Autoimmune hepatitis: an approach to disease understanding and management

Liver biopsy for assessment of suspected drug-induced liver injury in metabolic dysfunction-associated steatohepatitis clinical trials: Expert consensus from the Liver Forum

BACKGROUND

Causality assessment of suspected drug-induced liver injury (DILI) during metabolic dysfunction-associated steatohepatitis (MASH) clinical trials can be challenging, and liver biopsies are not routinely performed as part of this evaluation. While the field is moving away from liver biopsy as a diagnostic and prognostic tool, information not identified by non-invasive testing may be provided on histology.

AIM

To address the appropriate utilisation of liver biopsy as part of DILI causality assessment in this setting.

METHODS

From 2020 to 2022, the Liver Forum convened a series of webinars on issues pertaining to liver biopsy during MASH trials. The Histology Working Group was formed to generate a series of consensus documents addressing these challenges. This manuscript focuses on liver biopsy as part of DILI causality assessment.

RESULTS

Expert opinion, guidance and recommendations on the role of liver biopsy as part of causality assessment of suspected DILI occurring during clinical trials for a drug(s) being developed for MASH are provided. Lessons learned from prior MASH programs are reviewed and gaps identified.

CONCLUSIONS

Although there are no pathognomonic features, histologic evaluation of suspected DILI during MASH clinical trials may alter patient management, define the pattern and severity of injury, detect findings that favour a diagnosis of DILI versus MASH progression, identify prognostic features, characterise the clinicopathological phenotype of DILI, and/or define lesions that influence decisions about trial discontinuation and further development of the drug.

PD-L1 expression levels in mesenchymal stromal cells predict their therapeutic values for autoimmune hepatitis

BACKGROUND

Autoimmune hepatitis is a chronic inflammatory hepatic disorder with no effective treatment. Mesenchymal stromal cells (MSCs) have emerged as a promising treatment owing to their unique advantages. However, their heterogeneity is hampering use in clinical applications.

METHODS

Wharton's jelly derived MSCs (WJ-MSCs) were isolated from 58 human donors using current good manufacturing practice conditions. Gene expression profiles of the WJ-MSCs were analyzed by transcriptome and single-cell RNA-sequencing (scRNA-seq), and subsequent functional differences were assessed. Expression levels of programmed death-ligand 1 (PD-L1) were used as an indicator to screen WJ-MSCs with varied immunomodulation activities and assessed their corresponding therapeutic effects in a mouse model of concanavalin A-induced autoimmune hepatitis.

RESULTS

The 58 different donor-derived WJ-MSCs were grouped into six gene expression profile clusters. The gene in different clusters displayed obvious variations in cell proliferation, differentiation bias, trophic factor secretion, and immunoregulation. Data of scRNA-seq revealed four distinct WJ-MSCs subpopulations. Notably, the different immunosuppression capacities of WJ-MSCs were positively correlated with PD-L1 expression. WJ-MSCs with high expression of PD-L1 were therapeutically superior to WJ-MSCs with low PD-L1 expression in treating autoimmune hepatitis.

CONCLUSION

PD-L1 expression levels of WJ-MSCs could be regarded as an indicator to choose optimal MSCs for treating autoimmune disease. These findings provided novel insights into the quality control of MSCs and will inform improvements in the therapeutic benefits of MSCs.

AIPs-SnTCN: Predicting Anti-Inflammatory Peptides Using fastText and Transformer Encoder-Based Hybrid Word Embedding with Self-Normalized Temporal Convolutional Networks

Inflammation is a biologically resistant response to harmful stimuli, such as infection, damaged cells, toxic chemicals, or tissue injuries. Its purpose is to eradicate pathogenic micro-organisms or irritants and facilitate tissue repair. Prolonged inflammation can result in chronic inflammatory diseases. However, wet-laboratory-based treatments are costly and time-consuming and may have adverse side effects on normal cells. In the past decade, peptide therapeutics have gained significant attention due to their high specificity in targeting affected cells without affecting healthy cells. Motivated by the significance of peptide-based therapies, we developed a highly discriminative prediction model called AIPs-SnTCN to predict anti-inflammatory peptides accurately. The peptide samples are encoded using word embedding techniques such as skip-gram and attention-based bidirectional encoder representation using a transformer (BERT). The conjoint triad feature (CTF) also collects structure-based cluster profile features. The fused vector of word embedding and sequential features is formed to compensate for the limitations of single encoding methods. Support vector machine-based recursive feature elimination (SVM-RFE) is applied to choose the ranking-based optimal space. The optimized feature space is trained by using an improved self-normalized temporal convolutional network (SnTCN). The AIPs-SnTCN model achieved a predictive accuracy of 95.86% and an AUC of 0.97 by using training samples. In the case of the alternate training data set, our model obtained an accuracy of 92.04% and an AUC of 0.96. The proposed AIPs-SnTCN model outperformed existing models with an ∼19% higher accuracy and an ∼14% higher AUC value. The reliability and efficacy of our AIPs-SnTCN model make it a valuable tool for scientists and may play a beneficial role in pharmaceutical design and research academia.

