Autoimmune hepatitis--Update 2015

Total glucosides of paeony decreases apoptosis of hepatocytes and inhibits maturation of dendritic cells in autoimmune hepatitis

Total glucosides of paeony (TGP), an active mixture extracted from paeony root, has anti-inflammatory and immunoregulatory effects and is widely used for the treatment of autoimmune diseases such as rheumatoid arthritis. However, the role of TGP in autoimmune hepatitis (AIH) is still unknown. In this study, we aimed to investigate the effect of TGP in autoimmune liver disease (AILD) patients and in concanavalin A (Con A)-induced experimental autoimmune hepatitis (EAH). Changes in biochemical parameters of AILD patients showed that treatment with TGP exerts significant protective effects on liver function, as reflected by decreased levels of serum alanine transaminase, aspartate transaminase, γ-glutamyl transpeptidase and total bilirubin. In EAH mice, we found that pretreatment with TGP reduced the levels of serum liver enzyme levels, histopathological damage and hepatocyte apoptosis. Importantly, flow cytometry analysis showed that pretreatment with TGP reduced the infiltration of mature dendritic cells in the liver. In vitro, TGP pretreatment ameliorated the Con A-induced mitochondrial membrane potential decline, reactive oxygen species increase, and apoptosis increase in hepatocytes. In addition, the levels of Bax, Cleaved Caspase-3 and cytoplasmic Cytochrome C decreased during this process, whereas those of Bcl-2 and mitochondrial Cytochrome C increased. Therefore, TGP might decrease hepatocyte apoptosis through the mitochondrial apoptotic pathway. Moreover, the maturation of bone marrow dendritic cells was also inhibited by TGP treatment. In conclusion, TGP treatment ameliorates AIH by regulating hepatocyte apoptosis and DC maturation. TGP is a potential compound for AIH treatment.

Critical roles of conventional dendritic cells in autoimmune hepatitis via autophagy regulation

Autoimmune hepatitis (AIH) is a necroinflammatory disease associated with interactive cell populations of the innate and adaptive immune systems. The contribution of conventional dendritic cells (cDCs) to AIH and the underlying mechanism remain poorly understood. The frequency of peripheral mature cDCs increased in AIH patients and was positively correlated with disease severity. In experimental autoimmune hepatitis (EAH), hepatic accumulation of mature cDCs was observed, along with an increase in the periphery. Sequentially, bone marrow-derived dendritic cells (BMDC) from EAH mice exhibit more proinflammatory function than those from control mice. In vitro, ConA treatment promotes the maturation of BMDCs, which are characterized by higher expression of MHC-II, costimulatory molecules and cytokine secretion. ConA also induced the expression of autophagy-related protein and the formation of autophagosomes in DCs. To further investigate whether ConA-induced DC activation is associated with autophagy, we utilized 3-MA and bafilomycin A1 to block autophagy flux and accessed the maturation and function of DCs induced by ConA. 3-MA and bafilomycin A1 inhibited the mature status and proinflammatory cytokine secretion and diminished the proliferation and differentiation of CD4+ T cells when ConA-induced BMDCs cocultured CD4+ T cells. We demonstrated that cDCs contribute to the pathogenesis of AIH through excessive maturation. Aberrant autophagy flux plays a vital role in the immunogenic maturation of cDCs in AIH, and tolerogenic cDCs by inhibition of autophagy flux can be exploited as a new therapeutic approach for AIH.

Demethyleneberberine attenuates concanavalin A-induced autoimmune hepatitis in mice through inhibition of NF-κB and MAPK signaling

Demethyleneberberine (DMB) is a natural product which has been reported to possess mitochondria-targeting anti-oxidative and anti-inflammatory effect. However, the pharmacological action and molecular mechanism of DMB on autoimmune hepatitis (AIH) have not been explored. In this study, AIH was induced by intravenously injecting Con A (20 mg/kg) in mice for 8 h, and DMB protected against Con A-induced AIH, evidenced by obvious reduction of hepatic enzymes in serum and histological lesion. DMB significantly inhibited the infiltration of CD4⁺ T cell and Kupffer cell as well as the expression of inflammatory cytokines, such as TNF-α, IL-6, IL-1β and IFN-γ by ELISA and qPCR analysis. Western blotting analysis illustrated that DMB remarkably inhibited Con A-induced phosphorylation of IKK, IκB, NF-κB p65, ERK, JNK, p38 MAPK and STAT3 induced by Con A. Moreover, DMB also effectively suppressed hepatic oxidative stress with reduction of MDA and elevation of GSH. Taken together, our findings indicated that DMB could prevent Con A-induced AIH by regulating NF-κB and MAPK signaling, suggesting that DMB can serve as a promising candidate for therapy of AIH.

Plasma proteomic analysis of autoimmune hepatitis in an improved AIH mouse model

Background

The prevalence of autoimmune hepatitis (AIH) is increasing, and its early clinical diagnosis is difficult. The pathogenesis of AIH remains unclear, and AIH-related studies are largely limited because of lack of suitable mouse models.

Methods

To obtain a good tool for research on AIH, we first established an improved immune-mediated mouse model that can mimic the pathological process of AIH as in the human body, through repeated injections of human cytochrome P450 2D6 (CYP2D6) plasmid. Next, a proteomic analysis based on isobaric tag (IBT) technology was performed to detect the differentially expressed proteins (DEPs), and related biological functions and pathways in the plasma of AIH and normal mice. Finally, we performed enzyme-linked immunosorbent assay (ELISA) to further confirm the most abundant DEP in the plasma of patients with AIH.

Results

Autoantibodies and the characteristic pathology of AIH were observed in our mouse model. Inflammatory infiltration also increased in the livers of AIH mice over time and plateaued by day 42 post the first injection. Chronic hepatitis was most severe on day 35 with the development of fibrosis as well, and the plasma of AIH mice were collected for proteomic analysis. A total of 176 DEPs were found in this experiment, of which 148 DEPs were up-regulated and 28 DEPs were down-regulated. Thirty significant Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways (P < 0.05) were detected. Arginine biosynthesis was found to be the most significant pathway involved in the AIH process. During the Gene Ontology (GO) analysis, most DEPs were found to be involved in the binding, cellular, and metabolic processes. Using ELISA, the most overexpressed DEP, serum amyloid A 1 (SAA1), was confirmed to be increased specifically in the plasma of patients with AIH compared to other chronic hepatitis. Different plasma levels of SAA1 were also found related to different grades of inflammation and stages of fibrosis in the liver of patients with AIH.

Conclusions

Our study is the first to describe the proteomics analysis of a true sense of AIH mouse model, which is beneficial for a better understanding of AIH pathogenesis and identifying potential biomarkers for its clinical diagnosis.

