Assessment of the histopathological key features in autoimmune hepatitis

Histopathology of Autoimmune Hepatitis: An Update

Autoimmune hepatitis (AIH) is a rare immune-mediated chronic liver disease that is diagnosed based on a combination of biochemical, immunologic, and histologic features and the exclusion of other causes of liver disease. According to the new consensus criteria of the International Autoimmune Hepatitis Pathology Group (IAIHPG), the likely histologic features include a chronic hepatitis pattern of injury with a lymphoplasmacytic portal infiltrate, interface activity, and portal-based fibrosis. More than mild lobular hepatitis with any of the above features can also be diagnosed as likely AIH in the absence of features of another liver disease. Centrilobular injury with prominent hepatocellular necrosis and mononuclear inflammation may represent an acute-onset disease and indicate possible AIH in the absence of concurrent liver disease. Kupffer cell hyaline bodies and portal lymphocyte apoptosis are significantly associated with AIH, whereas emperipolesis and hepatocellular rosette formation are nonspecific features indicative of disease severity. Liver histology is an integral part of the clinical diagnostic scoring system and is required to confirm or support AIH diagnosis. Substitution of the histologic component of the simplified AIH scoring system with the consensus IAIHPG criteria has been proposed to optimize clinical diagnosis. This review explores the significant role of histopathology in AIH by analyzing its main features and current histologic diagnostic criteria, different AIH presentations, differential diagnosis, assessment of concurrent liver disease, and identification of AIH variants with primary cholangiopathy.

British Society of Gastroenterology guidelines for diagnosis and management of autoimmune hepatitis

Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease which, if untreated, often leads to cirrhosis, liver failure and death. The last British Society of Gastroenterology (BSG) guideline for the management of AIH was published in 2011. Since then, our understanding of AIH has advanced in many areas. This update to the previous guideline was commissioned by the BSG and developed by a multidisciplinary group. The aim of this guideline is to review and summarise the current evidence, in order to inform and guide diagnosis and management of patients with AIH and its variant syndromes. The main focus is on AIH in adults, but the guidelines should also be relevant to older children and adolescents.

Comparative Evaluation of Simplified and Modified Histologic Criteria in the Diagnosis of Chronic Autoimmune Hepatitis

Background

The present study aimed at comparing simplified and modified histologic criteria alone and along with other indicators in the diagnosis of chronic autoimmune hepatitis (AIH).

Materials and Methods

In this cross-sectional study, 48 cases were selected from slides and paraffin blocks of patients suspected of chronic AIH according to clinical and laboratory data, including serology and autoantibody findings and viral hepatitis test results. Then, scores equal to 1 (compatible hepatitis), 2 (typical hepatitis), ≤6 (probable hepatitis), and ≥7 (definite hepatitis) were calculated based on the simplified histologic criteria, modified histologic criteria, and these two criteria, along with other indicators including antinuclear antibodies (Ab), smooth muscle Ab or liver-kidney microsomal Ab or soluble liver antigen (Ag) and serum immunoglobulin G (IgG) and absence of viral hepatitis.

Results

The results of this study revealed that based on the simplified histologic criteria, 43.8% and 56.3% of these cases were assigned a score of 1 and 2 points, respectively. However, calculating the total score using the simplified criteria along with other indicators showed that 60.4% and 39.6% of cases were assigned a score ≤6 and ≥7 points, respectively. Moreover, the modified histologic criteria indicated that 25% and 75% of cases were assigned a score of 1 and 2 points, respectively.

Conclusion

According to the findings of the present study, the modified histologic criteria compared to the simplified histologic criteria identified a higher percentage of patients assigned a score of 2 points. Moreover, modified histologic criteria, along with other indicators, were more accurate in detecting definite AIH (score ≥7 points).

Liver diseases: epidemiology, causes, trends and predictions

As a highly complex organ with digestive, endocrine, and immune-regulatory functions, the liver is pivotal in maintaining physiological homeostasis through its roles in metabolism, detoxification, and immune response. Various factors including viruses, alcohol, metabolites, toxins, and other pathogenic agents can compromise liver function, leading to acute or chronic injury that may progress to end-stage liver diseases. While sharing common features, liver diseases exhibit distinct pathophysiological, clinical, and therapeutic profiles. Currently, liver diseases contribute to approximately 2 million deaths globally each year, imposing significant economic and social burdens worldwide. However, there is no cure for many kinds of liver diseases, partly due to a lack of thorough understanding of the development of these liver diseases. Therefore, this review provides a comprehensive examination of the epidemiology and characteristics of liver diseases, covering a spectrum from acute and chronic conditions to end-stage manifestations. We also highlight the multifaceted mechanisms underlying the initiation and progression of liver diseases, spanning molecular and cellular levels to organ networks. Additionally, this review offers updates on innovative diagnostic techniques, current treatments, and potential therapeutic targets presently under clinical evaluation. Recent advances in understanding the pathogenesis of liver diseases hold critical implications and translational value for the development of novel therapeutic strategies.

The utility of the mHAI scoring system in pediatric autoimmune hepatitis diagnosis and its association with treatment response

Autoimmune hepatitis (AIH) is a chronic inflammatory autoimmune disease with either acute or chronic presentation. Previous scoring systems have primarily focused on chronic hepatitis, but none have been validated in an acute setting of pediatric patients. This study aimed to: 1) summarize the clinicopathologic characteristics of pediatric AIH patients; 2) assess if the modified Hepatic Activity Index (mHAI) can be used in both acute and chronic presentations of pediatric AIH; 3) evaluate the association of initial mHAI scores with treatment response at various endpoints. Thirty-one pediatric AIH patients were categorized into acute and chronic presentation groups. Biopsies were reviewed using the mHAI grading and staging system. AIH treatment endpoints were analyzed: 4 weeks (response vs. non-response), 6 months (complete vs. insufficient response), and approximately 12 months (histological remission vs. non-remission). Patients with acute AIH had higher mean mHAI scores and more prominent interface activity. Those achieving complete response at 6 months had significantly higher mean mHAI scores compared to those with an insufficient response. Notably, patients demonstrating fibrosis reversal at the 1-year follow-up often had higher initial mHAI scores. The mHAI can be used to evaluate acute and chronic presentations of pediatric AIH. Acute pediatric AIH has a higher mHAI score with more severe activity. The patients with a higher mHAI have a greater likelihood of achieving a complete response to treatment at 6 months and subsequent improvement in fibrosis status.

Diagnosis of Autoimmune Hepatitis

Autoimmune hepatitis (AIH) presents a diagnostic challenge because it is relatively rare and heterogenous in presentation. This article presents the currently adopted approach to AIH diagnosis and explores the challenges with accurately identifying this disease entity. AIH offers no pathognomonic findings, instead relies on clinical presentation, serology, and histology to make the diagnosis. Diagnostic scoring systems support clinical judgment and serve as valuable tools in diagnosis and research. Histological analysis remains the cornerstone of diagnosis and to this day biopsy is essential to make the diagnosis.