Develop and validate a novel online AIHI-nomogram to predict severe liver inflammation in patients with autoimmune hepatitis

INTRODUCTION AND OBJECTIVES

Assessment of liver inflammation plays a vital role in the management of patients with autoimmune hepatitis (AIH). We aimed to establish and validate a nomogram to predict severe liver inflammation in AIH patients.

PATIENTS AND METHODS

AIH patients who underwent liver biopsy were included and randomly divided into a training set and a validation set. Independent predictors of severe liver inflammation were selected by the least absolute shrinkage and selection operator regression from the training set and used to conduct a nomogram. Receiver characteristic curves (ROC), calibration curves, and decision curve analysis (DCA) were adopted to evaluate the performance of nomogram.

RESULTS

Of the 213 patients, female patients accounted for 83.1% and the median age was 53.0 years. The albumin, gamma-glutamyl transpeptidase, total bilirubin, red cell distribution width, prothrombin time, and platelets were independent predictors of severe inflammation. An online AIHI-nomogram was established and was available at https://ndth-zzy.shinyapps.io/AIHI-nomogram/. The calibration curve revealed that the AIHI-nomogram had a good agreement with actual observation in the training and validation sets. The area under the ROCs of AIHI-nomogram were 0.795 in the training set and 0.759 in the validation set, showing significantly better performance than alanine aminotransferase and immunoglobulin G in the training and validation sets, as well in AIH patients with normal ALT in the training set. DCA indicated that the AIHI-nomogram was clinically useful.

CONCLUSIONS

This novel AIHI-nomogram provided an excellent prediction of severe liver inflammation in AIH patients and could be used for the better management of AIH.

An easy-to-use AIHF-nomogram to predict advanced liver fibrosis in patients with autoimmune hepatitis

Background

The evaluation of liver fibrosis is essential in the management of patients with autoimmune hepatitis (AIH). We aimed to establish and validate an easy-to-use nomogram to identify AIH patients with advanced liver fibrosis.

Methods

AIH patients who underwent liver biopsies were included and randomly divided into a training set and a validation set. The least absolute shrinkage and selection operator (LASSO) regression was used to select independent predictors of advanced liver fibrosis from the training set, which were utilized to establish a nomogram. The performance of the nomogram was evaluated using the receiver characteristic curve (ROC), calibration curve, and decision curve analysis (DCA).

Results

The median age of 235 patients with AIH was 54 years old, with 83.0% of them being female. Six independent factors associated with advanced fibrosis, including sex, age, red cell distribution width, platelets, alkaline phosphatase, and prothrombin time, were combined to construct a predictive AIH fibrosis (AIHF)-nomogram. The AIHF-nomogram showed good agreement with real observations in the training and validation sets, according to the calibration curve. The AIHF-nomogram performed significantly better than the fibrosis-4 and aminotransferase-to-platelet ratio scores in the training and validation sets, with an area under the ROCs for predicting advanced fibrosis of 0.804 in the training set and 0.781 in the validation set. DCA indicated that the AIHFI-nomogram was clinically useful. The nomogram will be available at http://ndth-zzy.shinyapps.io/AIHF-nomogram/as a web-based calculator.

Conclusions

The novel, easy-to-use web-based AIHF-nomogram model provides an insightful and applicable tool to identify AIH patients with advanced liver fibrosis.

