Pathogenesis of autoimmune hepatitis

Inflammasome Molecular Insights in Autoimmune Diseases

Autoimmune diseases (AIDs) emerge due to an irregular immune response towards self- and non-self-antigens. Inflammation commonly accompanies these conditions, with inflammatory factors and inflammasomes playing pivotal roles in their progression. Key concepts in molecular biology, inflammation, and molecular mimicry are crucial to understanding AID development. Exposure to foreign antigens can cause inflammation, potentially leading to AIDs through molecular mimicry triggered by cross-reactive epitopes. Molecular mimicry emerges as a key mechanism by which infectious or chemical agents trigger autoimmunity. In certain susceptible individuals, autoreactive T or B cells may be activated by a foreign antigen due to resemblances between foreign and self-peptides. Chronic inflammation, typically driven by abnormal immune responses, is strongly associated with AID pathogenesis. Inflammasomes, which are vital cytosolic multiprotein complexes assembled in response to infections and stress, are crucial to activating inflammatory processes in macrophages. Chronic inflammation, characterized by prolonged tissue injury and repair cycles, can significantly damage tissues, thereby increasing the risk of AIDs. Inhibiting inflammasomes, particularly in autoinflammatory disorders, has garnered significant interest, with pharmaceutical advancements targeting cytokines and inflammasomes showing promise in AID management.

Manganese Exacerbates ConA-Induced Liver Inflammation via the cGAS-STING Signaling Pathway

There is a potential association between the dysregulation of trace elements and impaired liver function. Elevated levels of manganese, an essential metal ion, have been observed in liver-related diseases, and excessive intake of manganese can worsen liver damage. However, the specific mechanisms underlying manganese-induced liver injury are not well understood. The aim of our study was to investigate the effects of excess manganese on autoimmune hepatitis (AIH) and elucidate its mechanisms. Our findings revealed that manganese exacerbates liver damage under ConA-induced inflammatory conditions. Transcriptomic and experimental data suggested that manganese enhances inflammatory signaling and contributes to the inflammatory microenvironment in the liver of AIH mice. Further investigations demonstrated that manganese exacerbates liver injury by activating the cGAS-STING signaling pathway and its downstream pro-inflammatory factors such as IFN[Formula: see text], IFN[Formula: see text], TNF[Formula: see text], and IL-6 in the liver of AIH mice. These results suggest that manganese overload promotes the progression of AIH by activating cGAS-STING-mediated inflammation, providing a new perspective for the treatment and prognosis of AIH.

SARS-CoV-2-Induced Autoimmune Hepatitis

Few case reports discuss the incidences of autoimmune hepatitis (AIH) in patients after SARS-CoV-2 infection. Here, we present a case of SARS-CoV-2-induced AIH in a male patient who came into the emergency department with complaints of weight loss, poor oral intake, nausea, dark-colored urine, clay-colored stools, and scleral icterus, which began two weeks after he tested positive for SARS-CoV-2 PCR. Liver biopsy and subsequent histology confirmed the diagnosis of AIH with the most probable etiology being SARS-CoV-2 infection. The patient was treated with N-acetylcysteine (NAC) and steroids with clinical improvement and eventual discharge home. Our goal is to provide a clinical presentation, treatment, and outcome in a patient with SARS-CoV-2-induced AIH.

The Usefulness of Extended Inflammation Parameters and Systemic Inflammatory Response Markers in the Diagnostics of Autoimmune Hepatitis