Characterization and functional prediction of the microRNAs differentially expressed in a mouse model of concanavalin A-induced autoimmune hepatitis

In order to investigate the altered expression of microRNAs (miRNAs) in the development of autoimmune hepatitis (AIH), the aberrantly expressed miRNAs in the concanavalin A (Con A)-induced AIH mouse model were identified for the first time with microarray in this study. A total of 49 miRNAs (31 up- and 18 down-regulated) were screened out, and the qRT-PCR validation results of 12 chosen miRNAs were consistent with the microarray data. Combined with the profiling of differently expressed mRNAs in the same model (data not shown), 959 predicted target genes (601 for up- and 358 for down-regulated miRNAs) were obtained according to the intersection of databases miRWalk and miRDB, and several hub genes were obtained from the regulatory networks, including Cadm1 and Mier3. These target genes were significantly enriched in the Gene ontology (GO) terms of "transcription, DNA-templated", and were annotated in 47 signaling pathways, comprising "Wnt signaling pathway", "Hippo signaling pathway", "Ferroptosis" and "mitogen-activated protein kinase (MAPK) signaling pathway", according to the GO and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. In the miRNA-GO-network, mmu-miR-193b-3p were exhibited in 33 GO terms of biological processes (BP), and the most significantly regulated GO term in BP categories was "regulation of transcription, DNA-templated". While in the miRNA-pathway-network, mmu-miR-7005-5p were enriched in 37 pathways, which was more than the other specifically expressed miRNAs, and the most significantly enriched pathways were "Endocytosis" and "MAPK signaling pathway". In conclusion, these differently expressed miRNAs seemed to be associated with the onset of AIH, and have the potential to serve as the new targets on the treatment of this disease.

Chemical induced inflammation of the liver breaks tolerance and results in autoimmune hepatitis in Balb/c mice

Autoimmune hepatitis (AIH) is a chronic liver disease mediated by immunity, and could lead to liver fibrosis and hepatocellular carcinoma. However, the mechanisms for breaking hepatic tolerance and driving AIH still remain elusive. We herein reported that the non-specific liver inflammation triggered by carbon tetrachloride (CCl₄) recruited high numbers of CD4+T, CD8+T and B cells, and elevated the expression of proinflammaitory cytokines in Balb/c mice, further breaking liver tolerance and inducing autoimmune response, AIH inflammation and liver fibrosis in the presence of CYP2D6 antigen mimicry. In contrast, adenovirus infection could not break liver tolerance and induce AIH in Balb/c mice even in the presence of CYP2D6 antigen mimicry. These results suggested that genetic predisposition could determine liver tolerance in Balb/c mice. The chemical induced inflammation in the liver breaks tolerance and might be considered important for the initiation and development of AIH in Balb/c mice.

Autoimmune Hepatitis-Immunologically Triggered Liver Pathogenesis-Diagnostic and Therapeutic Strategies

Autoimmune hepatitis (AIH) is a severe liver disease that arises in genetically predisposed male and female individuals worldwide. Diagnosis of AIH is made clinically applying diagnostic scores; however, the heterotopic disease phenotype often makes a rapid determination of disease challenging. AIH responds favorably to steroids and pharmacologic immunosuppression, and liver transplantation is only necessary in cases with acute liver failure or end-stage liver cirrhosis. Recurrence or development of de novo AIH after transplantation is possible, and treatment is similar to standard AIH therapy. Current experimental investigations of T cell-mediated autoimmune pathways and analysis of changes within the intestinal microbiome might advance our knowledge on the pathogenesis of AIH and trigger a spark of hope for novel therapeutic strategies.

Recurrence of disease following organ transplantation in autoimmune liver disease and systemic lupus erythematosus

Disease recurrence after organ transplantation associated with graft failure is a major clinical challenge in autoimmune diseases. Primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC) and autoimmune Hepatitis (AIH) are the three most common (autoimmune liver diseases) ALD for which liver transplantation (LT) is the most effective treatment option for patients with end-stage diseases. Although the 5- and 10-year survival rates of post-LT patients are remarkable (80-84% and 71-79% in PBC, 73-87% and 58-83% in PSC, 76-79% and 67-77% respectively in AIH patients), post-LT disease recurrence is not uncommon. Here, we summarize literature findings on disease recurrence of these ALD with emphasis on the incidence, risk factors and impact on long-term outcome. We noted that the incidence of disease recurrence varies between studies, which ranges from 53% to 10.9% in PBC, 8.2% to 44.7% in PSC and 7% to 42% in AIH. The variations are likely due to differences in study design, such as sample size, duration of studies and follow up time. This is further compounded by the lack of precise clinical diagnosis criteria and biomarkers of disease recurrence in these ALD, variation in post-LT treatment protocols to prevent disease recurrence and a multitude of risk factors associated with these ALD. While recurrence of PBC and AIH does not significantly impact long term outcome including overall survival, recurrent PSC patients often require another LT. Renal transplantation, like LT, is the treatment of choice in patients with end-stage lupus nephritis. While calcineurin inhibitor (CNI) and immunosuppressive drugs have improved the survival rate, post-transplant recurrence of lupus nephritis from surveillance-biopsy proven lupus nephritis range from 30% to 44%. On the other hand, recurrence of post-transplant lupus nephritis from registry survey analysis were only 1.1% to 2.4%. In general, risk factors associated with an increased frequency of post-transplant recurrence of autoimmune diseases are not clearly defined. Large scale multi-center studies are needed to further define guidelines for the diagnosis and clinical management to minimize disease recurrence and improve outcomes of post-transplant patients.

Association of Autoimmune Hepatitis and Cardiovascular Disease

BACKGROUND

Autoimmune Hepatitis is a chronic liver disease while Cardiovascular Disease is seen in inflammatory states. This study sought to determine if Cardiovascular Disease was associated with Autoimmune Hepatitis.

METHODS

The National Inpatient Sample selected patients with a primary diagnosis of Autoimmune Hepatitis and secondary diagnosis of Cardiovascular Disease in 2014. The primary outcome was the association of Autoimmune Hepatitis with Cardiovascular Disease. Secondary outcomes evaluated the hospital burden with Cardiovascular Disease.

RESULTS

16,375 patients with Autoimmune Hepatitis were included in the study. There was a decreased association between Autoimmune Hepatitis and Cardiovascular Disease (aOR 0.77, 95% CI 0.69-0.85, p < 0.00), Coronary Artery Disease, (aOR 0.75, 95% CI 0.67-0.85, p < 0.00), and Peripheral Vascular Disease (aOR 0.75, 95% CI 0.60-0.93, p = 0.01). Moreover, Coronary Artery Disease comprises 84% of the overall Cardiovascular Disease cohort and did not demonstrate significantly increased length of stay (aOR -0.53, 95% CI -1.16 to 0.12, p = 0.11) or hospitalization cost (aOR -6711, 95% CI -14336 to 912, p = 0.08).

DISCUSSION

The decreased association between Autoimmune Hepatitis and Cardiovascular Disease is likely multifactorial in etiology. Consequently, this observation requires further examination with prospective trials.

Noninvasive inflammatory markers for assessing liver fibrosis stage in autoimmune hepatitis patients

OBJECTIVE

To examine the accuracy of noninvasive inflammatory markers in predicting liver fibrosis stage in patients with autoimmune hepatitis (AIH).