Research Progress of Fecal Microbiota Transplantation in Liver Diseases

A growing body of evidence suggested that gut microbiota is associated with liver diseases through the gut-liver axis. The imbalance of gut microbiota could be correlated with the occurrence, development, and prognosis of a series of liver diseases, including alcoholic liver disease (ALD), non-alcoholic fatty liver disease (NAFLD), viral hepatitis, cirrhosis, primary sclerosing cholangitis (PSC), and hepatocellular carcinoma (HCC). Fecal microbiota transplantation (FMT) seems to be a method to normalize the patient's gut microbiota. This method has been traced back to the 4th century. In recent decade, FMT has been highly regarded in several clinical trials. As a novel approach to reconstruct the intestinal microecological balance, FMT has been used to treat the chronic liver diseases. Therefore, in this review, the role of FMT in the treatment of liver diseases was summarized. In addition, the relationship between gut and liver was explored through the gut-liver axis, and the definition, objectives, advantages, and procedures of FMT were described. Finally, the clinical value of FMT therapy in liver transplant (LT) recipients was briefly discussed.

Vitexin attenuates autoimmune hepatitis in mouse induced by syngeneic liver cytosolic proteins via activation of AMPK/AKT/GSK-3β/Nrf2 pathway

Autoimmune hepatitis (AIH) is a chronic progressive liver disease that currently does not have a successful therapeutic option. Vitexin, a bioflavonoid isolated from various medicinal plants, possesses a variety of activities; however, whether vitexin protects against AIH remains unclear. Therefore, the current study aims to investigate the hepatoprotective effects and mechanism of action of vitexin in both an experimental autoimmune hepatitis (EAH) mouse model and in D-galactosamine/lipopolysaccharide (D-GalN/LPS)-induced hepatocyte injury. Syngeneic liver antigen S100 was used to establish EAH. Vitexin treatment significantly decreased the infiltration of inflammatory and CD4⁺ T cells in the liver, reduced ALT and AST levels in the serum and attenuated hepatic injury due to oxidative stress. Moreover, vitexin mitigated the upregulation of Bax and cleaved caspase-3 and the downregulation of Bcl-2 in the livers of AIH mice. These regulations were accompanied by not only increased phosphorylation of AMPK, AKT and GSK-3β but also activation of Nrf2. Furthermore, vitexin inhibited apoptosis and the overexpression of inflammatory cytokines in D-GalN/LPS-treated AML12 cells. In addition, vitexin enhanced the phosphorylation of AMPK, AKT and GSK-3β. When AML12 cells were treated with an inhibitor of AMPK/AKT or specific siRNA targeting Nrf2, vitexin did not further induce the activation of Nrf2/HO-1. A molecular docking study confirmed that vitexin could interact with AMPK through hydrogen bonding interactions. In conclusion, vitexin ameliorated hepatic injury in EAH mice through activation of the AMPK/AKT/GSK-3β pathway and upregulation of the Nrf2 gene.

Evaluation of Validity and Efficiency of Diagnostic Criteria in Autoimmune Hepatitis in Children

BACKGROUND

Autoimmune hepatitis (AIH) is a progressive inflammatory liver disease with various clinical symptoms, but treatment and prevention of hepatic failure and cirrhosis is possible with early diagnosis. However, no specific test has been approved for the diagnosis of AIH. In 2008, the International Autoimmune Hepatitis Group (IAIHG) developed a simplified diagnostic scoring system that has been widely used in practice. Nevertheless, it cannot distinguish AIH from Primary Sclerosing Cholangitis (PSC) and consensus is lacking with respect to its validity, sensitivity, and applicability for children patients. The newer 2018 version also requires validation. The present study intends to evaluate the validity and efficiency of the IAIHG simplified scoring system and new scoring system in children with AIH.

METHODS

The present study is a non-interventional case-control study covering 152 patients with hepatic diseases (83 patients with AIH and 69 patients with Wilson disease (WD)). Titers of autoantibodies, IgG levels, hepatic histology, and absence of viral hepatitis were scored and calculated according to IAIHG diagnostic criteria. Statistics software package (SPSS) and draft receiver operating characteristic (ROC) curves was used to analyze data and determine value of diagnostic criteria.

RESULT

In our study, both scoring systems' accuracy was good in AIH diagnosis, although new score displays higher sensitivity and specificity, suggestive of greater accuracy and predictive strength.

CONCLUSION

Our study is the first validation study of the new scoring system in diagnosing AIH, and further studies require verifying this scoring system.