Autoimmune Hepatitis: From Evolution to Current Status-A Pathologist's Perspective

Autoimmune hepatitis (AIH) is a chronic, relapsing and remitting, immune-mediated liver disease that progresses to cirrhosis if left untreated. A significant number of patients may present with acute hepatitis or acute liver failure, which are often misdiagnosed as toxic liver injury. AIH shows a preponderance in young women but may be seen in children and the elderly. Diagnosis requires the integration of clinical, biochemical, and serologic parameters, along with supportive liver histology and exclusion of other causes of liver disease. Liver biopsy is a prerequisite for diagnosis of AIH, to assess severity and stage of disease, exclude other entities, and recognize any concurrent morbidities. No single biomarker or histologic feature is pathognomonic for AIH. The diagnostic and histologic criteria have undergone several modifications since the original scoring system was proposed by the International Autoimmune Hepatitis Group (IAIHG) in 1993. Recently, the IAIHG has proposed consensus recommendations for histologic criteria, relevant for both acute and chronic AIH. This review article will describe the evolving diagnostic criteria for AIH, with their limitations and utility, and with an emphasis on the role of liver histology in the diagnosis and management of AIH.

Comparison of four histological scoring systems for autoimmune hepatitis to improve diagnostic sensitivity

BACKGROUND/AIMS

The histological criteria in the 1999 and 2008 scoring systems proposed by the International Autoimmune Hepatitis Group (IAIHG) have their inherent limitations in diagnosing autoimmune hepatitis (AIH). In this study, we evaluated the histology components of four scoring systems (1. revised original scoring system ["1999 IAIHG"], 2. simplified scoring system ["2008 IAIHG"], 3. modified histologic criteria ["2017 UCSF"], and 4. a new histologic criteria proposed by the International AIH Pathology Group ["2022 IAHPG"]) in AIH patients.

METHODS

Medical records and liver biopsies were retrospectively reviewed for 68 patients from two independent medical institutions, diagnosed with AIH based on the 1999 IAIHG system between 2006 and 2016. The histological features were reviewed in detail, and the four histological scoring systems were compared.

RESULTS

Out of the 68 patients, 56 (82.4%) patients met the "probable" or "definite" AIH criteria of the 2008 IAIHG system, and the proportion of histologic score 2 (maximum) was 40/68 (58.8%). By applying the 2017 UCSF criteria, the number of histology score 2 increased to 60/68 (88.2%), and "probable" or "definite" AIH cases increased to 61/68 (89.7%). Finally, applying the 2022 IAHPG histology score resulted in the highest number of cases with histologic score 2 (64/68; 94.1%) and with a diagnosis of "probable" or "definite" AIH (62/68; 91.2%).

CONCLUSION

The recently proposed UCSF/IAHPG histological criteria increased the histology score of AIH. Substituting the histology component of the 2008 IAIHG system with the 2022 IAHPG criteria increased the sensitivity for diagnosing AIH (≥"Probable AIH") from 82.4% to 91.2%.

Development and validation of a noninvasive prediction model of autoimmune hepatitis in patients with liver diseases

BACKGROUND AND AIMS

There is no golden standard for the diagnosis of autoimmune hepatitis which still dependent on liver biopsy currently. So, we developed a noninvasive prediction model to help optimize the diagnosis of autoimmune hepatitis.

METHODS

From January 2017 to December 2019, 1739 patients who had undergone liver biopsy were seen in the second hospital of Nanjing, of which 128 were here for consultation. Clinical, laboratory, and histologic data were obtained retrospectively. Multivariable logistic regression analysis was employed to create a nomogram model that predicting the risk of autoimmune hepatitis. Internal and external validation was both performed to evaluate the model.

RESULTS

A total of 1288 patients with liver biopsy were enrolled (1184 from the second hospital of Nanjing, the remaining 104 from other centers). After the univariate and multivariate logistic regression analysis, nine variables including ALT, IgG, ALP/AST, ALB, ANA, AMA, HBsAg, age, and gender were selected to establish the noninvasive prediction model. The nomogram model exhibits good prediction in diagnosing autoimmune hepatitis with AUROC of 0.967 (95% CI: 0.776-0.891) in internal validation and 0.835 (95% CI: 0.752-0.919) in external validation.

CONCLUSIONS

ALT, IgG, ALP/AST, ALB, ANA, AMA, HBsAg, age, and gender are predictive factors for the diagnosis of autoimmune hepatitis in patients with unexplained liver diseases. The predictive nomogram model built by the nine predictors achieved good prediction for diagnosing autoimmune hepatitis.

Prevalence and significance of antimitochondrial antibodies in autoimmune hepatitis (AIH): Results from a large multicentre study of the International AIH Group

BACKGROUND & AIMS

Antimitochondrial antibodies (AMA) are specific markers for the diagnosis of primary biliary cholangitis (PBC) but can also be found occasionally in patients with autoimmune hepatitis (AIH). The present large multicentre cohort study assessed the prevalence and significance of AMA in AIH-patients.

METHODS

123 AMA-positive AIH-patients were investigated and compared with 711 age-matched AMA-negative AIH-patients and 69 patients with AIH/PBC variant.

RESULTS

AMA prevalence in AIH-patients was 5.1% (range: 1.2%-11.8%). AMA-positivity was associated with female sex (p = 0.031) in AMA-positive AIH-patients but not with liver biochemistry, bile duct injury on liver biopsy, disease severity at baseline and response to treatment compared to AMA-negative AIH-patients. Comparing AMA-positive AIH-patients to those with AIH/PBC variant, there was no difference in disease severity. Regarding liver histology, AIH/PBC variant patients were characterized by the presence of at least one feature of bile duct damage (p<0.001). Response to immunosuppressive treatment was similar among groups. From AMA-positive AIH patients only those with evidence of non-specific bile duct injury had higher risk to progress to cirrhosis (HR=4.314, 95%CI: 2.348-7.928; p<0.001). During follow-up, AMA-positive AIH-patients had higher risk to develop histological bile duct injury (HR 4.654, 95%CI 1.829-11.840; p = 0.001).

CONCLUSIONS

AMA presence is relatively common among AIH-patients, but their clinical significance seems important only when they co-exist with non-specific bile duct injury at the histological level. Therefore, a careful evaluation of liver biopsy seems of utmost importance in these patients.

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.

