Search Results (231)

Introduction/Aims: Myopathies with Tubular Aggregates (TAM) are rare, chronic neuromuscular disorders that may be inherited or acquired. The aim of this report is to present the diagnostic pathway and the challenges encountered in a family with three members affected by TAM caused by a rare ORAI1 variant. Case report: Two siblings (15 and 11 years old) developed severe rhabdomyolysis triggered by a viral respiratory infection. Histopathological analysis demonstrated numerous tubular aggregates with mild focal secondary inflammatory changes and no immunophenotypic evidence of autoimmune inflammatory myopathy. Whole-exome sequencing identified a likely pathogenic heterozygous missense variant, NM_032790.3(ORAI1):c.319G>A (p.Val107Met), in the ORAI1 gene, in both children and their asymptomatic mother. Conclusions: The identification of a rare ORAI1 variant in this family supports the association with TAM, broadens the spectrum of phenotypic presentation, and illustrates the phenotypic variability that may exist even among affected members of the same family. Careful interpretation of inflammatory changes in muscle biopsy, together with immunohistochemical and genetic findings, is essential to avoid misclassification of hereditary tubular aggregate myopathy as autoimmune inflammatory myopathy. Full article

Type 1 diabetes mellitus (T1DM) is regarded as an autoimmune disorder characterized by a progressive loss of β-cells, culminating in insulin deficiency and hyperglycemia. Currently, T1DM is managed through exogenous insulin administration. Continued efforts to decipher T1DM pathogenesis have yielded significant progress, which can be harnessed to develop disease-modifying therapeutic modalities. Immunological and genetic studies have demonstrated pathogenetic mechanisms that underpin the sensitivity and risk of developing autoimmunity, ultimately leading to the destruction of β-cells. Genetic and immunological studies, therefore, suggest that certain individuals are at risk of developing T1DM; and that autoantibodies against β-cells develop and circulate years before the onset of symptomatic T1DM. Furthermore, the onset of autoimmunity has been associated with specific triggers in genetically susceptible individuals. Recent developments have revealed how viral infections, gut dysbiosis, dietary factors, and obesity trigger autoimmunity and β-cell damage. In this review, we present the current, consolidated understanding of T1DM pathogenesis, informed by recent research. We further identify opportunities for early-detection strategies and drug development targeting the asymptomatic phase of T1DM to slow disease progression. Currently, immunomodulatory strategies have yielded promising outcomes in clinical trials. These strategies seek to target immune cells and inflammatory mediators implicated in the pathogenesis of T1DM. Other strategies include tolerogenic strategies against autoimmune cells, whilst others employ β-cell protection. The emergence of regenerative therapies also offers promising avenues toward T1DM. Full article

Background: Therapeutic plasma exchange (TPE) is increasingly used in pediatric neuroimmunological disorders; however, evidence remains limited, particularly for rare neuroinflammatory and infection-triggered encephalopathy syndromes. We aimed to describe the clinical characteristics, treatment patterns, and outcomes of critically ill children who underwent TPE for neuroimmunological disorders in a tertiary pediatric intensive care unit. Methods: This retrospective observational study included consecutive patients younger than 18 years who received TPE for neuroimmunological disorders between September 2020 and December 2025. Demographic characteristics, disease spectrum, TPE indications, treatment details, neuroimaging findings, cerebrospinal fluid (CSF) characteristics, and clinical outcomes were reviewed. Neurological outcome at hospital discharge was assessed using the Pediatric Cerebral Performance Category (PCPC) score. Results: Twenty-two patients were included. The median age was 104 months (IQR, 62.3–151.8), and 50% were female. Guillain–Barré syndrome (GBS) was the most common diagnosis (n = 6), followed by autoimmune encephalitis (n = 6), infection-triggered encephalopathy syndrome (ITES)/acute necrotizing encephalopathy (ANE) spectrum disorders (n = 4), myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) (n = 3), acute disseminated encephalomyelitis (ADEM) (n = 2), and mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) (n = 1). The median interval from symptom onset to TPE initiation was 9 days (IQR, 6–13), and patients underwent a median of 7 TPE sessions (IQR, 5–10.5). Nine patients (40.9%) required invasive mechanical ventilation and four (18.1%) required vasoactive support. Favorable neurological outcomes at hospital discharge were observed in 63.6% of patients, whereas 36.4% had unfavorable neurological outcomes. Mortality occurred in 13.6% of patients and was confined to severe encephalopathic syndromes. No major TPE-related complications were observed. Conclusions: TPE was used across a heterogeneous spectrum of pediatric neuroimmunological disorders, including both guideline-supported and non-standard indications. Approximately one-quarter of patients had conditions not specifically addressed in current ASFA recommendations, highlighting the gap between real-world clinical practice and the available evidence base. Multicenter studies are needed to better define the optimal role, timing, and patient selection criteria for TPE in pediatric neuroimmunology. Full article

