shares homologies with multiple viruses that might promote self-intolerance by molecular mimicry. Chemokines, especially CXCL9 and CXCL10, orchestrate the migration of effector cells to sites of injury and are associated with disease severity. Cells of the innate and adaptive immune responses promote tissue damage, and possible deficiencies in the number and function of regulatory T cells may facilitate the injurious process. Receptor-mediated apoptosis is the principal mechanism of hepatocyte loss, and cell-mediated and antibody-dependent mechanisms of cytotoxicity also contribute. Insights that explain autoimmune hepatitis will allow triggering exogenous antigens to be characterized, risk management to be improved, prognostic indices to be refined, and site-specific therapeutic interventions to emerge.
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Affiliation(s)
- Albert J Czaja
- Professor Emeritus of Medicine, Division of Gastroenterology and Hepatology, Mayo Clinic College of Medicine, 200 First Street S.W., Rochester, MN, 55905, USA.
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Yüksel M, Laukens D, Heindryckx F, Van Vlierberghe H, Geerts A, Wong FS, Wen L, Colle I. Hepatitis mouse models: from acute-to-chronic autoimmune hepatitis. Int J Exp Pathol 2014; 95:309-20. [PMID: 25112417 DOI: 10.1111/iep.12090] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 06/04/2014] [Indexed: 12/13/2022] Open
Abstract
Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease associated with interface hepatitis, raised plasma liver enzymes, the presence of autoantibodies and regulatory T-cell (Tregs) dysfunction. The clinical course is heterogeneous, manifested by a fulminant or indolent course. Although genetic predisposition is well accepted, the combination with currently undefined environmental factors is crucial for the development of the disease. Progress in the development of reliable animal models provides added understanding of the pathophysiology of AIH, and these will be very useful in evaluating potential therapeutics. It appears that artificially breaking tolerance in the liver is easy. However, maintaining this state of tolerance breakdown, to get chronic hepatitis, is difficult because liver immune homeostasis is strongly regulated by several immune response inhibitory mechanisms. For example, Tregs are crucial regulators in acute and chronic hepatitis, and C57BL/6 mice are most prone to experimental AIH. Immunization of C57BL/6 mice with liver (AIH) autoantigens (CYP2D6/FTCD or IL-4R) and the disturbance of liver regulatory mechanism(s), leading to experimental AIH, are likely to be most representative of human AIH pathology.
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Affiliation(s)
- Muhammed Yüksel
- Department of Hepatology and Gastroenterology, Ghent University, Ghent, Belgium; Department of Endocrinology, Yale School of Medicine, New Haven, CT, USA
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32
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Hirschfield GM, Karlsen TH. Genetic risks link autoimmune hepatitis to other autoimmune liver disease. Gastroenterology 2014; 147:270-3. [PMID: 24973678 DOI: 10.1053/j.gastro.2014.06.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Affiliation(s)
- Gideon M Hirschfield
- Centre for Liver Research and NIHR Biomedical Research Unit, University of Birmingham, Birmingham, UK.
| | - Tom Hemming Karlsen
- Norwegian PSC Research Center, Department of Transplantation Medicine, Division of Cancer Medicine, Surgery and Transplantation, Oslo University Hospital, Rikshospitalet and Institute of Clinical Medicine, Faculty of Medicine, University of Oslo and K.G. Jebsen Inflammation Research Centre, Research Institute of Internal Medicine, Oslo University Hospital, Oslo, Norway
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Abstract
Autoimmune disorders afflicting the liver comprise the bona fide autoimmune diseases, primary biliary cirrhosis, primary sclerosing cholangitis, and autoimmune hepatitis as well as drug-induced autoimmune-like diseases, such as halothane hepatitis. Whereas drug-induced forms of acute or chronic hepatitis often have a clear triggering factor, the etiology of classical autoimmune liver diseases is only poorly understood. Besides a genetic component present in disease susceptible individuals, environmental triggering factors are likely to play a role in the initiation and/or propagation of the disease. In this article, we will review on current evidence obtained from epidemiological associations, case studies, and findings in animal models for pathogens, to be involved in the etiology of autoimmune liver disease with a special focus on autoimmune hepatitis.
