Research gaps and opportunities in autoimmune hepatitis-Results of the international autoimmune hepatitis group research workshop 2022

Quo vadis autoimmune hepatitis? - Summary of the 5th international autoimmune hepatitis group research workshop 2024

Autoimmune hepatitis (AIH) is a rare chronic liver disease with an increasing incidence in many countries. Chronic autoimmune responses against the liver can cause hepatic and extrahepatic symptoms, decreased quality of life and reduced liver transplant-free survival if inadequately treated. Although standard treatment with corticosteroids and thiopurines improves the life expectancy of patients with AIH, remission rates and tolerability are generally overestimated and the development of alternative first-line and salvage therapies has been disappointingly slow compared to in rheumatological diseases or inflammatory bowel disease. Other gaps include the lack of disease-specific diagnostic markers for AIH. Similarly, the new entity of drug-induced autoimmune-like hepatitis underscores the need to re-evaluate previous diagnostic criteria. The International AIH Group (IAIHG) has initiated a series of research workshops over the last decade to promote the identification of research gaps and subsequently improve the pace of scientific progress by stimulating collaboration between expert centres. This review reports on the results of the 5th Research Workshop, held in Hannover, Germany in June 2024, and summarises the progress made since the 4th Workshop in 2022. Patient representatives from the European Reference Network (ERN) Rare Liver Youth Panel participated in the workshop. The specific objectives of this year's 5th Workshop were: (1) To further improve diagnostics. (2) Initiate clinical trials including knowledge transfer on drugs from extrahepatic immune-mediated diseases, including B cell-depleting CAR T cells. (3) Utilisation of multi-omics approaches to improve the understanding of disease pathogenesis. (4) Application of machine learning-based approaches established in oncology or transplantation medicine to improve diagnosis and outcome prediction in AIH.

Low socioeconomic status exacerbates unmet health-related needs in patients with autoimmune hepatitis

BACKGROUND AND AIMS

Diminished quality of life has been well characterized in patients with autoimmune hepatitis (AIH); however, the full spectrum of unmet needs is unclear. We hypothesized that there is a high burden of health-related unmet needs in patients with AIH, and this burden differs by socioeconomic status (SES).

METHODS

Members of the Autoimmune Hepatitis Association were invited online and by email to complete a modified version of the Systemic Lupus Erythematosus Patient Needs Questionnaire. Demographic and clinical data were also captured. Low SES was defined as annual household income <30 k, education level below high school, or moderate-high concern for transportation, food or housing. Multivariable logistic regression assessed the association between unmet health-related needs and SES.

RESULTS

There were 433 participants; 89.8% identified as women, 16.2% lived outside the US, and 25.6% were classified as low SES. Over 70% of respondents reported at least one moderate-high need in the health-related unmet need domains. In multivariable logistic regression, patients in the low-SES group reported significantly higher odds of unmet needs compared to the moderate-high-SES group: for adequate information about side effects (OR 1.64, 95% CI 1.06-2.53, p = 0.026), opportunity to speak with others with AIH (OR 2.34, 95% CI 1.50-3.66, p < 0.001), healthcare professionals acknowledging patient emotions (OR 2.41, 95% CI 1.56-3.74, p < 0.001) and being taken seriously by medical providers (OR 2.09, 95% CI 1.34-3.28, p = 0.001).

CONCLUSION

There is a high burden of health-related unmet needs in all patients with AIH that is exacerbated by low SES.

Glycyrrhizic acid alleviates concanavalin A-induced acute liver injury by regulating monocyte-derived macrophages

