Autoantibodies and liver disease: uses and abuses

Immunopathogenesis of Primary Biliary Cholangitis, Primary Sclerosing Cholangitis and Autoimmune Hepatitis: Themes and Concepts

Autoimmune liver diseases include primary biliary cholangitis, primary sclerosing cholangitis, and autoimmune hepatitis, a family of chronic immune-mediated disorders that target hepatocytes and cholangiocytes. Treatments remain nonspecific, variably effective, and noncurative, and the need for liver transplantation is disproportionate to their rarity. Development of effective therapies requires better knowledge of pathogenic mechanisms, including the roles of genetic risk, and how the environment and gut dysbiosis cause immune cell dysfunction and aberrant bile acid signaling. This review summarizes key etiologic and pathogenic concepts and themes relevant for clinical practice and how such learning can guide the development of new therapies for people living with autoimmune liver diseases.

Hepatic Encephalopathy Secondary to Non-cirrhotic Portosystemic Shunt

Hepatic encephalopathy is uncommon in the absence of cirrhosis. We report a 71-year-old woman who presented with altered mental status in the setting of hyperammonemia for the second time in 6 months. Magnetic resonance imaging of the abdomen revealed an uncommon portosystemic shunt involving an enlarged posterior branch of the right portal vein and an accessory right hepatic vein, with no features of cirrhosis. Appropriate management of these patients with ammonia-lowering therapy can reduce repeat episodes and improve quality of life. This case demonstrates the importance of diagnosing non-cirrhotic hepatic encephalopathy in patients with altered mental status.

Unveiling the interplay between NSAID-induced dysbiosis and autoimmune liver disease in children: insights into the hidden gateway to autism spectrum disorders. Evidence from ex vivo, in vivo, and clinical studies

Autism spectrum disorders (ASD) represent a diverse group of neuropsychiatric conditions, and recent evidence has suggested a connection between ASD and microbial dysbiosis. Immune and gastrointestinal dysfunction are associated with dysbiosis, and there are indications that modulating the microbiota could improve ASD-related behaviors. Additionally, recent findings highlighted the significant impact of microbiota on the development of autoimmune liver diseases, and the occurrence of autoimmune liver disease in children with ASD is noteworthy. In the present study, we conducted both an in vivo study and a clinical study to explore the relationship between indomethacin-induced dysbiosis, autoimmune hepatitis (AIH), and the development of ASD. Our results revealed that indomethacin administration induced intestinal dysbiosis and bacterial translocation, confirmed by microbiological analysis showing positive bacterial translocation in blood cultures. Furthermore, indomethacin administration led to disturbed intestinal permeability, evidenced by the activation of the NLRP3 inflammasomes pathway and elevation of downstream biomarkers (TLR4, IL18, caspase 1). The histological analysis supported these findings, showing widened intestinal tight junctions, decreased mucosal thickness, inflammatory cell infiltrates, and collagen deposition. Additionally, the disturbance of intestinal permeability was associated with immune activation in liver tissue and the development of AIH, as indicated by altered liver function, elevated ASMA and ANA in serum, and histological markers of autoimmune hepatitis. These results indicate that NSAID-induced intestinal dysbiosis and AIH are robust triggers for ASD existence. These findings were further confirmed by conducting a clinical study that involved children with ASD, autoimmune hepatitis (AIH), and a history of NSAID intake. Children exposed to NSAIDs in early life and complicated by dysbiosis and AIH exhibited elevated serum levels of NLRP3, IL18, liver enzymes, ASMA, ANA, JAK1, and IL6. Further, the correlation analysis demonstrated a positive relationship between the measured parameters and the severity of ASD. Our findings suggest a potential link between NSAIDs, dysbiosis-induced AIH, and the development of ASD. The identified markers hold promise as indicators for early diagnosis and prognosis of ASD. This research highlights the importance of maintaining healthy gut microbiota and supports the necessity for further investigation into the role of dysbiosis and AIH in the etiology of ASD.

Nomenclature, diagnosis and management of drug-induced autoimmune-like hepatitis (DI-ALH): An expert opinion meeting report

Drug-induced liver injury (DILI) can mimic almost all other liver disorders. A phenotype increasingly ascribed to drugs is autoimmune-like hepatitis (ALH). This article summarises the major topics discussed at a joint International Conference held between the Drug-Induced Liver Injury consortium and the International Autoimmune Hepatitis Group. DI-ALH is a liver injury with laboratory and/or histological features that may be indistinguishable from those of autoimmune hepatitis (AIH). Previous studies have revealed that patients with DI-ALH and those with idiopathic AIH have very similar clinical, biochemical, immunological and histological features. Differentiating DI-ALH from AIH is important as patients with DI-ALH rarely require long-term immunosuppression and the condition often resolves spontaneously after withdrawal of the implicated drug, whereas patients with AIH mostly require long-term immunosuppression. Therefore, revision of the diagnosis on long-term follow-up may be necessary in some cases. More than 40 different drugs including nitrofurantoin, methyldopa, hydralazine, minocycline, infliximab, herbal and dietary supplements (such as Khat and Tinospora cordifolia) have been implicated in DI-ALH. Understanding of DI-ALH is limited by the lack of specific markers of the disease that could allow for a precise diagnosis, while there is similarly no single feature which is diagnostic of AIH. We propose a management algorithm for patients with liver injury and an autoimmune phenotype. There is an urgent need to prospectively evaluate patients with DI-ALH systematically to enable definitive characterisation of this condition.

Primary sclerosing cholangitis and overlap features of autoimmune hepatitis: a coming of age or an age-ist problem?

Autoimmune liver diseases are siloed into three syndromes that define clinical practice. These classifiers can, and are, challenged by variant presentations across all ages, something inevitable to disease definitions that rely on interpreting inherently variable semi-quantitative/qualitative clinical, laboratory, pathological or radiological findings. Furthermore this remains premised by an ongoing absence of definable disease aetiologies. Clinicians thus encounter individuals with biochemical, serological, and histological manifestations that are common to both primary sclerosing cholangitis (PSC) and autoimmune hepatitis (AIH), often labelled as 'PSC/AIH-overlap'. In childhood the term 'autoimmune sclerosing cholangitis (ASC)' may be used, and some propose this to be a distinct disease process. In this article we champion the concept that ASC and PSC/AIH-overlap are not distinct entities. Rather, they represent inflammatory phases of PSC frequently manifesting earlier in disease course, most notably in younger patients. Ultimately, disease outcome remains that of a more classical PSC phenotype observed in later life. Thus, we argue that it is now time to align disease names and descriptions used by clinicians across all patient subpopulations, to help care become uniform and ageless. This will enhance collaborative studies and contribute ultimately to rational treatment advances.

