Autoimmune Liver Diseases and Rheumatoid Arthritis-Is There an Etiopathogenic Link?

Rheumatoid arthritis (RA) is a systemic immune-mediated disease that, in addition to the articular involvement, can have extra-articular manifestations. Even though liver damage in RA is not very common, associated autoimmune liver diseases (AILDs) may occur. The most common AILD associated with RA is primary biliary cirrhosis (PBC), followed by autoimmune hepatitis (AIH) and primary sclerosing cholangitis (PSC). There are common underlying mechanisms that play a role in the emergence of autoimmunity and inflammation in both rheumatic and autoimmune liver diseases. Genetic studies have revealed the existence of several common disease-associated genes shared between RA and AILDs, and infectious triggers, particularly those associated with recurrent or complicated urinary tract infections, are also speculated to be potential triggers for these conditions. Moreover, these diseases share common serologic patterns characterized by the presence of specific autoantibodies and hyper-gammaglobulinemia. In this study, we focus on reviewing the association between RA and AILDs regarding the prevalence and possible etiopathogenic link.

[Clinicopathological features of Sjogren's syndrome complicated with liver injury].

Objective: To study the clinicopathological features of Sjogren's syndrome (SS) with liver injury and to improve the understanding of this disease. Methods: Forty-nine patients with SS complicated with liver injury were collected from Beijing Ditan Hospital, Capital Medical University from October 2008 to January 2022. All patients underwent ultrasound-guided liver biopsy, and all specimens were stained with HE. The histopathologic characteristics were observed and the pathologic indexes were graded. Immunohistochemical stains for CK7, CK19, CD38, MUM1 and CD10 were performed by EnVision method; and special histochemical stains for reticulin, Masson's trichrome, Rhodanine, Prussian blue, periodic acid Schiff (PAS) and D-PAS stains were conducted. Results: The age of patients ranged from 31 to 66 years, including 3 males and 46 females. SS combined with drug-induced liver injury was the most common (22 cases, 44.9%), followed by autoimmune liver disease (13 cases, 26.5%, including primary biliary cholangitis in eight cases, autoimmune hepatitis in 3 cases, and PBC-AIH overlap syndrome in 2 cases), non-alcoholic fatty liver disease (NAFLD, 9 cases, 18.4%) and other lesions (5 cases, 10.2%; including 3 cases of nonspecific liver inflammation, 1 case of liver amyloidosis, and 1 case of porto-sinusoidal vascular disease). Among them, 28 cases (57.1%) were associated with obvious interlobular bile duct injury, mainly in SS combined with PBC group and drug-induced liver injury group. Twenty-three cases (46.9%) were associated with hepatocyte steatosis of varying degrees. In SS with autoimmune liver disease group, ISHAK score, degree of fibrosis bile duct injury, bile duct remodeling, lymphocyte infiltration of portal area, and plasma cell infiltration, MUM1 and CD38 expression; serum ALP and GGT, IgM; elevated globulin; positive AMA, proportion of AMA-M2 positive and IgM positive were all significantly higher than those in other groups(all P<0.05). Serum ALT, direct bilirubin and SSA positive ratio in SS combined with drug liver group were significantly higher than those in other groups(all P<0.05). The serum total cholesterol level in SS combined with PBC group (P=0.006) and NALFD group (P=0.011) were significantly higher than those in other groups (P<0.05). Conclusions: The pathologic manifestations of SS patients with liver injury are varied. The inflammatory lesions of SS patients with autoimmune liver disease are the most serious, and the inflammatory lesions of SS patients with non-alcoholic fatty liver disease and non-specific inflammation are mild. Comprehensive analysis of liver histopathologic changes and laboratory findings is helpful for the diagnosis of SS complicated with different types of liver injury.

Unprecedented complexity of six coexisting autoimmune diseases: A case report.