Autoimmune hepatitis (AIH) is characterized by persistent liver inflammation induced by aberrant immune responses. Glycyrrhizic acid (GA), a prominent bioactive ingredient of licorice, has shown potential as a safe and effective treatment for AIH. However, the immune regulatory mechanism by which GA exerts its therapeutic effect on AIH remains elusive. In this study, we found that GA intervention significantly alleviated ConA-induced acute liver injury in mice. Cytometry by time-of-flight (CyTOF) analysis revealed that GA increased the abundance of anti-inflammatory F4/80loCD11bhiMHCIIhi MoMF-1 and decreased the abundance of pro-inflammatory F4/80loCD11bhiiNOShi MoMF-3. Multiplex immunofluorescence demonstrated the infiltration of MoMFs in liver tissues. Single-cell RNA sequencing (scRNA-seq) analysis indicated that GA facilitated the immune activation in MoMFs, regulated gene expression of diverse cytokines secreted by MoMFs, and played a role in shaping the immune microenvironment. By integrating the results of CyTOF with scRNA-seq, our study comprehensively elucidates the immune landscape of ConA-induced liver injury following GA intervention, advancing the understanding of GA's mechanism of action. However, it is important to note that some single-cell data in this study remain raw and require further processing and annotation. Our findings suggest that GA alleviates ConA-induced acute liver injury by regulating the function of MoMFs, opening potential avenues for AIH treatment and management, and providing a theoretical basis for the design of novel MoMFs-centered immunotherapies.

IAIH-PG consensus for histological criteria of AIH: Multicentre validation with focus on chronic liver diseases in China

BACKGROUND AND AIMS

The International AIH Pathology Group (IAIH-PG) put forward the new histological criteria of autoimmune hepatitis (AIH) in 2022, which have not undergone adequate verification. In this study, we verified the applicability of the new histological criteria in the population of Chinese patients with chronic liver disease, comparing it with the simplified criteria.

METHODS

The gold standard for diagnosis in all patients was based on histological findings, combined with clinical manifestations and laboratory tests and determined after a follow-up period of at least 3 years. A total of 640 patients with various chronic liver diseases from multiple centres underwent scoring using the new histological criteria and the simplified criteria, comparing their diagnostic performance.

RESULTS

In this study, the new histological criteria showed a sensitivity of 73.6% and 100% for likely and possible AIH, with specificities of 100% and 69.0% respectively. The coincidence rates of possible AIH for the new histological criteria, simplified histological criteria and simplified score were 81.7%, 72.8% and 69.7% respectively. For likely AIH, the rates were 89.2%, 75.9% and 65.6% respectively. Based on the new histological criteria, all patients with AIH were correctly diagnosed. Specifically, 73.6% were diagnosed with likely AIH and 26.4% were possible AIH. Additionally, the simplified histological criteria achieved a diagnosis rate of 98.6% for AIH, while the simplified score could only diagnose 53.8% of AIH.

CONCLUSIONS

Compared with the simplified score and simplified histological criteria, the sensitivity and specificity of the new histological criteria for AIH were significantly improved. The results indicate that the new histological criteria exhibit high sensitivity and specificity for diagnosing AIH in China.

Autoimmune hepatitis: Current and future therapies

Autoimmune hepatitis (AIH) is a chronic inflammatory liver disease that can lead to cirrhosis and liver failure. AIH can present in all ages, races, and ethnicities, but it predominantly affects women. As a heterogeneous disease, AIH presents variably in different patients, making diagnosis and treatment a challenge. Currently, the standard treatment for AIH comprises immunosuppressants; however, their long-term use is associated with adverse effects. The pathogenesis of AIH is complex, involving T cells, macrophages, and plasma cells that invade the periportal parenchyma and lead to an inflammatory cascade that can result in liver damage. Due to the complexity of AIH pathogenesis, treatment targets several inflammatory pathways. However, unlike other autoimmune diseases in which targeted treatments have been approved, there has been little progress made in advancing the treatment paradigm for AIH. Major obstacles to progress include challenges in conducting clinical trials, particularly patient recruitment and ensuring a diverse range of backgrounds; poorly defined outcomes to assess treatment response and improved quality of life; and a lack of study designs that account for the stage of disease and variations in treatment. A focus on individualized and steroid-free treatment approaches is needed to improve AIH prognosis and minimize steroid-associated adverse effects.

A case of A20 haploinsufficiency complicated by autoimmune hepatitis

AIM

A20 haploinsufficiency (HA20) is a recently described autoinflammatory disease that manifests symptoms similar to those of Behçet's disease. However, little is known about the involvement of the liver in HA20. Here, we report a case of HA20 complicated by autoimmune hepatitis (AIH).