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Affiliation(s)
- Urs Christen
- Pharmazentrum Frankfurt/ZAFES, Goethe University Hospital , Frankfurt am Main , Germany
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Colvin KL, Cripe PJ, Ivy DD, Stenmark KR, Yeager ME. Bronchus-associated lymphoid tissue in pulmonary hypertension produces pathologic autoantibodies. Am J Respir Crit Care Med 2013; 188:1126-36. [PMID: 24093638 DOI: 10.1164/rccm.201302-0403oc] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
RATIONALE Autoimmunity has long been associated with pulmonary hypertension. Bronchus-associated lymphoid tissue plays important roles in antigen sampling and self-tolerance during infection and inflammation. OBJECTIVES We reasoned that activated bronchus-associated lymphoid tissue would be evident in rats with pulmonary hypertension, and that loss of self-tolerance would result in production of pathologic autoantibodies that drive vascular remodeling. METHODS We used animal models, histology, and gene expression assays to evaluate the role of bronchus-associated lymphoid tissue in pulmonary hypertension. MEASUREMENTS AND MAIN RESULTS Bronchus-associated lymphoid tissue was more numerous, larger, and more active in pulmonary hypertension compared with control animals. We found dendritic cells in and around lymphoid tissue, which were composed of CD3(+) T cells over a core of CD45RA(+) B cells. Antirat IgG and plasma from rats with pulmonary hypertension decorated B cells in lymphoid tissue, resistance vessels, and adventitia of large vessels. Lymphoid tissue in diseased rats was vascularized by aquaporin-1(+) high endothelial venules and vascular cell adhesion molecule-positive vessels. Autoantibodies are produced in bronchus-associated lymphoid tissue and, when bound to pulmonary adventitial fibroblasts, change their phenotype to one that may promote inflammation. Passive transfer of autoantibodies into rats caused pulmonary vascular remodeling and pulmonary hypertension. Diminution of lymphoid tissue reversed pulmonary hypertension, whereas immunologic blockade of CCR7 worsened pulmonary hypertension and hastened its onset. CONCLUSIONS Bronchus-associated lymphoid tissue expands in pulmonary hypertension and is autoimmunologically active. Loss of self-tolerance contributes to pulmonary vascular remodeling and pulmonary hypertension. Lymphoid tissue-directed therapies may be beneficial in treating pulmonary hypertension.
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Abstract
Autoimmune hepatitis (AIH) is a chronic inflammatory disease of the liver triggered by an immune-mediated attack, characterized by the presence of hypergammaglobulinemia, serum autoantibodies, interface hepatitis on histological examination, and good response to immunosuppressive therapy. In this article, we will review the role of genetic susceptibility, inducing factors, molecular mimicry, liver injury, and immune regulation imbalance in the pathogenesis of AIH. In addition, this article systematically describes the advances in research of AIH in terms of clinical features, serological characteristics, histologic features, diagnosis and therapy.