Open challenges in the management of autoimmune hepatitis

Autoimmune hepatitis (AIH) is a rare autoimmune disease of the liver with many open questions as regards its etiopathogenesis, natural history and clinical management. The classical picture of AIH is chronic hepatitis with fluctuating elevation of serum transaminases and Immunoglobulin G levels, the presence of circulating autoantibodies and typical histological features. However, atypical presentations do occur and are not well captured by current diagnostic scores, with important consequences in terms of missed diagnoses and delayed treatments. AIH is treated with corticosteroids and immunosuppressive drugs but up to 40% of patients do not achieve full biochemical response and are at risk of progressing to cirrhosis and liver failure. Moreover, standard therapies are associated by significant side-effects which may impair the quality of life of patients living with AIH. However, advances in the understanding of the underlying immunology of AIH is raising the prospect of novel therapies and optimization of existing therapeutic approaches to reduce side-effect burdens and potentially restore immunological tolerance. In this review we outlined the clinical characteristics, etiopathogenesis and management of AIH and current challenges in the diagnosis and management of AIH and provided evidence underlying the evolution of diagnostic and clinical management protocols.

MAdCAM-1 does not play a central role in the early pathophysiology of autoimmune hepatitis

INTRODUCTION

CD4+ T cells are thought to have a central role in the pathogenesis of autoimmune hepatitis (AIH). Mucosal addressin cell adhesion molecule-1 (MAdCAM-1) directs homing of CD4+ T cells in the alimentary tract and is a therapeutic target in inflammatory bowel diseases. Here we assessed MAdCAM-1 expression in AIH and viral hepatitis and related its expression with immune infiltrate analysis and histopathological key features.

METHODS

Hepatic portal areas of pretreatment biopsies (n=10) and follow-up biopsies (n=9) of patients with a confirmed diagnosis of AIH were assessed for MAdCAM-1 expression and infiltrate composition using immunohistochemistry and multispectral imaging (Vectra® Polaris™). Controls consisted of biopsies of patients with untreated chronic viral hepatitis B or C (n=22).

RESULTS

MAdCAM-1 expression on endothelium was sparsely present in portal fields of two treatment-naïve AIH patients. Three patients showed MAdCAM-1 expression within lymphoid aggregates. No expression of significance (including single-cell expression) was observed in the remaining 6 patients. In contrast, viral hepatitis C biopsies showed endothelial MAdCAM-1 expression in 8 of 13 untreated patients. Densities of both B-cells (CD20+) and CD4+ T-cells (CD3+ CD8-) were increased in AIH and viral hepatitis patients with MAdCAM-1 expression.

CONCLUSION

MAdCAM-1 was detected in liver biopsies in a minority of patients with AIH at the time of diagnosis suggesting no central role in its pathophysiology. Lymphoid or reticular MAdCAM-1 pattern expression was associated with more dense infiltrates of both B-cells and CD4⁺ T-cells, and may be related to the formation of secondary lymphoid follicles.

Diagnosis and management of autoimmune hepatitis

Autoimmune hepatitis is an inflammatory disease of the liver of unknown cause that may progress to liver cirrhosis and end stage liver failure if diagnosis is overlooked and treatment delayed. The clinical presentation is often that of acute hepatitis, sometimes very severe; less frequently, it can be insidious or completely asymptomatic. The disease can affect people of any age and is more common in women; its incidence and prevalence seem to be on the rise worldwide. An abnormal immune response targeting liver autoantigens and inducing persistent and self-perpetuating liver inflammation is the pathogenic mechanism of the disease. A specific set of autoantibodies, increased IgG concentrations, and histological demonstration of interface hepatitis and periportal necrosis are the diagnostic hallmarks of autoimmune hepatitis. Prompt response to treatment with corticosteroids and other immunomodulatory drugs is almost universal and supports the diagnosis. The aims of treatment are to induce and maintain long term remission of liver inflammation. Treatment can often even reverse liver fibrosis, thus preventing progression to advanced cirrhosis and its complications. Most patients need lifelong maintenance therapy, and repeated follow-up in experienced hands improves the quality of care and quality of life for affected patients.

The many faces and pathologic diagnostic challenges of autoimmune hepatitis

Autoimmune hepatitis (AIH) is an immune-mediated chronic inflammatory liver disease, characterized by hypergammaglobulinemia, the presence of specific autoantibodies, and typical abnormalities in liver histology. Prompt diagnosis and initiation of immunosuppressive treatment are necessary for both chronic and acute onset AIH to prevent progression to end-stage liver disease or fatal liver failure. However, the diagnosis of AIH is challenging mainly because of its heterogeneous clinical, serological and pathological features. Although portal lymphoplasmacytosis and interface hepatitis are the most typical histological features of AIH, many other histological features can be observed in AIH, including emperipolesis, hepatocyte rosettes, and Kupffer cell hyaline globules. Recent studies have questioned emperipolesis and hepatocyte rosette formation as typical features of AIH, and atypical clinical and histological presentations have also been recognized. This led an international working group to propose the modified AIH diagnostic criteria. However, it is well recognized that there are no pathognomonic characteristics that can be used to diagnose AIH and careful clinicopathological correlation is required to arrive at the correct diagnosis. The aim of this review is to summarize the histological features of AIH, its varied histopathologic spectrum, recent updates and major differential diagnoses in routine clinical practice.

Autoimmune serology testing in clinical practice: An updated roadmap for the diagnosis of autoimmune hepatitis

Diagnosis of autoimmune hepatitis (AIH) is in most cases challenging for clinicians as there is not a single specific laboratory or histological marker to diagnose or exclude the presence of the disease. The clinical spectrum of AIH varies from completely asymptomatic to acute-severe or even rarely fulminant hepatic failure, while everybody can be affected irrespective of age, gender, and ethnicity. The old revised and the newer simplified diagnostic scores have been established by the International Autoimmune Hepatitis Group (IAIHG) in 1999 and 2008, respectively, which are based on several clinical, laboratory and histological parameters. Additionally, a thorough differential diagnosis from other diseases mimicking AIH is absolutely indicated. In this context, autoantibodies detection in patients with suspected AIH is mandatory -even though not pathognomonic- not only for AIH diagnosis but furthermore, for AIH classification (AIH-type 1 and AIH-type 2). Although autoimmune serology can be supportive of AIH diagnosis in ≥95% of cases if testing has been performed according to the IAIHG guidelines, this is not the case under real-life circumstances in routine clinical laboratories. Clinicians should be careful both for the importance of the required testing and how to interpret the results and therefore, they should communicate and discuss with the laboratory personnel to achieve the maximum benefit for the patient. Herein, a detailed and updated review of the diagnostic work-up for AIH diagnosis under real-life conditions is given to minimize the underestimation and misdiagnosis of AIH which can result in progression of the disease and unfavourable outcomes.

Artificial intelligence for precision medicine in autoimmune liver disease

Autoimmune liver diseases (AiLDs) are rare autoimmune conditions of the liver and the biliary tree with unknown etiology and limited treatment options. AiLDs are inherently characterized by a high degree of complexity, which poses great challenges in understanding their etiopathogenesis, developing novel biomarkers and risk-stratification tools, and, eventually, generating new drugs. Artificial intelligence (AI) is considered one of the best candidates to support researchers and clinicians in making sense of biological complexity. In this review, we offer a primer on AI and machine learning for clinicians, and discuss recent available literature on its applications in medicine and more specifically how it can help to tackle major unmet needs in AiLDs.