PATIENTS AND METHODS

We enrolled 55 patients with AIH and 60 healthy controls in this study, and divided them into three groups: F0 (control); F1-F3 (noncirrhotic fibrosis); and F4 (cirrhosis). The following markers were analyzed for all participants: lymphocyte-to-neutrophil ratio (LNR); lymphocyte-to-platelet ratio (LPR); lymphocyte-to-monocyte ratio (LMR); immunoglobulin-to-platelet ratio (IGPR); aminotransferase-to-platelet ratio index (APRI); aspartate aminotransferase-to-alanine aminotransferase ratio (AAR); and fibrosis-4 score (FIB-4). The predictive accuracy of these noninvasive markers was assessed using area under the receiver operating characteristic curve. Multivariate ordinal logistic regression models were used to analyze associations between the noninvasive markers and liver fibrosis stage.

RESULTS

AAR, LPR, LMR, IGPR, APRI, and FIB-4 were linked to liver fibrosis-stage (P < 0.05), with correlation indices of - 0.219, 0.258, - 0.149, 0.647, 0.841, and 0.704, respectively, but not LNR (P = 0.093). area under the receiver operating characteristic curves of LPR, IGPR, AAR, LMR, APRI, and FIB-4 for detecting cirrhosis (F4 vs. F0-F3) were 0.936 (95% confidence interval: 0.870-1.000, P < 0.001), 0.939 (0.875-1.000, P < 0.001), 0.528 (0.319-0.738, P = 0.768), 0.555 (0.409-0.700, P = 0.568), 0.798 (0.694-0.902, P = 0.002), and 0.881 (0.796-0.967, P < 0.001). Our multivariate ordinal regression analysis showed that LPR and IGPR were associated independently with liver fibrosis stage, with a coefficient of 0.385 (95% confidence interval: 0.103-0.667, P = 0.007) and 14.903 (2.091-27.786, P = 0.023), respectively.

CONCLUSION

LPR and IGPR were associated independently with liver fibrosis stage in treatment-naive AIH, and were superior to APRI and FIB-4 in detecting cirrhosis.

The Contribution of B Cells in Autoimmune Liver Diseases

Autoreactive B cells can promote autoimmunity through antigen presentation to autoreactive T cells, production of autoantibodies, generation of cytokines promoting T cell activation and differentiation, and inhibition of regulatory T cells and B cells. Here, the authors highlight studies pertaining to B cell mechanisms associated with disease pathogenesis and outcomes in autoimmune hepatitis and the immune-mediated cholangiopathies (primary biliary cholangitis, primary sclerosing cholangitis, and biliary atresia). The vast majority of investigations focus on autoantibodies and future research endeavors should include deciphering the role of the B cell in T cell activation (through antigen presentation, cytokine/chemokine production, and inhibition of regulation). Targeting B cell mechanisms in the treatment of autoimmune liver diseases is also highlighted.

Methylprednisolone Decreases Mitochondria-Mediated Apoptosis and Autophagy Dysfunction in Hepatocytes of Experimental Autoimmune Hepatitis Model via the Akt/mTOR Signaling

Autoimmune hepatitis (AIH) is characterized by massive immune cell-mediated hepatocyte destruction. Glucocorticoids, particularly methylprednisolone (MP), are the most effective treatment for AIH; however, the mechanism underlying the effects of glucocorticoid treatment has not been fully elucidated. The present study explored the effects of MP on damaged hepatocytes in mice with concanavalin A (ConA)-induced experimental autoimmune hepatitis (EAH). C57BL/6 mice were divided into three groups: a normal control group (injected with normal saline), a ConA (20 mg/kg) group, and a ConA + MP (3.12 mg/kg) group. The serum levels of liver enzymes, cytokines, activated T cells, and apoptosis- and autophagy-associated marker proteins were determined 12 h after ConA injection. Human hepatocyte cell line LO2 was used to verify the effects of ConA and MP in vitro. MP treatment significantly decreased inflammatory reactions in the serum and liver tissues and activated the Akt/mTOR signaling pathway to inhibit apoptosis and autophagy in hepatocytes in vivo. Transmission electron microscopy (TEM) revealed fewer autophagosomes in the MP-treated group than in the ConA-treated group. MP treatment obviously suppressed apoptosis and mitochondrial membrane potential (ΔΨm) loss in hepatocytes in vitro. Furthermore, ConA treatment increased the levels of LC3-II, p62/SQSTM1, and Beclin-1, while bafilomycin A1 did not augment the levels of LC3-II. MP treatment decreased the levels of LC3-II, p62/SQSTM1, and Beclin-1 and upregulated the levels of phosphorylated (p)-Akt and p-mTOR. In conclusion, MP ameliorated mitochondria-mediated apoptosis and autophagy dysfunction in ConA-induced hepatocyte injury in vivo and in vitro via the Akt/mTOR signaling pathway.

Plasmacytoid dendritic cells protect against immune-mediated acute liver injury via IL-35

Acute liver failure (ALF) is a life-threatening condition, and liver transplantation is the only therapeutic option. Although immune dysregulation is central to its pathogenesis, the precise mechanism remains unclear. Here, we show that the number of peripheral and hepatic plasmacytoid DCs (pDCs) decrease during acute liver injury in both humans and mice. Selective depletion of pDCs in Siglechdtr/+ mice exacerbated concanavalin A-induced acute liver injury. In contrast, adoptively transferred BM-derived pDCs preferentially accumulated in the inflamed liver and protected against liver injury. This protective effect was independent of TLR7 and TLR9 signaling, since a similar effect occurred following transfer of MyD88-deficient pDCs. Alternatively, we found an unexpected immunosuppressive role of pDCs in an IL-35-dependent manner. Both Il12a and Ebi3, heterodimeric components of IL-35, were highly expressed in transferred pDCs and CD4+CD25+ Tregs. However, the protective effect of pDC transfer was completely lost in mice depleted of Tregs by anti-CD25 antibody. Moreover, pDCs derived from IL-35-deficient mice had less of a protective effect both in vivo and in vitro even in the presence of Tregs. These results highlight a unique aspect of pDCs in association with Tregs, serving as a guide for immunotherapeutic options in ALF.

Comparison of mycophenolate mofetil with standard treatment for autoimmune hepatitis: a meta-analysis

OBJECTIVE

To systematically evaluate the efficacy of mycophenolate mofetil (MMF) compared with the standard treatment for autoimmune hepatitis.

METHODS

Medline (PubMed), Embase, and Cochrane Library databases were searched between 1966 and June 2018 for studies on prednisone and/or azathioprine/mycophenolate mofetil in autoimmune hepatitis. The keywords and descriptor terms used were 'hepatitis', 'autoimmunity', 'prednisone', 'prednisolone', 'azathioprine', and 'mycophenolate mofetil'. The Z test and Cochrane Q test were used in the statistical analysis.

RESULTS

Seven hundred and eighty-eight related articles were found; 779 studies were excluded after further review. Ultimately, seven studies (583 participants) were included. The remission rate of aminotransferase and immunoglobulin (Ig)-G levels with standard treatment was 33.33-86.67%, and the nonresponse rate was 15.15-66.67%. Although the remission rate of the aminotransferase level with prednisone and MMF was 55.17-88.89% and that of the IgG level was 61.16-88.89%, the nonresponse rate was 6.42-33.33%. Remission rates of the aminotransferase level (P<0.05, I=49%) and IgG level (P<0.01, I=0) with MMF were superior to those of standard treatment, and the nonresponse rate was lower (P<0.01, I=0). For those with no response to the standard treatment who were switched to MMF, the remission rates were 0, 13.33, 22.22, 25, and 34.04%. Sequential treatment with MMF was effective (P<0.01, I=90%).