(1) Introduction: Autoimmune hepatitis (AIH) is a chronic disease. A persistent autoimmune reaction in the liver is significantly related to the systemic inflammatory response. Extended Inflammation Parameters (EIP) can be used to assess the activation of immune cells such as activated neutrophils (NEUT-RI and NEUT-GI) and activated lymphocytes (RE-LYMP and AS-LYMP) in the phase of active inflammation. The role of the systemic inflammatory response markers should also be emphasised, especially: NLR, PLR, and RLR, which have recently been widely studied as markers in autoimmune skin diseases or liver diseases. (2) Materials and Methods: The study included 30 patients with AIH and 30 healthy volunteers. The parameters of the EIP group (RE-LYMP, AS-LYMP, NEUT-RI, NEUT-GI), calculated haematological indices Red Blood Cell Distribution Width-to-Platelet Ratio (RPR), Mean Platelet Volume-to-Platelet Ratio (MPR), Neutrophil-to-Lymphocyte Ratio (NLR), Platelet-to-Lymphocyte Ratio (PLR), Red Blood Cell Distribution Width-to-Lymphocyte Ratio (RLR), and selected blood morphological and biochemical indices were analysed. The aim of the study was to assess the usefulness of the EIP and systemic inflammatory response markers in the diagnostics of AIH. (3) Results: Compared to the controls, the patients with AIH showed significantly higher EIP values: NEUT-RI (48.05 vs. 43.30), NEUT-GI (152.65 vs. 147.40), RE-LYMP (0.07 vs. 0.03), and the inflammatory response markers: MPR (0.05 vs. 0.04), RPR (0.07 vs. 0.05), and NLR (2.81 vs. 1.42. Among the examined markers, EIP has significant diagnostic potential: NEUT-RI (AUC = 0.86), NEUT-GI (AUC = 0.80), and RE-LYMP (AUC = 0.78), and so do calculated haematological indices, i.e., MPR (AUC = 0.75), PLR (AUC = 1.00), and RLR (AUC = 1.00) Moreover, the importance of NEUT-GI (AUC = 0.89), MPR (AUC = 0.93), PLR (AUC = 0.86), RPR (AUC = 0.91), and FIB-4 (AUC = 0.83) in the detection of liver fibrosis in the course of AIH has also been proven. (4) Conclusions: EIP and systemic inflammatory response markers may turn out to be useful in detecting AIH and in looking for features of already developed liver cirrhosis in its course.

Indicator of Inflammation and NETosis-Low-Density Granulocytes as a Biomarker of Autoimmune Hepatitis

Introduction. Interest in the potential role of low-density granulocytes (LDGs) in the development of autoimmune diseases has been renewed recently. Due to their pro-inflammatory action, more and more attention is paid to the role of LDGs, including those expressing the enzyme myeloperoxidase (MPO), in the development of autoimmune hepatitis (AIH). LDGs are actively involved in the formation of neutrophil extracellular traps (NETs). This phenomenon may favour the externalization of the autoantigen and lead to damage to internal organs, including the liver. Aim. The main aim of the study was to assess the diagnostic usefulness of the LDG percentage, including the fraction showing MPO expression as markers of systemic inflammation in AIH. Materials and methods. The study included a group of 25 patients with AIH and 20 healthy volunteers. Mononuclear cells, isolated from peripheral blood, were labelled with monoclonal antibodies conjugated to the appropriate fluorochromes (CD15-FITC, CD14-PE, CD10-PE-Cy5, MPO+) and then analyzed on a Navios Flow Cytometer (Beckman Coulter). Results. Patients with AIH had a higher median percentage of LDG (1.2 vs. 0.1; p = 0.0001) and LDG expressing MPO (0.8 vs. 0.3; p = 0.0017) when compared to healthy volunteers. Moreover, the percentage of LDG was characterised by 100% of sensitivity and 55% of specificity (AUC = 0.84; p < 0.0001), while the percentage of LDG expressing MPO was 92% of sensitivity and 55% of specificity (AUC = 0.78; p = 0.0001) in the detection of AIH. Conclusions. Assessment of inflammatory markers, such as the percentage of LDG and the percentage of LDG expressing MPO, may be helpful in assessing the phenomenon of an increased systemic inflammatory response and in assessing liver fibrosis (LC, Liver cirrhosis), which is inherent in liver decompensation. Taking into account the above arguments, the assessment of the percentage of LDG, including LDG expressing MPO, may turn out to be a useful marker in the diagnosis of AIH.

Vitamin D supplementation for autoimmune hepatitis: A need for further investigation

Autoimmune hepatitis is a chronic liver disease harboring an autoimmune basis and progressive character. Despite still obscurity in etiology and pathogenesis, some evidence supports the importance of sustaining the immune system. Vitamin D is a lipo-soluble vitamin, which has been identified as decreased in our body. It is often due to the daily habit change and decrease of individual sun exposure due to the increase of the ultraviolet-induced potential melanocytic transformation. Here, we emphasize the importance of vitamin D supplementation in patients affected with liver disease.