• Autoimmune hepatitis
• Liver
• Multiple sclerosis
• Primary biliary cholangitis

• Humans
• Multiple Sclerosis/complications
• Multiple Sclerosis/epidemiology
• Autoimmune Diseases/complications
• Autoimmune Diseases/epidemiology
• Liver Diseases/complications
• Liver Diseases/epidemiology
• Hepatitis, Autoimmune/complications
• Hepatitis, Autoimmune/epidemiology
• Inflammatory Bowel Diseases
• Psoriasis
• Liver Cirrhosis, Biliary

• Università di Foggia

• Primary Biliary Cholangitis
• Pruritus
• Risk Stratification
• Treatment

• Humans
• Female
• Male
• Liver Cirrhosis, Biliary/drug therapy
• Liver Cirrhosis, Biliary/complications
• Quality of Life
• Peroxisome Proliferator-Activated Receptors/therapeutic use
• Ursodeoxycholic Acid/therapeutic use
• Cholangitis/diagnosis
• Cholestasis
• Pruritus/etiology

• Apoptosis
• Bile acids
• Biliary epithelial cell
• Immune tolerance
• Microbiome
• Senescence
• X chromosome

• Female
• Humans
• Liver Cirrhosis, Biliary/metabolism
• Bile Ducts
• Bicarbonates/metabolism
• Antibodies, Antinuclear
• Cholangitis
• Bile Acids and Salts/metabolism
• Membrane Transport Proteins/metabolism

• GWAS
• Liver cells
• ORMDL3
• PBC
• Risk genes
• Single cell sequencing analysis

• Biliary Tract/cytology
• Biliary Tract/metabolism
• Cells, Cultured
• Genome-Wide Association Study
• Humans
• Liver Cirrhosis, Biliary/genetics
• Liver Cirrhosis, Biliary/metabolism
• Membrane Proteins/genetics
• Membrane Proteins/metabolism
• RNA-Seq
• Single-Cell Analysis/methods

• KYQD20201001 Scientific Research Foundation for Talents of Wenzhou Medical University

• Autoimmune diseases
• LAMP-2A
• T cell
• primary biliary cholangitis (PBC)

• CDR3
• High-throughput sequencing
• PBC
• Random nucleotide addition

• ERα
• MAPKs
• PBC
• inflammatory cellular phenotype
• pro-inflammatory cytokines

• Bile Ducts, Intrahepatic/metabolism
• Bile Ducts, Intrahepatic/pathology
• Biomarkers
• Cells, Cultured
• Cholangitis/etiology
• Cholangitis/metabolism
• Cholangitis/pathology
• Cytokines/blood
• Cytokines/metabolism
• Disease Susceptibility
• Estrogen Receptor alpha/genetics
• Estrogen Receptor alpha/metabolism
• Gene Expression Regulation
• Humans
• Immunohistochemistry
• Inflammation Mediators/blood
• Inflammation Mediators/metabolism
• Leukocytes, Mononuclear/immunology
• Leukocytes, Mononuclear/metabolism

• ERK-RSK signaling
• Intrahepatic biliary epithelial cells
• MC-LR
• Proliferation