Red cell distribution width to platelet ratio predicts liver fibrosis in patients with autoimmune hepatitis

Noninvasive tests for the assessment of liver fibrosis are highly needed for the management of patients with autoimmune hepatitis (AIH). We aimed to investigate the accuracy of red cell distribution width to platelet ratio (RPR) in predicting liver fibrosis in AIH patients. One hundred nineteen AIH patients who underwent liver biopsy were enrolled. Liver fibrosis stage was diagnosed using the Scheuer scoring system. The diagnostic accuracy was evaluated by the area under the receiver operating characteristic curve (AUROC). RPR values in AIH patients with S2-S4 (0.10, interquartile range [IQR] 0.08-0.15), S3-S4 (0.10, IQR 0.09-0.14), and S4 (0.14, IQR 0.09-0.19) were significantly higher than patients with S0-S1 (0.07, IQR 0.06-0.08, P < .001), S0-S2 (0.08, IQR 0.06-0.12, P = .025) and S0-S3 (0.09, IQR 0.07-0.13, P = .014), respectively. The RPR was positively correlated with fibrosis stages (r = 0.412, P < .001), while aspartate transaminase to platelet ratio index (APRI) and fibrosis-4 score (FIB-4) were not significantly associated with fibrosis stages in AIH patients. The AUROCs of RPR in identifying significant fibrosis (S2-S4), advanced fibrosis (S3-S4), and cirrhosis (S4) were 0.780 (95% confidence interval [CI] 0.696-0.865), 0.639 (95% CI 0.530-0.748), and 0.724 (95% CI 0.570-0.878), respectively. The AUROCs of RPR were significantly higher than APRI and FIB-4 in diagnosing significant fibrosis, advanced fibrosis, and cirrhosis. Our study demonstrates that the RPR is a simple predictor of liver fibrosis and is superior to APRI and FIB-4 in identifying liver fibrosis in AIH patients.

Alterations of gut microbiome in autoimmune hepatitis

OBJECTIVE

The significance of the liver-microbiome axis has been increasingly recognised as a major modulator of autoimmunity. The aim of this study was to take advantage of a large well-defined corticosteroids treatment-naïve group of patients with autoimmune hepatitis (AIH) to rigorously characterise gut dysbiosis compared with healthy controls.

DESIGN

We performed a cross-sectional study of individuals with AIH (n=91) and matched healthy controls (n=98) by 16S rRNA gene sequencing. An independent cohort of 28 patients and 34 controls was analysed to validate the results. All the patients were collected before corticosteroids therapy.

RESULTS

The gut microbiome of steroid treatment-naïve AIH was characterised with lower alpha-diversity (Shannon and observed operational taxonomic units, both p<0.01) and distinct overall microbial composition compared with healthy controls (p=0.002). Depletion of obligate anaerobes and expansion of potential pathobionts including Veillonella were associated with disease status. Of note, Veillonella dispar, the most strongly disease-associated taxa (p=8.85E-8), positively correlated with serum level of aspartate aminotransferase and liver inflammation. Furthermore, the combination of four patients with AIH-associated genera distinguished AIH from controls with an area under curves of approximately 0.8 in both exploration and validation cohorts. In addition, multiple predicted functional modules were altered in the AIH gut microbiome, including lipopolysaccharide biosynthesis as well as metabolism of amino acids that can be processed by bacteria to produce immunomodulatory metabolites.

CONCLUSION

Our study establishes compositional and functional alterations of gut microbiome in AIH and suggests the potential for using gut microbiota as non-invasive biomarkers to assess disease activity.

microRNA-143-3p attenuated development of hepatic fibrosis in autoimmune hepatitis through regulation of TAK1 phosphorylation

Autoimmune hepatitis (AIH) is a chronic liver disease due to autoimmune system attacks hepatocytes and causes inflammation and fibrosis. Intracellular signalling and miRNA may play an important role in regulation of liver injury. This study aimed to investigate the potential roles of microRNA 143 in a murine AIH model and a hepatocyte injury model. Murine AIH model was induced by hepatic antigen S100, and hepatocyte injury model was induced by LPS. Mice and AML12 cells were separated into six groups with or without the treatment of miRNA-143. Inflammation and fibrosis as well as gene expression were examined by different cellular and molecular techniques. The model was successfully established with the elevation of ALT and AST as well as inflammatory and fibrotic markers. Infection or transfection of mir-143 in mice or hepatocytes significantly attenuated the development of alleviation of hepatocyte injury. Moreover, the study demonstrated phosphorylation of TAK1-mediated miRNA-143 regulation of hepatic inflammation and fibrosis as well as hepatocyte injury. Our studies demonstrated a significant role of miRNA-143 in attenuation of liver injury in AIH mice and hepatocytes. miRNA-143 regulates inflammation and fibrosis through its regulation of TAK1 phosphorylation, which warrants TAK1 as a target for the development of new therapeutic strategy of autoimmune hepatitis.