Background: Anaplasmosis is an emerging tick-borne infection that typically presents as a non-specific febrile illness, with variable degrees of cytopenias and liver tests abnormalities. Severe complications remain atypical and uncommon. Case Report: We report a case of acute pulmonary embolism (PE) occurring during confirmed anaplasmosis in a 73-year-old male with no traditional thromboembolic risk factors. The patient presented with fever, constitutional symptoms, thrombocytopenia, leukopenia, and abnormal liver tests, raising suspicion for a tick-borne illness. Despite early clinical improvement on doxycycline, persistent tachycardia triggered further evaluation and uncovered an acute PE. Comprehensive workup at admission and repeated 14 months later excluded inherited and acquired thrombophilias, malignancies, autoimmune diseases, and alternative infectious etiologies. The patient was treated with doxycycline 100 mg orally twice daily for 10 days and anticoagulation with unfractionated heparin followed by 6 months of apixaban for a first episode of provoked PE. He attained complete clinical recovery without recurrence of thrombosis at the two-year follow-up. Discussion: Infectious diseases are increasingly recognized as contributors to thrombosis through inflammation-mediated hypercoagulability and endothelial dysfunction. Pulmonary involvement in anaplasmosis typically manifests as pneumonitis, pneumonia or acute respiratory distress syndrome, but thrombotic complications such as PE are exceedingly rare. This case highlights a rare but clinically significant vascular complication of anaplasmosis and underscores the importance of considering thromboembolic events in patients with persistent or unexplained tachycardia. Conclusions: As the incidence of anaplasmosis continues to rise, greater awareness of its potential cardiovascular manifestations is essential. Early recognition and prompt treatment with doxycycline remain critical, while further studies are needed to better define the thrombotic risk associated with this infection. Full article

Multiple sclerosis (MS) is a chronic immune-mediated disease of the central nervous system characterized by demyelination, neuroinflammation, and progressive neurodegeneration. While there is a small component of genetic susceptibility to MS risk, environmental factors, including infectious exposures, are gaining increased recognition as playing a critical role in MS initiation and progression. Viral infections, especially by Epstein–Barr virus (EBV), have emerged as strong candidates and triggers of MS symptoms, through antibody-mediated molecular mimicry and B-cell dysregulation. In contrast, parasitic infections, including helminths and select protozoa, appear to exert neuroprotective effects by skewing immune responses toward regulation and tolerance. In this review, we examine antibody-driven mechanisms by which viral pathogens promote autoimmunity in MS and contrast these with parasite-induced immunoregulatory pathways that suppress pathogenic inflammation. We further discuss diagnostic and therapeutic implications, highlighting how insights from infectious immunology may inform novel strategies for MS treatment. Full article