• AE2
• Biliary bicarbonate
• Cholangiocytes
• PBC
• miR-506

Primary biliary cholangitis (PBC) is considered a model autoimmune disease due to its signature anti‐mitochondrial antibody (AMA) autoantibody, female predominance, and relatively specific portal infiltration and cholestasis. The identification and cloning of the major mitochondrial autoantigens recognized by AMA have served as an immunologic platform to identify the earliest events involved in loss of tolerance. Despite the relatively high concordance rate in identical twins, genome‐wide association studies have not proven clinically useful and have led to suggestions of epigenetic events. To understand the natural history and etiology of PBC, several murine models have been developed, including spontaneous models, models induced by chemical xenobiotic immunization, and by “designer” mice with altered interferon metabolism. Herein, we describe five such models, including 1) NOD.c3c4 mice, 2) dominant negative form of transforming growth factor receptor type II mice, 3) interleukin‐2R α^−/− mice, 4) adenylate‐uridylate‐rich element Del^−/− mice, and 5) 2‐octynoic acid‐conjugated bovine serum albumin immunized mice. Individually there is no perfect murine model, but collectively the models point to loss of tolerance to PDC‐E2, the major mitochondrial autoantigen, as the earliest event that occurs before clinical disease is manifest. Although there is no direct association of AMA titer and PBC disease progression, it is noteworthy that the triad of PBC monocytes, biliary apotopes, and AMA leads to an intense proinflammatory cytokine burst. Further, the recurrence of PBC after liver transplantation indicates that, due to major histocompatibility complex restriction, disease activity must include not only adaptive immunity but also innate immune mechanisms. We postulate that successful treatment of PBC may require a personalized approach with therapies designed for different stages of disease. (Hepatology Communications 2017;1:275–287)

• antimitochondrial antibodies
• electron paramagnetic resonance spectroscopy
• e2 subunit of the pyruvate dehydrogenase
• inner lipoyl domain
• intein mediated ligation
• primary biliary cholangitis
• xenobiotics
• 2-octynoic acid

• Antibody Affinity
• Autoantibodies/blood
• Case-Control Studies
• Cholangitis/blood
• Cholangitis/chemically induced
• Cholangitis/immunology
• Electron Spin Resonance Spectroscopy
• Enzyme-Linked Immunosorbent Assay
• Humans
• Inteins
• Mitochondria/immunology
• Pyruvate Dehydrogenase (Lipoamide)/chemistry
• Pyruvate Dehydrogenase (Lipoamide)/drug effects
• Pyruvate Dehydrogenase (Lipoamide)/immunology
• Xenobiotics/toxicity

• R01 DK039588 NIDDK NIH HHS
• R01 DK067003 NIDDK NIH HHS
• R37 DK039588 NIDDK NIH HHS

The purpose of this review is to discuss reasons why immunosuppressive therapy so far failed in Primary Biliry Cholangitis.

Even targeted immunosuppressive therapy seems ineffective or potentially harmful.

Bile acid-mediated cholangiocyte damage, facilitated by insufficient bicarbonate secretion, seems to attenuate the anti-inflammatory and anti-fibrotic actions of immunosuppressant and immunomodulatory drugs in a clinically significant way.

• AMA
• Bicarbonate
• Cholestasis
• Immunosuppression
• OCA
• PBC
• UDCA

• Immune response
• Immunity
• Immunology and Microbiology Section
• Na+-independent Cl−/HCO3− anion exchanger AE2
• age-related changes
• intracellular pH homeostasis
• mouse model of autoimmune cholangitis
• self-tolerance breakdown

• Antimitochondrial antibodies
• E2 subunit of pyruvate dehydrogenase (PDC-E2)
• ELISA
• Luminex bead assay
• enzyme inhibition assay
• immunoblotting
• indirect immunofluorescence

The anatomical architecture of the human liver and the diversity of its immune components endow the liver with its physiological function of immune competence. Adaptive immunity is a major arm of the immune system that is organized in a highly specialized and systematic manner, thus providing long-lasting protection with immunological memory. Adaptive immunity consists of humoral immunity and cellular immunity. Cellular immunity is known to have a crucial role in controlling infection, cancer and autoimmune disorders in the liver. In this article, we will focus on hepatic virus infections, hepatocellular carcinoma and autoimmune disorders as examples to illustrate the current understanding of the contribution of T cells to cellular immunity in these maladies. Cellular immune suppression is primarily responsible for chronic viral infections and cancer. However, an uncontrolled auto-reactive immune response accounts for autoimmunity. Consequently, these immune abnormalities are ascribed to the quantitative and functional changes in adaptive immune cells and their subsets, innate immunocytes, chemokines, cytokines and various surface receptors on immune cells. A greater understanding of the complex orchestration of the hepatic adaptive immune regulators during homeostasis and immune competence are much needed to identify relevant targets for clinical intervention to treat immunological disorders in the liver.