Familial associations between autoimmune hepatitis and primary biliary cholangitis and other autoimmune diseases

Autoimmune hepatitis (AH) and primary biliary cirrhosis (PBC) are autoimmune diseases (AIDs) targeting cellular components of the liver. Being rare diseases, limited data are available about familial risks among these AIDs (concordant) or between them and other AIDs (discordant). We aimed to carry out an unbiased study on these AIDs based on medically diagnosed patients. We collected data on patients diagnosed in Swedish hospitals with AH, PBC and other AIDs and calculated familial standardized incidence ratios (SIRs) for concordant and discordant familial relative risks. The number of AH patients was 6,269, of whom 43.0% were male; patient numbers for PBC were 4,269, with 17.8% males. AH accounted for 0.8% and 0.6% of all hospitalized AIDs in Sweden. For AH only the familial risk between siblings was significant (3.83). For PBC the risks for offspring of parents (9.05) and siblings (10.88) were high, but only risk for females was significant. Spousal risks were very high, 5.91 and 6.07 for AH. Risk for AH was 2.21 in families of PBC, and it was 2.47 for PBC in families of AH patients. Among other AIDs, 14 showed a significant association with AH, compared to 16 AIDs with PBC. The surprising finding in this nation-wide family study on medically diagnosed patients was the high risk for AH (6.0) between spouses, which exceed the risk between siblings, suggesting the existence of strong environmental risk factors. AH and PBC were associated with multiple other AIDs. The results call attention to environmental factors in AID etiology which should also be in focus in taking anamnestic data from patients.

Cellular and Molecular Mechanisms of Autoimmune Hepatitis

Autoimmune hepatitis is an uncommon idiopathic syndrome of immune-mediated destruction of hepatocytes, typically associated with autoantibodies. The disease etiology is incompletely understood but includes a clear association with human leukocyte antigen (HLA) variants and other non-HLA gene variants, female sex, and the environment. Pathologically, there is a CD4+ T cell-rich lymphocytic inflammatory infiltrate with variable hepatocyte necrosis and subsequent hepatic fibrosis. Attempts to understand pathogenesis are informed by several monogenetic syndromes that may include autoimmune liver injury, by several drug and environmental agents that have been identified as triggers in a minority of cases, by human studies that point toward a central role for CD4+ effector and regulatory T cells, and by animal models of the disease. Nonspecific immunosuppression is the current standard therapy. Further understanding of the disease's cellular and molecular mechanisms may assist in the design of better-targeted therapies, aid the limitation of adverse effects from therapy, and inform individualized risk assessment and prognostication.

PreAIP: Computational Prediction of Anti-inflammatory Peptides by Integrating Multiple Complementary Features

Numerous inflammatory diseases and autoimmune disorders by therapeutic peptides have received substantial consideration; however, the exploration of anti-inflammatory peptides via biological experiments is often a time-consuming and expensive task. The development of novel in silico predictors is desired to classify potential anti-inflammatory peptides prior to in vitro investigation. Herein, an accurate predictor, called PreAIP (Predictor of Anti-Inflammatory Peptides) was developed by integrating multiple complementary features. We systematically investigated different types of features including primary sequence, evolutionary and structural information through a random forest classifier. The final PreAIP model achieved an AUC value of 0.833 in the training dataset via 10-fold cross-validation test, which was better than that of existing models. Moreover, we assessed the performance of the PreAIP with an AUC value of 0.840 on a test dataset to demonstrate that the proposed method outperformed the two existing methods. These results indicated that the PreAIP is an accurate predictor for identifying AIPs and contributes to the development of AIPs therapeutics and biomedical research. The curated datasets and the PreAIP are freely available at http://kurata14.bio.kyutech.ac.jp/PreAIP/.