CONCLUSION

Compared with the standard treatment, the combination of prednisone and MMF as a first-line treatment enables patients with autoimmune hepatitis to obtain higher remission rates of aminotransferase and IgG levels and a lower nonresponse rate. The validity and safety of long-term MMF use needs investigated further.

Autoimmune hepatitis in patients with multiple sclerosis: The role of immunomodulatory treatment

BACKGROUND

Development of autoimmune hepatitis (AIH) has been sporadically reported in patients with multiple sclerosis (MS) either concurrently or after treatment with immunomodulatory drugs, including interferon-beta (IFN-β) and steroids.

AIM

To report a large cohort of 14 patients with MS diagnosed with AIH during an assessment of deranged liver function tests (LFTs).

PATIENTS AND METHODS

From 2005 to 2017, we prospectively identified 14 (13 women) patients with MS who suffered also from AIH after investigation in our department for the presence of deranged LFTs. Age at diagnosis of MS was 36.7 ± 9.3 years while at diagnosis of AIH 43.1 ± 12 years.

RESULTS

AIH diagnosis was based on elevation of aminotransferases in all patients [alanine aminotransferase: 520 IU/L (range: 115-1219)], elevation of IgG in 6, compatible autoantibody profile in all, including 5 patients with liver-specific autoantibodies and typical or compatible histological features in 11 patients. 5 patients were under treatment with IFN-β plus methylprednisolone pulses, 3 with IFN-β plus oral steroids, 1 with IFN-β, 4 with methylprednisolone pulses whereas 1 patient was free of treatment. The median time from IFN-β initiation to the development of hepatitis was 12 months (range:1-120). Treatment for AIH was initiated in 13 patients with prednisolone (0.5-1 mg/kg/day) plus mycophenolate myfetil (2 g/day) in 10 and prednisolone plus azathioprine in 3 with complete and partial response in 11 and 2 patients, respectively.

CONCLUSIONS

The differential diagnosis of hepatitis in MS patients should include AIH and in particular when immunomodulatory treatment has been preceded. Autoantibody testing and liver histology play fundamental role in establishing a prompt diagnosis of AIH in these patients. Treatment of AIH in patients with MS seems safe and efficient as complete or partial response was recorded in all of our patients.

Autoimmune liver disease following acute hepatitis A infection

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

Rheumatologie und Hepatologie: Diagnostik und Therapie von autoimmunen Lebererkrankungen

Unter autoimmunen Lebererkrankungen werden im klassischen Sinne 3 verschiedene Entitäten, die Autoimmune Hepatitis (AIH), die Primär biliäre Cholangitis (PBC) und die Primär sklerosierende Cholangitis (PSC) verstanden. Der nachfolgende Übersichtartikel fokusiert auf die Diagnostik und die Therapie dieser 3 autoimmunen Lebererkrankungen und gibt eine Übersicht zu möglichen zusätzlich assoziierten Autoimmunerkrankungen.

Emerging novel treatments for autoimmune liver diseases

The etiology of autoimmune liver diseases, such as autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC), still remains largely unknown and no therapeutic agents that are able to "cure" these diseases have been developed. Although corticosteroids for AIH and ursodeoxycholic acid for PBC have been shown to significantly improve liver transplantation (LT)-free survival and are recommended as first-line drugs, treatment strategies for patients who show incomplete response to these drugs have not yet been fully established. No drug is significantly associated with long LT-free survival in PSC patients. Nevertheless, with progress in genetics, immunology, and cellular biology, several new compounds or antibodies are expected to have an effect on autoimmune liver diseases and several drugs are under consideration for clinical use. Although most clinical trials have been carried out in the USA or Europe, some are, or will be, undertaken in Japan in the future. In this review, the current standard-of-care of autoimmune liver diseases will be summarized, together with emerging novel treatments relevant to clinical practice in Japan.

Racial disparities in presentation and outcomes of paediatric autoimmune hepatitis

BACKGROUND & AIMS

Most studies on autoimmune hepatitis (AIH) in children are in predominantly Caucasian cohorts. Paediatric AIH in African Americans (AA) is understudied, with a dearth of clinical predictors of outcome, often leading to serious complications and even mortality. The aim of the study was to define disease presentation, progression, response to therapy and outcomes in paediatric AIH in a well-defined, large, single centre, demographically diverse population.

METHODS

We conducted a review of patients with AIH who were followed at this tertiary liver transplant centre. Clinical and laboratory covariates were assessed with regard to disease presentation, progression and outcomes in AA vs Non-AA children.

RESULTS

African Americans patients constituted 42% of this cohort. At 1-year follow-up, AA children were receiving significantly higher doses of steroids compared to non-AA. More AA presented with end-stage liver disease (ESLD) with high immunoglobulin G and GGT:platelet ratio. After adjusting for other risk factor variables like gender, age at presentation and ESLD, AA children were at 4.5 times higher risk for significant outcome liver transplant/death within the first 12 months of presentation. Post-transplant, recurrent AIH was seen in 50% of AA vs 8% in non-AA.

CONCLUSIONS

African American patients with AIH are more likely to present with ESLD and have an increased early risk for transplantation with high likelihood of disease recurrence post-transplantation. Studies are needed to delineate factors such as inherent biology, genetics and access to care. Early referral and tailored immunosuppressive regimens are required for AA patients with AIH.

[Severe acquired marrow aplasia and seronegative autoimmune hepatitis: a rare and serious association]

Les aplasies médullaires post hépatitiques sont des aplasies sévères survenant dans les 6 mois suivant au moins un épisode d'hépatite clinique d'installation rapide généralement séronégative pour les virus d'hépatite connus. Nous rapportons le cas d'un patient de 28 ans présentant une hépatite auto-immune révélée par un ictère avec hépatomégalie et cytolyse hépatique et confirmée par une ponction biopsie hépatique; se compliquant 4 mois plutard par l'apparition d'une pancytopénie liée à une aplasie médullaire sévère.

Type 2 Innate Lymphoid Cells in Liver and Gut: From Current Knowledge to Future Perspectives

Innate lymphoid cells (ILCs) represent a heterogeneous population of recently discovered immune cells that mirror the functions of adaptive T lymphocytes. However, ILCs are devoid of specific antigen receptors and cellular activation depends on environmental cytokines, rendering them as early regulators of immune responses. Type 2 innate lymphoid cells (ILC2s) respond to alarmins, such as interleukin-25 and -33 and shape Th2-associated immunity by expressing IL-5 and IL-13 in a GATA3-dependent manner. In addition, ILC2s express the epidermal growth factor-like molecule Amphiregulin thereby promoting regeneration of injured tissue during inflammation. The gut and liver confer nutrient metabolism and bidirectional exchange of products, known as the gut-liver axis. Accordingly, both organs are continuously exposed to a large variety of harmless antigens. This requires avoidance of immunity, which is established by a tolerogenic environment in the gut and liver. However, dysregulations within the one organ are assumed to influence vitality of the other and frequently promote chronic inflammatory settings with poor prognosis. Intensive research within the last years has revealed that ILC2s are involved in acute and chronic inflammatory settings of gut and liver. Here, we highlight the roles of ILC2s in intestinal and hepatic inflammation and discuss a regulatory potential.