Background: Increasing evidence suggests that COVID-19 can induce or exacerbate autoimmune disorders, including immune-mediated thyroid dysfunction. The most common autoimmune thyroid diseases are Graves’ disease and Hashimoto’s thyroiditis; the mechanisms by which viral infections like SARS-CoV-2 trigger these diseases are not fully understood. Objectives: This study aims to systematically review published clinical evidence on the presentation, laboratory characteristics, and outcomes of autoimmune thyroid diseases after COVID-19 infection. Methods: The review followed the PRISMA 2020 framework. Scopus, Web of Science, and PubMed were searched for English-language studies between January 2020 and December 2025 using the terms COVID-19, SARS-CoV-2, autoimmune thyroiditis, Graves’ disease, Hashimoto’s thyroiditis, and autoimmune thyroid disease. Results: In total, 46 studies (five cohort studies and 41 case reports/series) involving 3856 patients were analyzed. The findings indicate that a significant increase in TPOAb prevalence occurs post-COVID-19 infection (15.7% vs. 7.7% in controls). New-onset Graves’ disease (GD) post-COVID-19 presented with higher fT3/fT4 ratios and more aggressive thyrotoxicosis compared to non-viral cases. Rare but severe manifestations included thyrotoxic periodic paralysis, Hashimoto’s encephalopathy, and dilated cardiomyopathy. Conclusions: SARS-CoV-2 may act as a trigger for autoimmune thyroid diseases, particularly in moderate-to-severe infections; however, the strength of this association warrants further investigation with controlled prospective data. Standard therapy remains effective, but thyroid function monitoring is advisable during post-COVID-19 recovery. An interdisciplinary approach is essential for early diagnosis and management of systemic complications. Full article

The hypothesis that Group A beta-haemolytic Streptococcus (GAS) triggers an autoimmune cascade targeting basal ganglia dopaminergic circuits—producing obsessive–compulsive disorder (OCD), tic disorders, or chorea depending on the receptor subtype involved—is biologically compelling and supported by emerging molecular evidence. Yet PANDAS has remained a diagnostic conundrum since its original description in 1998, with ongoing uncertainty surrounding diagnostic criteria, the interpretation of streptococcal serology, and the distinction from primary neurodevelopmental disorders. This study aimed to review the diagnostic challenges of PANDAS, with focus on streptococcal serology interpretation, advances in dopamine receptor autoantibody biology, the genetic epidemiology of primary tic disorders, and the differential diagnosis of acute neuropsychiatric presentations in children. A structured narrative review was conducted using PubMed, MEDLINE, EMBASE, and the Cochrane Library for publications from 1998 to early 2025 addressing PANDAS, PANS, streptococcal antibodies, childhood movement disorders, autoimmune encephalitis, and the genetics of tic disorders. No currently available biomarker—including ASO, anti-DNase B, anti-basal-ganglia antibodies, or the Cunningham Panel—has demonstrated adequate individual-level diagnostic accuracy for PANDAS. Emerging molecular evidence identifies anti-D1R autoantibodies, acting via G protein-and beta-arrestin-mediated signalling, as candidate biomarkers for PANDAS/PANS neuropsychiatric phenotypes, and anti-D2R autoantibodies for Sydenham chorea movement phenotypes; independent replication in unselected populations is required. Primary tic disorders carry heritability estimates of 50–80% and first-degree familial risk ratios of approximately 18-fold in large population-based cohorts. Prospective blinded studies have not demonstrated a consistent population-level association between GAS infections and tic or OCD exacerbations: PANDAS and PANS remain diagnoses of exclusion. The high background prevalence of both GAS exposure and primary neurodevelopmental disorders in overlapping paediatric age ranges creates conditions for incidental temporal co-occurrence. In the absence of validated molecular biomarkers, diagnostic imprecision carries direct clinical consequences: children may be exposed to treatments with significant risk profiles—including IVIG, plasma exchange, and prolonged antibiotic prophylaxis—while evidence-based therapies are delayed. A stepwise diagnostic approach incorporating the full differential diagnosis is both an epistemological and a patient safety imperative. Full article