Prevalence and Significance of Autoantibody Seropositivity in Children with Wilson's Disease

Autoantibodies occur in healthy subjects as well as in children with Wilson's disease (WD), but their prevalence and significance are unknown. Thus, we aimed to assess the prevalence of autoantibodies and autoimmune markers, and their relationship to liver injury in WD children. The study included 74 WD and 75 healthy children as a control group. Patients with WD underwent transient elastography (TE) examinations, as well as determination of liver function tests, copper metabolism markers, and serum immunoglobulins (Ig). In the sera of the WD patients and controls, anti-nuclear (ANA), anti-smooth muscle, anti-mitochondrial, anti-parietal cell, anti-liver/kidney microsomal, anti-neutrophil cytoplasmic autoantibodies, and specific celiac antibodies were determined. Among the autoantibodies, only the prevalence of ANA in children with WD was higher than in the controls. There was no significant relationship between the presence of autoantibodies and liver steatosis or stiffness after TE. However, advanced liver stiffness (E > 8.2 kPa) was related to IgA, IgG, and gamma globulin production. The type of treatment did not influence the prevalence of autoantibodies. Our results suggest that autoimmune disturbances in WD might not be directly related to liver damage as expressed by steatosis and/or liver stiffness after TE.

Anti-F-Actin Antibody Positivity on Indirect Immunofluorescence Assay Following Chinese and Alternative Medicine Therapy: A Case Report

Immunofluorescence on human epithelial type 2 cells is the standard screening assay for the detection of antinuclear antibodies (ANA). Cytoplasmic speckled patterns are a common finding. However, the less commonly reported ones include the cytoplasmic fibrillar patterns on indirect immunofluorescence technique (IIFT). The cytoplasmic fibrillar patterns include the cytoplasmic linear (AC-15), cytoplasmic filamentous (AC-16), and cytoplasmic segmental (AC-17). We report a case of cytoplasmic linear (F-actin) detected through IIFT during ANA screening in a 77-year-old man and later reconfirmed on liver mosaic biochip through IIFT on vascular smooth muscle substrate (VSM-47) without features suggestive of anti-smooth muscle antibody involvement post-complementary and alternative medicine therapy initiation.

Autoantibodies: are they a clue for liver diseases?

Introduction

Autoantibody testing has contributed to both biological and clinical insights in managing patients with liver disease. These autoantibodies often have clinical value for the diagnosis, disease activity and/or prognosis.

Aim of the study

We aimed to investigate the potential application of auto-antibodies in different etiologies of non-autoimmune liver diseases.

Material and methods

This study was conducted on 53 infants and children with chronic liver diseases. The patients were subjected to clinical history and examination, laboratory investigations and abdominal ultrasound. Serum of all infants and children was tested for measurement of antiprothrombin antibody and anti-b2-glycoprotein I (ab2GPI) and anticardiolipin (ACL) auto-antibodies using a fully-automated enzyme linked immunosorbent assay (ELISA) system.

Results

The mean age of the infants with cholestatic liver diseases was significantly lower than those with metabolic liver diseases, hepatitis C virus (HCV) and vascular liver diseases (p < 0.05). The gender distribution was proportionate in all groups (p = 0.703). Autoantibodies showed significant variations among different etiologies of chronic liver diseases. he incidence of ab2GPI and ACL was significantly increased in both HCV (94.7% and 78.9%, respectively) and vascular liver diseases patients (90.9% and 72.7%, respectively) (p < 0.05). Antiprothrombin antibodies were found in 81.8% of vascular liver disease patients. Interestingly, all types of autoantibodies were deficient in cholestatic and metabolic liver diseases.

Conclusions

Testing for liver-related autoantibodies should be included in the workup of patients with chronic liver diseases. Further studies are needed to explain the cause-effect association of ACL, ab2GPI and antiprothrombin with chronic HCV and vascular liver diseases.

Positive autoantibodies in living liver donors

BACKGROUND

There is a nationwide shortage of organs available for liver transplantation. Living donors help meet this growing demand. Not uncommonly, donors will have positive autoantibodies. However, it is unclear whether donor positive autoantibodies are correlated with worse outcomes following living liver donor transplantations.

AIM

To analyze the significance of positive autoantibodies in donors on post-transplant outcomes in recipients.

METHODS

We performed a retrospective review of living liver donors who had undergone liver transplantation between January 1, 2012 and August 31, 2021. Demographic characteristics and pre-transplant data including antinuclear antibodies (ANA) and anti-smooth muscle antibody titers were collected in donors. Outcomes of interest were post-transplantation complications including mortality, biliary strictures, biliary leaks, infection, and rejection. Pediatric recipients and donors without measured pre-transplant autoantibody serologies were excluded from this study.

RESULTS

172 living donor liver transplantations were performed during the study period, of which 115 patients met inclusion criteria. 37 (32%) living donors were autoantibody-positive with a median ANA titer of 1:160 (range 1:80 to 1:1280) and median anti-SMA titer of 1:40 (range 1:20 to 1:160). There were no significant differences in baseline demographics between the autoantibody positive and negative donors. Post-transplantation rates of death (P value = 1), infections (P value = 0.66), and overall rates of complications (P value = 0.52) were similar between the autoantibody positive and negative groups. Higher incidences of anastomotic strictures and rejection were observed in the autoantibody positive group; however, these differences were not statistically significant (P value = 0.07 and P value = 0.30 respectively).

CONCLUSION

Isolated pre-transplant autoantibody positivity is not correlated to worse post-transplant outcomes in living liver donor transplants.

'Diagnostic downshift': clinical and system consequences of extrapolating secondary care testing tactics to primary care

Numerous drivers push specialist diagnostic approaches down to primary care ('diagnostic downshift'), intuitively welcomed by clinicians and patients. However, primary care's different population and processes result in under-recognised, unintended consequences. Testing performs poorer in primary care, with indication creep due to earlier, more undifferentiated presentation and reduced accuracy due to spectrum bias and the 'false-positive paradox'. In low-prevalence settings, tests without near-100% specificity have their useful yield eclipsed by greater incidental or false-positive findings. Ensuing cascades and multiplier effects can generate clinician workload, patient anxiety, further low-value tests, referrals, treatments and a potentially nocebic population 'disease' burden of unclear benefit. Increased diagnostics earlier in pathways can burden patients and stretch general practice (GP) workloads, inducing downstream service utilisation and unintended 'market failure' effects. Evidence is tenuous for reducing secondary care referrals, providing patient reassurance or meaningfully improving clinical outcomes. Subsequently, inflated investment in per capita testing, at a lower level in a healthcare system, may deliver diminishing or even negative economic returns. Test cost poorly represents 'value', neglecting under-recognised downstream consequences, which must be balanced against therapeutic yield. With lower positive predictive values, more tests are required per true diagnosis and cost-effectiveness is rarely robust. With fixed secondary care capacity, novel primary care testing is an added cost pressure, rarely reducing hospital activity. GP testing strategies require real-world evaluation, in primary care populations, of all downstream consequences. Test formularies should be scrutinised in view of the setting of care, with interventions to focus rational testing towards those with higher pretest probabilities, while improving interpretation and communication of results.