NUDT15 Polymorphism Confer Increased Susceptibility to Thiopurine-Induced Leukopenia in Patients With Autoimmune Hepatitis and Related Cirrhosis

The aim of this study was to investigate the influence of NUDT15 R139C and thiopurine S-methyltransferase (TPMT) on azathioprine (AZA) induced leukopenia in patients with autoimmune hepatitis (AIH) and related cirrhosis. A total of 149 Chinese AIH patients with a history of AZA treatment were retrospectively evaluated. The clinical and epidemiological characteristics of the patients were obtained from an electronic database and reviewed. NUDT15 (rs116855232) and TPMT^∗3C (rs1142345) SNPs were genotyped using a PCR method. Twelve patients developed leukopenia, and this adverse drug reaction was significantly associated with the T risk allele in NUDT15 [P < 0.00001, odds ratio = 20.41; 95% confidence interval (CI) (7.84, 53.13)], with the sensitivity and specificity of 91.67 and 89.05%, respectively. The median maintenance dosages for patients with the rs116855232 CC and CT genotypes were 1.23 (0.95, 1.53) mg ⋅ kg⁻¹ ⋅ d⁻¹ and 0.96 (0.83, 1.19) mg ⋅ kg⁻¹ ⋅ d⁻¹, respectively (P = 0.028). In contrast, no significant association was observed for TPMT^∗3C genotypes. Notably, subgroup analysis of the 13 patients with leukopenia before therapy, these white blood cell (WBC) counts did not show further reduction after AZA treatment and maintenance dosage was 1.13 (0.94, 1.60) mg ⋅ kg⁻¹ ⋅ d⁻¹. Therefore, NUDT15 polymorphism is significantly associated with thiopurine-induced leukopenia in Chinese patients with AIH and related cirrhosis. Adjusting the AZA dosage should be considered in patients according to the NUDT15 R139C genotypes.

High seroprevalence of anti-Hepatitis E antibodies in Austrian patients with autoimmune hepatitis

BACKGROUND & AIMS

Increasing numbers of autochthonous hepatitis E virus infections have been reported in Europe. Chronic infections have been shown in immune-compromised patients after solid organ transplantation. Hepatitis E virus might be a possible trigger for autoimmune hepatitis and might cause disease flares or relapses in the further course of disease. Aim of this study was to investigate the presence of hepatitis E virus antibodies and hepatitis E virus RNA, and to analyse their impact on immunosuppressive treatment in patients with autoimmune hepatitis.

METHODS

Sera from 92 autoimmune hepatitis patients (73/79.3% female, age: 42.2 ± 16.3 years [mean ± SD]) were tested. Patients were scored according to the simplified and revised scoring systems of the International Autoimmune Hepatitis Group. The prevalence of anti- hepatitis E virus antibodies (Beijing Wantai Biological Pharmacy Enterprises Co., Ltd, Beijing, China) and hepatitis E virus RNA was determined.

RESULTS

19/20.7% autoimmune hepatitis patients tested positive for hepatitis E virus-IgG, which was higher than in previous reports of healthy Austrian individuals (12.4%, P = 0.031); hepatitis E virus RNA was not detectable in any patient. Anti-hepatitis E virus positive patients were older (49.5 ± 9.5 vs 40.4 ± 17.2 years [mean ± SD], P = 0.033) but did not differ in laboratory findings at diagnosis (AST: 14.6 [1.3-70.6] vs 9.5 [0.7-62.7] × ULN [median/range]; P = 0.387, alanine aminotransferase: 18.3 [1.6-62.7] vs. 12.9 [0.8-62.6] × ULN; P = 0.511; IgG: 1.4 [1.0-2.5] vs 1.3 [0.6-3.8] g/dL × ULN; P = 0.278) nor in alanine aminotransferase levels after six months (0.7 [0.5-2.4] vs 1.0 U/L × ULN [0.1-22.4]; P = 0.077).

CONCLUSIONS

No chronic hepatitis E virus infection was observed in our cohort of autoimmune hepatitis patients. Anti- hepatitis E virus-IgG positive patients were older and the seroprevalence was nearly twice as high as reported previously in healthy Austrian individuals, suggesting that hepatitis E virus-infection might act as trigger for the development of autoimmune hepatitis.

Hepatocellular carcinoma in patients with autoimmune hepatitis - a systematic review of the literature published between 1989-2016

BACKGROUND AND AIMS

Liver cancer is one of the most common cause of deaths from cancer. Hepatocellular carcinoma (HCC) was reported at a frequency of 7% of patients with autoimmune hepatitis (AIH) - related cirrhosis in 1988. We aimed to provide a systematic literature review on the frequency of HCC in patients with AIH, after the discovery of hepatitis C virus (HCV), in order to avoid any possible confounding etiology.

METHODS

A literature search of the PubMed database between 1989-2016 was performed, using the relevant keywords "hepatocellular carcinoma" and "autoimmune hepatitis". We followed the PRISMA statement guidelines during the preparation of this review.

RESULTS

Eleven studies (n=8,460 patients with AIH) were retained for the final analysis. HCC was diagnosed in 0-12.3% of the AIH patients included in these studies. The overall occurrence of HCC in patients with AIH was estimated in two studies, at 5.1% and 6.2%, respectively. In patients with AIH and cirrhosis, the percentage of HCC varied between 0.2%-12.3%. The proportion of HCC in patients with AIH without cirrhosis was estimated at 1.03%. The percentage of cirrhosis in AIH patients varied from 18.7% to 83.3% in Japan, and from 12% to 50.2% in the other areas. The mean follow-up of the patients with AIH was of 10 years.

CONCLUSIONS

The development of HCC in patients with AIH appeared to be similar before and after the discovery of HCV, and it was mainly associated to cirrhosis. The number of patients developing cirrhosis in relation with AIH was impressive. The long evolution of AIH to cirrhosis and, eventually, to HCC, has been be suggested.

Association of CARD10 rs6000782 and TNF rs1799724 variants with paediatric-onset autoimmune hepatitis

Although the pathogenesis of paediatric-onset autoimmune hepatitis (pAIH) remains incompletely understood, genetic variants and environmental factors are known to be involved. Caspase recruitment domain family member 10 (CARD10) is a scaffold protein that participates in a complex pathway activating nuclear factor kappa-B (NFκB) and tumour necrosis factor alpha (TNF-α). This study aimed to investigate the association of CARD10 rs6000782 (g.37928186A > C) and TNF gene promoter rs1799724 (c.-1037C > T) variants with pAIH susceptibility in a cohort of Egyptian children. The research was also extended to assess the relationship of these variants with levels of NFκB-p65 and TNF-α. Fifty-six pAIH patients and 44 age- and sex-matched healthy controls were included. Variant genotyping was performed by polymerase chain reaction (PCR). Serum NFκB-p65 and TNF-α levels were measured using enzyme-linked immunosorbent assays (ELISAs). rs6000782 C and rs1799724 T alleles, separate or in combination, were significantly increased in pAIH patients compared to controls. Serum levels of NFκB-p65 and TNF-α were higher in pAIH differentiating both groups. Moreover, the recessive model of rs6000782 revealed a significant association with the levels of both NFκB-p65 and TNF-α. In conclusion, rs6000782 and rs1799724 variants are potential genetic risk factors for pAIH predisposition, with the former affecting NFκB-p65 and TNF-α levels. Overall, the inflammatory cascade was associated with the degree of liver cell destruction. Clinically, screening and genetic counselling are recommended for relatives of pAIH patients.