Systemic lupus erythematosus (SLE) is a prototypic systemic autoimmune disorder arising from the convergence of genetic susceptibility, epigenetic remodeling, environmental exposures, and dysregulated immune networks. Although traditionally characterized by autoantibody production and immune complex mediated tissue injury, advances in genomics, systems immunology, and multi-omics profiling have revealed that lupus represents a multilayered failure of immune homeostasis driven by interconnected molecular circuits. Genetic variants enriched in regulatory immune enhancers establish a permissive transcriptional landscape that sensitizes innate nucleic acid sensing pathways and interferon signaling. Epigenetic remodeling further amplifies inflammatory transcriptional programs, while environmental triggers such as ultraviolet radiation and viral infection initiate bursts of nucleic acid release and immune activation. Defective apoptotic cell clearance, mediated in part by scavenger receptor dysfunction and complement abnormalities, increases the availability of immunogenic nucleic acids that engage pattern recognition receptors and drive chronic type I interferon production. This interferon-dominated environment rewires immune cell metabolism, alters differentiation trajectories of T and B lymphocytes, and sustains autoreactive immune circuits. Emerging multi-omics studies reveal distinct molecular endotypes defined by interferon signatures, metabolic states, and immune cell composition, highlighting the heterogeneity of disease mechanisms across patients. In this review, we integrate genetic, epigenetic, metabolic, and immunological insights to propose a systems-level model of lupus pathogenesis in which defective debris clearance, nucleic acid sensing, interferon amplification, and metabolic reprograming form a self-reinforcing pathogenic network. Understanding this integrated molecular architecture provides a foundation for biomarker-guided therapeutic strategies and precision medicine approaches aimed at disrupting the key nodes that sustain chronic autoimmunity in SLE. Full article

This study is a narrative review of natural killer (NK) cells in Behcet disease (BD). BD is an inflammatory disorder with manifestations in mucosal tissues. Unlike autoimmune diseases that generate autoantibodies, BD is believed to be an autoinflammatory disease triggered by innate immune cells rather than adaptive cells. Hyperactivation of neutrophils causes vasculitis and thrombosis, and they migrate into cutaneous and ocular lesions. Dominance of M1 macrophages promotes the differentiation of Th1 cells. Moreover, the cross-reaction of bacterial heat shock proteins induces production of cytokines such as IL-4 and IFN-γ in γδT cells, which alters the balance between Th1 and Th2 phenotypes. Nevertheless, NK cells play more critical roles in BD pathogenesis than other innate immune cells because not only is their activity precisely controlled by the interaction between ligands and receptors, but NK1 shift also elicits Th1 dominance. The genetic factors associated with BD are HLA-B51 and major histocompatibility complex class I-related chain A (MICA), which stimulate NK receptors as ligands. Improperly processed peptides dysregulate their interaction with NK receptors, triggering the inflammatory response. NK1 and NK2 subsets represent cytokine production in relapse and remission periods; however, the cytotoxicity of NK cells in relapse is lower than that in remission periods. It still remains unclear how NK cells are activated recurrently and expand cytokine production. This review highlights the regulation of gene expression encoding NK receptors, tissue-resident NK cells, and adaptive NK cells to discuss their potential for relapse. Splicing variants and readthrough genes encoding NK receptors easily alter cytokine production. Moreover, tissue-resident NK cells in mucosal tissues and adaptive NK cells that memorize the virus infection have the potential to trigger hyperactivation in relapse. Full article

Background: Guillain–Barré syndrome (GBS) is an autoimmune peripheral neuropathy that can lead to paralysis and respiratory failure. In addition to infections, several drugs have been suggested as potential triggers of GBS. This study investigated drug-associated GBS using a spontaneous adverse event reporting database through disproportionality analysis for signal detection and time-to-onset analysis. Methods: The Japanese Adverse Drug Event Report (JADER) database was analyzed to assess more than 4000 drugs for potential associations with GBS. Signal detection was performed using reporting odds ratios, Fisher’s exact test, and total report counts. For vaccines and immune checkpoint inhibitors, time-to-onset patterns were further evaluated using Weibull distribution analysis. Results: Disproportionality signals suggesting potential associations with GBS were identified for 45 drugs, including vaccines, immune checkpoint inhibitors, tumor necrosis factor-α inhibitors, other anticancer drugs, antifungal agents, and interferons. Reports following vaccination were most frequently observed within 1–3 weeks after administration of coronavirus disease 2019 (COVID-19), influenza, and pneumococcal vaccines, and within 1–3 months after human papillomavirus 2-valent vaccination, with a gradual decrease thereafter. Reports following immune checkpoint inhibitor use were most frequently observed 1–3 months after nivolumab, ipilimumab, and pembrolizumab administration, whereas atezolizumab showed a peak in reporting within 1–3 weeks. In contrast to vaccine-related reports, no clear temporal trend in reporting was observed. Conclusions: Drugs that modulate immune function, including vaccines and immune checkpoint inhibitors, may be associated with reported GBS events. Vaccine-related reports showed an early concentration in time to onset, whereas immune checkpoint inhibitor-related reports did not demonstrate a clear temporal pattern. These findings should be interpreted as hypothesis-generating and warrant further investigation. Full article

