IntroductionPropylthiouracil (PTU) is typically used as first line therapy for hyperthyroidism but is associated with a spectrum of adverse effects including vasculitis, that may lead to acute renal failure and exceptionally to pancreatitis, represents the most severe.Case descriptionHere we present the case of a 43-year-old woman with a history of Graves’ disease until recently on PTU therapy, who presented with fever and myalgia complicated by cold agglutinin disease, acute renal failure and pancreatitis. Subsequent laboratory studies and thorough physical examination excluding other causes revealed the presence of antibodies against leukocyte proteinase 3. Prompt initiation of immunosuppressive therapy and plasmapheresis led to immediate improvement of the patient’s clinical condition and laboratory tests.ConclusionClinicians should maintain a high index of suspicion for autoimmune phenomena in patients receiving PTU even after cessation of the medication. Early recognition, immediate discontinuation of the drug, and timely initiation of immunosuppressive therapy are essential to prevent irreversible organ damage.LEARNING POINTSPropylthiouracil is a well described trigger for the development of drug-induced vasculitis, seldom even long after cessation of therapy.In patients presenting with multi-organ failure the differential diagnosis should broaden to include systemic autoimmune vasculitis with atypical features.The cornerstone of therapy in drug induced autoimmune vasculitis is the immediate withdrawal of the offending agent and initiation of immunosuppressive therapy.

RATIONALE Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare autoimmune vasculitis characterized by severe asthma, eosinophilia, and anti-neutrophil cytoplasmic autoantibody (ANCA) positivity in ∼40% of patients. γδ T cells are unconventional lymphocytes that bridge innate and adaptive immunity and are increasingly implicated in autoimmunity through early IL-17A secretion and pro-inflammatory activation. Their role in EGPA, however, remains unclear. OBJECTIVE The objective of this study was to define γδ T cell frequency, phenotype and cytokine secretion in EGPA compared with asthma and healthy controls. METHODS Peripheral blood and sputum were collected from EGPA (n = 20), asthma (n = 18) and healthy controls (n = 54). Flow cytometry assessed CD4+, CD8+ and γδ T cell subsets, PD-1, EOMES and T-bet expression, and cytokine production. RESULTS Peripheral γδ T cells were significantly reduced in EGPA and asthma versus healthy controls (p < 0.01). EGPA patients showed increased PD-1 expression on γδ T cells (p < 0.01) and a higher proportion of IL-17A–producing γδ T cells (p < 0.05). IL-17A production by CD4+ and CD8+ T cells was similar across groups. γδ T cells were not linked to IL-5–driven eosinophilic inflammation, and no associations were found between γδ T cell profiles and clinical vasculitis. A trend toward higher serum IL-17A in EGPA patients with vasculitis was observed (p = 0.0747). T cell subsets did not correlate with serum or sputum ANCA levels. CONCLUSION EGPA is associated with peripheral γδ T cell dysregulation characterized by reduced frequency, elevated IL-17A secretion, and increased PD-1 expression, independent of IL-5–driven eosinophilic inflammation. These findings suggest a potential role for γδ T cells in EGPA pathogenesis and warrant further mechanistic investigation.