Chronic Liver Disease: A Mimic of Systemic Lupus Erythematosus

Humoral immune responses can produce autoantibodies against self-cellular proteins and nucleic acids without the presence of autoimmune diseases. Numerous kinds of autoantibodies are detected in liver diseases such as viral hepatitis, alcoholic liver disease (ALD), and nonalcoholic fatty liver disease (NAFLD), where their production could be secondary to hepatocellular inflammation and necrosis. Hence, the presence of an autoantibody does not necessarily indicate the presence of autoimmune disease; nor does it predict its severity and potential response to therapy. In literature, the spectrum and methods of diagnosis of liver disease in lupus are well described. However, chronic liver disease can manifest with signs similar to those in lupus, and it is important to recognize that autoantibodies in patients with chronic liver disease can be seen without the presence of autoimmune rheumatic disease. In this report, we discuss a very interesting case of a middle-aged female with a history of ALD presenting with calciphylaxis, thrombocytopenia, hypocomplementemia, and positive serologies, but without any clinical evidence of autoimmune rheumatic disease.

Pathology of autoimmune hepatitis

Autoimmune hepatitis (AIH) is a relatively rare non-resolving chronic liver disease, which mainly affects women. It is characterized by hypergammaglobulinemia, circulating autoantibodies, interface hepatitis on liver histology and a favourable response to immunosuppression. The putative mechanism for the development of autoimmune hepatitis is thought to be the interaction between genetic predisposition, environmental triggers and failure of the native immune system.

AIH still remains a major diagnostic and therapeutic challenge, mainly because it is a very heterogeneous disease. Prompt and timely diagnosis is crucial since, if left untreated, AIH has a high mortality rate. Histological demonstration of hepatitis is required for the diagnosis of AIH and, therefore, liver biopsy is mandatory in the initial diagnostic work-up, before treatment. In this review, we summarize the histological features of AIH with the main aim of highlighting the most important clinical-pathological hallmarks useful in the routine diagnostic practice.

The significance of cytoplasmic antinuclear antibody patterns in autoimmune liver disease

We aimed to determine the significance of cytoplasmic antinuclear antibody (ANA) patterns using computer-aided immunofluorescence microscopy in patients with autoimmune liver diseases (AILD). ANA staining pattern was identified by treating cultured human epithelial type 2 (HEp-2) cells with the sera of the patients. Medical records of patients with suspected AILD who had positive cytoplasmic ANA patterns between February 2017 and November 2019 were retrospectively reviewed for clinical, laboratory, and immunological data. Cytoplasmic ANA patterns of AILD and non-AILD groups were compared. Further subgroup analysis of patients with AILD who had reticular or speckled cytoplasmic ANA patterns was conducted. We found that among the 196 patients with positive cytoplasmic ANA patterns, 113 (57.6%) were diagnosed with AILD. The percentage of reticular cytoplasmic pattern was higher in the AILD group than that in the non-AILD group (64.0% vs. 21.9%, p < 0.001). Furthermore, patients with AILD who exhibited a reticular ANA pattern demonstrated a higher positive rate for anti-mitochondrial antibodies (66.7% vs. 2.6%, p < 0.001) than those who exhibited the speckled ANA pattern. Moreover, AILD patients with the reticular ANA pattern displayed a lower positive rate for anti-smooth muscle antibodies (0% vs. 45%, p < 0.001) and nuclear ANA pattern (73.2% vs. 97.5%, p = 0.003) than those with the speckled ANA pattern. Therefore, cytoplasmic ANA patterns could be used to guide AILD characterization in suspected AILD cases, especially as the reticular ANA pattern is strongly associated with AILD. Thus, it is important to check cytoplasmic ANA patterns for AILD evaluation, even when nuclear ANA patterns are negative.

Cellular therapies for the treatment of immune-mediated GI and liver disease

INTRODUCTION

Immune-mediated liver and gastrointestinal diseases are chronic conditions that lack curative treatments. Despite advances in the understanding and treatment of these conditions, they frequently remain refractory to treatment and represent a significant unmet need. Cellular therapies are an emerging option and hold the potential to have a major impact.

DATA SOURCES

A literature review was carried out using Pubmed. Keywords used for search were 'ATMP', 'immune mediated', 'autoimmune liver disease' and 'immune mediated gastrointestinal conditions', 'cell therapy', 'MSC', 'HSCT', 'Regulatory T cells', 'GVHD', 'Coeliac disease' 'IBD', 'PSC', 'AIH', 'PBC'. No new data were generated or analysed in support of this review.

AREAS OF AGREEMENT

There is substantial evidence from clinical trials to support the use of cell therapies as a treatment for immune-mediated liver and gastrointestinal conditions. Cellular therapy products have the ability to 'reset' the dysregulated immune system and this in turn can offer a longer term remission. There are ongoing clinical trials with mesenchymal stromal cells (MSCs) and other cells to evidence their efficacy profile and fill the gaps in current knowledge. Insights gained will inform future trial designs and subsequent therapeutic applications.

AREAS OF CONTROVERSY

There remains some uncertainty around the extrapolation of results from animal studies to clinical trials. Longevity of the therapeutic effects seen after the use of cell therapy needs to be scrutinized further. Heterogeneity in the selection of cells, source, methods of productions and cell administration pose challenges to the interpretation of the data.

GROWING POINTS

MSCs are emerging as a key therapeutic cells in immune-mediated liver and gastrointestinal conditions. Ongoing trials with these cells will provide new insights and a better understanding thus informing future larger scale studies.

AREAS TIMELY FOR DEVELOPING RESEARCH

Larger scale clinical trials to build on the evidence from small studies regarding safety and efficacy of cellular therapy are still needed before cellular therapies can become off the shelf treatments. Alignment of academia and industry to standardize the processes involved in cell selection, manipulation and expansion and subsequent use in clinical trials is an important avenue to explore further.

Recent Progress in Prediction Systems for Drug-induced Liver Injury Using in vitro Cell Culture

BACKGROUND

In order to avoid drug-induced liver injury (DILI), in vitro assays, which enable the assessment of both metabolic activation and immune reaction processes that ultimately result in DILI, are needed.

OBJECTIVE

In this study, the recent progress in the application of in vitro assays using cell culture systems is reviewed for potential DILI-causing drugs/xenobiotics and a mechanistic study on DILI, as well as for the limitations of in vitro cell culture systems for DILI research.

METHODS

Information related to DILI was collected through a literature search of the PubMed database.

RESULTS

The initial biological event for the onset of DILI is the formation of cellular protein adducts after drugs have been metabolically activated by drug metabolizing enzymes. The damaged peptides derived from protein adducts lead to the activation of CD4+ helper T lymphocytes and recognition by CD8+ cytotoxic T lymphocytes, which destroy hepatocytes through immunological reactions. Because DILI is a major cause of drug attrition and drug withdrawal, numerous in vitro systems consisting of hepatocytes and immune/inflammatory cells, or spheroids of human primary hepatocytes containing non-parenchymal cells have been developed. These cellular-based systems have identified DILIinducing drugs with approximately 50% sensitivity and 90% specificity.