Measuring Apoptosis and Necrosis in Cholestatic Liver Injury

Cholestasis can be induced by obstruction of bile ducts or intrahepatic toxicity of drugs and chemicals. However, the mode of cell death during cholestasis, i.e., apoptosis or necrosis, has been controversial. There are fundamental reasons for the controversies, both of which are discussed here, namely the design of experiments and the use of parameters with limited specificity for a certain mode of cell death. Based on the assumption that cholestatic liver injury is caused by accumulation of bile acids, rodent (mainly rat) hepatocytes have been exposed to hydrophobic, glycine-conjugated bile acids, which resulted in apoptotic cell death. The problems with this experimental design are that in rodents bile acids are predominantly taurine conjugated and rodent hepatocytes are never exposed to these levels of glycine-conjugated bile acids. In contrast, taurine-conjugated bile acids trigger inflammatory gene activation in rodent hepatocytes and a necro-inflammatory injury in vivo. On the other hand, human hepatocytes are more resistant to glycine-conjugated bile acids and die by necrosis when exposed to high biliary levels of these bile acids. In this chapter, we describe multiple assays including the caspase activity assay, which is specific for apoptosis, and the general cell death assays alanine aminotransferase or lactate dehydrogenase activities in cell culture medium or plasma. An increase in these enzyme activities without caspase activity indicates necrotic cell death. Thus, both the experimental design and the selection of cell death parameters are critical for the relevance of the experiments for the human pathophysiology.

TLR2/4 ligand-amplified liver inflammation promotes initiation of autoimmune hepatitis due to sustained IL-6/IL-12/IL-4/IL-25 expression

Autoimmune hepatitis (AIH), a serious autoimmune liver disease, can be a lifelong illness, leading to fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). So far the mechanisms for disease initiation are largely unknown. Here we report that the amplified non-AIH liver inflammation could promote the initiation of AIH due to the sustained increase of IL-6, IL-12, IL-4, and IL-25 in the liver. The liver injury resulting from virus (adenovirus) or chemicals (CCl₄) could induce an amplified (stronger/long-lasting) hepatic inflammation by releasing the ligands for TLR2/TLR4. The amplified inflammation resulted in the increase of multiple cytokines and chemokines in the liver. Among them, the sustained increase of IL-6/IL-12 resulted in the activation of STAT3 and STAT4 in hepatic CD4⁺CD25⁺ Treg cells, thus suppressing Foxp3 gene expression to reduce the suppressive function of Treg cells in the liver, but not those in the spleen. The increase of IL-12 and the impairment of Treg function promoted Th1 response in presence of self-mimicking antigen (human CYP2D6). Intriguingly, the amplified inflammation resulted in the increase of IL-4 and IL-25 in the liver. The moderate increase of IL-4 was sufficient for cooperating with IL-25 to initiate Th2 response, but inefficient in suppressing Th1 response, favoring the initiation of autoimmune response. Consequently, either adenovirus/CYP2D6 or CCl₄/CYP2D6 could induce the autoimmune response and AIH in the mice, leading to hepatic fibrosis. The findings in this study suggest that the amplified non-AIH inflammation in the liver could be a driving force for the initiation of autoimmune response and AIH.

Role of altered immune cells in liver diseases: a review

Immune cells play an important role in controlling liver tumorigenesis, viral hepatitis, liver fibrosis and contribute to pathogenesis of liver inflammation and injury. Accumulating evidence suggests the effectiveness of natural killer (NK) cells and Kupffer cells (KCs) against viral hepatitis, hepatocellular damage, liver fibrosis, and carcinogenesis. Activation of natural killer cells provides a novel therapeutic strategy to cure liver related diseases. This review discusses the emerging roles of immune cells in liver disorders and it will provide baseline data to scientists to design better therapies for treatment.

Twenty-Year Comparative Analysis of Patients With Autoimmune Liver Diseases on Transplant Waitlists

BACKGROUND & AIMS

The rarity of autoimmune liver disease poses challenges to epidemiology studies. However, waitlists for liver transplantation can be used to study patients with end-stage liver diseases. We used these waitlists to assess trends in numbers and demographics of patients awaiting liver transplant for primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC), or autoimmune hepatitis (AIH).

METHODS

We collected data from UK and US national registries for all adults on liver transplant waitlists, from January 1, 1995, through December 31, 2014. We analyzed data from patients with PBC (n = 1434 in the United Kingdom and n = 5598 in the United States), PSC (n = 1093 in the United Kingdom and n = 6820 in the United States), and AIH (n = 538 in the United Kingdom and n = 4949 in the United States). Numbers of listings per year were adjusted to the estimated populations during each year. Regression analyses were used to examine trends and comparative statistics were used to evaluate differences in individual characteristics among groups.