INTRODUCTION: Autoimmune disorders often exhibit interconnectedness, although encountering multiple autoimmune conditions in a single patient is uncommon. Multiple autoimmune syndrome is characterized by the presence of at least three distinct autoimmune diseases in an individual. This report outlines the case of a middle-aged woman diagnosed with autoimmune thyroiditis, Sjögren's syndrome, scleroderma, autoimmune hepatitis, primary biliary cirrhosis, and antisynthetase syndrome. Additionally, it includes a literature review encompassing multiple autoimmune syndromes involving five or more autoimmune diseases. OBSERVATION: A 57-year-old woman, with no previous medical history, presented with fever, extensive muscle weakness, progressive exertional dyspnea, inflammatory polyarthralgia, dysphagia, and dry mouth. Clinical examination revealed muscular deficit in the scapular and pelvic girdles, distal muscular deficit, synovitis in the wrists, and features indicative of "mechanic's hand". Laboratory examinations showed cytolysis, cholestasis, elevated muscle enzymes, hypergammaglobulinemia and elevated thyroid stimulating hormone. Immunoassays showed positive results for antinuclear antibodies, anti-histidyl-t-RNA synthetase, anti-Sjögren's-syndrome-related antigen A, anti-ribonucleic-acid-polymerase-III-RP155, anti-fibrillarin, anti-mitochondrial, anti-liver/kidney microsomal type 1, anti-glycoprotein 210, and anti-thyroid peroxidase antibodies. Further investigations led to the diagnosis of a multiple autoimmune syndrome involving autoimmune thyroiditis, Sjögren's syndrome, scleroderma, autoimmune hepatitis, primary biliary cirrhosis, and antisynthetase syndrome. The patient received treatment with intravenous immunoglobulins, corticosteroids, azathioprine, and ursodeoxycholic acid, which resulted in favorable clinical and biological outcomes. CONCLUSION: This patient presented with six concurrent distinct autoimmune disorders, categorizing this case as a type two multiple autoimmune syndrome. The identification of antisynthetase syndrome notably distinguishes this case.

Management of hepatocellular carcinoma, an important cause of death in Japanese autoimmune hepatitis patients.

BACKGROUND: Hepatocellular carcinoma (HCC) in autoimmune hepatitis (AIH) was considered rare but is increasing with prolonged prognosis. Its impact on the overall prognosis of AIH is unknown, and treatment has not been established. AIM: To investigate the risk factors and prognosis of HCC in patients with AIH and identify appropriate management strategies. METHODS: We studied patients with AIH including background liver disease, sex, age, complications, treatment, response to treatment, liver fibrosis, prognosis, and treatment. RESULTS: In 131 patients, deaths due to liver failure were more common early after the onset of AIH; however, deaths due to HCC increased gradually. HCC was observed in 12 patients (median age, 70 years; male/female, 4/8; cirrhosis at onset, 11; median time to carcinogenesis, 7 years). Cirrhosis at diagnosis was identified as a risk factor for carcinogenesis in the multivariate analysis (odds ratio, 41.36; p < 0.0001) and cumulative cancer rates were high. Multidisciplinary therapy other than immune checkpoint inhibitors was administered as treatment for HCC. Two of the three patients who used molecular-targeted drugs discontinued the treatment because of adverse events. CONCLUSION: HCC is an important cause of death in patients with AIH. Currently available drug therapies are limited and early detection is desirable. TRIAL REGISTRATION: This trial was retrospectively registered in the Ethics Committee of Kagawa University School of Medicine under the identifier 2019 - 238, registered on 4 Feb 2020.

Prevalence of autoimmune thyroiditis among children with autoimmune hepatitis.