CONCLUSION

Different co-culture systems consisting of human hepatocyte-derived cells and other immune/inflammatory cells have enabled the identification of DILI-causing drugs and of the actual mechanisms of action.

First-in-human randomised trial and follow-up study of Plasmodium falciparum blood-stage malaria vaccine BK-SE36 with CpG-ODN(K3)

BACKGROUND

BK-SE36 is blood-stage malaria vaccine candidate that is undergoing clinical trials. Here, the safety and immunogenicity of BK-SE36 with a novel adjuvant, CpG-ODN(K3) (thus, BK-SE36/CpG) was assessed in a phase 1a trial in Japan.

METHODS

An investigator-initiated, randomised, single-blind, placebo-controlled, dose-escalation study was conducted at Osaka University Hospital with 26 healthy malaria naïve Japanese male adults. The trial was conducted in two stages: Stage/Group 1, half-dose (n = 7 for BK-SE36/CpG and n = 3 for control) and Stage/Group 2, full-dose (n = 11 for BK-SE36/CpG and n = 5 for control). There were two intramuscular vaccinations 21 days apart for both half-dose (0.5 ml: 50 µg SE36 + 500 µg aluminum + 500 µg K3) and full-dose (1.0 ml: 100 µg SE36 + 1000 µg aluminum + 1000 µg K3). A one-year follow-up was done to monitor changes in autoimmune markers and vaccine-induced antibody response.

RESULTS

BK-SE36/CpG was well tolerated. Vaccination site reactions were similar to those observed with BK-SE36. During the trial and follow-up period, no subject had clinical evidence of autoimmune disease. The full-dose group had significantly higher titres than the half-dose group (Student's t-test, p = 0.002) at 21 days post-second vaccination. Antibody titres remained above baseline values during 12 months of follow-up. The vaccine induced antibody was mostly composed of IgG1 and IgM, and recognised epitopes close to the polyserine region located in the middle of SE36.

CONCLUSIONS

BK-SE36/CpG has an acceptable safety profile. Use of CpG-ODN(K3) greatly enhanced immunogenicity in malaria naïve Japanese adults when compared to BK-SE36 alone. The utility of BK-SE36/CpG is currently under evaluation in a malaria endemic setting in West Africa.

TRIAL REGISTRATION

JMACCT Clinical Trial Registry JMA-IIA00109.

Cholestatic Liver Diseases: A Primer for Generalists and Subspecialists

Cholestasis describes impairment in bile formation or flow which can manifest clinically with fatigue, pruritus, and jaundice. The differential diagnosis of cholestatic liver diseases is broad, and the etiologies of cholestasis vary in the anatomical location of the defect and acuity of presentation. Cholestasis may occur in a variety of clinical scenarios. Therefore, it is important for a diverse audience with varied clinical practices to have a basic understanding of manifestations of cholestatic liver diseases.

Consensus guidelines: best practices for detection, assessment and management of suspected acute drug-induced liver injury occurring during clinical trials in adults with chronic cholestatic liver disease

BACKGROUND

Improved knowledge of the molecular pathophysiology and immunopathogenesis of cholestatic liver diseases in recent years has led to an increased interest in developing novel therapies. Patients with cholestatic liver disease often require different approaches to assessment and management of suspected drug-induced liver injury (DILI) compared to those with healthy livers and those with parenchymal liver diseases. At present, there are no regulatory guidelines or society position papers, that systematically address best practices pertaining to detection of DILI in these patients.

AIMS

To outline best practices for detection, assessment and management of suspected acute DILI during clinical trials in adults with the cholestatic liver diseases - Primary Biliary Cholangitis (PBC) and Primary Sclerosing Cholangitis (PSC).

METHODS

This is one of the several papers developed by the IQ DILI Initiative, which is comprised of members from 16 pharmaceutical companies, in collaboration with DILI experts from academia and regulatory agencies. The contents are the result of an extensive literature review, as well as in-depth discussions among industry, regulatory and academic DILI experts, to achieve consensus recommendations on DILI-related issues occurring during clinical trials for cholestatic liver diseases.

RESULTS

Recommended best practices are outlined pertaining to hepatic eligibility criteria, monitoring of liver tests, approach to a suspected DILI signal, and hepatic discontinuation rules.

CONCLUSIONS

This paper provides a framework for the approach to detection, assessment and management of suspected acute DILI occurring during clinical trials in adults with cholestatic liver disease.

Potential Involvement of Salmonella Infection in Autoimmunity

In this work, we investigated the potential effects of nontyphoidal Salmonella infection on autoantibody (AA) formation. The titer and profiles of autoantibodies in the sera of patients with acute salmonellosis due to Salmonella enterica serovar Typhimurium (S. Typhimurium) or Salmonella enterica serovar Enteritidis (S. Enteritidis) infection, as well as in convalescent patients, were determined with indirect immunofluorescence. A significant increase of autoantibodies in acute diseases caused by both serotypes of Salmonella and during post infection by S. Enteritidis was detected. Antibody profile analysis by multivariate statistics revealed that this increase was non-specific and was not dependent on the infectious agent or disease stage. The results obtained suggest that nontyphoidal Salmonella infection contributes to the generation of autoantibodies and may play a role in autoimmune disease.

Meta-Analysis of Antinuclear Antibodies in the Diagnosis of Antimitochondrial Antibody-Negative Primary Biliary Cholangitis

Objective

The diagnostic value of antinuclear antibodies (ANAs) including anti-gp210 and anti-sp100 for primary biliary cholangitis/cirrhosis (PBC) has been widely reported. However, their diagnostic performances for antimitochondrial antibody- (AMA-) negative PBC were less well elucidated. Therefore, the aim of the current meta-analysis was to evaluate the diagnostic accuracy of ANAs in patients with AMA-negative PBC.

Materials and Methods

Literature on the diagnostic value of biomarkers for AMA-negative PBC was systematically searched in PubMed, MEDLINE, EMBASE, and the Cochrane Library. The qualities of the retrieved studies were assessed by the Quality Assessment of Diagnostic Accuracy Studies-version 2 (QUADAS-2) scale. Pooled sensitivity and specificity of the biomarkers were calculated with random-effects models. The areas under the summary receiver operating characteristic (AUSROC) curves were used to evaluate the overall diagnostic performance of ANAs.

Results

A total of 11 studies (400 AMA-negative PBC patients and 6217 controls) were finally included in the meta-analysis. ANAs had an overall sensitivity of 27% (95% CI: 20%, 35%) and specificity of 98% (95% CI: 97%, 99%). The pooled sensitivities for anti-gp210 and anti-sp100 were 23% (95% CI: 13%, 37%) and 25% (95% CI: 13%, 43%), respectively, and their specificities were 99% (95% CI: 97%, 100%) and 97% (95% CI: 93%, 98%), respectively.