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36
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Luong KVQ, Nguyen LTH. The role of vitamin d in autoimmune hepatitis. J Clin Med Res 2013; 5:407-15. [PMID: 24171052 PMCID: PMC3808258 DOI: 10.4021/jocmr1505w] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2013] [Indexed: 12/21/2022] Open
Abstract
Autoimmune hepatitis is an inflammation of the liver characterized by the presence of peri-portal hepatitis, hypergammaglobulinemia, and the serum autoantibodies. The disease is classified into 2 distinct types according to the nature of auto-antibodies. Disturbances of the calcium-parathyroid hormone-vitamin D axis are frequently associated with chronic liver disease. Patients with AIH have a high prevalence of vitamin D deficiency. Genetic studies have provided the opportunity to determine which proteins link vitamin D to AIH pathology, namely, the major histocompatibility complex class II molecules, vitamin D receptors, toll-like receptors, cytotoxic T lymphocyte antigen-4, cytochrome P450 CYP2D6, regulatory T cells (Tregs) and the forkhead/winged helix transcription factor 3. Vitamin D also exerts its effect on AIH through non-genomic factors, namely, mitogen-activated protein kinase signaling pathways, γδT cells, interferon-gamma nitric oxide synthase, and reactive oxygen stress. In conclusion, vitamin D may have a beneficial role in AIH and improves liver function in concanavalin A-induced mouse AIH. Calcitriol is best used for AIH because it is the active form of a vitamin D3 metabolite and its receptors are present in sinusoidal endothelial cells, Kupffer cells, stellate cells of normal livers, and the biliary cell line.
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37
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Hintermann E, Ehser J, Bayer M, Pfeilschifter JM, Christen U. Mechanism of autoimmune hepatic fibrogenesis induced by an adenovirus encoding the human liver autoantigen cytochrome P450 2D6. J Autoimmun 2013; 44:49-60. [PMID: 23809878 DOI: 10.1016/j.jaut.2013.05.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 05/06/2013] [Accepted: 05/09/2013] [Indexed: 01/03/2023]
Abstract
Autoimmune hepatitis type 2 (AIH-2) is a severe autoimmune liver disease with unknown etiology. We recently developed the CYP2D6 mouse model for AIH-2, in which mice are challenged with an adenovirus (Ad-2D6) expressing human cytochrome P450 2D6 (hCYP2D6), the major autoantigen in AIH-2. Such mice develop chronic hepatitis with cellular infiltrations and generation of hCYP2D6-specific antibodies and T cells. Importantly, the CYP2D6 model represents the only model displaying chronic fibrosis allowing for a detailed investigation of the mechanisms of chronic autoimmune-mediated liver fibrogenesis. We found that hCYP2D6-dependent chronic activation of hepatic stellate cells (HSC) resulted in an increased extracellular matrix deposition and elevated expression of α-smooth muscle actin predominantly in and underneath the liver capsule. The route of Ad-2D6 infection dramatically influenced the activation and trafficking of inflammatory monocytes, NK cells and hCYP2D6-specific T cells. Intraperitoneal Ad-2D6 infection caused subcapsular fibrosis and persistent clustering of inflammatory monocytes. In contrast, intravenous infection caused an accumulation of hCYP2D6-specific CD4 T cells throughout the liver parenchyma and induced a strong NK cell response preventing chronic HSC activation and fibrosis. In summary, we found that the location of the initial site of inflammation and autoantigen expression caused a differential cellular trafficking and activation and thereby determined the outcome of AIH-2-like hepatic damage and fibrosis.
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Affiliation(s)
- Edith Hintermann
- Pharmazentrum Frankfurt/ZAFES, Johann Wolfgang Goethe University, Frankfurt am Main, Germany
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38
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Abstract
Antibodies play an important role in autoimmune liver diseases, such as autoimmune hepatitis (AIH). On the one hand, they are essential diagnostic markers to identify not only the presentation of AIH, but also the AIH subtype characterized by the presence of particular antibodies to target autoantigens in the liver. On the other hand, such autoantibodies might be directly involved in the etiology and/or pathogenesis of AIH. This review will reflect on the evidence of how specific autoantibodies influence AIH and will further provide insight into the necessities for generating therapeutic antibodies to treat AIH in the future.