CASE PRESENTATION

A 33-year-old woman was previously diagnosed with HA20 and chronic thyroiditis, and was treated with prednisolone (PSL; 7.5 mg/day) and levothyroxine sodium hydrate (125 μg/day). She experienced general malaise and jaundice, and biochemical evaluation revealed elevated liver function with an aspartate aminotransferase level of 817 U/L, an alanine aminotransferase level of 833 U/L, and a total bilirubin of 8.3 mg/dL. Pathological evaluation of the liver biopsy revealed interface hepatitis and the patient was diagnosed with acute exacerbation of AIH. Upon increasing the PSL dose to 60 mg/day, the liver enzyme levels rapidly decreased. During tapering of PSL, azathioprine 50 mg/day was added, and there was no relapse of AIH with combination therapy of PSL 7 mg/day and azathioprine 50 mg/day.

CONCLUSION

This is the first report of biopsy-proven AIH in an Asian patient with HA20. This case has significant implications for the pathogenesis and treatment of AIH in patients with HA20.

Advancements in autoimmune hepatitis management: Perspectives for future guidelines

The first-line treatment for autoimmune hepatitis involves the use of prednisone or prednisolone either as monotherapy or in combination with azathioprine (AZA). Budesonide has shown promise in inducing a complete biochemical response (CBR) with fewer adverse effects and is considered an optional first-line treatment, particularly for patients without cirrhosis; however, it is worth noting that the design of that study favored budesonide. A recent real-life study revealed higher CBR rates with prednisone when equivalent initial doses were administered. Current guidelines recommend mycophenolate mofetil (MMF) for patients who are intolerant to AZA. It is important to mention that the evidence supporting this recommendation is weak, primarily consisting of case series. Nevertheless, MMF has demonstrated superiority to AZA in the context of renal transplant. Recent comparative studies have shown higher CBR rates, lower therapeutic failure rates, and reduced intolerance in the MMF group. These findings may influence future guidelines, potentially leading to a significant modification in the first-line treatment of autoimmune hepatitis. Until recently, the only alternative to corticosteroids was lifelong maintenance treatment with AZA, which comes with notable risks, such as skin cancer and lymphoma. Prospective trials are essential for a more comprehensive assessment of treatment suspension strategies, whether relying on histological criteria, strict biochemical criteria, or a combination of both. Single-center studies using chloroquine diphosphate have shown promising results in significantly reducing relapse rates compared to placebo. However, these interesting findings have yet to be replicated by other research groups. Additionally, second-line drugs, such as tacrolimus, rituximab, and infliximab, should be subjected to controlled trials for further evaluation.

STING modulates iron metabolism to promote liver injury and inflammation in acute immune hepatitis

The pathogenesis of Autoimmune Hepatitis (AIH) is closely associated with perturbations in iron ion metabolism, during which Stimulator of Interferon Genes (STING) plays an important role. However, the precise regulatory mechanism remains elusive. In this study, we investigated the relationship between iron dysregulation and STING activation in Concanavalin A (ConA)-induced AIH liver injury. STING knockout (STING-/-) mice and AAV (Adeno-Associated virus)-Sting1-RNAi-treated mice were involved and subjected in AIH. We observed that increased iron dysregulation was linked with STING activation, but this effect was effectively reversed by the administration of iron chelating agent Desferoxamine (DFO) and the antioxidant Ferrostatin-1 (Fer-1). Notably, the iron transport protein Transferrin (TF) and Transferrin Receptor (TfR) exhibited significant accumulation in AIH along with upregulated expression of ferritin protein. Additionally, the deficiency of STING reduced hepatic iron accumulation, mitigated oxidative stress, and attenuated macrophage activation during ConA treatment. Furthermore, liver-specific knockdown of STING using AAV-Sting1-RNAi significantly ameliorated liver iron dysregulation and oxidative stress response induced by Kupffer cells (KCs). KC-derived STING exacerbates liver damage severity in AIH through promoting disturbances in hepatic iron ion metabolism as well as oxidative stress response. These findings provide valuable insights into the pathogenesis of AIH and may pave the way for potential therapeutic strategies targeting STING and iron metabolism in the future.