Search Results (126)

Autoimmune liver diseases (AILDs) represent a diverse spectrum of chronic inflammatory conditions characterized primarily by compromised hepatic immune tolerance, including autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and primary sclerosing cholangitis (PSC). Recent evidence positions macrophages as pivotal players in AILDs pathogenesis, attributable to their multifaceted roles in inflammation amplification, immune regulation, and fibrogenesis. In the context of AILDs, macrophages exhibit marked polarization imbalance, increased recruitment of monocytes, and impaired clearance of apoptotic cells. Through complex interactions with T lymphocytes and hepatic stellate cells, macrophages orchestrate a pathological milieu promoting inflammation and fibrosis. Notably, diverse programmed cell death (PCD) modalities—autophagy, necroptosis, pyroptosis, and ferroptosis—not only determine macrophage survival and functional phenotype but also significantly impact cytokine release, phenotypic plasticity, and the trajectory of immunopathological progression. This review synthesizes current understandings of macrophage-driven immunoregulatory mechanisms in AILDs, characterizes the regulatory attributes of various macrophage-related PCD processes, and evaluates their relevance in experimental disease models. Furthermore, we highlight recent advancements in biomarker identification and targeted therapeutic strategies. Comprehensive elucidation of the interplay between macrophage immunological activity and programmed cell death pathways promises to inform novel, personalized therapeutic approaches for patients with AILDs. Full article

Background/Objectives: Retinal ischemia–reperfusion (I/R) injury is a common mechanism in glaucoma, diabetic retinopathy, and retinal vein occlusion, leading to progressive loss of retinal ganglion cells (RGCs). This study investigates the regulatory role of miR-21-5p and its interaction with Signal Transducer and Activator of Transcription 3 (STAT3) in retinal I/R injury. Methods: An acute intraocular hypertension (AIH) rat model was used to induce retinal I/R. The interaction between miR-21-5p and STAT3 was examined by dual-luciferase reporter assays. miR-21-5p and STAT3 expression were quantified by qRT-PCR and Western blotting. Retinal morphology, microglial polarization, and RGC survival were assessed by H&E staining and immunofluorescence. In vitro, microglia and RGCs were subjected to oxygen–glucose deprivation/reperfusion (OGD/R), and microglial-conditioned media (MCM) were applied to RGCs. Results: (1) miR-21-5p ameliorated AIH-induced retinal damage in vivo. (2) Overexpression of miR-21-5p inhibits M1 polarization of RM cultured in vitro. (3) MCM from miR-21-5p-overexpressing microglia attenuated OGD/R-induced RGC death. (4) miR-21-5p downregulates STAT3 expression to inhibit RM M1 polarization. (5) miR-21-5p down-regulation of STAT3 levels inhibits M1 polarization and reduces apoptosis of RGCs in retinal microglia of AIH rats. Conclusions: miR-21-5p alleviates retinal I/R injury by restraining microglial M1 polarization through direct repression of STAT3, thereby promoting RGC survival. These findings identify the miR-21-5p/STAT3 axis as a potential therapeutic target for ischemic retinal diseases. Full article