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Affiliation(s)
- Urs Christen
- Pharmazentrum Frankfurt/ZAFES, Goethe University Hospital Frankfurt, Theodor-Stern Kai 7, 60590 Frankfurt am Main, Germany
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39
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Abstract
The mechanisms leading to the onset and perpetuation of systemic and tissue-specific autoimmune diseases are complex, and numerous hypotheses have been proposed or confirmed over the past 12 months. It is particularly of note that the number of articles published during 2011 in the major immunology and autoimmunity journals increased by 3 % compared to the previous year. The present article is dedicated to a brief review of the reported data and, albeit not comprehensive of all articles, is aimed at identifying common and future themes. First, clinical researchers were particularly dedicated to defining refractory forms of diseases and to discuss the use and switch of therapeutic monoclonal antibodies in everyday practice. Second, following the plethora of genome-wide association studies reported in most multifactorial diseases, it became clear that genomics cannot fully explain the individual susceptibility and additional environmental or epigenetic factors are necessary. Both these components were widely investigated, both in organ-specific (i.e., type 1 diabetes) and systemic (i.e., systemic lupus erythematosus) diseases. Third, a large number of 2011 works published in the autoimmunity area are dedicated to dissect pathogenetic mechanisms of tolerance breakdown in general or in specific conditions. While our understanding of T regulatory and Th17 cells has significantly increased in 2011, it is of note that most of the proposed lines of evidence identify potential targets for future treatments and should not be overlooked.
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40
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Achenza MIS, Meda F, Brunetta E, Selmi C. Serum autoantibodies for the diagnosis and management of autoimmune liver diseases. Expert Rev Gastroenterol Hepatol 2012; 6:717-29. [PMID: 23237257 DOI: 10.1586/egh.12.58] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The spectrum of autoimmune liver diseases (AILD) includes primary biliary cirrhosis, primary sclerosing cholangitis and autoimmune hepatitis. The immunological mechanisms triggering the initiation and perpetuation of AILD remains unknown, while autoantigens are now recognized in most cases, and are generally nontraditional in their widespread distribution. Sensitive and specific methods for the detection of serum autoantibodies in patients affected by AILD represent a challenge for researchers and clinicians who desire to obtain an early and certain diagnosis as well as markers of disease control. To this regard, the use and interpretation of serum autoantibodies in AILD may be seen as paradigmatic for the large gaps in our knowledge based on the lack of true population-based studies. The present review article will critically discuss the available evidence on the use of autoantibody findings in the diagnosis or management of autoimmune liver disease.
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Affiliation(s)
- Maria I S Achenza
- Rheumatology and Clinical Immunology, Humanitas Clinical and Research Center, Rozzano, Milan, Italy
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41
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Roggenbuck D, Mytilinaiou MG, Lapin SV, Reinhold D, Conrad K. Asialoglycoprotein receptor (ASGPR): a peculiar target of liver-specific autoimmunity. AUTO- IMMUNITY HIGHLIGHTS 2012; 3:119-25. [PMID: 26000135 PMCID: PMC4389076 DOI: 10.1007/s13317-012-0041-4] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Accepted: 10/11/2012] [Indexed: 12/11/2022]
Abstract
Asialoglycoprotein receptor (ASGPR) autoantibodies have been considered specific markers of autoimmune hepatitis (AIH). The exact mechanisms responsible for the development of these autoantibodies and leading to autoimmunity to this peculiar liver receptor remain elusive. Furthermore, loss of T cell tolerance to ASGPR has been demonstrated in patients with AIH, but it is poorly understood whether such liver-specific T cell responses bear a pathogenic potential and/or participate in the precipitation of AIH. Newly developed enzyme-linked immunosorbent assays have led to the investigation of the sensitivity and specificity of anti-ASGPR antibodies for AIH. The present review provides an overview of the diagnostic and clinical relevance of anti-ASGPR antibodies. A thorough investigation of the autoreactivity against ASGPR may assist efforts to understand liver autoimmunity in susceptible individuals.