BACKGROUND: Autoimmune hepatitis (AIH) is an organ specific autoimmune disease, which can manifest at any age of life. there is a high prevalence of extrahepatic autoimmune diseases in patients with AIH. Autoimmune thyroid diseases (ATDs) are the most frequent extrahepatic autoimmune disorders among patients with AIH. Aim of work is to detect the frequency of ATDs among Egyptian children with AIH. METHODS: This research is a cross-sectional study conducted on 58 children with AIH aged ≤ 18 years. All patients were tested for free triiodothyronine (FT3), free tetraiodothyronine (FT4), thyroid stimulating hormone (TSH), anti-thyroid peroxidase (anti-TPO) and antithyroglobulin (anti-TG). Thyroid ultrasound (US) and thyroid scan were performed for patients with abnormal thyroid profile, borderline values, positive anti-TPO or anti-TG. RESULTS: The mean ± standard deviation (SD) for the age of the patients was 11.3 ± 4.5 years. Out of 58 patients of AIH, 28 patients (48.3%) had associated other autoimmune diseases. Autoimmune thyroiditis was the most common associated autoimmune disease being present in 10 patients (17.2%). The thyroid status of AIT patients showed that 6 patients (60%) were euthyroid, 3 patients (30%) had subclinical hypothyroidism and only one patient (10%) was hyperthyroid. CONCLUSION: Autoimmune hepatitis in Egyptian children is commonly associated with other autoimmune diseases. Autoimmune thyroiditis is the most common to be associated with AIH in pediatric patients. As it is not usually clinically manifesting, regular screening for AIT in children with AIH is mandatory.

Complementary and alternative medicines and liver disease.

Complementary and alternative medicines (CAM) include conventional medical treatments. Patients worldwide use CAM at alarming rates; thus, reports of CAM-related DILI have been on the rise. The clinical presentations include asymptomatic liver test abnormalities, acute hepatitis with or without jaundice, acute cholestatic liver disease (bland or with hepatitis), acute liver failure, severe hepatitis with features of portal hypertension, and acute decompensation of known or unknown cirrhosis that can lead to acute-on-chronic liver failure. Acute hepatitis with or without necrosis, hepatocellular and canalicular cholestasis, herb-induced or CAM-triggered autoimmune hepatitis, granulomatous hepatitis, severe steatohepatitis, and vanishing bile duct syndrome are common liver biopsy findings in CAM-DILI. The presence of preexisting liver disease predicts severe liver injury, risk of progression to liver failure, and decreased transplant-free survival in patients with CAM-DILI. This review discusses global epidemiology and trends in CAM-DILI, clinical presentation, assessment and outcomes, commonly emerging threats in the context of hepatotoxic herbs, pragmatic assessment of "liver beneficial" herbs and health care myths, patient communication, regulatory framework, and future directions on research in CAM.

Management of autoimmune hepatitis induced by hepatitis delta virus.

Approximately 12-72 million people worldwide are co-infected with hepatitis B virus (HBV) and hepatitis delta virus (HDV). This concurrent infection can lead to several severe outcomes with hepatic disease, such as cirrhosis, fulminant hepatitis, and hepatocellular carcinoma, being the most common. Over the past few decades, a correlation between viral hepatitis and autoimmune diseases has been reported. Furthermore, autoantibodies have been detected in the serum of patients co-infected with HBV/HDV, and autoimmune features have been reported. However, to date, very few cases of clinically significant autoimmune hepatitis (AIH) have been reported in patients with HDV infection, mainly in those who have received treatment with pegylated interferon. Interestingly, there are some patients with HBV infection and AIH in whom HDV infection is unearthed after receiving treatment with immunosuppressants. Consequently, several questions remain unanswered with the challenge to distinguish whether it is autoimmune or "autoimmune-like" hepatitis being the most crucial. Second, it remains uncertain whether autoimmunity is induced by HBV or delta virus. Finally, we investigated whether the cause of AIH lies in the previous treatment of HDV with pegylated interferon. These pressing issues should be elucidated to clarify whether new antiviral treatments for HDV, such as Bulevirtide or immu-nosuppressive drugs, are more appropriate for the management of patients with HDV and AIH.

The prevalence and disease course of autoimmune liver diseases in Greenland.