Introduction Granulomatosis with polyangiitis (GPA) is an autoimmune vasculitis which predominantly affects the respiratory system and kidneys. Immunosuppressive therapy effectively induces remission, but also may cause life-threatening complications. Consequently, maintaining balance between disease control and the risk of treatment-related adverse events is crucial in the therapeutic process. Case description In January 2020, a 62-year-old woman was admitted to a local hospital with unintentional weight loss, malaise, ascites and oliguria ongoing for several weeks. Chest high-resolution computed tomography revealed lung infiltrates with cavitary lesions, suggestive of Staphylococcus aureus pneumonia (Fig. 1 ). Unsuccessful treatment with antibiotics, together with oral and labial ulcerations, raised the suspicion of GPA. The diagnosis was confirmed by the presence of elevated levels of proteinase 3 antineutrophil cytoplasmic autoantibody (PR3-ANCA). Progressive renal failure required hemodialysis (HD) via a tunneled catheter. Plasmapheresis, intravenous prednisolone, and cyclophosphamide were initiated. In June 2023, the patient was readmitted with suspected pneumonia and radiological progression of pulmonary lesions. Bronchioalveolar lavage cultures yielded Acinetobacter baumannii and Candida krusei, prompting initiation of targeted therapy with amikacin, colistin, and micafungin. Echocardiography revealed a thrombus in the right atrium and intravenous catheter distal tip thickening. Although positron emission tomography suggested fungal endocarditis, repeated blood and catheter cultures were negative. However, continuation of antifungal therapy resulted in clinical improvement. After creating an arteriovascular shunt on the right arm, HD was continued. Persistent pulmonary progression, elevated PR3-ANCA levels and hearing loss prompted qualification for rituximab. In September 2023, the patient developed right arm cellulitis due to the right subclavian vein thrombosis, which was treated with piperacillin-tazobactam. Endovascular embolisation of the lateral rami of the cephalic vein contributed to the reduction of cellulitis. After subsidence of inflammation, rituximab treatment was initiated in December 2023. Conclusions The underlying disease and its treatment can cause severe infections and thrombotic events, contributing to the complexity of GPA management. This case shows that systematic reassessment and individualised therapy are essential to maintaining the effectiveness of the treatment, along with minimising treatment-related morbidity.

BACKGROUND Granulomatosis with polyangiitis (GPA), formerly known as Wegener granulomatosis, is a rare autoimmune vasculitis that predominantly affects the respiratory tract and kidneys. Pancreatic involvement is exceedingly uncommon and often misinterpreted as malignancy because of overlapping clinical, radiological, and cytological features. CASE REPORT A 62-year-old man presented with low-grade fever, abdominal bloating, and weight loss for 3 months. Positron emission tomography-computed tomography (PET-CT) revealed a metabolically active mass in the pancreatic body and tail with fluorodeoxyglucose-avid hilar and right cervical lymphadenopathy, raising suspicion of metastatic pancreatic adenocarcinoma. Initial endoscopic ultrasound-guided fine-needle aspiration was interpreted as consistent with well-differentiated adenocarcinoma, representing a false-positive cytologic diagnosis in retrospect, and the patient received 1 cycle of chemotherapy. On referral, systemic evaluation revealed hemoptysis and renal dysfunction, and renal biopsy demonstrated pauci-immune crescentic glomerulonephritis in the setting of high-titer PR3-ANCA positivity, which constituted the decisive diagnostic inflection point overturning the initial malignancy diagnosis. Biopsy from the cervical lump revealed inflamed submandibular gland tissue. A diagnosis of GPA with rare pancreatic involvement was made. The patient responded remarkably to rituximab and corticosteroids, with near-complete disappearance of the pancreatic mass on follow-up imaging. CONCLUSIONS This case exemplifies the diagnostic pitfalls when GPA presents as an isolated pancreatic mass. Fluorodeoxyglucose-PET findings and atypical cytology can mimic adenocarcinoma, leading to inappropriate therapy. Immunologic assays, including C-ANCA, IgG4, and complement levels, alongside histopathological evaluation from multiple sites, are essential for accurate differentiation. Literature review reveals fewer than 15 similar cases, many subjected to unnecessary resections. In patients with systemic features and pancreatic lesions, GPA should be considered a differential diagnosis. Early immunologic testing and multidisciplinary evaluation are key to avoiding misdiagnosis.