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Affiliation(s)
- Dirk Roggenbuck
- Faculty of Natural Sciences, University of Applied Sciences, Großenhainer Str. 57, 01968 Senftenberg, Germany
- GA Generic Assays GmbH, 15827 Dahlewitz/Berlin, Germany
| | - Maria G. Mytilinaiou
- Division of Transplantation Immunology and Mucosal Biology, Institute of Liver Studies, King’s College London School of Medicine at King’s College Hospital, London, UK
| | - Sergey V. Lapin
- Laboratory of Autoimmune Diagnostics, St. Petersburg Pavlov State Medical University, St.Petersburg, Russia
| | - Dirk Reinhold
- Institute of Molecular and Clinical Immunology, Otto-von-Guericke University, Magdeburg, Germany
| | - Karsten Conrad
- Institute of Immunology, Technical University Dresden, Dresden, Germany
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Ehser J, Holdener M, Christen S, Bayer M, Pfeilschifter JM, Hintermann E, Bogdanos D, Christen U. Molecular mimicry rather than identity breaks T-cell tolerance in the CYP2D6 mouse model for human autoimmune hepatitis. J Autoimmun 2012. [PMID: 23200317 DOI: 10.1016/j.jaut.2012.11.001] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
In our novel mouse model for autoimmune hepatitis (AIH), wildtype FVB mice infected with an Adenovirus (Ad) expressing the major AIH autoantigen human cytochrome P450 2D6 (hCYP2D6) show persistent histological and immunological features associated with AIH, including the generation of anti-hCYP2D6 antibodies with an epitope specificity identical to LKM-1 autoantibodies in AIH-patients. Since FVB mice do not express hCYP2D6, the immune response was directed against mouse CYP (mCYP) homologues. Additional expression of hCYP2D6 in transgenic mice resulted in amelioration of the liver disease. In the present study we used the CYP2D6 model to assess why tolerance breakdown and induction of autoimmune liver disease is more efficient if the triggering antigen is similar but not identical to the target autoantigen. We found that in contrast to the specificity and magnitude of anti-hCYP2D6 antibody responses, T-cell responses differ profoundly between wildtype and transgenic mice. Detailed T-cell epitope mapping studies show a robust, antigen-specific T-cell reactivity in FVB mice largely directed against one CD4 and three CD8 epitopes, activating a total of approximately 1% CD4 and 10% CD8 T-cells, respectively, while infected hCYP2D6 mice generated almost no hCYP2D6-specific T-cells. The frequency of hCYP2D6-specific T-cells was approximately 3-fold higher in the liver compared with the spleen. Amino acid sequence comparison revealed that the immunodominant epitopes were located in hCYP2D6-segments of intermediate homology between hCYP2D6 and its mCYP homologues. Our data indicate that self/non-self molecular mimicry, rather than molecular identity, is a prerequisite for breaking T-cell tolerance in the liver.
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Affiliation(s)
- Janine Ehser
- Pharmazentrum Frankfurt/ZAFES, Klinikum der Johann Wolfgang Goethe Universität, Theodor-Stern Kai 7, 60590 Frankfurt am Main, Germany
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Cusick MF, Libbey JE, Fujinami RS. Molecular mimicry as a mechanism of autoimmune disease. Clin Rev Allergy Immunol 2012; 42:102-11. [PMID: 22095454 PMCID: PMC3266166 DOI: 10.1007/s12016-011-8294-7] [Citation(s) in RCA: 332] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A variety of mechanisms have been suggested as the means by which infections can initiate and/or exacerbate autoimmune diseases. One mechanism is molecular mimicry, where a foreign antigen shares sequence or structural similarities with self-antigens. Molecular mimicry has typically been characterized on an antibody or T cell level. However, structural relatedness between pathogen and self does not account for T cell activation in a number of autoimmune diseases. A proposed mechanism that could have been misinterpreted for molecular mimicry is the expression of dual T cell receptors (TCR) on a single T cell. These T cells have dual reactivity to both foreign and self-antigens leaving the host vulnerable to foreign insults capable of triggering an autoimmune response. In this review, we briefly discuss what is known about molecular mimicry followed by a discussion of the current understanding of dual TCRs. Finally, we discuss three mechanisms, including molecular mimicry, dual TCRs, and chimeric TCRs, by which dual reactivity of the T cell may play a role in autoimmune diseases.