Drug-induced autoimmune hepatitis (DIAIH) is a rare and complex disorder caused by drugs that are commonly metabolized by hepatic microsomal cytochrome P450 (CYP) pathways. Whereas DIAIH presents generally with a single clinical flare, in rare cases its clinical course shows two different, consecutively emerging flares. The aim of this report was to analyze details of this rare but interesting phenomenon and to help improve appropriate causality evaluation in patients with suspected iDILI or DIAIH to provide better insight into the pathomechanistic steps leading the diseases. A clinical course with two flares was found in a DIAIH patient treated with varenicline, a smoking cessation drug, and in another patient experiencing DIAIH following intravenous application of infliximab used to treat ankylosing spondylitis. In both patients, the first flare was determined as a typical liver injury with increased serum activities of alanine aminotransferase (ALT) and normal titers of serum autoimmune parameters, classified as an acute liver injury analogous to idiosyncratic DILI (iDILI), with verified causality using a modified version of RUCAM (Roussel Uclaf Causality Assessment Method). After an interval of around two months from the cessation of varenicline use, the second flare emerged, as evidenced by increased serum ALT values now associated with newly increased serum autoimmune titers of antinuclear antibodies (ANAs), classifying this flare as hepatic autoimmune injury with verified causality for varenicline using the simplified autoimmune hepatitis (AIH) score. A similar clinical DIAIH course of a continuous disease with two flares was described for the second patient, who received infliximab and experienced an interval of one month between the first and second flare. Interestingly to note, neither varenicline nor infliximab is degraded via a CYP pathway, and the metabolic disposition of both drugs is low. In sum, DIAIH can develop with two consecutive flares caused by two drugs not metabolized by CYPs and with slow drug disposition, raising the question of whether this phenomenon of two flares can occur in additional cases of DIAIH due to other drugs metabolized by CYPs or non-CYPs, a question to be resolved by DILI experts in future cases of iDILI and DIAIH. Full article

Fibrosis is a pathological process characterized by the excessive accumulation of extracellular matrix (ECM), particularly collagen, leading to tissue scarring, architectural distortion, and organ dysfunction. While fibrosis is a physiological component of wound healing, its persistence and dysregulation can drive chronic tissue damage and organ dysfunction. In autoimmune diseases, fibrosis arises from prolonged inflammation and immune system dysregulation, creating a vicious cycle that exacerbates tissue injury and promotes disease progression. This review provides a comprehensive overview of the fibrotic processes across a range of immune-mediated and autoimmune conditions, including systemic sclerosis (SSc), morphea, autoimmune hepatitis (AIH), systemic lupus erythematosus (SLE), Sjögren’s syndrome (SS), inflammatory bowel disease (IBD), and rheumatoid arthritis (RA), Finally, we discuss current and emerging antifibrotic strategies aimed at interrupting pathological ECM remodeling and restoring tissue homeostasis. Full article

Background/Objectives: Binding of bactericidal/permeability-increasing (BPI) protein to Gram-negative (GN) bacteria plays a major role in bacterial elimination. The relationship between BPI-antineutrophil cytoplasmic autoantibodies (ANCA), persistent infections and immunoinflammatory diseases has not been elucidated. Methods: In total, 193 ANCA-positive patients detected by IIF with ANCA-associated vasculitides (AAV, n-40), connective tissue diseases (CTD, n-28), drug-induced vasculitides (DIV, n-17), ulcerative colitis (UC, n-24), UC with primary sclerosing cholangitis (UC/PSC, n-14), Crohn’s disease (CD, n-10), autoimmune hepatitis (AIH, n-19) and chronic infections (n-41) were tested using the BPI-ANCA quantitative and semiquantitative ELISA (ANCA-profile: BPI, proteinase 3, myeloperoxidase, elastase, cathepsin G, lactoferrin). BPI-ANCA were analyzed in 52 healthy persons. Results: A total of 46/193 (23.8%) patients had BPI-ANCA positivity. BPI-ANCA were more frequently present in patients with prolonged GN bacterial infections and inflammatory bowel diseases than in AAV, DIV, AIH, CTD and healthy controls (p < 0.001). UC/PSC patients more frequently had BPI-ANCA than UC and CD patients (p < 0.001). GN bacterial infections more frequently had BPI-ANCA than Gram-positive bacterial infections (p < 0.001). Infections caused by Pseudomonas aeruginosa and Mycobacterium tuberculosis had monospecific BPI-ANCA (sensitivity 79% and 71%, respectively). UC/PSC and chronic GN bacterial infections caused by Klebsiella pneumoniae, Proteus mirabilis, or Escherichia coli had multispecific BPI-ANCA (sensitivity 64% and 100%, respectively). Odds ratio analysis showed that patients with IBD who were positive for multispecific BPI-ANCA had a 13.5-fold increased risk of UC/PSC (95% CI 2.98–61.18). Conclusions: Monospecific BPI-ANCA may be a valuable biomarker for persistent Pseudomonas aeruginosa and Mycobacterium tuberculosis infections. In contrast, multispecific BPI-ANCA are associated with UC/PSC and persistent infections caused by intestinal Gram-negative bacteria. Suppression of antimicrobial function by multispecific BPI-ANCA could impair the elimination of Gram-negative bacteria, sustaining the immunoinflammation. Dysregulated antimicrobial response might be the target of immunomodulatory therapy in the initial phase of BPI-ANCA-positive UC/PSC. Full article