Abstract Background/Aims Aortitis is defined as inflammation of the aortic wall. Whilst most commonly autoimmune in aetiology, infectious and drug-induced aortitis are important differentials. Granulocyte-colony stimulating factor (G-CSF) plays a major role in the prevention of neutropenic sepsis in many chemotherapy regimens. G-CSF-induced aortitis is a rare but serious complication of this treatment. Methods This case report presents a 72-year-old female undergoing Folfirinox chemotherapy for biopsy-proven locally advanced pancreatic cancer. Seven days after her second dose of G-CSF, she presented with central chest pain and significantly elevated inflammatory markers. CT aorta showed thickening and cuffing around the aortic arch and proximal descending thoracic aorta. Initially managed as a Type B intramural haematoma, she was discharged after two days of monitoring. She represented two days later with severe chest pain and worsening inflammatory markers, with a white cell count of 28x109/L and CRP of 348mg/l. A repeat CT aorta showed progression of the inflammation in the aortic arch and descending thoracic aorta. A subsequent PET-CT demonstrated diffuse raised uptake at the aortic walls in keeping with active aortitis. Auto-antibody screen was negative, and serum IgG subclasses were within normal limits. There was no evidence of infection found on extensive screening. A diagnosis of G-CSF aortitis was made. Results Whilst existing literature suggests modest doses of oral Prednisolone are generally sufficient to manage G-CSF induced aortitis, the extensive and rapidly progressive nature of her disease led to the decision to treat her initially with high dose IV Methylprednisolone, followed by a weaning course of oral Prednisolone. She made a good clinical recovery, with significant biochemical and radiological improvement by the time of hospital discharge, and remains well now. Conclusion G-CSF is a rare but important cause of acute aortitis which is likely underreported. G-CSF induced aortitis is more frequently observed in women over the age of 60 and appears to be more prevalent in patients with breast cancer. Clinical signs differentiating it from autoimmune large vessel vasculitis include an often-rapid onset of symptoms with pain in the chest, neck, abdomen or back, along with high fever and markedly elevated inflammatory markers. Early detection and treatment can potentially prevent serious complications including aortic dissection. Disclosure E. Burnett: None. A. Abdul Malek: None. F. Cooles: None.

The neuroinvasive and neurotropic character of coronaviruses is a likely reason for neurological complications which may occur during acute COVID illness and sometimes persist or newly emerge in the post-acute phase. Terminology and temporal classification remain heterogeneous. A retrospective case series was conducted in a single center (Department of Neurology, Bielański Hospital, Warsaw, Poland). Medical records from March 2020 to December 2023 were screened. Inclusion criteria: (1) confirmed SARS-CoV-2 infection (polymerase chain reaction or antigen test and radiological findings), (2) new neurological syndrome within acute, post-acute, or post-COVID interval, and (3) diagnostic documentation. Exclusion criteria: alternative established etiology fully explaining the neurological condition. Six cases were selected for detailed analysis due to diagnostic completeness as well as etiological and temporal diversity. Cases included: (1) persistent neurocognitive and sensory symptoms (post-COVID), (2) acute ischemic stroke with internal carotid artery dissection during severe COVID-19, (3) cytotoxic lesion of the corpus callosum (CLOCC) during acute COVID-19, (4) Guillain–Barré syndrome (post-acute), (5) longitudinally extensive transverse myelitis (post-acute), and (6) delayed autoimmune cerebral vasculitis (post-COVID). Neurological presentations ranged from mild persistent symptoms to fatal outcome. Neurological complications span inflammatory, vascular, and autoimmune mechanisms across distinct temporal phases of SARS-CoV-2 infection. Precise temporal classification and systematic diagnostic protocols are essential. Prospective longitudinal studies integrating biomarkers and standardized neuroimaging are required.

Investigating the Relationship Human Parvovirus B19 Infection in Benign and Malignant Salivary Gland Tumors.