Background: Brucellosis is a globally distributed zoonotic disease characterized by highly variable clinical manifestations that may mimic systemic autoimmune and inflammatory disorders. In Europe, where the incidence of brucellosis is relatively low, limited clinical awareness may contribute to delayed diagnosis and inappropriate management. In addition to zoonotic transmission, Brucella species are a well-recognized cause of laboratory-acquired infections (LAIs) among microbiology laboratory personnel. Methods: We report a case of laboratory-acquired Brucella abortus infection in a young woman presenting with undulant fever, arthralgia, systemic inflammation, elevated ferritin levels, and antinuclear antibody (ANA) positivity. Microbiological confirmation was achieved through serological testing (ELISA), repeat blood cultures, species-specific quantitative PCR, and whole-genome sequencing (WGS) followed by core genome multilocus sequence typing (cgMLST). Results: Initial laboratory evaluation revealed elevated C-reactive protein, mildly increased ferritin levels (146 ng/mL), abnormal liver enzyme levels, and rising ANA titers (from 1:160 to 1:320), raising suspicion of a systemic autoimmune disorder and prompting consideration of corticosteroid therapy. Although the initial blood culture was negative, subsequent molecular diagnostics and repeat cultures confirmed B. abortus infection. Epidemiological investigation suggested a possible occupational exposure in a diagnostic microbiology laboratory, consistent with a laboratory-acquired infection. Genomic analysis classified the isolate as sequence type 1 (ST1) and demonstrated zero allelic differences compared with the ST1 reference strain. Targeted antimicrobial therapy resulted in complete clinical recovery, supporting an infection-triggered immune response rather than primary autoimmunity. Conclusions: Acute brucellosis should be considered in the differential diagnosis of febrile syndromes accompanied by autoimmune-like laboratory abnormalities, even in low-incidence regions. This case highlights the diagnostic challenges posed by laboratory-acquired brucellosis and underscores the importance of early microbiological investigation and strict biosafety awareness in laboratory settings. Full article

Lyme disease (LD) is classically defined as a tick-borne infection caused by Borrelia burgdorferi sensu lato (Bbsl). However, accumulating evidence indicates that, beyond microbial persistence, Bbsl infection can initiate sustained immune dysregulation and post-infectious inflammatory phenotypes in a subset of patients. This narrative review integrates open-access experimental, translational, and clinical data and discusses LD within the spectrum of infection-triggered, immune-mediated processes. We review key immunopathogenic mechanisms, including dysregulated innate immune activation, type I interferon (IFN-I) signaling, T helper 1 and T helper 17 (Th1/Th17) polarization with regulatory T-cell (Treg) insufficiency, antigen persistence (notably borrelial peptidoglycan), and pathways linking infection to autoimmunity such as molecular mimicry, epitope spreading, and human leukocyte antigen (HLA)-restricted susceptibility. These mechanisms are integrated with immune-mediated clinical manifestations affecting the central nervous system (CNS), peripheral nervous system (PNS), musculoskeletal system, heart, skin, and hematologic compartment. Finally, we discuss translational implications for diagnosis, biomarker-guided stratification, and emerging therapeutic strategies that extend beyond antimicrobial therapy, while addressing current controversies and limitations. This framework supports a mechanistic model in which Lyme disease-associated morbidity in selected patients reflects persistent immune activation and dysregulated host responses triggered by infection. Full article