Polyamines (PAs), including putrescine, spermidine, spermine, and thermospermine, play essential roles in plant growth, development, and responses to stress. However, the structure and function of PA biosynthetic genes in pepper remain poorly characterized. This study aimed to identify PA biosynthesis genes in the pepper genome using bioinformatics approaches and to assess their expression under various stress conditions. A total of 16 PA biosynthesis-related genes were identified, representing members of the arginine decarboxylase (ADC), ornithine decarboxylase (ODC), agmatine iminohydrolase (AIH), N-carbamoylputrescine amidohydrolase (CPA), S-adenosylmethionine decarboxylase (SAMDC), spermidine synthase (SPDS), spermine synthase (SPMS), and ACAULIS5 (ACL5) gene families. These genes encode proteins with an average molecular weight of approximately 40 kDa, primarily localized in the mitochondria and cytoplasm. Promoter analysis revealed multiple cis-acting elements associated with stress and phytohormone responsiveness. Gene expression was induced by various abiotic stresses, including saline-alkaline, drought, heat, cold, and hydrogen peroxide, as well as by phytohormones such as abscisic acid, ethylene, salicylic acid, auxin, and gibberellin. Overall, this study provides a comprehensive analysis of PA biosynthesis genes in pepper and highlights their potential roles in stress adaptation and hormone signalling, offering a foundation for further exploration of PA-mediated stress tolerance mechanisms. Full article

Background and objective: Thiopurines (azathioprine (AZA) and 6-mercaptopurine (6-MP)), used to maintain remission in inflammatory bowel diseases (Crohn’s disease (CD), ulcerative colitis (CU)) and autoimmune hepatitis (AIH), are responsible for a number of adverse effects. One is leukopenia, mainly due to neutropenia and less known lymphopenia. This study aimed to assess the incidence rate of lymphopenia in pediatric patients with CD, CU, and AIH treated with azathioprine (AZA) and to evaluate the impact of lymphopenia on the occurrence of opportunistic infections and its relationship with disease activity, treatment, and nutritional status. Materials and methods: A retrospective analysis was carried out in ninety-eight (98) paediatric patients, suffering from CD, CU, or AIH and treated with AZA, in order to assay blood cell count and thiopurine metabolite levels, assess the mean AZA dose, measure the anthropometric parameters, evaluate disease activity vs. the treatment administered, and to find out concomitant infections. Results: Lymphopenia was diagnosed in twenty-two (22) children and evaluated as severe in two (2) cases, which were associated with treatment discontinuation. The percentage of patients with lymphopenia in the CD group (34.5%) was significantly higher vs. the CU (3.7%) and AIH (7.7%) groups. The prevalence rates of the patients with low and moderate-to-high disease activity were 13.9% and 46.1%, respectively. The patients with lymphopenia demonstrated higher prevalence rates of mild respiratory tract and skin infections (identified in 32%). No cases of opportunistic infections were reported. Conclusions: Lymphopenia affected approximately one-quarter of the patients observed, the condition being transient in most cases and not demanding any therapy modifications. In no case was it associated with the occurrence of any opportunistic infections. It was significantly more common in the patients with Crohn’s disease and the subgroup with a more intense course of the disease, obviously suggesting a need for more frequent follow-up of the patients in those subgroups. The AZA therapy did not seem to be associated with lymphopenia occurrence in any significant way. Full article