Conclusions

ANAs exhibited high specificity but low sensitivity and therefore could be used as reliable biomarkers to reduce the necessity of liver histology.

EASL Clinical Practice Guidelines: Drug-induced liver injury

Idiosyncratic (unpredictable) drug-induced liver injury is one of the most challenging liver disorders faced by hepatologists, because of the myriad of drugs used in clinical practice, available herbs and dietary supplements with hepatotoxic potential, the ability of the condition to present with a variety of clinical and pathological phenotypes and the current absence of specific biomarkers. This makes the diagnosis of drug-induced liver injury an uncertain process, requiring a high degree of awareness of the condition and the careful exclusion of alternative aetiologies of liver disease. Idiosyncratic hepatotoxicity can be severe, leading to a particularly serious variety of acute liver failure for which no effective therapy has yet been developed. These Clinical Practice Guidelines summarize the available evidence on risk factors, diagnosis, management and risk minimization strategies for drug-induced liver jury.

Autoimmune liver disease following acute hepatitis A infection

A male patient in his late 30s presented to our outpatient clinic at Mortimer Market Centre with worsening liver transaminases tests 2 months after a resolved acute hepatitis A infection. A diagnosis of parainfectious autoimmune-like hepatitis phenomena was made based on the history, laboratory and histological features.

Diagnosis and Management of Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is a chronic, cholestatic, autoimmune disease with a variable progressive course. PBC can cause debilitating symptoms including fatigue and pruritus and, if left untreated, is associated with a high risk of cirrhosis and related complications, liver failure, and death. Recent changes to the PBC landscape include a name change, updated guidelines for diagnosis and treatment as well as new treatment options that have recently become available. Practicing clinicians face many unanswered questions when managing PBC. To assist these healthcare providers in managing patients with PBC, the American College of Gastroenterology (ACG) Institute for Clinical Research & Education, in collaboration with the Chronic Liver Disease Foundation (CLDF), organized a panel of experts to evaluate and summarize the most current and relevant peer-reviewed literature regarding PBC. This, combined with the extensive experience and clinical expertise of this expert panel, led to the formation of this clinical guidance on the diagnosis and management of PBC.

Pharmacogenomics of drug-induced liver injury (DILI): Molecular biology to clinical applications

A 21-year old woman was admitted to hospital with a two-week history of painless jaundice, fatigue and anorexia having previously been fit and well. One month prior to presentation, the patient had taken a five-day course of amoxicillin-clavulanic acid for an infected skin cyst. Otherwise, she was only on the oral contraceptive pill and reported minimal alcohol intake. On examination, she was deeply jaundiced, but alert and oriented with no asterixis. She had no stigmata of chronic liver disease, but hepatomegaly extending 3 cm from below the right subcostal margin was evident. Investigations showed: white cell count 13.4 × 10⁹/L (normal 3.6-9.3), haemoglobin 11.8 g/dl (normal 11-15), platelet count 356 × 10⁹/L (normal 170-420), sodium 138 mmol/L (normal 134-144), potassium 3.5 mmol/L (normal 3.5-5.0), creatinine 32 µmol/L (normal 40-75), albumin 30 g/L (normal 35-48), alanine aminotransferase 707 IU/L (normal 15-54), alkaline phosphatase 151 IU/L (normal 30-130), bilirubin 384 µmol/L (normal 7-31) and prothrombin time 27.2 s (normal 11.7-14). Screening for hepatitis A, B, C, E, Epstein-Barr virus, cytomegalovirus and autoimmune hepatitis was negative. Tests for anti-smooth muscle, antinuclear, and anti-liver-kidney microsomal-1 antibodies were negative; immunoglobulin levels and ceruloplasmin levels were normal. Liver ultrasonography demonstrated a liver of normal contour with no biliary dilatation, a normal spleen size and patent vessels. Liver biopsy revealed severe portal interface hepatitis with lobular inflammation and scant plasma cells. Her clinical condition deteriorated in the following days with prothrombin time and bilirubin rising to 56.6 s and 470 µmol/L, respectively. At follow-up after 11 days, her alanine aminotransferase level was 1,931 IU/L. She developed grade 2 hepatic encephalopathy 14 days after presentation, and was listed for a super-urgent liver transplant. Human leucocyte antigen (HLA) typing was performed as a part of preparatory investigations and showed the patient carried the HLA haplotype HLA-DRB1∗15:02-DQB1∗06:01. Following orthotopic transplantation of a deceased donor graft her explant histology revealed severe ongoing hepatitis with multi-acinar necrosis (Fig. 1A and B). This case raised a number of important questions about the diagnosis of drug-induced liver injury and tools available for clinicians to make the best decisions for patient care: In this Grand Rounds article, we will explore these questions, describing the pathophysiology, diagnostic and prognostic biomarkers, and clinical management of drug-induced liver injury. We will also discuss ongoing areas of uncertainty.

A case series evaluating the impact of Hepatitis C eradication using direct acting antivirals on primary biliary cholangitis-associated autoimmunity

BACKGROUND

Chronic Hepatitis C Virus (HCV) infection has been commonly linked to the development of autoimmunity, in part through activation of B cells. B cells are also postulated to play a pathogenic role in the autoimmune liver disease Primary Biliary Cholangitis (PBC). Patients with concurrent PBC and HCV infection carry an increased risk of more progressive disease, although the mechanism underlying this effect is poorly understood. Utilizing a case series of patients with concurrent PBC and HCV, the aim of this study was to evaluate for the potential impact of HCV eradication upon autoimmunity/autoantibody production.

CASE PRESENTATION

A case series evaluating three patients with co-existing PBC-HCV infection receiving non-interferon based HCV treatments with direct-acting antivirals (DAA). One of three patient received Ursodeoxycholic acid (UDCA; 13 mg/kg/day) during the treatment period. Sustained virological response (SVR) to DAA's was assessed using a HCV Quantitative Nucleic Acid Test (Abbott). Autoantibodies associated with autoimmune liver diseases (including PBC) and liver biochemistry, were measured before, during and after DAA treatment (Mitogen Advanced Diagnostics Laboratory, Calgary, Canada). All patients achieved an SVR, as determined by negative HCV RNA test 12 weeks post-DAA therapy. Titres of anti-mitochondrial antibodies (AMA-M2), anti- branched-chain 2-oxo-acid dehydrogenase complex and 2-oxo glutarate dehydrogenase complex (anti-3E-BPO), and anti- tripartite motif-containing protein 21 (TRIM21/Ro52) remained unchanged, despite successful HCV eradication. Two of the three patients exhibited a transient decrease in some autoantibody titres during DAA treatment, but these returned to baseline levels post-DAA therapy.

CONCLUSIONS

Within the limitations of a case series, our results suggest that HCV co-infection may not be a significant driver of PBC-related autoimmunity/autoantibody production. However, a larger n-value is required to truly assess for the effect of HCV eradication on autoantibody production.

