Towards personalised medicine in autoimmune hepatitis: Measurement of thiopurine metabolites results in higher biochemical response rates

EASL Clinical Practice Guidelines on the management of autoimmune hepatitis

Autoimmune hepatitis (AIH) is a chronic liver disease of unknown aetiology which may affect any patient irrespective of age, sex, and ethnicity. At baseline, the clinical spectrum of the disease varies largely from asymptomatic cases to acute liver failure with massive hepatocyte necrosis. The aim of these EASL guidelines is to provide updated guidance on the diagnosis and management of AIH both in adults and children. Updated guidance on the management of patients with variants and specific forms of AIH is also provided, as is detailed guidance on the management of AIH-associated cirrhosis, including surveillance for portal hypertension and hepatocellular carcinoma, as well as liver transplantation in decompensated cirrhosis.

Update in clinical science: Autoimmune hepatitis

Autoimmune hepatitis (AIH) is an enigmatic, relatively rare disease with a variable spectrum of presentation whose pathogenesis, diagnosis and management remain a major challenge. We have performed a review of recent developments in basic science, epidemiology, clinical science, therapeutics, and regulatory science, evaluating the challenges associated with the application of translational research and clinical trial design to a condition that is a chameleon in nature, where outcomes range from relatively benign disease through cirrhosis and acute liver failure. This review is focused on developments from 2020 onwards so we can present a forward-looking view on the challenges and remaining questions that must be addressed to improve patient care and outcomes in AIH. We also outline areas of debate and offer insights into these areas.

Response to azathioprine treatment in autoimmune hepatitis is dependent on glutathione transferase genotypes

BACKGROUND

Azathioprine (AZA) is part of the standard treatment for autoimmune hepatitis (AIH). The first step in the complex bioconversion of AZA to active metabolites is mediated by glutathione transferases (GSTs).

AIMS

Elucidate the association between GSTM1 and GSTT1 copy number variation (CNV), genetic variation in GSTA2, GSTP1, and inosine-triphosphate-pyrophosphatase, and the response to AZA in AIH.

METHODS

Genotyping was performed in AIH patients (n = 131) on AZA, and in a Swedish background population (n = 283). Thiopurine metabolites in blood erythrocytes were determined by high performance liquid chromatography.

RESULTS

GSTM1 and GSTT1 CNV were associated with treatment response to AZA. Gene deletion of GSTM1-but not of GSTT1-was associated with the liver transaminase levels. None of the studied genetic variants were associated with the thiopurine metabolite concentrations, suggesting non-enzymatic mechanisms of GSTM1 and GSTT1 in the context of AZA efficacy in AIH. The prevalence of GSTM1 and GSTT1 CNV genotypes was similar in AIH and in the background population.

CONCLUSION

This study shows the effects of GSTM1 and GSTT1 CNV on AZA efficacy in AIH, not previously described. It also elaborates on the impact of the definition of treatment response, on the importance of the various GSTs studied. Furthermore, the GSTM1 and GSTT1 CNV frequencies previously reported in European populations were confirmed.

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

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

Role of B-Cell Inhibition in Autoimmune Hepatitis: Lessons Learnt From Systemic Lupus Erythematosus

Autoimmune hepatitis (AIH) is a chronic liver disease characterized by histological, clinical, and laboratory findings, including elevated liver enzymes, immunoglobulin G (IgG), and autoantibodies. Belimumab, a monoclonal antibody targeting B-lymphocyte stimulator (BLyS), is primarily approved for systemic lupus erythematosus (SLE) but shows promise in improving liver function tests (LFTs) in patients with concurrent AIH and SLE. We present the case of a 24-year-old female diagnosed with AIH and SLE, whose elevated LFTs initially resisted standard azathioprine therapy. Upon switching to mycophenolate and belimumab, a notable reduction in LFTs was observed. This case highlights belimumab's potential as an adjunct therapy in AIH, especially in patients with overlapping autoimmune conditions, supporting its role in reducing systemic inflammation and autoimmune activity.

Current practice in the management of paediatric autoimmune liver disease in Europe

OBJECTIVE

Paediatric autoimmune liver disease (pAILD) is a rare condition with serious health implications. Notwithstanding treatment advancements, areas of uncertainty and knowledge gaps still exist. We here investigated the real-life approach to pAILD management in Europe.

METHODS

A survey was distributed to members of the European Rare Liver Disease Reference Network (ERN RARE-LIVER) and the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) Hepatology Interest Group. Information was gathered regarding clinical activity, medications used, and access to paediatric drug formulations at each site.