Galectin-3 (Gal-3) is a carbohydrate binding lectin, with multiple roles in inflammatory diseases and autoimmunity including its antiapoptotic effect on epithelial cells. In particular, increased expression of Gal-3 in epithelial cells is protective from apoptosis. Based on the thesis that apoptosis of biliary epithelial cells (BECs) is critical to the pathogenesis of Primary Biliary Cholangitis (PBC), we have analyzed the role of Gal-3 in the murine model of autoimmune cholangitis. We took advantage of Gal-3 knockout mice and immunized them with a mimotope of the major mitochondrial autoantigen of PBC, 2-octynoic acid (2-OA) coupled to BSA (2OA-BSA) and evaluated the natural history of subsequent disease, compared to control wild-type mice, by measuring levels of antibodies to PDC-E2, immunohistology of liver, and expression of Gal-3. We report herein that deletion of Gal-3 significantly exacerbates autoimmune cholangitis in these mice. This is manifested by increased periportal infiltrations, bile duct damage, granulomas and fibrosis. Interestingly, the BECs of Gal-3 knockout mice had a higher response to apoptotic stimuli and there were more pro-inflammatory lymphocytes and dendritic cells (DCs) in the livers of Gal-3 knockout mice. In conclusion, Gal-3 plays a protective role in the pathways that lead to the inflammatory destruction of biliary epithelial cells.

Data from genome wide association studies and geoepidemiological studies established that a combination of genetic predisposition and environmental stimulation is required for the loss of tolerance in primary biliary cholangitis (PBC). The serologic hallmark of PBC are the presence of high titer anti-mitochondrial autoantibodies (AMA) that recognize the lipoyl domain of the mitochondrial pyruvate dehydrogenase E2 (PDC-E2) subunit. Extensive efforts have been directed to investigate the molecular basis of AMA. Recently, experimental data has pointed to the thesis that the breaking of tolerance to PDC-E2 is a pivotal event in the initial etiology of PBC, including environmental xenobiotics including those commonly found in cosmetics and food additives, suggesting that chemical modification of the PDC-E2 epitope may render its vulnerable to become a neo-antigen and trigger an immune response in genetically susceptible hosts. Here, we will discuss the natural history, genetics and immunobiology of PBC and structural constraints of PDC-E2 in AMA recognition which makes it vulnerable to chemical modification.

• Antimitochondrial autoantibodies
• Primary biliary cholangitis
• Pyruvate dehydrogenase E2
• Breaking of tolerance
• Xenobiotics

• Acetaminophen/adverse effects
• Animals
• Autoantibodies/metabolism
• Autoantigens/immunology
• Chemical and Drug Induced Liver Injury/etiology
• Cholangitis/etiology
• Cholangitis/immunology
• Dihydrolipoyllysine-Residue Acetyltransferase/immunology
• Disease Models, Animal
• Humans
• Immune Tolerance
• Mice
• Mitochondria/immunology
• Mitochondrial Proteins/immunology
• Molecular Mimicry
• Thioctic Acid/immunology
• Xenobiotics/adverse effects

• primary biliary cirrhosis
• biliary epithelial cell
• salivary gland epithelial cell
• uroepithelium
• apoptosis
• senescence
• mucosal immunity
• epithelitis
• genetics
• epigenetics

• Apoptosis/physiology
• Bile Ducts/immunology
• Bile Ducts/pathology
• Humans
• Liver Cirrhosis, Biliary/immunology
• Salivary Glands/immunology