A review of histopathologic features of pediatric autoimmune liver disease

Content available: Audio Recording.

Histopathologist and clinician interface in diagnosis and management of autoimmune hepatitis

Diagnosis of AIH is based on a combination of clinical, laboratory and histological information. It has been formalised by diagnostic scoring systems, to which liver biopsy contributes substantially. Diagnostic biopsy is thus, desirable in nearly all patients. An adequate biopsy size, provision by clinicians of adequate information to histopathologists and active discussion at regular meetings are all important for accurate histological diagnosis. Recently, the specificity of some features previously thought to suggest AIH has been questioned, and new recommendations for histological diagnosis have been proposed, although not yet validated. The histology of acutely presenting AIH and that of severe or fulminant AIH include some characteristic features. Primary biliary cholangitis, primary sclerosing cholangitis and non-alcoholic fatty liver disease may co-exist with AIH on biopsy. Liver biopsy also enables grading of severity of inflammation and staging of fibrosis. Presence of cirrhosis is a poor prognostic marker. Repeat liver biopsy after achieving biochemical remission, although not performed routinely, enables assessment of (a) histological remission, a favourable prognostic indicator and (b) fibrosis progression. It can thus help determine further management.

Consensus recommendations for histological criteria of autoimmune hepatitis from the International AIH Pathology Group: Results of a workshop on AIH histology hosted by the European Reference Network on Hepatological Diseases and the European Society of Pathology: Results of a workshop on AIH histology hosted by the European Reference Network on Hepatological Diseases and the European Society of Pathology

BACKGROUND & AIMS

Diagnostic histological criteria for autoimmune hepatitis (AIH) have not been clearly established. Previously published criteria focused mainly on chronic AIH, in which inflammatory changes mainly occur in portal/periportal regions and may not be applicable to acute presentation of AIH, in which inflammatory changes are typically predominantly lobular in location. International consensus criteria for the diagnosis and assessment of disease severity in both acute and chronic AIH are thus urgently needed.

METHODS

Seventeen expert liver pathologists convened at an international workshop and subsequently used a modified Delphi panel approach to establish consensus criteria for the histopathological diagnosis of AIH.

RESULTS

The consensus view is that liver biopsy should remain standard for diagnosing AIH. AIH is considered likely, if there is a predominantly portal lymphoplasmacytic hepatitis with more than mild interface activity and/or more than mild lobular hepatitis in the absence of histological features suggestive of another liver disease. AIH is also considered likely if there is predominantly lobular hepatitis with or without centrilobular necroinflammation and at least one of the following features: portal lymphoplasmacytic hepatitis, interface hepatitis or portal-based fibrosis, in the absence of histological features suggestive of another liver disease. Emperipolesis and hepatocellular rosettes are not regarded as being specific for AIH.

CONCLUSIONS

The criteria proposed in this consensus statement provide a uniform approach to the histological diagnosis of AIH, which is relevant for patients with an acute as well as a chronic presentation and to more accurately reflect the current understanding of liver pathology in AIH.

B cells in autoimmune hepatitis: bystanders or central players?

B cells are central for the adaptive immune system to mount successful immune responses not only as antibody producers but also as regulators of cellular immunity. These multifaceted features are also reflected in autoimmunity where autoreactive B cells can fuel disease by production of cytotoxic autoantibodies, presentation of autoantigens to autoreactive T cells, and secretion of cytokines and chemokines that either promote detrimental immune activation or impair regulatory T and B cells. The role of B cells and autoantibodies in autoimmune hepatitis (AIH) have been controversially discussed, with typical autoantibodies and hypergammaglobulinemia indicating a key role, while strong HLA class II association suggests T cells as key players. In this review, we summarize current knowledge on B cells in AIH and how different B cell subpopulations may drive AIH progression beyond autoantibodies. We also discuss recent findings of B cell-directed therapies in AIH.

Observation of Voriconazole in the Treatment of Liver Failure Complicated With Invasive Pulmonary Fungal Infection Induced by Chinese Patent Medicine in Teenagers: 2 Case Reports

Background: Drug-induced liver injury (DILI) caused by Chinese patent medicines is increasing in China. The incidence of invasive fungal infections (IFIs) is increasing due to the suppression of the immune function in greater numbers of patients. Invasive procedures such as deep vein catheterization and the use of glucocorticoids are also predisposing factors to IFIs. The clinical presentation of IFI in teenagers is often atypical, challenging to diagnose, difficult to treat, and associated with a high fatality rate. Case presentation: Herein, we report 2 teenagers with liver failure after receiving oral Chinese patent medicines. Case 1 was a 14-year-old boy who presented with subacute liver failure who had been administered a Chinese patent medicine that included acetaminophen. Administration of glucocorticoids and non-bioartificial liver treatment improved his condition. Subsequently, invasive pulmonary Aspergillus (IPA) was diagnosed and was successfully treated with voriconazole for 85 days. Case 2 was a 17-year-old girl who presented with acute liver failure after taking the Chinese patent medicine QubaiBabuqi tablets for vitiligo. Chest computed tomography (CT) revealed multiple pulmonary nodules with an intermittent low-grade fever, and she was diagnosed with IPA. She was initially treated with caspofungin (23 days) and then voriconazole (406 days) for 429 days. Her liver function returned to normal, and lung lesions were absorbed in 2 patients. At the same time, two to three histopathological examinations of the liver biopsy showed that the drug-induced autoimmune-like phenomena could be improved by glucocorticoid therapy. Conclusion: To the best of our knowledge, this is the first report of the successful treatment of 2 cases of liver failure (Child-Pugh class C) caused by Chinese patent medicines complicated with IPA in teenagers. Drug-induced autoimmune-like phenomena could be improved by glucocorticoid therapy.

Acute liver injury following methylprednisolone pulse therapy: 13 cases from a prospectively collected cohort

BACKGROUND AND AIM

Drug-induced liver injury (DILI) remains a challenging diagnosis requiring exclusion of other causes of liver injury, concise medical history taking to identify potential causative medication and creation of a plausible temporal relation to attribute said liver injury to a potentially hepatotoxic agent. In spite of corticosteroids being considered an effective treatment for DILI in some patients, methylprednisolone (MPS) has been associated with liver injury of varying severity.

METHODS

We analyzed data of our prospective study on potentially hepatotoxic drugs (NCT02353455), identified 13 cases of MPS-associated liver injury and performed an analysis of clinical, laboratory and histopathological characteristics. For all available liver biopsy specimens, expert histopathological analysis was performed.

RESULTS

Thirteen patients with a variety of primarily neurologic autoimmune diseases treated with MPS developed subsequent liver injury with a median latency of 5 weeks. Liver injury was severe or required transplantation in six patients. Injury typically occurred after repeated pulsing was hepatocellular and responded swiftly to prednisolone administration. For those patients who received in house-follow up, relapse after discontinuation of immunosuppression was not observed. Histopathological features of MPS-DILI comprised both interface and periportal hepatitis with mixed inflammatory infiltrates, similar to autoimmune hepatitis (AIH) features.