Immune checkpoint inhibitors (ICIs) are effective cancer therapies but often cause serious immune-related adverse events (irAEs). Patients with preexisting autoimmune diseases, including vasculitis, are excluded from trials. We aimed to evaluate the frequency, severity, and outcomes of vasculitis flares and irAEs in this population. We performed a retrospective review of cancer patients with prior vasculitis treated with ICIs at our institution and conducted a literature search for additional cases. Data included baseline features, vasculitis flares, irAEs, treatments, and tumor response. Twenty-five patients were identified (16 from our institution and 9 from the literature). Median age was 71 years; 13 (52%) were female. Vasculitis types included giant cell arteritis (GCA, n=9), granulomatosis with polyangiitis (GPA, n=8), eosinophilic granulomatosis with polyangiitis (EGPA, n=2), leukocytoclastic vasculitis (n=2), other cutaneous vasculitis (n=2), and Henoch-Schönlein purpura and Behçet disease (1 each). Cancer types were diverse. Most patients received anti-programmed death-1 monotherapy (n=17). Eight patients (31%) experienced a vasculitis flare after ICI initiation (2/9 GCA, 4/8 GPA, 2/4 cutaneous vasculitis). Flares occurred after a median of seven weeks. Treatment included glucocorticoids in seven patients, combined with biologic or cytotoxic agents depending on vasculitis type. Seven of eight flares resolved, and four patients continued ICI therapy. Three additional patients developed de novo irAEs: severe hepatitis (n=1), grade 3 colitis (n=1), and grade 3 autoimmune hemolytic anemia (n=1), all improving with treatment. One patient with GCA died due to a flare; no deaths were attributed to de novo irAEs. Overall, more than one-third of patients achieved a favorable tumor response. Nearly one-third of patients with preexisting vasculitis experienced a disease flare during ICI therapy, with one fatal case. For most, outcomes were favorable with effective flare management. Preexisting vasculitis should not be considered an absolute contraindication for cancer immunotherapy with ICI.

Behçet syndrome (BS) is a systemic autoimmune vasculitis characterized by immune dysregulation involving multiple immune cell subsets. CD161+ Treg cells exhibit proinflammatory properties and impair immune regulation during inflammation. This study aimed to investigate the alterations in CD161+ Treg cells in BS and their clinical relevance, particularly in disease pathogenesis and neurologic involvement. This prospective multicenter study included 182 patients diagnosed with BS at the three hospitals between 2018 and 2024, 166 patients with systemic lupus erythematosus (SLE) and 149 patients with rheumatoid arthritis (RA) and 114 patients with healthy controls (HCs). Demographic and clinical data were recorded. CD4+CD25highCD127lowCD161+ T cells (CD161+ Treg cells) in peripheral blood were analyzed via flow cytometry. Statistical analysis included the Wilcoxon rank-sum test, Fisher's exact test, and logistic regression, with P < 0.05 considered significant. Patients with BS had a significantly higher proportion among total Treg cells and CD4+ T cells, as well as higher absolute number of CD161+ Treg cells compared to HCs. CD161+ Treg cell levels negatively correlated with Foxp3+ Treg cells and positively correlated with Teff cells. Patients with BS had higher absolute number of CD161+ Treg cells than that in patients with SLE and in patients with RA. Moreover, patients with BS with higher erythrocyte sedimentation rate or C-reactive protein or with neurologic involvement exhibited higher CD161+ Treg cells, which were identified as a risk factor for neurologic involvement. Among 41 patients with BS observed after treatment, CD161+ Treg cells significantly decreased, correlating with reduced disease activity. Patients with BS exhibit an increased CD161+ Treg cells in peripheral blood, which may contribute to immune dysregulation and neurologic involvement. The reduction of CD161+ Treg cells following treatment suggests their potential role as a biomarker for disease activity in BS.

Methotrexate(MTX) is widely used in rheumatology practice for rheumatoid arthritis and many other conditions, including psoriatic arthritis, autoimmune connective tissue diseases, sarcoidosis, and vasculitis. The most common adverse effects of MTX include nausea, fatigue, dizziness, headache, stomatitis and abdominal pain. Serious adverse effects include hepatotoxicity, pulmonary toxicity, nephrotoxicity, myelosuppression and increased risk of lymphoproliferative disorders. In our review of the literature, case reports of sexual dysfunction have beeen reported during MTX therapy. We report here one case of sexual dysfunction during MTX therapy.