Patterns of disease progression and incidence of complications in primary biliary cholangitis (PBC)

Clinical outcome for patients with primary biliary cholangitis (PBC) is dictated by development of cirrhosis, portal hypertension and its associated complications; including for some, a predisposition toward hepatocellular carcinoma. However rates of clinical progression vary, and accurately identifying disease course is of critical importance to patients, clinicians, as well as industry, who are committed to developing new effective and life-prolonging therapy as well as treating symptoms that appear disproportionate to underlying disease severity. Patients seek reassurance and guidance as to their own prognosis, and clinicians wish to confidently recognise those at highest risk of poor outcomes as equally as they strive to reassure individuals with a more favourable disease trajectory. International registries have facilitated a much greater knowledge of disease incidence and heterogeneity of presenting phenotypes. In so doing they highlight the opportunity to provide a more individualized estimate of the clinical course that patients experience, and have led to a renewed approach to risk stratification; both in terms of 'hard outcomes' and also disease-associated complications in PBC specifically.

Gastrointestinal Manifestations of Systemic Sclerosis

Systemic sclerosis (SSc) is a rare autoimmune disease characterized by fibroproliferative alterations of the microvasculature leading to fibrosis and loss of function of the skin and internal organs. Gastrointestinal manifestations of SSc are the most commonly encountered complications of the disease affecting nearly 90% of the SSc population. Among these complications, the esophagus and the anorectum are the most commonly affected. However, this devastating disorder does not spare any part of the gastrointestinal tract (GIT), and includes the oral cavity, esophagus, stomach, small and large bowels as well as the liver and pancreas. In this review, we present the current understanding of the pathophysiologic mechanisms of SSc including vasculopathy, endothelial to mesenchymal transformation as well as the autoimmune pathogenetic pathways. We also discuss the clinical presentation and diagnosis of each part of the GIT affected by SSc. Finally, we highlight the latest developments in the management of this disease, addressing the severe malnutrition that affects this vulnerable patient population and ways to assess and improve the nutritional status of the patients.

Evaluation of classical and novel autoantibodies for the diagnosis of Primary Biliary Cholangitis-Autoimmune Hepatitis Overlap Syndrome (PBC-AIH OS)

Background and aims

Up to 20% of Primary Biliary Cholangitis (PBC) patients are estimated to have features that overlap with Autoimmune Hepatitis (AIH). Patients with PBC-AIH overlap syndrome (PBC-AIH OS) have been reported to exhibit suboptimal responses to ursodeoxycholic acid therapy, and are more likely to progress to cirrhosis. Anti-double stranded DNA (anti-dsDNA) and anti-p53 have been previously suggested to be potential autoantibodies for identifying patients with PBC-AIH OS. In our well defined PBC patient cohorts, a comprehensive assessment of various classical and novel autoantibodies was evaluated for their utility in identifying PBC-AIH OS patients.

Methods

PBC-AIH OS was classified according to the Paris criteria and PBC as per the European Association for the Study of the Liver guidelines. Biobanked serum samples from 197 patients at the University of Calgary Liver Unit and the University of Alberta were analyzed for classical and novel autoantibodies. Anti-dsDNA was measured by the Crithidia luciliae immunofluorescence (CLIFT) assay (1:20 dilution) and chemiluminescence (CIA: QUANTA Flash®, Inova Diagnostics, San Diego). Anti-p53, anti-Ro52/TRIM21, anti-YB 1, anti-GW182, anti-Ge-1, and anti-Ago 2 were measured by either an addressable laser bead immunoassay (ALBIA) or line immunoassay (LIA). Autoantibodies against MIT3, gp210, sp100, LKM1, SLA, and the novel autoantibodies Hexokinase-1 (HK-1), and Kelch like protein 12 (KLHL-12) were measured using QUANTA Lite® ELISA assays. We applied non-parametric methods to compare the biomarkers frequencies between study groups. We used multivariate adjusted models and AUROC to compare the diagnostic accuracy of the different autoantibodies alone or in combination with serum biochemistry.

Results

16 out of 197 PBC patients (8.1%) were classified as PBC-AIH OS. Compared to PBC patients, PBC-AIH OS patients were similar in age (median: 59 vs. 63, P = 0.21) and female predominance (94% vs. 89%, P = 1.00). Anti-dsDNA-by CLIFT (37.5% in PBC-AIH OS vs 9.9% in PBC alone, P <0.01) was the only autoantibody associated with PBC-AIH OS; a finding consistent with previous reports. Significant elevation in serum ALT (62 IU/L in PBC-AIH OS vs 37 IU/L in PBC alone, P < 0.01), and serum IgG (17.6 g/L in OS vs 12.1 g/L in PBC alone, P <0.01) were observed in patients with PBC-AIH OS receiving medical/immunosuppressive therapy. In a multivariate model, positive anti-dsDNA by CLIFT, ALT and IgG were significant predictors of PBC-AIH OS with an area under the receiver operator curve (AUROC) value of 0.84.

Conclusions

Consistent with previous findings, the presence of anti-dsDNA by CLIFT is associated with PBC-AIH OS. Contrary to previous reports, anti-p53 was not associated with PBC-AIH OS. Our comprehensive evaluation of various classical and novel autoantibody biomarkers including Ro52/TRIM21, anti-p53, anti-KLHL-12 and anti-HK-1 were not significantly associated with PBC-AIH OS. Our findings highlight the ongoing need for the research and development of new autoantibody biomarkers to aid in the diagnosis of PBC-AIH OS.

[Autoimmune hepatitis: Immunological diagnosis]

Autoimmune hepatopathies (AIHT) including autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC) and autoimmune cholangitis (AIC), represent an impressive entities in clinical practice. Their pathogenesis is not perfectly elucidated. Several factors are involved in the initiation of hepatic autoimmune and inflammatory phenomena such as genetic predisposition, molecular mimicry and/or abnormalities of T-regulatory lymphocytes. AIHT have a wide spectrum of presentation, ranging from asymptomatic forms to severe acute liver failure. The diagnosis of AIHT is based on the presence of hyperglobulinemia, cytolysis, cholestasis, typical even specific circulating auto-antibodies, distinctive of AIH or PBC, and histological abnormalities as well as necrosis and inflammation. Anti-F actin, anti-LKM1, anti-LC1 antibodies permit to distinguish between AIH type 1 and AIH type 2. Anti-SLA/LP antibodies are rather associated to more severe hepatitis, and particularly useful for the diagnosis of seronegative AIH for other the antibodies. Due to the relevant diagnostic value of anti-M2, anti-Sp100, and anti-gp210 antibodies, the diagnosis of PBC is more affordable than that of PSC and AIC. Based on clinical data, the immunological diagnosis of AIHT takes advantage of the various specialized laboratory techniques including immunofluorescence, immunodot or blot, and the Elisa systems, provided of a closer collaboration between the biologist and the physician.