Extrahepatic autoimmune diseases in patients with autoimmune hepatitis and their relatives: A Danish nationwide cohort study

BACKGROUND & AIMS

It is widely accepted that patients with autoimmune hepatitis have an increased prevalence of extrahepatic autoimmune diseases. It is believed that the patients' relatives share this trait, but it has not been studied in a satisfactory setting. We conducted a nationwide registry-based cohort study on this issue.

METHODS

From Danish healthcare registries 1994-2015, we included 2745 patients with autoimmune hepatitis, 17 812 of their first- and second-degree relatives and 27 450 general population controls matched with the patients for sex and age. We compared the sex- and age-specific prevalence of extrahepatic autoimmune diseases between the patients with autoimmune hepatitis, their relatives and the controls. We computed the prevalence ratio as a measure of the relative prevalence, using the controls as reference group.

RESULTS

In the patients with autoimmune hepatitis, the prevalence ratio of extrahepatic autoimmune diseases ranged from 7 to 10 until age 30 years (prevalence ratio at age 20 = 9.92; 95% confidence interval 6.21-15.83), after which it gradually decreased to about 2 (prevalence ratio at age 80 = 2.37; 95% confidence interval 1.89-3.00). Neither first- nor second-degree relatives had an increased prevalence of extrahepatic autoimmune diseases (prevalence ratio for relatives at age 20 = 1.11; 95% confidence interval 0.72-1.70; prevalence ratio at age 80 = 0.96; 95% confidence interval 0.70-1.31).

CONCLUSIONS

Danish patients with autoimmune hepatitis were highly prone to extrahepatic autoimmune diseases, but their relatives were not.

Editorial: "real world data" of AIH-time to connect!

Linked Content

This article is linked to Liberal et al paper. To view this article visit https://doi.org/10.1111/apt.13907.

Systematic review: diagnostic accuracy of non-invasive tests for staging liver fibrosis in autoimmune hepatitis

BACKGROUND AND AIMS

Non-invasive fibrosis assessment has been highly recommended in many liver diseases. However, comparative diagnostic accuracy of laboratory markers, ultrasound and magnetic resonance elastography (MRE) for fibrosis in autoimmune hepatitis (AIH) patients has not been established.

METHODS

Medline, Embase and Cochrane Library were searched. Primary outcome was significant fibrosis (SF), advanced fibrosis (AF) and cirrhosis, defined as Metavir stage F ≥ 2, F ≥ 3 and F = 4 according to liver biopsy. Hierarchical summary receiver operating characteristic curve (ROC) model was used to evaluate diagnostic accuracy of non-invasive methods. Summary area under ROC (AUROC) and diagnostic odds ratio (DOR) with 95% confidence interval (CI) were calculated. The Grading of Recommendations Assessment, Development and Evaluation system was used to assess quality of evidence.

RESULTS

Overall, 16 studies with 861 patients were included, comparing aspartate aminotransferase to platelet ratio index (APRI), fibrosis-4 index (FIB-4), aspartate aminotransferase/alanine aminotransferase ratio, transient elastography (TE), acoustic radiation force impulse, shear wave elastography and MRE versus liver biopsy. Among all non-invasive markers, TE had good performance for fibrosis staging. Summary AUROCs and DORs of TE were 0.90 (95% CI 0.87, 0.92) and 23.7, 0.91 (95% CI 0.89, 0.93) and 31.6, 0.89 (95% CI 0.86, 0.92) and 80.5 for staging SF, AF and cirrhosis, whereas APRI and FIB-4 showed poor performance for detecting AF (DOR, 4.6 and 4.7) and cirrhosis (DOR, 5.5 and 12.9).

CONCLUSIONS

TE performs well to stage liver fibrosis in patients with AIH, compared with other laboratory non-invasive indexes. Nevertheless, diagnostic accuracy of APRI and FIB-4 is poor.

Inequity of care provision and outcome disparity in autoimmune hepatitis in the United Kingdom

BACKGROUND

Treatment paradigms in autoimmune hepatitis (AIH) have remained largely unchanged for decades. Studies report ≤20% of patients have sub-optimal treatment response with most requiring long-term therapy.

AIM

The United Kingdom Autoimmune Hepatitis (UK-AIH) study was established to evaluate current treatment practice and outcomes, determine the unmet needs of patients, and develop and implement improved treatment approaches.

METHODS

The United Kingdom Autoimmune Hepatitis study is a cross-sectional cohort study examining secondary care management of prevalent adult patients with a clinical diagnosis of autoimmune hepatitis. Enrolment began in March 2014. Prevalent cases were defined as having been diagnosed and treated for >1 year. Demographic data, biochemistry, treatment history and response, and care location were collected.

RESULTS

In total, 1249 patients were recruited; 635 were cared for in transplant units and 614 in non-transplant centres (81% female with median age at diagnosis 50 years). Overall, 29 treatment regimens were reported and biochemical remission rate was 59%. Remission rates were significantly higher in transplant compared to non-transplant centres (62 vs 55%, P = 0.028). 55% have ongoing corticosteroid exposure; 9% are receiving prednisolone monotherapy. Those aged ≤20 years at diagnosis were more likely to develop cirrhosis and place of care was associated with an aggressive disease phenotype.

CONCLUSIONS

There are significant discrepancies in the care received by patients with autoimmune hepatitis in the UK. A high proportion remains on corticosteroids and there is significant treatment variability. Patients receiving care in transplant centres were more likely to achieve and maintain remission. Overall poor remission rates suggest that there are significant unmet therapeutic needs for patients with autoimmune hepatitis.

Family occurrence of autoimmune hepatitis: A Danish nationwide registry-based cohort study

BACKGROUND & AIMS

It is widely believed that autoimmune hepatitis accumulates in families, but the degree of familial clustering has not been clarified. We conducted a population-based study on the family occurrence of autoimmune hepatitis.

METHODS

Through Danish nationwide registries we identified 8,582 first-degree and 9,230 second-degree relatives of index patients diagnosed with autoimmune hepatitis in 1994-2015; and 64 co-twins of index patients diagnosed with autoimmune hepatitis in 1977-2011. For first- and second-degree relatives we calculated the sex- and age-adjusted standardized incidence ratio of autoimmune hepatitis relative to the general population, and we calculated the cumulative risk, i.e. the cumulative incidence, of developing autoimmune hepatitis from the time of the index patient's diagnosis. For co-twins, we estimated the standardized incidence ratio and the concordance rate of autoimmune hepatitis.