RESULTS

Thirty-six centres from 22 European countries responded to the survey. The majority are exclusively paediatric units (86%). Among participants, 80% follow <50 children with pAILD, of which 25%-50% are <10 years old in 44% of centres. All centres use predniso(lo)ne as first-line therapy, alone (15/36) or with azathioprine (21/36). Azathioprine and mycophenolate are the preferred second-line options in centres using first-line steroid monotherapy (11/15) or combined steroid-azathioprine (19/21), respectively. Tacrolimus is used as third-line agent in 15/36 centres. Proactive measurement of drug metabolites and target levels vary widely among centres. Paediatric predniso(lo)ne formulations are commercially available in 7/22 European countries, azathioprine in 3, mycophenolate in 14, tacrolimus in 15 and ursodeoxycholic acid in 14. When paediatric formulations are unavailable, children are treated with magisterial preparations or 'solid' formulations (crushed or intact).

CONCLUSIONS

Treatment of pAILD in Europe varies widely in terms of medications used and treatment monitoring. Availability of paediatric drug formulations across Europe is limited. Collaborative initiatives are needed to define evidence-based strategies for management of pAILD and to promote an equal, age-appropriate treatment for affected children.

Hard-to-treat autoimmune hepatitis and primary biliary cholangitis: The dawn of a new era of pharmacological treatment

Patients with hard-to-treat autoimmune hepatitis (AIH) or primary biliary cholangitis (PBC) are defined a posteriori as those who do not show a sufficient response or are intolerant to pharmacological treatments, thus not achieving biochemical surrogate endpoints that are associated with long-term liver-related-event-free survival. The absence of a recently harmonized definition of 'complete biochemical response within 6 months (CBR≤6M)', which is defined as the normalization of serum transaminase and IgG levels below the upper limit of normal at ≤6 months after treatment initiation, is regarded as hard-to-treat AIH. The implementation of CBR≤6M, in turn, has been facilitating clinical trials, e.g., between azathioprine and mycophenolate mofetil, to reconsider appropriate first-line steroid sparing agents, leading to a reduction in the number of hard-to-treat AIH cases. Regarding PBC, one of the disseminated definitions of hard-to-treat patients is the absence of POISE criteria, which are evaluated at 12 months with serum alkaline phosphatase and bilirubin levels, after the introduction of ursodeoxycholic acid. Hard-to-treat PBC not meeting the POISE criteria has very recently been the target population for the U.S. FDA-approved second-line drugs, elafibranor and seladelpar. In future pharmacological treatment of AIH and PBC, the primary objective for AIH is likely to focus on lowering the number of hard-to-treat patients with personalized steroid sparing treatment regimens. A challenging goal in PBC treatment is the further optimization of treatment surrogate endpoints, even to the stricter alkaline phosphatase normalization, with which an indication of second- or later-line drugs might be expanded, but could ultimately lengthen patients' long-term survival.

Optimizing thiopurine therapy in autoimmune hepatitis: A multicenter study on monitoring metabolite profiles and co-therapy with allopurinol

BACKGROUND AND AIMS

In autoimmune hepatitis, achieving complete biochemical remission (CBR) with current weight-based thiopurine dosing is challenging. We investigated whether patients could be stratified regarding CBR according to a target range of thiopurine metabolites. Moreover, we explored the effects of azathioprine dosage increases and co-therapy of allopurinol with low-dose thiopurines on metabolite profiles and treatment response.

APPROACH AND RESULTS

The relation between metabolites and treatment response was assessed in 337 individuals from 4 European centers. In a global, cross-sectional analysis, active metabolites 6-thioguanine nucleotides (6TGN) were similar in those with and without CBR. However, analyzing patients with sequential measurements over 4 years (N = 146) revealed higher average 6TGN levels in those with stable CBR (260 pmol/0.2 mL) compared to those failing to maintain CBR (181 pmol/0.2 mL; p = 0.0014) or never achieving CBR (153 pmol/0.2 mL; p < 0.0001), with an optimal 6TGN cutoff of ≥223 pmol/0.2 mL (sensitivity: 76% and specificity: 78%). Only 42% exhibited 6TGN ≥223 pmol/0.2 mL following weight-based dosing, as doses weakly correlated with 6TGN but with 6-methylmercaptopurine (6MMP), a metabolite associated with toxicity. Azathioprine dose increases led to preferential 6MMP formation (+127% vs. 6TGN +34%; p < 0.0001). Conversely, adding allopurinol to thiopurines in difficult-to-treat patients (N = 36) raised 6TGN (168→321 pmol/0.2 mL; p < 0.0001) and lowered 6MMP (2125→184 pmol/0.2 mL; p < 0.0001), resulting in improved transaminases in all patients and long-term CBR in 75%.