Anti-glomerular basement membrane (anti-GBM) disease is a rare, fulminant autoimmune small-vessel vasculitis characterized by rapidly progressive glomerulonephritis (RPGN), with or without pulmonary haemorrhage. Detection of circulating anti-GBM antibodies is traditionally considered central to diagnosis; however, seronegative variants pose a significant diagnostic challenge, particularly in regions where infection-related and ANCA-associated glomerulonephritides are more prevalent. We report the case of a 45-year-old male from South India who presented with subacute onset bilateral pedal edema, facial puffiness, and progressive exertional dyspnoea. Laboratory evaluation revealed nephrotic-range proteinuria, active urinary sediment, and rapidly worsening renal dysfunction. Extensive serological evaluation, including anti-GBM antibodies, antinuclear antibodies, and ANCA, was negative. Given the clinical suspicion of RPGN, renal biopsy was performed and demonstrated crescentic glomerulonephritis with linear IgG deposition along the glomerular basement membrane on immunofluorescence, establishing the diagnosis of anti-GBM disease.

Wiskott-Aldrich syndrome (WAS) is a rare X-linked primary immunodeficiency characterized by microthrombocytopenia, eczema, and recurrent infections. While autoimmune complications are common in WAS, including autoimmune hemolytic anemia, vasculitis, and glomerulonephritis, type 1 diabetes has not been previously described. We report a 37-year-old man with longstanding leukopenia and recurrent infections who was diagnosed with WAS after genetic testing revealed a gain-of-function mutation in the WAS gene. During pre-transplant evaluation for hematopoietic stem cell transplantation, he was incidentally found to have a blood glucose level over 600 mg/dL and an A1c of 12.8%, along with classic symptoms of new-onset diabetes. Antibody testing confirmed autoimmune diabetes with elevated GAD65 and ZnT8 antibodies, and C-peptide of 1.2 ng/mL, with a glucose of 186 mg/dL. He was started on intravenous insulin and later discharged home on a basal-bolus regimen. To our knowledge, this is the first reported case of GAD65 and ZnT8 positive autoimmune diabetes in a patient with WAS. This case expands the spectrum of autoimmune disease associated with WAS and underscores the importance of maintaining a high index of suspicion for atypical autoimmune presentations in patients with WAS.

ANK2-MAVS signaling dysfunction triggers mitochondrial stress and enhances IL-8 mediated inflammatory responses in Takayasu arteritis.

Patient: Female, 70-year-oldFinal Diagnosis: Granulomatosis with polyangiitis (GPA)Symptoms: Sinusitis • persistent cough • anemia • weight loss • foot numbness and swellingClinical Procedure: —Specialty: ImmunologyObjective: Rare diseaseBackgroundAnti-neutrophil cytoplasmic antibodies (ANCAs) are associated with a group of small-vessel vasculitides collectively known as ANCA-associated vasculitis (AAV), which can lead to rapidly progressive glomerulonephritis and multisystem involvement. In addition to other autoimmune diseases, AAV has been increasingly reported following SARS-CoV-2 infection.Case ReportWe present the case of a 70-year-old woman with a past medical history of atrial fibrillation, sick sinus syndrome, breast cancer, gastroesophageal reflux disease, and anxiety, who developed a rare phenomenon of dual ANCA-positive pauci-immune glomerulonephritis following coronavirus disease 2019 (COVID-19). She initially presented with refractory sinusitis and a persistent cough. Over 5 months, she developed iron-deficiency anemia and, eventually, a rapid decline in renal function. Serologic testing revealed dual positivity for anti-proteinase 3 (PR3, c-ANCA) and anti-myeloperoxidase (MPO, p-ANCA). Renal biopsy confirmed pauci-immune glomerulonephritis. She was ultimately diagnosed with granulomatosis with polyangiitis (GPA).ConclusionsThis case highlights a potential post-infectious autoimmune phenomenon triggered by SARS-CoV-2 and underscores the importance of considering AAV in patients with unexplained systemic symptoms and renal dysfunction after COVID-19. Furthermore, the mechanism of AAV seroconversion and disease progression may be linked to the ability of SARS-CoV-2 to induce the formation of neutrophil extracellular traps (NETs) through both direct viral-neutrophil interactions and cytokine-mediated inflammation. Our findings contribute to the growing body of evidence linking viral infections to the emergence of autoimmune vasculitis.