Background: Although immune complex formation is widely acknowledged as the etiological agent for the development of systemic lupus erythematosus, polyarteritis nodosa, reactive arthritis, etc., its roles in chronic hepatitis are less understood. This study aims to compare the immunohistochemistry profile of immune complex deposition in patients with chronic hepatitis B (CHB) and autoimmune hepatitis (AIH). Methods: Immunohistochemistry of C4d, a widely used marker for complement deposition was employed on liver biopsies from 72 and 15 patients with CHB and AIH, respectively. Statistical analysis was performed to analyze its prevalence and its association with a range of clinical and histological parameters. Results: Among the 15 AIH biopsies examined, C4d deposition was observed in 11 cases (73.3%), the majority of which showed a periportal staining pattern (10/11). In CHB, 61 (84.7%) of 72 cases tested positive for C4d, which did not differ significantly with that of AIH. While the periportal pattern was predominantly observed in CHB cases, positive staining in central veins, sinusoids, and hepatic parenchyma were also documented. In particular, C4d deposition is significantly associated with elevated serum ALT and liver inflammation in CHB. Of note, in specimens with a patchy parenchymal C4d staining pattern, a spatially correlated HBsAg IHC signal was observed in adjacent sections from the same tissue. Conclusions: These data suggest an involvement of immune complex-mediated immunopathy in autoimmune hepatitis and HBV-induced hepatitis. The positive intrahepatic C4d signal was associated with heightened liver inflammation. The colocalization of the C4d signal on hepatocytes with HBsAg strongly suggests a causal relationship between viral activity and complement deposition. These observations align with our recent evidence implicating the contribution of capsid–antibody complexes in the pathogenesis of CHB. Full article

Autoimmune hepatitis (AIH) is linked to an increased risk of hepatocellular carcinoma (HCC). However, the precise connection between the two remains unclear. GPR81, a G-protein-coupled receptor located on the membranes of various cell types, plays a role in numerous physiological processes. We established an AIH animal model and activated GPR81 using the agonist 3,5-dihydroxybenzoic acid (3,5-DHBA). Additionally, the effect of GPR81 inhibition on tumor and immune cell dynamics was examined using the HepG2, Hep3B, and Hepa1-6 cell lines with the antagonist 3-hydroxybutyric acid (3-OBA). Our results demonstrated that 3,5-DHBA treatment reduced T cell and pro-inflammatory cytokine secretion, while MDSC secretion increased, inhibiting Concanavalin A (Con A)-induced AIH. The inhibition of GPR81 by 3-OBA suppressed HCC cell proliferation and invasion, reduced tumor volume and weight, and downregulated PD-L1 expression. Furthermore, CTL and DC activity in the spleen and tumors increased, while MDSC activity decreased. This study confirms that GPR81 plays an important role in both inflammation and tumorigenesis, suggesting that GPR81 may serve as a bridge in the transformation of inflammation into cancer. Modulating GPR81 activity may provide a novel therapeutic strategy for hepatitis and cancer. Full article

Autoimmune hepatitis (AIH) is the most common liver disease caused by autoimmunity. In Japan, the number of patients with AIH has been increasing in recent years. AIH develops as a result of the loss of immune tolerance to autoantigens in the liver. Drug-induced liver injury (DILI) is an extremely important cause of liver injury in clinical practice and should always be kept in mind in the differential diagnosis. Recently, DILI caused by immune checkpoint inhibitors has been attracting attention. For the diagnosis of DILI, it is important to carefully exclude other possible causes of liver injury and obtain a detailed history of medications and the timing of their use. On the other hand, drug-induced AIH, like hepatitis, also exists and is clinically important because it is often difficult to differentiate from idiopathic AIH. A solid understanding of the pathogenesis of both AIH and DILI is essential for clinicians. This article provides an overview of AIH and DILI in Japan, including the latest findings. Full article