CONCLUSIONS

Maintaining CBR in autoimmune hepatitis was associated with 6TGN ≥223 pmol/0.2 mL. For patients who fail to achieve CBR and therapeutic 6TGN levels despite thiopurine dose increase due to preferential 6MMP formation, comedication of allopurinol alongside low-dose thiopurines represents an efficient alternative.

Detailed resume of S-methyltransferases: Categories, structures, biological functions and research advancements in related pathophysiology and pharmacotherapy

Methylation is a vital chemical reaction in the metabolism of many drugs, neurotransmitters, hormones, and exogenous compounds. Among them, S-methylation plays a significant role in the biotransformation of sulfur-containing compounds, particularly chemicals with sulfhydryl groups. Currently, only three S-methyltransferases have been reported: thiopurine methyltransferase (TPMT), thiol methyltransferase (TMT), and thioether methyltransferase (TEMT). These enzymes are involved in various biological processes such as gene regulation, signal transduction, protein repair, tumor progression, and biosynthesis and degradation reactions in animals, plants, and microorganisms. Furthermore, they play pivotal roles in the metabolic pathways of essential drugs and contribute to the advancement of diseases such as tumors. This paper reviews the research progress on relevant structural features, metabolic mechanisms, inhibitor development, and influencing factors (gene polymorphism, S-adenosylmethionine level, race, sex, age, and disease) of S-methyltransferases. We hope that a better comprehension of S-methyltransferases will help to provide a reference for the development of novel strategies for related disorders and improve long-term efficacy.

[Treatment of autoimmune hepatitis-First-line, second-line and third-line treatment]

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 6‑mercaptopurine 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.

Top-Down Proteomics Detection of Potential Salivary Biomarkers for Autoimmune Liver Diseases Classification

(1) Autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC) are autoimmune liver diseases characterized by chronic hepatic inflammation and progressive liver fibrosis. The possible use of saliva as a diagnostic tool has been explored in several oral and systemic diseases. The use of proteomics for personalized medicine is a rapidly emerging field. (2) Salivary proteomic data of 36 healthy controls (HCs), 36 AIH and 36 PBC patients, obtained by liquid chromatography/mass spectrometry top-down pipeline, were analyzed by multiple Mann-Whitney test, Kendall correlation, Random Forest (RF) analysis and Linear Discriminant Analysis (LDA); (3) Mann-Whitney tests provided indications on the panel of differentially expressed salivary proteins and peptides, namely cystatin A, statherin, histatin 3, histatin 5 and histatin 6, which were elevated in AIH patients with respect to both HCs and PBC patients, while S100A12, S100A9 short, cystatin S1, S2, SN and C showed varied levels in PBC with respect to HCs and/or AIH patients. RF analysis evidenced a panel of salivary proteins/peptides able to classify with good accuracy PBC vs. HCs (83.3%), AIH vs. HCs (79.9%) and PBC vs. AIH (80.2%); (4) RF appears to be an attractive machine-learning tool suited for classification of AIH and PBC based on their different salivary proteomic profiles.

Noninvasive biomarkers for the diagnosis and management of autoimmune hepatitis

Autoimmune hepatitis (AIH) is a rare disease of unclear etiology characterized by loss of self-tolerance that can lead to liver injury, cirrhosis, and acute liver failure. First-line treatment consists of systemic corticosteroids, or budesonide, and azathioprine, to which most patients are initially responsive, although predictors of response are lacking. Relapses are very common, correlate with histological activity despite normal serum transaminases, and increase hepatic fibrosis. Furthermore, current regimens lead to adverse effects and reduced quality of life, whereas medication titration is imprecise. Biomarkers that can predict the clinical course of disease, identify patients at elevated risk for relapse, and improve monitoring and medication dosing beyond current practice would have high clinical value. Herein, we review novel candidate biomarkers in adult and pediatric AIH based on prespecified criteria, including gene expression profiles, proteins, metabolites, and immune cell phenotypes in different stages of AIH. We also discuss biomarkers relevant to AIH from other immune diseases. We conclude with proposed future directions in which biomarker implementation into clinical practice could lead to advances in personalized therapeutic management of AIH.