Kawasaki disease (KD) is an acute autoimmune vasculitis that predominantly affects children under 5 years of age. Although immune dysregulation is considered central to KD pathogenesis, the cellular heterogeneity and regulatory mechanisms underlying this process remain incompletely understood. Single-cell multi-omics technologies provide an opportunity to characterize immune alterations at high resolution. Peripheral blood mononuclear cells (PBMCs) were obtained from two children with typical KD and two age-matched healthy controls. Integrated single-cell RNA sequencing (scRNA-seq) and single-cell assay for transposase-accessible chromatin sequencing (scATAC-seq) were performed to characterize immune cell composition, transcriptional profiles, and chromatin accessibility. Comparative analyses were conducted to identify altered immune cell subsets and dysregulated signaling pathways in KD. Children with KD exhibited marked immune dysregulation, characterized by altered proportions and functional states of multiple PBMC subsets, including T cells, B cells, and natural killer (NK) cells. Notably, specific NK cell subsets were associated with the pathogenesis of intravenous immunoglobulin (IVIG)-resistant KD. Pathway analyses revealed significant dysregulation of toll-like receptor signaling, B cell and T cell receptor signaling, Th17 and Th1/Th2 differentiation, NK cell-mediated cytotoxicity, and platelet activation pathways. By integrating scRNA-seq and scATAC-seq data, this study delineates the heterogeneity of immune cell populations in KD at the single-cell level. The findings highlight coordinated immune and platelet activation pathways that may contribute to KD-associated inflammation and IVIG resistance. These results provide mechanistic insights into KD immunopathogenesis and suggest potential cellular and molecular targets for therapeutic intervention.

BackgroundThe intolerance of the body to neutrophil antigens drives the pathogenesis of childhood anti-neutrophil cytoplasmic autoantibody-associated vasculitis (AAV), making neutrophils a central focus of research on the disease’s underlying mechanisms.MethodsWe performed single-cell RNA sequencing on 18 peripheral blood samples (including three healthy human samples, twelve samples from patients with different types of AAV, and three samples from patients after AAV treatment) to investigate neutrophil heterogeneity in AAV. These bioinformatics findings were subsequently validated through comprehensive experimental approaches, including in vitro cellular assays, in vivo animal studies, clinical sample analyses, and correlation with patient clinical data.ResultsIn AAV, neutrophils were reclassified into seven distinct clusters, Neutrophils2 (N2, CD10+CD11B++) exhibited significant expansion (P<0.01), while Neutrophils5 (N5, CD10−CD11B++) showed a trend toward increase (P>0.05). This phenomenon has been confirmed by the experimental autoimmune vasculitis model (CD10+CD11B++, P<0.001; CD10−CD11B++, P<0.05). The bioinformatics results indicated that both CD10+CD11B++ neutrophils and CD10−CD11B++ neutrophils exhibited dominant pro-inflammatory activities, including neutrophil activation, reactive oxygen species production, neutrophil extracellular trap formation, and degranulation. Pseudotime trajectory and RNA velocity analyses indicated direct differentiation of CD10+CD11B++ neutrophils from CD10−CD11B++ neutrophils. Experiments using HL-60 cells demonstrated that the peripheral blood microenvironment of AAV promotes the generation of CD11B++ neutrophils (P<0.001). Functionally relevant metabolic profiling revealed a substantial reduction in glutamine metabolism in the CD10+CD11B++ neutrophils of AAV patients compared to controls (P<0.001), which was restored following treatment (P<0.001). Experimental results demonstrated that increasing glutamine concentration in the microenvironment of HL-60 cells can decrease the production of CD11B++ neutrophils (P<0.001). Clinical data demonstrate that peripheral blood GGT concentrations increase in patients following treatment (P<0.01).ConclusionThese findings identify two novel pathogenic neutrophil subsets and suggest that modulation of glutamine metabolism is a promising avenue for further investigation as a potential therapeutic strategy in childhood AAV.