• apoptosis
• shotgun proteomics
• apoptotic bodies
• biliary epithelial cells

• cholangiocytes
• intrahepatic bile ducts
• apoptosis
• mitochondrial antigens

• ACA
• ALD
• ALP
• AMA
• IIFL
• LT
• PBC
• SSc
• alkaline phosphatase
• anti-centromere antibody
• anti-mitochondrial antibody
• autoimmune liver disease
• dSSc
• diffuse cutaneous SSc
• indirect immunoflourescence
• lSSc
• limited cutaneous SSc
• liver transplantation
• primary biliary cirrhosis
• systemic sclerosis

Background and Aim. Neonatal hemochromatosis (NH) is characterised by severe liver injury and extrahepatic siderosis sparing the reticuloendothelial system. Its aetiology is obscure, although it has been proposed as an alloimmune disease, resulting from immunological reaction to self-antigens (alloantigens) which the body recognizes as foreign. We studied an infant with NH and his mother whose sera contained antimitochondrial antibody (AMA), the hallmark of primary biliary cirrhosis (PBC). Material and Methods. To investigate the origin of AMA in the infant, we studied isotype distributions in serum from the mother and infant. Serum samples were obtained at diagnosis of NH, after liver transplantation (LT; age 1 month), and over the ensuing 17 months. Results. At NH diagnosis, infant and maternal serum contained AMA of the IgG isotype, predominantly of the G3 and G1 subclasses. AMA strongly reacted against the pyruvate dehydrogenase complex E2 subunit (PDC-E2), the major PBC-specific AMA autoantigen. Anti-PDC-E2 responses in both infant and mother declined over time, being present 2 months after LT (mother and child) and absent 10 months later (mother) and 17 months later (child). Conclusion. The association of maternally transferred IgG1 and IgG3 subclass AMA with the appearance of liver damage in an infant with NH may suggest a causal link between antibody and liver damage.

AIM: To investigate the presence of autoantibodies directed against liver sinusoidal cells in primary biliary cirrhosis (PBC).

METHODS: Liver biopsies from 21 PBC patients were studied and compared with 12 liver biopsies from disease controls [3 patients with hepatitis B (HBV) virus, 3 patients with hepatitis C virus (HCV), 3 patients with non-alcoholic steatohepatitis and 3 patients with acute alcoholic hepatitis (AAH)]. As healthy controls, we used tissue specimens adjacent to metastatic liver adenocarcinoma. Normal serum was taken from staff members of the unit. The determination of the cell type targeted by autoantibodies present in the patients sera was performed by indirect immunofluorescence (IIF) analysis using paraffin-embedded liver sections as a substrate. Sera from homologous or heterologous PBC patients or sera from the disease control group were used as primary antibodies. The presence of autoantibodies was identified using confocal microscopy.

RESULTS: In total, 18/21 (85.7%) PBC patients exhibited positive staining in the sinusoidal cells, 10/21 (47.6%) in lymphocytes, 8/21 (38%) in cholangiocytes and 7/21 (33.3%) in hepatocytes, when homologous serum and fluorescein isothiocyanate-conjugated immunoglobulin type G (IgG) secondary antibody were used. PBC sections incubated with heterologous PBC serum showed reduced staining (20% for sinusoidal cells, 20% for lymphocytes, 20% for cholangiocytes and 13.3% for hepatocytes). When IgM immunoglobulin, instead of IgG, was used as secondary antibody, positive staining was observed in 75% of lymphocytes, 62.5% of cholangiocytes, 37.5% of hepatocytes and 50% of the sinusoidal cells with a much stronger staining intensity. No staining was observed when either normal or PBC sera were used as a primary antibody on liver sections from the disease control group. When PBC sera were incubated with healthy control sections, weak positive staining of cholangiocytes was observed in 3/21 (14.3%) PBC serum samples. Steatohepatitis serum on PBC sections gave a positive staining of some hepatocytes and lymphocytes but no staining on viral hepatitis sections. Incubation with HBV sera stained some hepatocytes, cholangiocytes and intra-sinusoidal or portal lymphocytes of PBC, HBV and AAH patients but not HCV patients.

CONCLUSION: In this study, for the first time in diseased liver tissue, we have demonstrated that a large proportion of PBC patients have disease specific autoantibodies against liver sinusoidal cells.