From pruritus to CREST syndrome in a middle aged woman

CREST syndrome, a subtype of scleroderma and Primary Biliary Cholangitis, is an autoimmune disease where the immune system is causing a progressive slow damage to the bile ducts. We report the case of a 67-year-old female patient presenting symptoms indicative of CREST syndrome. During her hospitalization in the internal medicine clinic and after the appropriate imaging and laboratory investigation the diagnosis of CREST syndrome was confirmed, and she was also diagnosed with PBC. This case adds up to a list of literature sources and several case reports which indicate the association of PBC and CREST syndrome, including the accompanied clinical symptoms and musculoskeletal manifestations of the latter.

Autoantibody profiles in autoimmune hepatitis and chronic hepatitis C identifies similarities in patients with severe disease

AIM

To determine how the auto-antibodies (Abs) profiles overlap in chronic hepatitis C infection (CHC) and autoimmune hepatitis (AIH) and correlate to liver disease.

METHODS

Levels of antinuclear Ab, smooth muscle antibody (SMA) and liver/kidney microsomal-1 (LKM-1) Ab and markers of liver damage were determined in the sera of 50 patients with CHC infection, 20 AIH patients and 20 healthy controls using enzyme linked immunosorbent assay and other immune assays.

RESULTS

We found that AIH patients had more severe liver disease as determined by elevation of total IgG, alkaline phosphatase, total serum bilirubin and serum transaminases and significantly higher prevalence of the three non-organ-specific autoantibodies (auto-Abs) than CHC patients. Antinuclear Ab, SMA and LKM-1 Ab were also present in 36% of CHC patients and related to disease severity. CHC cases positive for auto-Abs were directly comparable to AIH in respect of most markers of liver damage and total IgG. These cases had longer disease duration compared with auto-Ab negative cases, but there was no difference in gender, age or viral load. KLM-1⁺ Ab CHC cases showed best overlap with AIH.

CONCLUSION

Auto-Ab levels in CHC may be important markers of disease severity and positive cases have a disease similar to AIH. Auto-Abs might have a pathogenic role as indicated by elevated markers of liver damage. Future studies will unravel any novel associations between these two diseases, whether genetic or other.

Clinical relevance of combined anti-mitochondrial M2 detection assays for primary biliary cirrhosis

BACKGROUND

Antimitochondrial antibody (AMA) is a specific serologic marker in primary biliary cirrhosis (PBC). The aim of this study was to evaluate the clinical relevance of combined AMA assays.

METHODS

Sera were obtained from 79 patients with PBC and 108 patients with other liver disease. They were tested by indirect immunofluorescence (IIF) using rat kidney/stomach tissue and HEp2 cells as substrate, 4 AMA-M2 assays, anti-sp100, and anti-gp210 assays.

RESULTS

Using IIF-AMA with cut-off titer of 1:40, the sensitivity and specificity for PBC were 88.6% and 87.0%, respectively. A cut-off titer of 1:80 improved the specificity to 93.5%. The 4 commercial assay kits using AMA-M2 autoantibodies showed sensitivity of 55.7-79.7% and specificity of 91.7-95.4% with moderate to good agreement. AMA-M2 assays using both native and recombinant E2 antigens had higher sensitivity. ANAs on HEp2 cells, anti-sp100, and anti-gp210 were detected in 67.1%, 13.9-15.2%, and 22.8-27.8% of PBC patients, respectively. Additional AMA-M2 specific assays in IIF-AMA negative and low titer positive (1:40) sera increased the sensitivity and specificity to 88.6% and 90.7%, respectively.

CONCLUSIONS

Serological diagnosis for PBC using IIF with high titer cut-off and additional AMA-M2 specific tests by ELISA or LIA in IIF-negative sera should be used.

The diagnosis of antimitochondrial antibody-negative primary biliary cholangitis

Autoimmune liver diseases are heterogenous disorders that share largely non-specific clinical, serological and pathological features. The correct diagnosis requires discriminative features which are highly specific, for example high-titer antimitochondrial antibodies (AMA) and florid duct lesion in primary biliary cholangitis (PBC). However, the imperfect sensitivities of these characteristic features and abuse of scoring systems led to many artificial diagnoses such as overlap syndromes and outliers for example "autoimmune cholangitis" which is now called as "AMA-negative PBC". Patients lacking detectable AMA (up to 20% in indirect immunofluorescence - IF), but otherwise presenting signs and symptoms of PBC should be regarded as affected by "AMA-negative PBC" because they seem to follow a natural history similar to that of their AMA positive counterparts. The complementary use of IF, ELISA and immunoblotting have disclosed that the majority of patients initially considered AMA-negative are in fact AMA positive. Moreover, the use of PBC-specific ANA's like Gp210 and sp100 have diminished the AMA-negative cases (if truly exists!) to less than 5%. The histological spectrum of PBC includes typical florid duct lesions and/or compatible features such as non-specific hepatitic and biliary findings. In the absence of florid duct lesion and AMA positivity, histology alone cannot differentiate PBC from other biliary disorders. However, the analysis of compatible histological features with the clinical, serological and imaging findings usually points to a specific diagnosis. In this review, we present serological, clinical and pathological pitfalls regarding AMA-negative PBC including illustrative cases and a diagnostic algorithm.

The prevalence of autoantibody and its relationship with genotypes of hepatitis C virus in patients with chronic hepatitis C virus infection

The prevalence of autoantibody in the patients with chronic hepatitis C infection, and the relationship between the autoantibodies and HCV genotypes were investigated in this study. One hundred and eight anti-HCV positive and 86 anti-HCV negative patients were included in the study. Anti-HCV were studied by enzyme immunassay (EIA). HCV RNA was determined by real time polymerase chain reaction (PCR) and HCV genotypes were determined by a reverse-line blot hybridization. Anti-nuclear antibodies (ANA), anti-smooth muscle antibodies (ASMA), Anti-mitochondrial antibodies (AMA), liver kidney microsomal antibodies (LKM) were detected by indirect immunofluorescence assay. Among patients, 13 (12.03%) of 108 were positive for at least one autoantibody. The positivity was not observed in control group. The most prevalent autoantibody in anti-HCV positive group was ANA. ANA was positive in six HCV patients with genotype 1. In HCV patients with genotype 1, the frequencies of ANA, ASMA, AMA and LKM1 were six, two, three and one, respectively. In HCV patients with genotype 2, ANA was positive one patient and ASMA, AMA and LKM1 were not detected in HCV patients with genotype 2. In conclusion, the autoantibodies in patients with chronic hepatitis C in the study were low as compared to those reported in previous studies.

Serological markers of autoimmunity in children with hepatitis A: relation to acute and fulminant presentation

OBJECTIVES

Hepatitis A virus (HAV) infection tends to be a self-limiting disease without serious sequelae, but fulminant hepatitis, with a high mortality, develops in 0.1-0.2% of the cases. Sometimes, HAV infection precipitates autoimmune hepatitis (AIH). We aimed to assess the frequency and clinical significance of serologic markers of autoimmunity during hepatitis A infection with an acute or fulminant presentation compared with those in AIH.