RESULTS

Over the total study period, listings for PBC were 1.2 and 1.0 per million population per year in the United Kingdom and United States, respectively; for PSC, 0.9 and 1.2 per million population per year; and for AIH, 0.5 and 0.8 per million population per year. Over the period studied, numbers of listings for PBC decreased by 50% in both countries; changes in numbers of listings for PSC and AIH were smaller and not consistent between countries. By 2014, PSC had become the leading indication for liver transplantation among patients with autoimmune liver diseases in both countries. Median patient ages at time of listing were lower than those reported as median age of diagnosis for AIH and PBC. The ratio of women:men with PBC decreased by almost 50% from 1995 through 2014. Men with PSC were placed on the waitlist with higher disease severity scores than women in both countries. Among patients with PBC, those of black race were under-represented on waitlists from both countries. Among patients with PSC, Hispanics were under-represented on waitlists in the United States. Patients of non-white races were placed on waitlists at younger ages for all diseases; age differences in waitlist placement varied by up to 10 years, depending on race, among patients with PBC.

CONCLUSIONS

In an analysis of data collected from UK and US national liver transplant registries over 20 years, we found that PSC has become the leading indication for liver transplantation among patients with autoimmune liver diseases. Numbers of patients with PBC placed on waitlists, and the ratio of women:men with PBC, each decreased by almost 50%, possibly due to increased treatment with ursodeoxycholic acid. Within groups of patients on the transplant waitlist for PBC, PSC, or AIH, we found differences in age, sex, disease severity scores, and ethnicity between diseases and countries that require further study.

Sodium butyrate ameliorates S100/FCA-induced autoimmune hepatitis through regulation of intestinal tight junction and toll-like receptor 4 signaling pathway

BACKGROUND AND AIM

Recent investigation revealed that dysbiosis in the gut flora and disruption of permeability of intestinal barrier are possible causes for the development of autoimmune hepatitis. Supplementation of sodium butyrate has been suggested to protect liver injury from disrupted permeability of small intestine. In current study, we employed S100/Freund's complete adjuvant induced autoimmune hepatitis to investigate therapeutic efficacy of sodium butyrate and its mechanism in the liver and upper small intestine.

METHODS

C57BL/6 mice were employed and divided into three groups - control group (n=8), autoimmune hepatitis group (n=12) and autoimmune hepatitis with treatment of sodium butyrate group (n=12). Histological staining and western blot analyses were employed to evaluate liver and upper small intestine morphology and gene expression respectively.

RESULTS

The findings revealed that S100/Freund's complete adjuvant caused liver injury and disruption of upper small intestine villi. Sodium butyrate attenuated the injuries and prevented migration of Escherichia coli into the liver. Moreover, the effect of sodium butyrate on protection of injuries of the liver and upper small intestine could be due to inhibition of toll-like receptor 4 signaling pathway, as well as its down-regulation of inflammatory cytokines - interleukin-6 and tumor necrosis factor-a.

CONCLUSIONS

Sodium butyrate can prevent liver injury by maintaining the integrity of small intestine and inhibiting inflammatory response in S100/Freund's complete adjuvant induced autoimmune hepatitis.

Platelet count to spleen diameter ratio non-invasively identifies severe fibrosis and cirrhosis in patients with autoimmune hepatitis

BACKGROUND AND AIM

Non-invasive markers are essential to assess the progression of chronic liver diseases to fibrosis/ cirrhosis and the effectiveness of therapeutic strategies. The aim of this study was to evaluate the ability of non-invasive markers to identify significant fibrosis, severe fibrosis, and cirrhosis in patients with autoimmune hepatitis (AIH).

METHODS

Seventy-six patients with AIH were enrolled in the study and analyzed for the following parameters of liver fibrosis: Fibrosis 4 score (FIB-4), aspartate aminotransferase (AST) to alanine aminotransferase (ALT) ratio (AAR), AST to platelet count ratio (APRI), and platelet count to spleen diameter (PC/SD) ratio. All patients underwent liver biopsy. The diagnostic accuracy of tests was evaluated by the area under the receiver operating characteristic curve (AUROC).

RESULTS

Among the 76 AIH patients, 55 (72.3%) had significant fibrosis (≥ F2), 37 (48.7%) had severe fibrosis (≥ F3), and 29 (38.2%) had cirrhosis (F4). PC/SD ratio (AUROC = 0.840) was superior to AAR (AUROC = 0.756), FIB-4 (AUROC = 0.702), and APRI (AUROC = 0.626) in discriminating between mild and significant fibrosis (≥ F2). The AUROCs of PC/SD ratio, FIB-4, AAR, and APRI were 0.884, 0.742, 0.731, and 0.707, respectively, for severe fibrosis (≥ F3); 0.968, 0.795, 0.744, and 0.723, respectively, for cirrhosis (F4). PC/SD ratio correctly identified 85.1% of patients with severe fibrosis, and 89.6% of patients with cirrhosis.