Neutrophils are among the early responders of the innate immune system and play a key role in host defense against viral infections. Beyond their classical antimicrobial functions, neutrophils can engage in a specialized defense mechanism by releasing web-like extracellular DNA known as neutrophil extracellular traps (NETs). These extracellular traps are a mesh-like network of chromatin DNA decorated with cellular components, including histones, proteases, and antimicrobial enzymes, that function to contain and limit the spread of pathogens. While NET formation contributes to antiviral immunity, accumulating evidence indicates that excessive or dysregulated NET formation can significantly contribute to immunopathology during viral infections. Thus, depending on the context and outcome, NET formation may be viewed as a double-edged sword. Therefore, understanding the regulatory mechanisms governing NET formation and its harmful effects is critical for developing therapeutic strategies that enhance antiviral defense while minimizing tissue damage. In this review, we provide a comprehensive overview of the molecular mechanisms that drive NET formation and clearance, with a particular focus on how viruses modulate these processes to influence disease outcome. We also discuss the pathways underlying NET formation and subsequent neutrophil cell death (NETosis), including canonical and non-canonical pathways, and highlight key signaling axes involving SYK, MAPKs, and NF-κB. Using SARS-CoV-2 and hepatitis B virus as representative models, we examine how different viral components trigger, exploit, or evade NET targeting and how persistent accumulation of NETs can contribute to hyperinflammation, progressive tissue injury, and post-viral syndromes. We further explore emerging evidence linking impaired NET clearance and neutrophil heterogeneity, particularly low-density neutrophils (LDNs), to chronic inflammation and post-viral sequelae such as long COVID and autoimmune hepatitis. Finally, we summarize current and emerging therapeutic strategies aimed at modulating NET formation or enhancing NET clearance. Altogether, this review underscores the dual nature of NETs in viral infections, highlighting their potential roles in antiviral defense and tissue injury, and provides a framework for the development of targeted interventions to limit virus-induced immunopathology. Full article

Background: Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an autoimmune disorder frequently associated with ovarian teratomas in young women. Although infectious triggers have been proposed to contribute to immune activation, direct evidence linking viral presence within tumor tissue to disease pathogenesis remains limited. Case Presentation: An 18-year-old woman presented with acute neuropsychiatric symptoms, fever, gastrointestinal prodrome, and rapidly progressive behavioral disturbance progressing to encephalopathy. Cerebrospinal fluid and blood test results, together with clinical features, supported the diagnosis of anti-NMDAR encephalitis. Imaging identified an ovarian mass, and surgical resection was performed. Histopathology confirmed a mature teratoma containing neuroglial elements. Molecular analysis detected parvovirus B19 DNA within the resected teratomatous tissue. No systemic viremia or active central nervous system viral infection was identified. The patient received immunotherapy combined with tumor removal, with subsequent clinical improvement. Discussion: Ovarian teratomas remain a critical etiologic factor in anti-NMDAR encephalitis and mandate prompt surgical management. Detection of B19 viral DNA within teratomatous neuroglial tissue raises the hypothesis that viral persistence could enhance local immune activation and autoantibody generation. However, in this case polymerase chain reaction positivity does not indicate active infection, and the biological significance of this finding remains uncertain. Conclusions: This case documents rare detection of B19V DNA within an ovarian teratomatous tissue in anti-NMDAR encephalitis. The observation is hypothesis-generating rather than causal; established management priorities remain immunotherapy and tumor resection, and viral nucleic acid detection should be interpreted within the broader clinical context. Full article

Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease characterized by cholestasis, which can progress to end-stage liver disease and even hepatocellular carcinoma. Its onset is typically triggered by complex interactions between genetic and environmental factors. In recent years, epidemiological and mechanistic studies have highlighted bacterial and fungal infections as potential key environmental factors in PBC pathogenesis. Bacteria may be associated with PBC autoimmunity through mechanisms such as molecular mimicry. Gut microbiota dysbiosis has been linked to aberrant immune recognition, altered metabolites, and intestinal barrier disruption, which may contribute to the aggravation of liver injury. Case reports of fungal infections suggest an association with poor prognosis in PBC, although the underlying mechanisms remain to be elucidated. This review systematically summarizes existing clinical epidemiological data, microbiome association studies, and mechanistic evidence; synthesizes the possible molecular mechanisms linking bacterial infections to PBC development and progression; discusses the potential role of the gut microbiota in PBC progression; and analyzes the possible molecular mechanisms underlying the poor prognosis associated with fungal infections in PBC. This study aims to provide valuable insights for developing optimal prevention, diagnosis, and treatment strategies targeting bacterial and fungal infections in PBC. Full article