Autoimmune liver diseases are rare serious diseases causing chronic inflammation and fibrosis in the liver parenchyma and bile ducts. Yet, the prevalence and burden of autoimmune liver diseases are largely unexplored in Arctic native populations. We investigated the prevalence and management of autoimmune liver diseases in Greenland using nationwide cross-sectional register data and subsequent medical chart reviews validating diagnoses and extracting liver histology examinations and medical treatments. The overall prevalence of autoimmune liver diseases in Greenland was 24.6 per 100,000 (95% CI: 14.7-41.3). This was based on 7 patients with autoimmune hepatitis (AIH) (12.3 per 100,000), 3 patients with primary biliary cholangitis (PBC) (5.3 per 100,000), 4 patients with AIH/PBC overlap disease (7.0 per 100,000), and no patients with primary sclerosing cholangitis. All diagnoses were confirmed by liver histology examinations. Medical treatments adhered to internal recommendations and induced complete remission in most patients with AIH, and complete or partial remission in 1 patient with PBC and 3 patients with AIH/PBC overlap disease. One patient had established cirrhosis at the time of diagnosis, while 2 patients progressed to cirrhosis. In conclusion, the prevalence of autoimmune liver diseases was lower in Greenland than in Scandinavia and among Alaska Inuit.

Berberine alleviates concanavalin A-induced autoimmune hepatitis in mice by modulating the gut microbiota.

BACKGROUND: Autoimmune hepatitis (AIH) is an immune-mediated liver disease of unknown etiology accompanied by intestinal dysbiosis and a damaged intestinal barrier. Berberine (BBR) is a traditional antibacterial medicine that has a variety of pharmacological properties. It has been reported that BBR alleviates AIH, but relevant mechanisms remain to be fully explored. METHODS: BBR was orally administered at doses of 100 mg⋅kg-1⋅d-1 for 7 days to mice before concanavalin A-induced AIH model establishment. Histopathological, immunohistochemical, immunofluorescence, western blotting, ELISA, 16S rRNA analysis, flow cytometry, real-time quantitative PCR, and fecal microbiota transplantation studies were performed to ascertain BBR effects and mechanisms in AIH mice. RESULTS: We found that liver necrosis and apoptosis were decreased upon BBR administration; the levels of serum transaminase, serum lipopolysaccharide, liver proinflammatory factors TNF-α, interferon-γ, IL-1ß, and IL-17A, and the proportion of Th17 cells in spleen cells were all reduced, while the anti-inflammatory factor IL-10 and regulatory T cell proportions were increased. Moreover, BBR treatment increased beneficial and reduced harmful bacteria in the gut. BBR also strengthened ileal barrier function by increasing the expression of the tight junction proteins zonula occludens-1 and occludin, thereby blocking lipopolysaccharide translocation, preventing lipopolysaccharide/toll-like receptor 4 (TLR4)/ NF-κB pathway activation, and inhibiting inflammatory factor production in the liver. Fecal microbiota transplantation from BBR to model mice also showed that BBR potentially alleviated AIH by altering the gut microbiota. CONCLUSIONS: BBR alleviated concanavalin A-induced AIH by modulating the gut microbiota and related immune regulation. These results shed more light on potential BBR therapeutic strategies for AIH.

Onset of acute severe autoimmune hepatitis after severe acute respiratory syndrome coronavirus 2 infection: a case report.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can trigger autoimmune inflammation in the liver, leading to acute autoimmune hepatitis (AIH). We herein report a case involving a 39-year-old woman with a 23-day history of yellow skin and urine. Using the revised original scoring system of the International AIH Group, we definitively diagnosed the patient with acute severe AIH (AS-AIH). She began treatment with 80 mg/day intravenous methylprednisolone, which was gradually reduced and followed by eventual transition to oral methylprednisolone. The patient finally achieved a biochemical response after 30 days of therapy, and liver transplantation was avoided. Clinicians should be aware that the onset of AS-AIH after SARS-CoV-2 infection differs from the onset of conventional AIH with respect to its clinical and pathological features. Early diagnosis and timely glucocorticoid treatment are crucial in improving outcomes.