DISCUSSION

MPS-related liver injury can be life-threatening, occurs with considerable latency and after repeat dosing. Regular surveillance of hepatic biochemistry should therefore be routinely performed also after discharge to avoid further MPS-related liver injury during repeat application. Swift response to prednisolone but not histologic features can be helpful to discriminate MPS-DILI from AIH.

Kupffer Cell Hyaline Globules in Children With Autoimmune Hepatitis

BACKGROUND

Hyaline globules (HGs) in the cytoplasm of Kupffer cells (KCs) have been appraised for being a typical feature of autoimmune hepatitis (AIH). This study aimed to determine how useful Kupffer cell hyaline globules (KCHGs) are in diagnosing AIH vs. other causes of pediatric chronic liver diseases (PCLDs).

MATERIALS AND METHODS

This retrospective study recruited 124 children; 58 with AIH, 50 with chronic hepatitis C virus (HCV) infection, and 16 with Wilson's disease (WD). Two pathologists retrieved paraffin blocks of liver biopsies and prepared new cut sections for Periodic acid-Schiff-Diastase (PAS-D) stain. They independently examined liver biopsies before starting treatment. Two pediatricians reviewed medical records for demographic, clinical, laboratory, and serological findings.

RESULTS

Females represented 48.6% of the studied children with a median age of 5.8 (4.9) years. Pathologists identified KCHGs in 67.24%, 12.5%, and 6.0% of AIH, WD, and HCV affected children respectively, P < 0.001. A significantly higher proportion of seropositive than seronegative AIH patients had KCHGs (77.5% vs. 50.0%), (P < 0.05). In multivariate analysis, KCHGs and prolonged prothrombin time were the only significant predictors that differentiate between AIH and the other studied PCLDs. The odds ratio of having AIH increased 68 times if KCHGs were seen. Among children with AIH, the presence of KCHGs was associated with higher median levels of direct bilirubin 2.2 (1.3) vs. 1.2 (2.2), and immunoglobulin G 3.2 (1.9) vs. 2.0 (1.7), (P < 0.05), but not to histopathological findings or hepatic fibrosis and activity.

CONCLUSIONS

KCHGs are key indicators that can differentiate between AIH and other PCLDs, and between seropositive and seronegative AIH.

Quantification of polyreactive immunoglobulin G facilitates the diagnosis of autoimmune hepatitis

BACKGROUND AND AIMS

Detection of autoantibodies is a mainstay of diagnosing autoimmune hepatitis (AIH). However, conventional autoantibodies for the workup of AIH lack either sensitivity or specificity, leading to substantial diagnostic uncertainty. We aimed to identify more accurate serological markers of AIH with a protein macroarray.

APPROACH AND RESULTS

During the search for more-precise autoantibodies to distinguish AIH from non-AIH liver diseases (non-AIH-LD), IgG antibodies with binding capacities to many human and foreign proteins were identified with a protein macroarray and confirmed with solid-phase ELISAs in AIH patients. Subsequently, polyreactive IgG (pIgG) was exemplarily quantified by reactivity against human huntingtin-interacting protein 1-related protein in bovine serum albumin blocked ELISA (HIP1R/BSA). The diagnostic fidelity of HIP1R/BSA binding pIgG to diagnose AIH was assessed in a retrospective training, a retrospective multicenter validation, and a prospective validation cohort in cryoconserved samples from 1,568 adults from 10 centers from eight countries. Reactivity against HIP1R/BSA had a 25% and 14% higher specificity to diagnose AIH than conventional antinuclear and antismooth muscle antibodies, a significantly higher sensitivity than liver kidney microsomal antibodies and antisoluble liver antigen/liver pancreas antigen, and a 12%-20% higher accuracy than conventional autoantibodies. Importantly, HIP1R/BSA reactivity was present in up to 88% of patients with seronegative AIH and in up to 71% of AIH patients with normal IgG levels. Under therapy, pIgG returns to background levels of non-AIH-LD.

CONCLUSIONS

pIgG could be used as a promising marker to improve the diagnostic workup of liver diseases with a higher specificity for AIH compared to conventional autoantibodies and a utility in autoantibody-negative AIH. Likewise, pIgG could be a major source of assay interference in untreated AIH.

Wilson disease and the differential diagnosis of its hepatic manifestations: a narrative review of clinical, laboratory, and liver histological features

Objective

The goal of the present work is to provide an overview of the differential diagnosis of Wilson disease.

Background

Wilson disease is a rare condition due to copper accumulation primarily in the liver and brain. Although there is no definitive cure, current anti-copper treatments are associated with better outcomes if initiated early and if the diagnosis is made promptly. However, diagnostic delays are frequent and often Wilson disease represents a diagnostic challenge. The diagnosis ultimately relies on a combination of clinical, laboratory and genetic findings, and it is crucial that clinicians list Wilson disease in their differential diagnosis, especially in patients presenting with a hepatocellular pattern of liver injury. Some biochemical and liver histological features of Wilson disease overlap with those of more common conditions including nonalcoholic fatty liver disease, alcohol-associated liver disease, and autoimmune hepatitis. In particular, hepatic steatosis, hepatocyte glycogenated nuclei, ballooning degeneration, and Mallory-Denk bodies are often identified in Wilson disease as well as more common liver diseases. In addition, the natural history of liver damage in Wilson disease and the risk of developing liver cancer are largely understudied.

Methods

We conducted an enlarged review of published papers on Wilson disease focusing on its diagnosis and distinctive clinical and liver pathology features in relation to common non-cholestatic liver diseases with the final goal in aiding clinicians in the diagnostic process of this rare but treatable condition.

Conclusions

Aside from markedly altered copper metabolism, Wilson disease has essentially no pathognomonic features that can distinguish it from more common liver diseases. Clinicians should be aware of this challenge and consider Wilson disease in patients presenting with a hepatocellular pattern of liver injury.