Drug-induced autoimmune hepatitis (DIAIH) is a relatively new subtype of idiosyncratic drug-induced liver injury (iDILI), but the features of DIAIH have been variably described due to the inhomogeneity of assessed study cohorts. The aim of this analysis is to harmonize DIAIH cohorts by unifying causality assessments, which may help characterize the features of DIAIH. Methods: Published reports of DIAIH cases were evaluated for the causality assessment methods used to verify the diagnosis of DIAIH. This disorder consists of two parts, i.e., the iDILI part and the autoimmune (AIH) part, whereby each part needs a specific diagnostic algorithm. The validated and scoring Roussel Uclaf Causality Assessment (RUCAM) is privileged for assessing the iDILI part, and the validated, simplified AIH score is the perfect choice for evaluating the AIH part. The analysis of DIAIH publications revealed that 12/20 reports (60%) presented cases assessed by both the RUCAM and the simplified AIH score, providing 49 drugs and drug combinations as causative drugs in up to 25 cases of DIAIH. Serum alanine aminotransferase activities of up to 3489 UL and high titers of autoimmune parameters such as anti-nuclear antibodies, anti-smooth-muscle antibodies, and soluble liver antigen antibodies supported DIAIH diagnosis. In contrast, 4/20 reports (20%) applied only RUCAM, and 2/20 reports (10%) used only the simplified AIH score; these 6 reports therefore provided insufficient criteria for a valid DIAIH diagnosis. Moreover, 2/20 reports (10%) did not use any causality algorithm, providing elusive features of DIAIH. While DIAIH is clearly restricted to drugs as responsible agents, this term is erroneously used to refer to disease induced by non-drugs such as herbs, green tea, dimethoate (an organophosphate insecticide), dietary supplements, biologics, herbal remedies, different viruses, and bacteria, as well as vaccines. For diseases induced by these agents, a better term could be, for instance, non-drug-induced autoimmune hepatitis. Drug cessation and immunotherapy with corticosteroids and azathioprine comprise the treatment of choice. The characteristics of DIAIH can best be described if both the RUCAM and the simplified AIH score are used concomitantly. Full article

Sjogren’s disease (SjD) is a systemic autoimmune disease primarily affecting the exocrine glands. Systemic manifestations, including hepatic involvement, are increasingly recognized. This study aimed to delineate the clinical features and associated factors of autoimmune hepatic involvement in SjD. A retrospective analysis was conducted on patients diagnosed with SjD at Seoul St. Mary’s Hospital over the past 10 years. Autoimmune hepatic involvement was defined by fulfilling diagnostic criteria for autoimmune hepatitis (AIH) or primary biliary cholangitis (PBC). Clinical, serological, and demographic data were obtained from medical records. Among 1119 patients with SjD, 51 (4.6%) had autoimmune hepatic involvement. AIH (64.7%) was the most common type, followed by PBC (27.5%) and overlapping disease (7.8%). Compared to those without hepatic involvement, affected patients were older at diagnosis (p = 0.003) and showed higher frequencies of thrombocytopenia, splenomegaly, anti-centromere antibody (ACA), and elevated antinuclear antibody titers as measured by indirect immunofluorescence (IFI-HEp-2) (all p < 0.001). Multivariable analysis identified splenomegaly, elevated IFI-HEp-2 titer, and ACA positivity as independent factors associated with hepatic involvement. Most patients responded well to immunosuppressive therapy, with only a small proportion (15.7%) progressing to liver fibrosis. Autoimmune hepatic involvement is relatively uncommon but clinically meaningful in patients with SjD. Full article