Disseminated mucormycosis is a rare, angioinvasive fungal infection predominantly affecting immunocompromised individuals, especially those with poorly controlled diabetes. A 57-year-old Palestinian woman presented with sudden unilateral blindness, ophthalmoplegia, facial numbness, and ptosis, with hyperglycemia. Early brain MRI/MRA/MRV findings were normal, suggesting that giant cell arteritis, or other autoimmune vasculitis, was suspected; thus, IV steroids were administered. Subsequently, her condition progressed to bilateral fixed pupils, complete ophthalmoplegia, and palatal black necrosis. Subsequent imaging and sinus biopsy confirmed disseminated mucormycosis. Treatment included intravenous Amphotericin B, anticoagulation, functional endoscopic sinus surgery, and later left eye enucleation. Despite maximal therapy, she developed a large hemorrhagic venous infarction and ultimately died. Mucormycosis can initially mimic autoimmune or vascular neuro-ophthalmic disease and may present with normal imaging. In acute vision loss with hyperglycemia, maintaining early suspicion and avoiding corticosteroids until fungal infection is excluded are essential to prevent rapid, fatal progression.

Regulatory T cells (Tregs) are a unique class of immunosuppressive cells that play a key role in managing immune-related diseases. Growing evidence indicates that the immunosuppressive effects of Tregs also rely on cell-to-cell interactions that are facilitated by the secretion of extracellular vesicles (EVs). Treg-derived EVs (Treg-EVs) are lipid bilayer vesicles that are released from Tregs and have been shown to promote intercellular communication and facilitate immune regulation by transferring various messenger RNAs (mRNAs), microRNAs (miRNAs), and proteins. miRNAs are small, noncoding RNA molecules that regulate gene expression after transcription and can influence multiple target genes by binding to the 3'-untranslated region (UTR) of target mRNAs to exert influence on a wide array of cellular functions. Although the roles of miRNAs and Treg-EVs in various diseases have been extensively studied, the regulatory functions of the different miRNAs within Treg-EVs in immune-related diseases remain largely unexplored. In this narrative review, we investigate the functional roles of Tregs and their derived EVs in immune regulation. Then, we discuss the specific roles of miRNAs within Treg-EVs in the context of rheumatoid arthritis (RA), inflammatory bowel disease (IBD), autoimmune vasculitis, multiple sclerosis (MS), and kidney and skin allografts by investigating recent research in autoimmune diseases and transplantation. In these situations, different Treg-EVs can support the treatment of immune-related conditions by delivering miRNAs to specific immune cells and promoting immunosuppression through multiple mechanisms.

Clinical and diagnostic characteristics of autoimmune, infectious, and cryptogenic central nervous system vasculitis at a tertiary care center.

Kawasaki disease (KD) is an acute autoimmune vasculitis and the most common cause of acute vasculitis and acquired heart disease in children. 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA) was identified as a potential therapeutic drug for KD, although its mechanism remained unclear. HCAECs were treated with TNF and serum from patients with KD to construct a KD cell model. CCK8, Elisa, and flow cytometry were performed to evaluate cell function, and western blot was used to detect target proteins. TNF and KD serum induced endoplasmic reticulum stress (ERS) and apoptosis in HCAECs. AUDA alleviated ERS and apoptosis induced by TNF or KD serum, as well as the inhibition of cell viability. Mechanistically, STAT1 transcription enhancer (2-NP) 2-NP inhibited the promoting effect of AUDA on cell proliferation and blocked the inhibitory effect of AUDA on ERS in TNF or KD serum-treated HCAECs. AUDA inhibits TNF and KD serum-induced ERS and apoptosis. This study improves our understanding of the pathogenesis of KD and provides a potential theoretical basis for its treatment.