Recombinant Ax21 protein is a promising subunit vaccine candidate against Stenotrophomonas maltophilia in a murine infection model

Stenotrophomonas maltophilia is an emerging pathogen that can cause several disease manifestations such as bacteremia, meningitis, respiratory tract infections and others. More seriously, this pathogen has a highly evolving antibiotic resistance profile. Antibiotic misuse is further aggravating the situation by inducing the development of multi- and even pan-resistance. Thus, employing diverse strategies to overcome this increasing antibiotic resistance is of paramount importance. In general, vaccination is one of these strategies that prevents the onset of infection, provides long term protection against infection, and most importantly diminishes the antibiotic consumption, thus, resulting in controlling resistance. Unfortunately, vaccine research concerning S. maltophilia is very scarce in the literature. Ax21 protein is an outer membrane protein implicated in several virulence mechanisms of S. maltophilia such as quorum sensing, biofilm formation, and antibiotic resistance. Our computational analysis of Ax21 revealed its potential immunogenicity. In the current study, Ax21 protein of S. maltophilia was cloned and heterologously expressed in Escherichia coli. Mice were immunized with the purified recombinant antigen using Bacillus Calmette-Guérin(BCG) and incomplete Freund's adjuvant (IFA) as immune-adjuvants. Enzyme-linked immunosorbent assay (ELISA) revealed significant antigen-specific IgG1, IgG2a and total IgG levels in immunized mice which reflected successful immune stimulation. Immunized mice that were challenged with S. maltophilia showed a substantialreduction in bacterial bioburden in lungs, liver, kidneys, and heart. In addition, liver histological examination demonstrated a remarkable decrease in pathological signs such as necrosis, vacuolation, bile duct fibrosis and necrosis, infiltration of inflammatory cells, and hemorrhage. Whole cell ELISA and opsonophagocytic assay confirmed the ability of serum antibodies from immunized mice to bind and facilitate phagocytosis of S. maltophilia, respectively. To our knowledge, this is the first report to demonstrate the vaccine protective efficacy of Ax21 outer membrane protein against S. maltophilia infection.

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.

[Autoimmune liver diseases]

Autoimmune liver diseases comprise a spectrum of progredient idiopathic inflammatory diseases. Typical histological features of autoimmune hepatitis (AIH) include the pattern of chronic hepatitis with predominant plasma cell-rich interface activity, rosetting of hepatocytes, and emperipolesis. Florid bile duct lesions are the key feature of primary biliary cholangitis (PBC); onion-like periductal fibrosis characterizes the primary sclerosing cholangitis (PSC). Variants of AIH, or overlap syndromes, show intersecting histomorphologic findings with PBC or PSC. The diagnosis of the different autoimmune inflammatory liver diseases is based on clinical presentation, a hepatitic or cholestatic pattern of liver enzymes, immuno-serological findings, image analysis in PSC, and liver biopsy as a facultative or obligatory adjunct. Liver biopsy plays a major role in the diagnosis of AIH, small-duct PSC, AMA-negative PBC, IgG4-related diseases, overlap syndrome, and in the recognition of concurrent liver diseases, especially drug-induced liver diseases. Herewith pathologists can help clinicians find adequate therapy for different autoimmune inflammatory liver diseases.

Congestive hepatopathy and acute pancreatitis as severe complications of mixed connective tissue disease

Mixed connective tissue disease (MCTD) causes multiple organ dysfunctions, such as joint swelling, pulmonary fibrosis and hypertension, and serositis, but hepatopancreatic complications are rare. Here, we report a case of young man who exhibited acute severe liver dysfunction. He also had impaired cardiac function: both ventriculi were hypokinetic, but pulmonary hypertension and pericarditis were not observed. Since his liver and cardiac function markedly improved after commencing furosemide and carperitide, we considered congestive hepatopathy due to MCTD and accompanying heart failure. Heart failure and congestive hepatopathy recurred and he was treated with diuretics and prednisolone, but he passed away by co-occurrence of acute hemorrhagic pancreatitis. Necropsy revealed chronic hepatic congestion but not accompanying autoimmune hepatitis and hepatic vasculitis. We should consider congestive hepatopathy and hemorrhagic pancreatitis as serious complications of MCTD.

Morphometric changes and imaging findings of diffuse liver disease in relation to intrahepatic hemodynamics

Diffuse hepatic diseases have a variety of etiologies, with each showing characteristic morphometric changes. These changes are closely related to micro- and macro-level intrahepatic hemodynamics, in addition to the specific underlying pathophysiology. Short-term disorders in intrahepatic hemodynamics caused by each pathophysiological condition are compensated for by the balance of blood perfusion systems using potential trans-sinusoidal, transversal, and transplexal routes of communication (micro-hemodynamics), while long-term alterations to the intrahepatic hemodynamics result in an increase in total hepatic vascular resistance. Blood flow disorders induced by this increased vascular resistance elicit hepatic cellular necrosis and fibrosis. These changes should be uniformly widespread throughout the whole liver. However, morphometric changes do not occur uniformly, with shrinkage or enlargement not occurring homogeneously. Against this background, several macro-intrahepatic hemodynamic effects arise, such as asymmetrical and complicating morphometric structures of the liver, intricate anatomy of portal venous flow and hepatic venous drainage, and zonal differentiation between central and peripheral zones. These hemodynamic factors and pathophysiological changes are related to characteristic morphometric changes in a complicated manner, based on the combination of selective atrophy and compensatory hypertrophy (atrophy-hypertrophy complex). These changes can be clearly depicted on CT and MR imaging.

Relation Between Immunohistochemical Expression of Hippo Pathway Effectors and Chronic Hepatitis Induced Fibrosis in Egyptian Patients

OBJECTIVE

Chronic hepatitis is a global health problem especially in Egypt. Hepatic fibrosis is a common end clinical manifestation of many chronic liver diseases. Although it is a wound-healing process, excessive accumulation of fibrillary collagen leads to architectural damage, cirrhosis and liver failure. Recently, a few studies have linked Hippo pathway effectors of yes-associated protein (YAP) and its paralog transcriptional coactivator with PDZ-binding motif (TAZ) to extracellular matrix deposition and ongoing fibrosis.

MATERIAL AND METHOD

Immunohistochemical expression of YAP and TAZ were analyzed in 121 liver needle core biopsies (91 core biopsies of chronic viral hepatitis, 20 biopsies of autoimmune hepatitis and 10 normal liver cores).

RESULTS

YAP and TAZ nuclear localization was absent in all normal liver cores. Autoimmune hepatitis cases showed higher nuclear expression of both YAP and TAZ in comparison to chronic viral cases. YAP and TAZ expression were correlated with severity of hepatocyte injury together with fibrosis in chronic viral cases but these correlations were absent in AIH cases despite the pronounced increase of YAP and TAZ nuclear localization.

CONCLUSION

The correlation between Hippo effectors activation and fibrosis in chronic viral hepatitis patients emphasize their role in the development and advancement of hepatic scarring and highlight the use of both YAP and TAZ as novel targets to ameliorate liver fibrosis.

Exploration the significance of Tfh and related molecules on C57BL/6 mice model of experimental autoimmune hepatitis

BACKGROUND

This study aimed at establishing the autoimmune hepatitis (AIH) model of C57BL/6 mice, and examining the expression and significance of T follicular helper (Tfh) cells, T follicular regulatory (Tfr) cells, effector B cells and other indicators in this experimental autoimmune hepatitis (EAH) model.

METHODS

C57BL/6 mice in experimental group were administered by intraperitoneal injection after fully emulsified on 1st day and 7th day with 0.5 mL of 0.5-2.0 g/L S-100 and an equal volume of Buddha Complete Adjuvant (CFA). The levels of serum alanine transaminase (ALT), aspartate aminotransferase (AST), and interleukin-21 (IL-21) were tested by the corresponding kit. Tfr, Tfh and B cell subsets were quantified by flow cytometry. Histological pathology was completed by pathological section experiments.