[Treatment of autoimmune hepatitis-First-line, second-line and third-line treatment]. / Therapie der Autoimmunhepatitis ­ Erst­, Zweit- und Drittlinientherapie.

Autoimmune hepatitis (AIH) is a rare autoimmune inflammation of the liver mostly with a chronic course, which can also be acutely manifested up to acute liver failure. It affects women 3-4 times more frequently than men and can be diagnosed in all age groups. In one third of the patients a liver cirrhosis is present at the time of diagnosis. It is characterized by a hepatic inflammation pattern, a polyclonal hypergammaglobulinemia of immunoglobulin G and the detection of autoantibodies. A liver biopsy is necessary to make the diagnosis. The AIH is histologically characterized in particular by a lymphoplasmacytic infiltrate in the portal fields. In cases with a relevant disease activity, AIH is typically treated by immunosuppression. The immunosuppressive treatment is associated with a prevention of disease progression to liver cirrhosis and a better survival. The success of treatment is measured by achieving biochemical remission, i.e., normalization of the transaminase and immunoglobulin G levels as a good noninvasive predictor of a histological remission. Another treatment target is an improvement of the symptoms of the patient. The first-line treatment consists of a glucocorticoid, mostly prednisolone or in cases without advanced fibrosis budesonide, and azothioprine. For reduction of steroid-specific treatment side effects the maintenance treatment should be carried out steroid-free whenever possible. In cases of insufficient response to azothioprine or side effects a treatment attempt using antimetabolites, such as 6­mercaptopurine or mycophenolate mofetil is primarily carried out as second-line treatment. For patients who do not achieve biochemical remission through first-line or second-line treatment, a variety of medications are available for third-line treatment, e.g., rituximab, calcineurin inhibitors or antitumor necrosis factor (anti-TNF) antibodies. Third-line treatment should be carried out in expert centers and registered in the European Reference Network for Rare Liver Diseases in order to improve the currently sparse database for these forms of treatment in the future.

The role of amino acid metabolism in autoimmune hepatitis.

Autoimmune hepatitis (AIH) is an inflammatory chronic liver disease with persistent and recurrent immune-mediated liver injury. The exact cause of AIH is still not fully understood, but it is believed to be primarily due to an abnormal activation of the immune system, leading to autoimmune injury caused by the breakdown of autoimmune tolerance. Although the pathogenesis of AIH remains unclear, recent studies have shown that abnormalities in amino acid metabolism play significant roles in its development. These abnormalities in amino acid metabolism can lead to remodeling of metabolic processes, activation of signaling pathways, and immune responses, which may present new opportunities for clinical intervention in AIH. In this paper, we first briefly outline the recent progress of clinically relevant research on AIH, focusing on the role of specific amino acid metabolism (including glutamine, cysteine, tryptophan, branched-chain amino acids, etc.) and their associated metabolites, as well as related pathways, in the development of AIH. Furthermore, we discuss the scientific issues that remain to be resolved regarding amino acid metabolism, AIH development and related clinical interventions, with the aim of contributing to the future development of amino acid metabolism-based as a new target for the clinical diagnosis and treatment of AIH.

Autoimmune liver disease triggered by SARS-CoV-2: a case report and review of the literature.

BACKGROUND: An increasing number of coronavirus disease 2019 (COVID-19) related autoimmune hepatitis (AIH) and autoimmune liver disease (AILD) has been already described so far in the last three years. This rise has set up some diagnostic and therapeutic concerns, although steroid therapy has mostly been efficient, avoiding main significant side effects. CASE REPORT: We report the case of a 52-year-old subject displaying liver function impairment at the laboratory tests while positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) swab. Needle liver biopsy showed severe portal inflammation, interface hepatitis, lobular inflammation, abundant plasma cells, bridging necrosis, endothelialitis, bile duct vanishing disease, and ductular reaction. The diagnosis of autoimmune liver disease (AILD) was performed. After a month of steroid and ursodeoxycholic acid medications, liver function fully recovered. Azathioprine was introduced, and steroids were gradually reduced. CONCLUSIONS: Probably triggered by the SARS-CoV-2-induced cytokine storm, the association between COVID-19 and autoimmune-related inflammatory injury may display a particular paradigm of AILD pathogenesis.