RESULTS

In first-degree relatives, there were six incident autoimmune hepatitis diagnoses during 64,020 years of follow-up: the standardized incidence ratio was 4.9 (95% CI 1.8-10.7), and the 10-year cumulative risk was 0.10% (95% CI 0.04-0.23). In the second-degree relatives, there were no incident autoimmune hepatitis diagnoses (expected number assuming incidence rate as in the Danish general population = 0.8). In the co-twins, there was one incident autoimmune hepatitis diagnosis during 1,112 years of follow-up, and the standardized incidence ratio was 53.9 (95% CI 1.4-300.4). The probandwise concordance rate, a measure of heritability, was higher in monozygotic than in dizygotic twins (8.7% [95% CI 1.1-28.0] vs. 0%).

CONCLUSIONS

This nationwide study indicates that only first-degree relatives of index patients with autoimmune hepatitis are at increased risk of autoimmune hepatitis from the time of the index patient's diagnosis, but the absolute risk is very low.

LAY SUMMARY

Autoimmune hepatitis is a chronic liver disease caused by a dysfunctional immune system. It is widely believed that autoimmune hepatitis accumulates in families. We studied the family members of patients with autoimmune hepatitis from the entire Danish population. We found that autoimmune hepatitis does accumulate in families, but the risk of autoimmune hepatitis in the family members is very low.

NLRP3 Inflammasome and IL-33: Novel Players in Sterile Liver Inflammation

In sterile liver inflammation, danger signals are released in response to tissue injury to alert the immune system; e.g., by activation of the NLRP3 inflammasome. Recently, IL-33 has been identified as a novel type of danger signal or “alarmin”, which is released from damaged and necrotic cells. IL-33 is a pleiotropic cytokine that targets a broad range of immune cells and exhibits pro- and anti-inflammatory properties dependent on the disease. This review summarizes the immunomodulatory roles of the NLRP3 inflammasome and IL-33 in sterile liver inflammation and highlights potential therapeutic strategies targeting these pathways in liver disease.

Pregnancy and birth outcomes in a Danish nationwide cohort of women with autoimmune hepatitis and matched population controls

BACKGROUND

Many patients with autoimmune hepatitis are women of fertile age. Some concerns of these patients are related to pregnancy.

AIM

To conduct a nationwide study on risk of miscarriage, birth rate, and birth outcomes in women with autoimmune hepatitis.

METHODS

From Danish healthcare registries, 1994-2015, we identified 179 births in 103 women with autoimmune hepatitis, 70 of which were first-time singleton births, and 1623 births in 1051 age-matched women (population controls), 662 of which were first-time singleton births. We calculated the risk of miscarriage and the birth rate after autoimmune hepatitis diagnosis in women with autoimmune hepatitis and controls. We used logistic regression to compare the odds of adverse birth outcomes (preterm birth, small for gestational age, congenital malformations and stillbirth) between women with autoimmune hepatitis and controls, adjusting for maternal age and smoking habits.

RESULTS

The risk of miscarriage was similar in women with autoimmune hepatitis and controls: risk ratio 1.17 (95% confidence interval 0.81-1.68). The first-time birth rate, including singleton and multiple births, per 1000 person-years in women with autoimmune hepatitis was 37 (95% confidence interval 29-46), in controls 32 (95% confidence interval 30-35). Age at first-births was similar in women with autoimmune hepatitis and controls. Women with autoimmune hepatitis had an increased risk of preterm birth (adjusted odds ratio 3.19, 95% confidence interval 1.53-6.64) and small for gestational age babies (adjusted odds ratio = 3.20, 95% confidence interval 0.33-31.29), but not of congenital malformations (adjusted odds ratio = 1.27, 95% confidence interval 0.48-3.34) or stillbirth. Birth outcomes did not differ in autoimmune hepatitis patients on or off immunosuppression, and with or without cirrhosis.

CONCLUSIONS

In Danish women with autoimmune hepatitis, fertility was unaffected. They had an increased risk of preterm birth and small for gestational age children, but not of congenital malformations or stillbirth.

Analysis of Differentially Expressed Proteins Involved in Autoimmune Cirrhosis and Normal Serum by iTRAQ Proteomics

PURPOSE

In order to study the candidate biomarkers in autoimmune cirrhosis (AIC).

EXPERIMENTAL DESIGN

Isobaric tags are first implemented for relative and absolute quantitation technology on proteins prepared from serum obtained from AIC and normal controls. Proteins found to be differentially expressed are identified with liquid chromatography electrospray ionization tandem mass spectrometry by using a Q Exactive classic ion trap mass spectrometer.

RESULTS

108 proteins (32 upregulated and 76 downregulated proteins) are identified from AIC samples, compared with the normal controls. Gene Ontology enrichment analysis, KEGG pathway analysis, and protein-protein interaction map by STRING show that they associate with multiple functional groups, including ion binding activity, peptidase activity, and enzyme regulator activity. Finally, the von Willebrand factor, insulin-like growth factor-binding protein complex acid labile subunit, transthyretin, adiponectin proteins are identified with western blot as candidate biomarkers for AIC.

CONCLUSIONS AND CLINICAL RELEVANCE

These findings offer a comprehensive profile of the AIC proteome about candidate biomarkers and provide a useful basis for further analysis of the pathogenic mechanism of AIC.

Autoimmune Hepatitis in the Elderly: Diagnosis and Pharmacologic Management

Autoimmune hepatitis (AIH) may present as acute or chronic hepatitis in the elderly. Advanced hepatic fibrosis and cirrhosis are common on first presentation in this population. In this review, we discuss the presentation, approach to diagnosis and management of AIH in the elderly. As polypharmacy is common in the elderly, careful medication use history is essential for detecting drug-induced AIH-like hepatitis. Steroid-sparing or minimizing therapeutic regimens are preferred to treat AIH in the elderly. For the purpose of induction, budesonide or lower dose prednisone in combination with azathioprine (AZA) regimens are preferred over high-dose prednisone monotherapy due to the higher risk of side effects of the later in the elderly. The goal of maintenance therapy should be to achieve full biochemical and histologic remission. Bone density monitoring and interventions to prevent steroid-related bone disease should be implemented throughout the course of the disease. Liver transplantation should be considered in the elderly patient with liver failure or early hepatocellular carcinoma if there are no significant comorbidities or compromise in functional status.

Clinical and prognostic implications of acute onset of Autoimmune Hepatitis: An Italian multicentre study

Autoimmune Hepatitis (AIH) can present under clinical profile as acute hepatitis of unexplained cause. We analyzed clinical, therapeutical and prognostic implications of AIH presenting as acute hepatitis in a cohort of patients admitted to 3 referral Centres in Italy. AIH onset was considered acute when transaminases were higher than 10 times the normal limit and/or bilirubin higher than 5 mg/ml (irrespectively from the histology, available only in 62% of cases). Among 479 patients diagnosed as AIH, 202 (43%) met the criteria of acute onset. This former group of patients on the basis of the histology has been subdivided in the "genuine" acute onset (83 pts) and acute "on chronic" onset (45 pts) At onset, clinical acute AIH showed significantly higher ALT, bilirubin and INR levels (p < 0.001 for all), lower albumin values (p = 0.001), similar IgG levels; Response to treatment was similar between the two groups. The progression to liver cirrhosis or its complications was significantly less frequent in acute onset AIH (13% vs. 22%, p = 0.02). The "genuine" acute patients showed a higher albumin serum levels (40 vs. 36, p = 0.001), lower INR levels (1.12 vs. 1.26, p = 0.002) and less tendency to the progression of liver disease (7% vs. 12%, p = NS) with respect to acute "on chronic" onset patients. Clinical acute hepatitis represents a common presentation of AIH, responds to standard immunosuppression regimen and would seem to be correlated with a better long-term prognosis.