RESULTS

In comparison with that in the healthy controls (HC), significantly increased numbers of serum ALT and AST, Tfr, IL-21 was observed. The hepatic lobules and hepatocyte cords were severely disorganized.

CONCLUSION

The results of liver pathological changes and serum index changes were similar to the chronic and progressive pathogenesis and pathology of AIH patients, providing a detailed pathological basis for the basic research and clinical experiments of AIH.

Autoimmune hepatitis in human immunodeficiency virus-infected patients: A case series and review of the literature

BACKGROUND

Abnormal liver chemistry is a common problem in human immunodeficiency virus (HIV)-infected patients. Common causes of abnormal liver enzymes in this population include viral hepatitis B/C or opportunistic infection, drug toxicity, and neoplasm. Autoimmune hepatitis is a rare cause of hepatitis in HIV-infected individuals; however, this condition has been increasingly reported over the past few years.

CASE SUMMARY

We present 13 HIV-infected patients (5 males and 8 females) who developed autoimmune hepatitis (AIH) after their immune status was restored, i.e. all patients had stable viral suppression with undetectable HIV viral loads, and median CD4+ counts of 557 cells/× 106 L. Eleven patients presented with chronic persistent elevation of aminotransferase enzyme levels. One patient presented with acute hepatitis and the other patient presented with jaundice. The median levels of aspartate aminotransferase and alanine aminotransferase enzymes were 178 and 177 U/mL, respectively. Elevation of immunoglobulin G levels was present in 11 (85%) patients. Antinuclear antibody and anti-smooth muscle antibody were positive in 11 (85%) and 5 (38%) patients. Liver biopsy was performed in all patients. They had histopathological findings compatible with AIH. The patients were started on prednisolone for remission induction, with good response. After improvement of the liver chemistry, the dose of prednisolone was tapered, and azathioprine was added as life-long maintenance therapy. At the last follow-up visit, all were doing well, without HIV viral rebound or infectious complications.

CONCLUSION

This report underscores the emergence of autoimmune hepatitis in the context of HIV infection.

Biliary features in liver histology of children with autoimmune liver disease

OBJECTIVES AND STUDY

Various degrees of biliary changes are considered to be part of the histological picture of children with pediatrics autoimmune liver disease (AILD), but the literature is scarce and confusing. We aimed to describe the characteristics of children with AILD (autoimmune hepatitis, AIH, and autoimmune sclerosing cholangitis, ASC) focusing on the prevalence and type of biliary abnormalities on initial biopsy to see whether ASC was predictable on histological ground.

METHODS

The files of children diagnosed with AILD were reviewed. The Ishak score was used to grade inflammation and fibrosis on biopsy; a biliary score was built to grade bile duct injury. Demographic, laboratory and histological features at diagnosis were reported and compared between the two groups (AIH vs ASC).

RESULTS

Forty-one patients were diagnosed with AIH (n = 24), ASC (n = 13) and PSC (n = 4) between 2009 and 2018. Twenty-nine patients [F = 76%, AIH = 20, ASC = 9, median age at diagnosis 11.7 (range 2.2-17.8)] were included in the study; 12 (4 with PSC) were excluded. Prevalence of inflammatory bowel disease was higher in ASC group (56% vs 10% in AIH, p < 0.05). On histology 17% had cirrhosis. The grade of biliopathy with AILD was moderate in 72% and severe in 31%, and overall more prominent in ASC (p = 0.031). The inflammation of the bile ducts was classified as "multifocal" or "diffuse" mainly in ASC patients (89% vs 45% in AIH, p = 0.043). Periductular fibrosis was reported in 52% of AILD patients, with a higher mean score in ASC group (p < 0.05). However, ductular reaction, biliary metaplasia and granulomatous cholangitis were equally reported in AIH and ASC, providing no clear-cut for the distinction of the two entities in the global histological evaluation.

CONCLUSIONS

Majority of patients with pediatrics AILD have "moderate" or "severe" features of biliopathy; AIH and ASC are not easily distinguishable on histological ground at diagnosis, and therefore, the cholangiogram remains the only effective tool to differentiate patients with AIH from those with ASC. Further prospective studies are needed to better define histological biliary features in AILD, assess if the biliopathy responds to immunosuppressive treatment and evaluate its impact on long-term outcome.

Autoimmune hepatitis and complexities in management

Autoimmune hepatitis (AIH) is a rare heterogenous immune-mediated liver disease that for the majority has effective therapy, usually resulting in excellent prognosis. Treatment is based on immunosuppression using standard therapy with corticosteroids and azathioprine. Second-line therapeutic options exist for those who are non-responders ('difficult to treat AIH') or intolerant to standard therapy; however, their use is not standardised, and in addition, there is vast variation in practice and efficacy. Given the rarity of AIH, expertise in its management can be limited to large referral programmes. In this case-based review, we aim to discuss common clinical dilemmas encountered by clinicians managing adult patients with AIH and address the related competencies in the 2010 Gastroenterology curriculum.

Primary Biliary Cholangitis and Autoimmune Hepatitis

Primary biliary cholangitis and autoimmune hepatitis are common autoimmune diseases of the liver. Both have typical clinical presentations, including certain autoantibodies on serologic testing. Histologic features are also often typical: primary biliary cholangitis shows bile duct destruction (sometimes with granulomas), and autoimmune hepatitis shows prominent portal and lobular lymphoplasmacytic inflammation. Both have a wide differential diagnosis, including one another; they may also simultaneously occur within the same patient. Careful use of clinical and histologic criteria may be necessary for diagnosis. First-line therapy is immunosuppression for autoimmune hepatitis and ursodeoxycholic acid for primary biliary cholangitis. Both diseases may progress to cirrhosis.

Diagnosis, presentation and initial severity of Autoimmune Hepatitis (AIH) in patients attending 28 hospitals in the UK

BACKGROUND & AIMS

There is limited information regarding patients with AIH outside relatively few large centres. We describe here the presenting features of patients with AIH, collected as part of an audit involving 28 UK hospitals.

METHODS

Patients (incident since 1/1/2007 or prevalent since 1/1/2000) were ≥18 years and either met 1999 International AIH Group (IAIHG) diagnostic criteria (n = 1164), or received immunosuppressive therapy for clinically diagnosed AIH (n = 103).