The frequency and clinical significance of antibodies to soluble liver antigen/liver pancreas in autoimmune hepatitis: a prospective single-center study.

BACKGROUND AND AIMS: Soluble liver antigen/liver pancreas antibodies (anti-SLA/LP) are specific markers for autoimmune hepatitis (AIH) that have been associated with a distinct clinical phenotype and a more aggressive form of AIH. We prospectively evaluated the frequency and clinical significance of anti-SLA/LP in Turkish patients with AIH. MATERIAL AND METHODS: We prospectively included patients diagnosed with AIH between January 2018 and May 2023. Autoantibodies were detected using by immunofluorescence and immunoblot. RESULTS: We included 61 (80%, female) AIH patients with a median age of 31 years (15-78) at the time of diagnosis. Anti-SLA/LP was detected in 20% ( n  = 12) of the patients. Baseline characteristics, treatment responses and outcomes were similar among anti-SLA/LP-positive and anti-SLA/LP-negative AIH patients. Anti-SLA/LP-positive patients had significantly higher biochemical response rates after 4 weeks (100 vs. 67%, P  = 0.027), 3 months (100 vs. 39%, P  < 0.001), 6 months (100 vs. 69%, P  = 0.041) of therapy but not after 12 months (100 vs. 76%, P  = 0.103) and at the end of follow-up (100 vs. 91%, P  = 0.328). Relapse rates following treatment response were similar in patients with and without anti-SLA/LP (22 vs. 23%, P  = 0.956). Second-line therapies (tacrolimus and mycophenolate mofetil) were given to seven (11%) patients, all were anti-SLA/LP-negative. Two of these progressed into end-stage liver disease and both underwent liver transplantation. CONCLUSION: Our study results suggest that anti-SLA/LP positivity does not entail clinically distinct or severe features in AIH. In our cohort, anti-SLA/LP-positive patients showed a quicker response to immunosuppressive therapy.

Multi-omics approaches for drug-response characterization in primary biliary cholangitis and autoimmune hepatitis variant syndrome.

BACKGROUND: Primary biliary cholangitis (PBC) and autoimmune hepatitis (AIH) variant syndrome (VS) exhibit a complex overlap of AIH features with PBC, leading to poorer prognoses than those with PBC or AIH alone. The biomarkers associated with drug response and potential molecular mechanisms in this syndrome have not been fully elucidated. METHODS: Whole-transcriptome sequencing was employed to discern differentially expressed (DE) RNAs within good responders (GR) and poor responders (PR) among patients with PBC/AIH VS. Subsequent gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were conducted for the identified DE RNAs. Plasma metabolomics was employed to delineate the metabolic profiles distinguishing PR and GR groups. The quantification of immune cell profiles and associated cytokines was achieved through flow cytometry and immunoassay technology. Uni- and multivariable logistic regression analyses were conducted to construct a predictive model for insufficient biochemical response. The performance of the model was assessed by computing the area under the receiver operating characteristic (AUC) curve, sensitivity, and specificity. FINDINGS: The analysis identified 224 differentially expressed (DE) mRNAs, 189 DE long non-coding RNAs, 39 DE circular RNAs, and 63 DE microRNAs. Functional pathway analysis revealed enrichment in lipid metabolic pathways and immune response. Metabolomics disclosed dysregulated lipid metabolism and identified PC (18:2/18:2) and PC (16:0/20:3) as predictors. CD4+ T helper (Th) cells, including Th2 cells and regulatory T cells (Tregs), were upregulated in the GR group. Pro-inflammatory cytokines (IFN-γ, TNF-α, IL-9, and IL-17) were downregulated in the GR group, while anti-inflammatory cytokines (IL-10, IL-4, IL-5, and IL-22) were elevated. Regulatory networks were constructed, identifying CACNA1H and ACAA1 as target genes. A predictive model based on these indicators demonstrated an AUC of 0.986 in the primary cohort and an AUC of 0.940 in the validation cohort for predicting complete biochemical response. CONCLUSION: A combined model integrating genomic, metabolic, and cytokinomic features demonstrated high accuracy in predicting insufficient biochemical response in patients with PBC/AIH VS. Early recognition of individuals at elevated risk for insufficient response allows for the prompt initiation of additional treatments.