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.

Animal models of autoimmune hepatitis

Many animal models for autoimmune hepatitis (AIH) have been described in the past. Most models had to deal with the relative immunosuppressive environment of the liver. Therefore, some models used a combination of several triggering factors often on a susceptible background to generate an aggressive immune response that targets the liver. In addition, in order to be able to track the immune response the models used specific model autoantigens as targets that are either not present or have not been identified as a natural autoantigen in AIH patients. Thereby the feasibility of such models is somewhat questionable. Although many historic approaches included challenges of experimental animals with liver homogenates it was only in the last decade that natural occurring liver autoantigens have been used in animal models. This article reflects on the requirements for breaking liver tolerance and on how an ideal experimental model for AIH would look like. In addition, it discusses historic as well as recent animal models in the context of feasibility of induction, similarity of the clinical outcome to human AIH, and gain of knowledge for possible future therapies.

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.

Deletion of the C6orf120 gene with unknown function ameliorates autoimmune hepatitis induced by concanavalin A

The present study was conducted to characterize the C6orf120 gene, by using C6orf120 gene-deleted rats (C6orf120^-/-), to determine its role in the development and severity of autoimmune hepatitis induced by concanavalin A (Con A), as well as the underlying mechanisms. We found that following Con A injection, C6orf120^-/- rats were less susceptible to developing autoimmune hepatitis with low levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) post challenge. Additionally, C6orf120 deficiency increased the frequency of cluster of differentiation (CD)4⁺ CD25⁺ Forkhead box P3⁺ regulatory T cells (Tregs) among intrahepatic lymphocytes, splenocytes, peripheral blood mononuclear cells, and CD4⁺ T in vitro. Moreover, C6orf120 deficiency downregulated interleukin (IL)-1β, IL-6, tumor necrosis factor alpha-α, interferon-γ and IL-17a secretion in the plasma and liver tissues. Our results indicated that the C6orf120 gene-deleted rats were less susceptible to Con A-induced autoimmune hepatitis, which may be partly related to the increased frequency of Tregs and inhibited secretion of inflammatory cytokines.

Nonviral or Drug-Induced Etiologies of Acute Liver Failure

Acute liver failure (ALF) is a rare but highly fatal condition. The most common causes include drug-induced and viral hepatitis, but other less common etiologies, especially autoimmune hepatitis, Budd-Chiari syndrome, and Wilson disease, need to be considered. Because diagnosis is frequently tied to potential for reversibility of ALF and prognosis, early identification in a timely manner is crucial. Other causes of ALF are more easily recognizable based on specific circumstances, such as ALF in pregnancy or ischemic hepatitis. Ultimately, maintaining a wide differential diagnosis in patients with ALF is essential to identifying the proper treatment and prognosis.

Ultrasound findings in autoimmune hepatitis

Ultrasound findings in autoimmune hepatitis (AIH) have not been reported systematically so far. The use of reliable and accurate noninvasive methods for determining fibrosis stage is important in evaluation of treatment efficacy and fibrosis regression in AIH. Imaging plays an important role in detection of complications and ruling out other possible causes of chronic liver diseases. Ultrasound elastography cut-off values in AIH patients are not the same as those in patients with chronic viral hepatitis or non-alcoholic fatty liver disease. AIH is characterized by wide fluctuations in inflammatory activity. Here we report on current knowledge of ultrasound findings in AIH.

Autoimmune hepatitis

Autoimmune hepatitis (AIH) is a severe liver disease that affects children and adults worldwide. The diagnosis of AIH relies on increased serum transaminase and immunoglobulin G levels, presence of autoantibodies and interface hepatitis on liver histology. AIH arises in genetically predisposed individuals when a trigger, such as exposure to a virus, leads to a T cell-mediated autoimmune response directed against liver autoantigens; this immune response is permitted by inadequate regulatory immune control leading to a loss of tolerance. AIH responds favourably to immunosuppressive treatment, which should be started as soon as the diagnosis is made. Standard regimens include fairly high initial doses of corticosteroids (prednisone or prednisolone), which are tapered gradually as azathioprine is introduced. For those patients who do not respond to standard treatment, second-line drugs should be considered, including mycophenolate mofetil, calcineurin inhibitors, mechanistic target of rapamycin (mTOR) inhibitors and biologic agents, which should be administered only in specialized hepatology centres. Liver transplantation is a life-saving option for those who progress to end-stage liver disease, although AIH can recur or develop de novo after transplantation. In-depth investigation of immune pathways and analysis of changes to the intestinal microbiota should advance our knowledge of the pathogenesis of AIH and lead to novel, tailored and better tolerated therapies.

NOD-Like Receptor Protein 3 Inflammasome-Dependent IL-1β Accelerated ConA-Induced Hepatitis

Autoimmune hepatitis (AIH) is a progressive inflammatory disorders of unknown etiology, characterized by immune-mediated destruction of hepatocytes and massive production of cytokines. Interleukin-1β is a pleiotropic proinflammatory cytokine and well known to be critical in a variety of autoimmune diseases. However, the role of interleukin-1β (IL-1β) in AIH is still indistinct. Here, we first investigated the significance of NOD-like receptor protein 3 (NLRP3) inflammasome-dependent IL-1β in the pathogenesis of AIH with a murine model of immune-mediated hepatitis induced by Concanavalin A (ConA). In ConA-treated mice, pathogenic elevated NLRP3, Cleaved caspase-1 and IL-1β levels, as well as an inflammatory cell death known as pyroptosis predominantly occurred in the livers. Strikingly, NLRP3^−/− and caspase-1^−/− mice were broadly protected from hepatitis as determined by decreased histological liver injury, serum aminotransferase (ALT)/aspartate transaminase levels, and pyroptosis. In vivo intervention with recombinant human interleukin-1 receptor antagonist (rhIL-1Ra) strongly suppressed ConA-induced hepatitis by decreasing tumor necrosis factor-alpha (TNF-α) and interleukin-17 (IL-17) secretion, and inflammatory cell infiltration into livers. Additionally, rhIL-1Ra-pretreated mice developed significantly reduced NLRP3 inflammasome activation and reactive oxygen species (ROS) generation. Scavenging of ROS by N-acetyl-cysteine also attenuated NLRP3 inflammasome activation and liver inflammation, indicating that the essential role of ROS in mediating NLRP3 inflammasome activation in ConA-induced hepatitis. In conclusion, our results demonstrated that NLRP3 inflammasome-dependent IL-1β production was crucial in the pathogenesis of ConA-induced hepatitis, which shed light on the development of promising therapeutic strategies for AIH by blocking NLRP3 inflammasome and IL-1β.