Autoimmune hepatitis in pregnancy: Pearls and pitfalls

Autoimmune hepatitis (AIH) in pregnancy has many unique considerations. Evidence provided from single center studies with patient level data and nationwide population studies provide valuable insight into this complex situation. Because a planned pregnancy is a safer pregnancy, preconception counseling is a crucial opportunity to optimize care and risk stratify women with AIH. Women with chronic liver disease who receive preconception advice and counseling are more likely to achieve stable liver disease at conception and undergo appropriate variceal surveillance. Loss of biochemical response in pregnancy is associated with adverse outcomes in unstable disease. New onset AIH in pregnancy should be managed with classical treatment regimens. The continued use of immunosuppression in pregnancy, with the exception of mycophenolate mofetil, has not shown to adversely affect the rates of stillbirth or congenital malformation. Previously adopted immunosuppression withdrawal paradigms in pregnancy should no longer be considered advantageous, because remission loss postdelivery is likely (12%-86%). Population studies, report improved outcomes with preterm birth rates falling from 20% to 9%-13% in AIH pregnancies over a 20-year period. Newer data have also demonstrated an increased risk of gestational diabetes and hypertensive complications in AIH pregnancy, which has implications for management and preeclampsia prevention with aspirin use. This review aims to provide the framework to guide and manage pregnancy in AIH outlining pearls and pitfalls to ensure optimal outcomes for mother, baby and to reduce variation in practice.

Autoimmmune hepatitis

Autoimmune hepatitis (AIH) is a T-cell mediated, inflammatory liver disease affecting all ages and characterized by female preponderance, elevated serum transaminase and immunoglobulin G levels, positive circulating autoantibodies, and presence of interface hepatitis at liver histology. AIH type 1, affecting both adults and children, is defined by positive anti-nuclear and/or anti-smooth muscle antibodies, while type 2 AIH, affecting mostly children, is defined by positive anti-liver-kidney microsomal type 1 and/or anti-liver cytosol type 1 antibody. While the autoantigens of type 2 AIH are well defined, being the cytochrome P4502D6 (CYP2D6) and the formiminotransferase cyclodeaminase (FTCD), in type 1 AIH they remain to be identified. AIH-1 predisposition is conferred by possession of the MHC class II HLA DRB1*03 at all ages, while DRB1*04 predisposes to late onset disease; AIH-2 is associated with possession of DRB1*07 and DRB1*03. The majority of patients responds well to standard immunosuppressive treatment, based on steroid and azathioprine; second- and third-line drugs should be considered in case of intolerance or insufficient response. This review offers a comprehensive overview of pathophysiological and clinical aspects of AIH.

First Results From a Propensity Matching Trial of Mycophenolate Mofetil vs. Azathioprine in Treatment-Naive AIH Patients

Background/Aims

As previous real-world studies and meta-analyses have shown that mycophenolate mofetil (MMF) might have better efficacy than azathioprine (AZA) in autoimmune hepatitis (AIH), we conducted a propensity matching study to assess the efficacy and safety of MMF vs. AZA.

Methods

All 126 consecutive treatment-naive adult AIH patients, diagnosed and followed in our department since 2016, were included. Patients received prednisolone 0.5-1 mg/kg/day plus either AZA 1-2 mg/kg/day or 1.5-2 g/day MMF. The tapering of prednisolone was identical between groups.

Results

After propensity matching score and adjustment for known factors affecting response to treatment and outcome, 64 patients were included in the study (MMF = 32 and AZA = 32). Rates of non-response, complete biochemical response (CBR) at 6 and 12 months, and prednisolone withdrawal (6 months, 12 months, and end of follow-up) were identical between groups. However, MMF treatment was significantly associated with CBR at the end of follow-up [odds ratio (OR) 11.259; 95% CI: 1.3-97.4, p = 0.028]. AZA patients were more prone to stop treatment due to AZA intolerance/insufficient response (p = 0.0001). At the end of follow-up, the overall efficacy of each schedule was also significantly higher in the MMF group compared to the AZA group (p = 0.0001).

Conclusion

We showed for the first time in a propensity matching study that MMF can be used as first-line therapy in AIH as attested by the significantly higher CBR at end of follow-up compared to AZA. Whether this better efficacy is also associated with higher histological remission rates and sustained CBR off immunosuppression needs further evaluation.