Autoimmune hepatitis: Brighton Collaboration case definition and guidelines for data collection, analysis, and presentation of immunisation safety data.

This report introduces a Brighton Collaboration (BC) case definition for autoimmune hepatitis (AIH), which has been classified as a priority adverse event of special interest (AESI), as there were possible cases seen following COVID-19 vaccination. The case definition was developed by a group of subject matter and BC process experts to facilitate safety data comparability across pre- and post-licensure clinical trials, as well as pharmacovigilance activities in multiple settings with diverse resources and healthcare access. The usual BC case definition development process was followed in an expedited manner, and took two months to complete, including finalising the manuscript for publication, instead of the usual 1 year development time. It includes a systematic review of the literature and an expert consensus to define levels of diagnostic certainty for AIH, and provides specific guidelines for data collection and analysis. Histology, serological and biochemical tests and exclusion of alternate diagnosis were considered necessary to define the levels of certainty (definitive, probable and possible). AEFI reports of suspected AIH were independently classified by the WG members to test its useability and these classifications were used to finalise the case definition. The document underwent peer review by external AIH experts and a Reference Group of vaccine safety stakeholders in high-, low- and middle-income countries to ensure case definition useability, applicability, and scientific integrity. The expedited process can be replicated for development of other standardised case definitions for priority AESIs for endemics and epidemics. While applicable to cases reported following immunisation, the case definition is independent of lapsed time following vaccination and, as such, can also be used to determine background incidence for vaccinated and unvaccinated control groups in studies of causal association. While use of this case definition is also appropriate for the study of safety of other products including drugs, it is not meant to guide clinical case management.

[Drug-induced autoimmune-like liver injury]. / Arzneimittelinduzierte immunvermittelte Leberschädigung.

Drug-induced liver injury (DILI) is a rare yet potentially life-threatening disease. Besides intrinsic DILI, which is mainly caused by paracetamol overdosing and which is dose-dependent and predictable, there is idiosyncratic DILI-an unpredictable and dose-independent injury of the liver caused by certain medications that only occurs in a minority of patients taking this drug. The reason why some patients react with DILI towards a specific drug is still unknown. However, the immune system plays a central role, which is underlined by the association of certain human leukocyte antigen (HLA) polymorphisms and DILI caused by specific drug classes. Due to the immunological processes that lead to the liver injury in DILI, there are great overlaps regarding laboratory and histological parameters between DILI and autoimmune hepatitis (AIH). Differentiating DILI and AIH can therefore be challenging, especially at the time of presentation. In addition, there are other immunologically mediated DILI phenotypes, in particular the newly defined drug-induced autoimmune-like hepatitis (DI-ALH) and liver injuries caused by checkpoint inhibitors (CPI). DI-ALH is characterized by autoimmune features and good responses towards corticosteroids, with the difference that DI-ALH mostly does not relapse after discontinuation of corticosteroids. CPI-induced liver injury has become more frequent with the rising use of those drugs and is characterized by a distinct histopathological pattern with granulomatous hepatitis and infiltration dominated by cytotoxic T cells. Similarly, the recently recognized liver injury following vaccinations also shows an autoimmune phenotype; however, in contrast to AIH, cytotoxic T cells seem to dominate the inflammatory infiltrates in the liver.