METHODS

The study included 126 children: 46 with HAV infection (33 with acute and 13 with fulminant presentation), 53 with AIH, and 27 healthy controls. In all, we measured autoantibodies titer (antinuclear antibody, antismooth muscle antibody, and liver kidney microsomal antibody-1) and serum gammaglobulins.

RESULTS

Autoantibodies were detected in the majority of HAV (63.1%) and AIH (79.2%) groups, but in none of the controls. Gammaglobulins were significantly higher in the HAV group (1.93±0.57 g/dl) than in the controls (1.32±0.29 g/dl), but lower than that in the AIH group (2.93±1.2 g/dl) (P<0.0001 for all). In the HAV group, gammaglobulins were significantly higher in those with fulminant (2.21±0.46 g/dl) than in those with acute presentation (1.82±0.57 g/dl) (P=0.019), but comparable with that in AIH (P=0.095). Gammaglobulins correlated significantly with disease severity in both HAV and AIH groups.

CONCLUSION

Hypergammaglobulinemia and a high occurrence of autoantibodies are encountered in HAV infection. This may support the immunological basis of its pathogenesis. Moreover, the higher gammaglobulins in fulminant HAV, with an insignificant difference from that in AIH, suggest that a more aggressive immunological reaction is related to this presentation.

[Review of overlap syndromes in autoimmune liver diseases. Diagnostic and therapeutic difficulties]

Overlap syndromes are biochemical, serological, histological and radiological overlaps across the classic autoimmune liver diseases in the presence of autoimmun hepatitis and primary biliary cirrhosis or primary sclerosing cholangitis. The exact prevalence of the disease is not known, but it may vary between 5% and 20%. Because it has no generally accepted diagnostic criteria, clinical signs, biochemical, serological, radiological and histological findings are evaluated together. Treatment depends on the predominant feature of the overlap syndrome; ursodeoxycholic acid and/or immunsuppressive (corticosteroid) treatment are used, based on observations from retrospective, non-randomized studies.

The immunobiology and pathophysiology of primary biliary cirrhosis

Primary biliary cirrhosis (PBC) is an autoimmune disease characterized by clinical homogeneity among patients, an overwhelming female predominance, production of a multilineage immune response to mitochondrial autoantigens, inflammation of small bile ducts, and in some patients the development of fibrosis and cirrhosis. The targets in this disease are small bile ducts, and the prototypic serologic response includes antimitochondrial antibodies (AMAs). Several key observations have greatly advanced our understanding of PBC. First, the multilineage immune response, including AMAs, is directed at the E2 component of the 2-oxo-dehydrogenase pathway, particularly PDC-E2. Second, such autoantibodies may be identified years before the clinical diagnosis of disease. Third, the autoreactive T cell precursor frequency for both CD4 and CD8 cells is significantly higher in liver and regional lymph node than in blood, so the multilineage antimitochondrial response may be required for the development of this disease. Fourth, the apotope of biliary cells contains intact PDC-E2; this apotope, in a setting that includes granulocyte macrophage colony-stimulating factor-stimulated macrophages and AMAs, produces an intense proinflammatory response. Fifth, several mouse models of PBC highlight the importance of loss of tolerance to PDC-E2 as well as a critical role for the interleukin (IL)-12 signaling pathway. Finally, genome-wide association studies suggest an important role for the IL-12 pathway in disease susceptibility. Taken together, these findings have resulted in a better understanding of the mechanism for selective biliary cell destruction and have also suggested unique pathways for therapeutic intervention.

Autoantibodies in liver disease: important clues for the diagnosis, disease activity and prognosis

It has been well established that numerous kinds of autoantibodies have been detected in liver disease. Some kinds of autoantibodies may be helpful in the diagnosis of autoimmune liver diseases including autoimmune hepatitis, primary biliary cirrhosis or primary sclerosing cholangitis. However, these autoantibodies are present even in sera of patients with viral hepatitis, drug-induced hepatitis, alcoholic liver disease, non-alcoholic fatty liver disease and hepatocelluar carcinoma as well as in sera of patients with autoimmune liver diseases. Other kinds of autoantibodies are recognized as predictive hallmarks for disease activity or prognosis in liver diseases. On the other hand, treatment with interferon initiates the production of several types of autoantibodies in patients with chronic hepatitis C virus infection. Some of autoantibodies induced by interferon may postulate the treatment outcome in those patients. Recent studies also revealed the close correlation between oxidative stress and the production of autoantibodies in liver diseases. This article primarily reviews the recent advances of autoantibodies in the liver diseases and discusses the clinical significance of these autoantibodies.

Review article: overlap syndromes and autoimmune liver disease

BACKGROUND

Autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) all nestle within the family of autoimmune liver diseases, whereby the result of immune-mediated liver injury gives rise to varied clinical presentations. Some patients demonstrate a phenotype whereby there is evidence of either PBC or PSC together with overlapping features of AIH. Due to an absence of well-validated diagnostic criteria and a lack of large therapeutic trials, treatment of overlap conditions is empiric and extrapolated from data derived from the primary autoimmune liver diseases.

AIMS

To review overlaps in the context of autoimmune liver diseases.

METHODS

General and specific review of published articles using PubMed, Medline and Ovid search engines, alongside pre-existing clinical management protocols, guidelines, and the authors' own knowledge of the published literature.

RESULTS

The challenges in diagnosis, clinical presentation, determining natural history and outcome of overlaps are presented, as well as present-day management suggestions, some based on evidence, others on consensus and opinion.

CONCLUSIONS

Overlapping autoimmune features, be they clinical, serological, histological or radiological are not infrequent, but appropriate diagnosis remains hindered by a lack of standardised diagnostic criteria. Optimum care for those with suspected overlap should thus focus on attention to detail over the fundamental aspects of timely secure diagnosis of the dominant disease entity. Clinicians should counsel patients carefully with regard to the risks and benefits of treatment, bearing in mind the paucity of randomised and controlled outcome data for medical interventions.

Diagnosis of primary biliary cirrhosis

Primary biliary cirrhosis is the archetypal autoimmune liver disease, with the disease label describing a chronic granulomatous lymphocytic small bile duct cholangitis, which now most commonly presents asymptomatically and at an early pre-cirrhotic stage. Disease is more common than thought, with 1 in 1000 women over the age of 40 affected. Characteristic immunologic features of the disease assist clinicians in ready non-invasive diagnosis of patients, even if asymptomatic with only anicteric/cholestatic liver biochemical profiles. Over 90% of patients are anti-mitochondrial antibody positive, and for those negative, a significant proportion have highly specific anti-nuclear antibody profiles. Liver biopsy remains useful in certain settings where clarity is needed to confirm diagnosis, exclude alternative disease, and assess the relative contribution of PBC to other co-existent liver injury, and seeks to demonstrate in particular the classic bile duct lesions, as well as the degree of interface activity.