• Primary biliary cirrhosis
• Autoantibodies
• Sinusoidal cells
• Cholangiocytes
• Liver tissue

• primary biliary cirrhosis
• murine models
• autoimmunity
• cholangitis

• Apoptosis
• Apotopes
• Biliary epithelial cells
• IL12
• Macrophages
• Mitochondrial antigens

Unlike other autoimmune liver diseases, primary biliary cirrhosis (PBC) has never been reported in early childhood, while type 2 autoimmune hepatitis (AIH) is eminently a paediatric disease.

We describe a case of type 2 AIH with serological positivity for PBC-specific anti-mitochondrial antibodies (AMA) in a 3-year old girl. We found this observation intriguing as AMA and indeed an overlap with PBC are virtually absent in Type 2 AIH, a pediatric form of AIH which is distinct precisely because it is characterized by pathognomonic anti-liver kidney microsomal type 1 (LKM-1) showing a remarkable antigen-specificity directed against cytochrome P4502D6. We also review the literature in relation to AMA positivity in paediatric age and adolescence. In our case, the presence of AIH-2-specific anti-LKM-1 and PBC-specific AMA was confirmed by indirect immunofluorescence (IIF), and immunoblotting and ELISA based on recombinant mitochondrial antigens. The clinical, laboratory and histological features of the child are given in detail. Interestingly the mother was AMA positive without other features of PBC. The child was successfully treated with immunosuppression and five years after the original diagnosis is on a low dose of prednisolone and azathioprine, with no signs of relapse. Anti-LKM-1 antibodies are still present in low titres. AMA were detectable for the first 4 years after the diagnosis and disappeared later.

This is the first case report in the literature of AIH type 2 with an unexpected PBC-specific AMA positivity in a young child. Response to immunosuppressive treatment was satisfactory and similar to that described in AIH. A review of published reports on AMA positivity in paediatric age shows that the antibody may arise in the context of immunodeficiency and is variably associated with liver damage.

• Animals
• Antibodies, Bacterial/biosynthesis
• Antibodies, Bacterial/genetics
• Antibodies, Bacterial/immunology
• Antigen-Antibody Reactions
• Bacterial Proteins/analysis
• Bacterial Proteins/immunology
• Cloning, Molecular
• Escherichia coli/metabolism
• Genome, Bacterial
• Humans
• Oligopeptides/genetics
• Oligopeptides/immunology
• Oligopeptides/metabolism
• Open Reading Frames/genetics
• Peptide Library
• Recombinant Proteins/genetics
• Recombinant Proteins/immunology
• Recombinant Proteins/metabolism
• Salmonella Infections/diagnosis
• Salmonella Infections, Animal/immunology
• Salmonella Infections, Animal/metabolism
• Salmonella typhimurium/metabolism
• Single-Chain Antibodies/genetics
• Single-Chain Antibodies/immunology
• Single-Chain Antibodies/metabolism
• Swine

Primary biliary cirrhosis (PBC) is a cholestatic liver disease of autoimmune origin, characterised by the destruction of small intrahepatic bile ducts. The disease has an unpredictable clinical course but may progress to fibrosis and cirrhosis. The diagnostic hallmark of PBC is the presence of disease-specific antimitochondrial antibodies (AMA), which are pathognomonic for the development of PBC. The disease overwhelmingly affects females, with some cases of male PBC being reported. The reasons underlying the low incidence of males with PBC are largely unknown. Epidemiological studies estimate that approximately 7–11% of PBC patients are males. There does not appear to be any histological, serological, or biochemical differences between male and female PBC, although the symptomatology may differ, with males being at higher risk of life-threatening complications such as gastrointestinal bleeding and hepatoma. Studies on X chromosome and sex hormones are of interest when studying the low preponderance of PBC in males; however, these studies are far from conclusive. This paper will critically analyze the literature surrounding PBC in males.