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Affiliation(s)
- Matthew F Cusick
- Department of Pathology, University of Utah, Salt Lake City, UT 84132, USA
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44
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Rigopoulou EI, Roggenbuck D, Smyk DS, Liaskos C, Mytilinaiou MG, Feist E, Conrad K, Bogdanos DP. Asialoglycoprotein receptor (ASGPR) as target autoantigen in liver autoimmunity: lost and found. Autoimmun Rev 2012; 12:260-9. [PMID: 22571878 DOI: 10.1016/j.autrev.2012.04.005] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 04/23/2012] [Indexed: 12/11/2022]
Abstract
Asialoglycoprotein receptor (ASGPR) has attracted the attention of liver immunologists for many years. This liver-specific lectin was found to be a major B and T cell autoantigenic target in patients with autoimmune liver diseases, and in particular in autoimmune hepatitis (AIH). This review discusses the biological significance of ASGPR and its relevance to the pathogenesis of autoimmune and virus-triggered liver diseases. We also discuss emerging data on the diagnostic and clinical relevance of anti-ASGPR antibodies in light of recent reports based on commercially available anti-ASGPR enzyme-linked immunosorbent assays. Finally, we critically revisit the data reporting on disease-specific cellular immune responses against ASGPR and their relevance in relation to the pathogenesis of AIH.
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Affiliation(s)
- Eirini I Rigopoulou
- Department of Medicine, University Hospital of Larissa, University of Thessaly Medical School, Viopolis 41110, Larissa, Greece.
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Abstract
Autoimmune hepatitis is a rare but life threatening autoimmune disease of the liver of unknown etiology(1,2). In the past many attempts have been made to generate an animal model that reflects the characteristics of the human disease (3-5). However, in various models the induction of disease was rather complex and often hepatitis was only transient(3-5). Therefore, we have developed a straightforward mouse model that uses the major human autoantigen in type 2 autoimmune hepatitis (AIH-2), namely hCYP2D6, as a trigger(6). Type 1 liver-kidney microsomal antibodies (LKM-1) antibodies recognizing hCYP2D6 are the hallmark of AIH-2(7,8). Delivery of hCYP2D6 into wildtype FVB or C57BL/6 mice was by an Adenovirus construct (Ad-2D6) that ensures a direct delivery of the triggering antigen to the liver. Thus, the ensuing local inflammation generates a fertile field(9) for the subsequent development of autoimmunity. A combination of intravenous and intraperitoneal injection of Ad-2D6 is the most effective route to induce a long-lasting autoimmune damage to the liver (section 1). Here we provide a detailed protocol on how autoimmune liver disease is induced in the CYP2D6 model and how the different aspects of liver damage can be assessed. First, the serum levels of markers indicating hepatocyte destruction, such as aminotransferases, as well as the titers of hCYP2D6 antibodies are determined by sampling blood retroorbitaly (section 2). Second, the hCYP2D6-specific T cell response is characterized by collecting lymphocytes from the spleen and the liver. In order to obtain pure liver lymphocytes, the livers are perfused by PBS via the portal vein (section 3), digested in collagen and purified over a Percoll gradient (section 4). The frequency of hCYP2D6-specific T cells is analyzed by stimulation with hCYP2D6 peptides and identification of IFNγ-producing cells by flow cytometry (section 5). Third, cellular infiltration and fibrosis is determined by immunohistochemistry of liver sections (section 6). Such analysis regimen has to be conducted at several times after initiation of the disease in order to prove the chronic nature of the model. The magnitude of the immune response characterized by the frequency and activity of hCYP2D6-specific T and/or B cells and the degree of the liver damage and fibrosis have to be assessed for a subsequent evaluation of possible treatments to prevent, delay or abrogate the autodestructive process of the liver.
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Affiliation(s)
- Edith Hintermann
- Pharmazentrum Frankfurt / ZAFES, Goethe University Hospital Frankfurt
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