CONCLUSIONS

PC/SD ratio proved to be a simple non-invasive tool to correctly identify AIH patients with severe fibrosis and cirrhosis, thereby reducing the need for a liver biopsy in these patients.

Selection and use of immunosuppressive therapies after liver transplantation: current German practice

In recent years, immunosuppression (IS) after liver transplantation (LT) has become increasingly diversified as the choice of agents has expanded and clinicians seek to optimize the balance of immunosuppressive potency with the risk of adverse events in individual patients. Calcineurin inhibitors (CNIs) are the primary agents used for patients undergoing liver transplantation. Other therapeutic agents like interleukin-2 receptor antagonists are not universally administered, but can be considered for the delay or reduction in CNI exposure. An early addition of mycophenolate mofetil (MMF) or the mTOR inhibitor everolimus also allows for the reduction in the CNI dose. To reduce the risk of malignancy, in particular of skin tumors, as well as to prevent the deterioration of renal function, everolimus-based therapy may be advantageous. Apart from patients with autoimmune hepatitis, steroids are withdrawn within 3-6 months after transplantation. Overall, immunosuppression can only be standardized in a limited proportion of patients due to specific clinical requirements and risk factors. Future studies should attempt to refine accurate individualization of the immunosuppressive regimen in specific difficult-to-treat patient subpopulations.

NKT cell subsets as key participants in liver physiology and pathology

Natural killer T (NKT) cells are innate-like lymphocytes that generally recognize lipid antigens and are enriched in microvascular compartments of the liver. NKT cells can be activated by self- or microbial-lipid antigens and by signaling through toll-like receptors. Following activation, NKT cells rapidly secrete pro-inflammatory or anti-inflammatory cytokines and chemokines, and thereby determine the milieu for subsequent immunity or tolerance. It is becoming clear that two different subsets of NKT cells-type I and type II-have different modes of antigen recognition and have opposing roles in inflammatory liver diseases. Here we focus mainly on the roles of both NKT cell subsets in the maintenance of immune tolerance and inflammatory diseases in liver. Furthermore, how the differential activation of type I and type II NKT cells influences other innate cells and adaptive immune cells to result in important consequences for tissue integrity is discussed. It is crucial that better reagents, including CD1d tetramers, be used in clinical studies to define the roles of NKT cells in liver diseases in patients.

Using GWAS to identify genetic predisposition in hepatic autoimmunity

Primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC) and autoimmune hepatitis (AIH) represent the three major hepatic autoimmune conditions. Patient morbidity and mortality remain high across these three diseases, and an unmet need for rational therapy exists. Disease understanding has focused on combining clinical and laboratory based science to provide better insights into the joint host and environmental factors necessary for the initiation, and perpetuation, of hepato-biliary inflammation. Twin studies, family studies, population studies and an inter-relationship with other autoimmune phenomena suggest a genetic component to risk for each disease. Until recently, understanding of this genetic risk has been limited to HLA haplotypes. Associations with risk-conferring and protective HLA haplotypes are present in all three diseases. Over the last few years, genome-wide association studies (GWAS), and related genetic association studies, have greatly increased understanding of the genetic risk signature of these three diseases and autoimmunity in general. Here we consider the rationale for GWAS in general and with specific reference to hepatic autoimmunity. We consider the process of GWAS, and highlight major findings to date. Potential functional implications of key findings are discussed including the IL-12/STAT4 pathway in PBC and the CD28/IL-2 pathway in PSC. We describe the marked pleiotropy demonstrated by PBC and PSC, which is consistent with other autoimmune diseases. Further, we focus on specific gene associations including SH2B3, which is common to all three diseases, and FUT2 in PSC, which represents a link between environment and genetics. We review attempts to translate GWAS findings into basic laboratory models including in vivo systems and highlight where clinical observations relate to genetics. Finally we describe deficiencies in GWAS to date and consider future study of genetics in hepatic autoimmunity.

Metabolism of glycerophospholipid, bile acid and retinol is correlated with the early outcomes of autoimmune hepatitis

This study first reports the metabolic variations at the early stage of the liver injury related to autoimmune hepatitis.