RESULTS

Of 1267 patients (80% women, 91% Caucasian, age (median(range)) 55(8-86) years, 0.5% had acute viral hepatitis (CMV/EBV/HEV); 2% were taking Nitrofurantoin and 0.7% Khat. Twenty-one percent had clinical decompensation and/or a MELD score of >15. Time from first abnormal liver tests to diagnosis was ≥1 year in 19% and was longer in jaundiced vs non-jaundiced patients. HBV and HCV serology were undocumented in 4%, serum immunoglobulins in 31% and autoantibodies in 11%-27%. When documented, ≥1 antibody was present in 83%. LKM-1-positive and autoantibody-negative patients had more severe disease. Histological cirrhosis was reported in 23%, interface hepatitis 88%, predominant lymphocytes/plasma cells 75%, rosettes 19% and emperipolesis 0.4%. Only 65% of those meeting 1999 IAIHG criteria also met simplified IAIHG criteria. University Hospitals compared to District General Hospitals, were more likely to report histological features of AIH.

CONCLUSIONS

This cohort from across the UK is older than other multicentre AIH cohorts. One-fifth had decompensation or MELD >15. Diagnosis was delayed in 19%, diagnostic testing was incomplete in one-third and rosettes and emperipolesis were infrequently reported.

Differential Diagnosis of Hepatic Necrosis Encountered at Autopsy

The liver is subject to a variety of extrinsic and intrinsic insults that manifest with both specific and nonspecific patterns of necrosis. In the autopsy setting, these patterns are often encountered as incidental findings or even causes of death. There are several etiologies of hepatic necrosis, including toxins, drug injuries, viral infections, ischemic injuries, and metabolic disease, all of which possess overlapping gross and histologic presentations. Nonetheless, patterned necrosis in the context of clinical and demographic history allows for the forensic pathologist to develop a differential diagnosis, which may then be pruned into a specific or likely cause. The aim of the following review is to elucidate these patterns in the context of the liver diseases from which they arise with the goal developing a differential diagnosis and ultimate determination of etiology. Acad Forensic Pathol. 2018 8(2): 256-295.

Diagnosis and Management of Pediatric Autoimmune Liver Disease: ESPGHAN Hepatology Committee Position Statement

Paediatric autoimmune liver disease is characterized by inflammatory liver histology, circulating autoantibodies, and increased levels of IgG, in the absence of a known etiology. Three conditions have a likely autoimmune pathogenesis: autoimmune hepatitis (AIH), autoimmune sclerosing cholangitis, and de novo AIH after liver transplantation. Two types of pediatric AIH are recognized according to seropositivity for smooth muscle and/or antinuclear antibody (AIH-1) or liver kidney microsomal type 1 and/or anti-liver cytosol type 1 antibodies (AIH-2).Pertinent issues addressing the diagnosis, treatment, and long-term follow-up were formulated by a core group of ESPGHAN members. They have commissioned the first authors with execution of this project. Initially, they have performed a systematic literature search on MEDLINE, ResearchGate, and Mendeley databases during the last 30 years and produced a document focusing on prospective and retrospective studies in children. The ESPGHAN core group and ESPGHAN Hepatology Committee members voted on each recommendation, using a formal voting technique.

Antihistone Autoantibodies in Dobermans With Hepatitis

Background

Immune system involvement is suggested as an underlying cause for Doberman hepatitis (DH) based on female predisposition, lymphocyte infiltration, abnormal hepatocyte expression of major histocompatibility complex class II antigens, and homozygosity for dog leukocyte antigen DRB1*00601.

Objective

To measure serum antinuclear antibodies (ANA) and serum antihistone antibodies (AHA) in Dobermans with hepatitis. To determine whether increased serum ANA or serum AHA could be used to support the diagnosis of Doberman hepatitis (DH).

Animals

Privately owned 25 subclinically and 13 clinically affected DH Dobermans and 17 healthy control Dobermans.

Methods

Case–control study. Indirect immunofluorescence (IIF) microscopy and line blot tests were employed for the ANA pilot studies and an enzyme‐linked immunosorbent assay (ELISA) assay for detection of IgG AHA.

Results

Indirect immunofluorescence revealed ANA‐positive cases, and line blot showed AHA reactivity. In ELISA, importantly increased concentrations of AHA were found in 92% (23/25) of dogs in the subclinical stage and 84.6% (11 of 13) of dogs in the clinical stage of DH compared with no control dogs (0/17) (P < 0.0005). The mean AHA absorbance values of the blood samples obtained from the 25 subclinical DH dogs (1.36 ± 0.60, mean ± SD) and the 13 clinically affected dogs (1.46 ± 0.49) were significantly higher than in 17 control dogs (0.51 ± 0.18; P < 0.0001).

Conclusions and Clinical Importance

As the presence of AHA indicates autoimmune activity, our results favor an autoimmune background as one cause for DH. Antihistone antibody could represent a novel means for screening Dobermans with increased serum alanine transaminase concentrations and suspicion of DH.

Challenges and difficulties in pathological diagnosis of autoimmune hepatitis

Autoimmune hepatitis (AIH) with acute presentation is widely recognized as a distinct clinical entity, and its clinicopathology has been extensively studied. In most cases, AIH with acute presentation is merely acute exacerbation of classical chronic AIH, but pure acute-onset AIH without previous symptoms of chronic liver disease is also encountered. Rapid diagnosis and initiation of immunosuppressive treatment are necessary for both acute exacerbation and acute-onset to prevent fatal liver failure. The diagnostic criteria commonly used for classical AIH are generally applicable to acute exacerbation, but acute-onset AIH may present with additional pathological features. These features include an acute hepatitis phase characterized by centrilobular necrosis. However, centrilobular necrosis is also a feature of drug-induced liver injury, and there are no known histological characteristics exclusive to acute-onset AIH. Moreover, the possibilities of drug-induced AIH and immune-mediated drug-induced liver injury make diagnosis even more difficult. At present, liver biopsy is mandatory for the diagnosis of AIH with acute presentation, but careful consideration of all clinicopathological signs is necessary for differential diagnosis.

Glassy droplet inclusions within the cytoplasm of Kupffer cells: A novel ultrastructural feature for the diagnosis of pediatric autoimmune hepatitis

Since Kupffer cells/macrophages (KCs/MPs) may be involved in the pathogenesis of autoimmune hepatitis (AIH), this pioneer study was undertaken to evaluate KCs/MPs in pediatric AIH in transmission-electron microscope.

METHODS

Ultrastructural analyses were performed using liver biopsies from 14 children with clinicopathologically diagnosed AIH.

RESULTS

In all AIH children, ultrastructural findings revealed changes in the cells lining sinusoidal vessels, especially KCs/MPs and endothelial cells. KCs/MPs showed increased phagocytic activity and damaged mitochondria, frequently with accompanying intense fibrosis. In 10/14 AIH patients, the cytoplasm of sinusoidal KCs/MPs contained characteristic glassy droplet inclusions. They were round, sharply circumscribed, and contained homogeneous material and distinct translucent fields. Their ultrastructure was identical with the Russel bodies of plasma cells, which were also found in liver biopsies in the same patients.

CONCLUSION

Ultrastructural identification of characteristic cytoplasmic droplets with glassy appearance in KCs/MPs, never before described in AIH, provides a useful novel morphological feature in the diagnosis of this disease.