Autoimmune hepatitis (AIH) and drug-induced liver injury (DILI) are major causes of liver inflammation with distinct pathophysiology but overlapping clinical features. Among acute cases, DILI is a key differential diagnosis for AIH, especially when drug history is unclear or the injury is non-dose-dependent. Mechanisms of DILI include direct toxicity, metabolic idiosyncrasies, and immune-mediated responses that can mimic AIH. Moreover, certain drugs can induce AIH-like syndromes, further complicating the diagnosis. While causality assessment tools aid initial evaluations, liver biopsy remains valuable for distinguishing AIH from DILI; given these complexities, hepatologist consultation is often essential to ensure appropriate diagnosis and treatment management. Full article

Background and aims: The CC5, CXC3, and CC2 chemokines (CK) are known to play a role in the pathogenesis of autoimmune hepatitis (AIH). However, no data are available on their potential utility as markers of disease progression or response to treatment. Material and methods: We analyzed their role as markers of remission in a population of patients with AIH. We retrospectively investigated the kinetics of RANTES (CCL5), IP-10 (CXCL10), and MCP-1 (CCL2) in 48 patients with AIH at the time of treatment initiation and also in 32 at biochemical, clinical and histological remission. Forty-nine healthy donors (HDs) served as controls. Results: At baseline, IP-10 and MCP-1 levels were higher in AIH patients than in HDs (261 vs. 101 pg/mL and 689 vs. 330 pg/mL, p < 0.01), and RANTES levels showed no differences. Correlations were observed between RANTES and IgG concentrations (r = 0.36 p = 0.04) and between IP-10 and Ishak’s grade (r = 0.52 p = 0.02). At remission, in 32 patients, while IP-10 and MCP-1 values showed a significant decrease from baseline reaching HD levels (261 vs. 106 pg/mL and 689 vs. 387 pg/mL, p < 0.01), RANTES did not. However, two kinetics patterns emerged, with 20 patients showing lower and 12 higher baseline RANTES values compared to HDs (29,450 pg/mL and 70,960 pg/mL vs. 52,010 pg/mL, p < 0.01). The former required longer treatment to reach remission and had higher Ishak’s grades than the latter (p < 0.01). Conclusions: RANTES, IP-10, and MCP-1 may help in predicting response to treatment and stable remission and in supporting the decision if and when to discontinue immune suppressive therapy. Full article

Pediatric gastroenterology is entering a pivotal phase marked by significant challenges and emerging opportunities in treating conditions like celiac disease (CeD), eosinophilic esophagitis (EoE), inflammatory bowel disease (IBD), and autoimmune hepatitis (AIH) pose significant clinical hurdles, but new therapeutic avenues are emerging. Advances in precision medicine, particularly proteomics, are reshaping care by tailoring treatments to individual patient characteristics. For CeD, therapies like gluten-degrading enzymes (latiglutenase, Kuma030) and zonulin inhibitors (larazotide acetate) show promise, though clinical outcomes are inconsistent. Immunotherapy and microbiota modulation, including probiotics and fecal microbiota transplantation (FMT), are also under exploration, with potential benefits in symptom management. Transglutaminase 2 inhibitors like ZED-1227 could help prevent gluten-induced damage. Monoclonal antibodies targeting immune pathways, such as AMG 714 and larazotide acetate, require further validation in pediatric populations. In EoE, biologics like dupilumab, cendakimab, dectrekumab (IL-13 inhibitors), and mepolizumab, reslizumab, and benralizumab (IL-5/IL-5R inhibitors) show varying efficacy, while thymic stromal lymphopoietin (TSLP) inhibitors like tezepelumab are also being investigated. These therapies require more pediatric-specific research to optimize their use. For IBD, biologics like vedolizumab, ustekinumab, and risankizumab, as well as small molecules like tofacitinib, etrasimod, and upadacitinib, are emerging treatments. New medications for individuals with refractory or steroid-dependent AIH have been explored. Personalized therapy, integrating precision medicine, therapeutic drug monitoring, and lifestyle changes, is increasingly guiding pediatric IBD management. This narrative review explores recent breakthroughs in treating CeD, EoE, IBD, and AIH, with a focus on pediatric studies when available, and discusses the growing role of proteomics in advancing personalized gastroenterological care. Full article