Immunological Medicine最新文献

The study of Inborn Errors of Immunity (IEIs) is critical for understanding the complex mechanisms of the human immune response to infectious diseases. Specific IEIs, characterized by selective susceptibility to certain pathogens, have enhanced our understanding of the key molecular pathways and cellular subsets involved in host defense against pathogens. These insights revealed that patients with anti-cytokine autoantibodies exhibit phenotypes similar to those with pathogenic mutations in genes encoding signaling molecules. This new disease concept is currently categorized as 'Phenocopies of IEI'. This category includes anti-cytokine autoantibodies targeting IL-17/IL-22, IFN-γ, IL-6, GM-CSF, and type I IFNs. Abundant anti-cytokine autoantibodies deplete corresponding cytokines, impair signaling pathways, and increase susceptibility to specific pathogens. We herein demonstrate the clinical and etiological significance of anti-cytokine autoantibodies in human immunity to pathogens. Insights from studies of rare IEIs underscore the pathological importance of cytokine-targeting autoantibodies. Simultaneously, the diverse clinical phenotype of patients with these autoantibodies suggests that the influences of cytokine dysfunction are broader than previously recognized. Furthermore, comprehensive studies prompted by the COVID-19 pandemic highlighted the substantial clinical impact of autoantibodies and their potential role in shaping the outcomes of infectious disease.

Postural orthostatic tachycardia syndrome (POTS) is characterized by exaggerated orthostatic tachycardia in the absence of orthostatic hypotension. The pathophysiology of POTS may involve hypovolemia, autonomic neuropathy, a hyperadrenergic state, and cardiovascular deconditioning, any of which can co-occur in the same patient. Furthermore, there is growing evidence of the role of autoimmunity in a subset of POTS cases. In recent years, investigators have described an increased rate of autoimmune comorbidities as evidenced by the finding of several types of neural receptor autoantibody and non-specific autoimmune marker in patients with POTS. In particular, the association of the disease with several types of anti-G protein-coupled receptor (GPCR) antibodies and POTS has frequently been noted. A previous study reported that autoantibodies to muscarinic AChRs may play an important role in POTS with persistent, gastrointestinal symptoms. To date, POTS is recognized as one of the sequelae of coronavirus disease 2019 (COVID-19) and its frequency and pathogenesis are still largely unknown. Multiple autoantibody types occur in COVID-related, autonomic disorders, suggesting the presence of autoimmune pathology in these disorders. Herein, we review the association of anti-GPCR autoantibodies with disorders of the autonomic nervous system, in particular POTS, and provide a new perspective for understanding POTS-related autoimmunity.

Myasthenia gravis (MG), which affects the endplate region of the postsynaptic neuromuscular junction, is the best-understood autoimmune disease. MG is driven by anti-acetylcholine receptor (AChR) or muscle-specific receptor tyrosine kinase, and 65% of MG patients have anti-AChR-positive generalized MG. Experimental autoimmune MG is a useful model to investigate the pathogenic mechanisms of anti-AChR antibodies and to evaluate the efficacy of new immunotherapies. Since long-term drug treatment is usually necessary for MG patients, the selection of immunotherapy must be chosen based on an understanding of the pathophysiology, including the roles of the thymus, T cells, B cells, autoantibodies, and neuromuscular junction. The main pathogenic mechanism of MG is the activation of the complement system caused by the attack of anti-AChR antibodies. Molecular technology using the neonatal Fc receptor (FcRn) is currently being applied to the development of new MG therapies. Many biological drugs targeting B cells, interleukin-6, FcRn and complement show promise as potential therapeutics for anti-AChR-positive generalized MG. With regard to anti-AChR antibody detection, the overall agreement rate between radioimmunoassay and enzyme linked immunosorbent assay is 91%, with positive agreement of 87% and negative agreement of 99%.

In recent years, various myositis-specific and myositis-associated autoantibodies have been identified in idiopathic inflammatory myopathies, including dermatomyositis (DM), anti-synthetase syndrome (ASS), immune-mediated necrotizing myopathy (IMNM), and inclusion body myositis (IBM). These autoantibodies exhibit unique characteristics in terms of organ involvement, severity, and treatment response, making their understanding crucial for accurate diagnosis and effective therapy. This review provides a comprehensive overview of the clinical features of recently discovered myositis-specific and associated autoantibodies, while exploring their potential roles in the pathogenesis and exacerbation of myositis. Key findings include the production of anti-TIF1γ antibodies in model mice, the upregulation of Mi2-related genes in anti-Mi2 antibody-positive dermatomyositis muscle tissue, and Jo-1 antigen-induced T cell activation, shedding light on whether disease mechanisms are driven by autoantibodies or autoantigens.

Our aim is to determine the number of leukocytes, T lymphocytes and B lymphocytes and the expression of activation markers CD200 and CD23 on B lymphocytes in atopic dermatitis (AD) patients (treated and not treated with dupilumab) during the pollen season. We examined 29 patients not treated with dupilumab, 24 patients treated with dupilumab and 40 healthy subjects as a control group. The count of T and B lymphocytes and their subsets were assessed by flow cytometry. The non-parametric Kruskal-Wallis one-factor analysis of variance with post hoc by Dunn's test with Bonferroni's modification was used for statistical processing. Although there was a significant improvement in skin findings in patients treated with dupilumab, the changes in immunological profile show a persistent altered immune response characterized by dysregulation and overactivation of B lymphocytes. Dupilumab therapy leads to normalization of relative T regulatory lymphocytes and total memory B lymphocytes and to decreased count of absolute CD8⁺ T lymphocytes. Why carry out this study?Studies investigating the immunological profile of atopic dermatitis (AD) patients during the pollen season are rare. There are no studies investigating the count of B lymphocytes (CD5⁺, CD22⁺ and CD73⁺ B lymphocytes) and the expression of activation markers CD23 and CD200 on B lymphocytes and on their subsets during pollen season in AD patients treated and non-treated with dupilumab therapy.What was learned from the study?In atopic dermatitis (AD) patients with and without dupilumab therapy, we confirmed the significantly higher count of absolute neutrophils, absolute monocytes, absolute eosinophils, absolute basophils, non-switched B lymphocytes, transitional B lymphocytes, CD23 memory, naive, non-switched, switched and total CD23 B lymphocytes, the relative count of CD200 memory and CD200 switched B lymphocytes.In dupilumab treated patients, we confirmed the significantly higher count of relative eosinophils, relative CD16⁺ eosinophils, relative CD200 non-switched B lymphocytes and lower count of absolute CD8⁺ T lymphocytes. Further studies should focus on investigating the effect of dupilumab on CD8⁺ T lymphocytes and their subpopulations.In patients without dupilumab therapy, we confirmed the significantly higher count of relative neutrophils, relative T regulatory lymphocytes and total memory B lymphocytes.The changes in the count of CD5⁺, CD22⁺ and CD73⁺ B lymphocytes were not observed during pollen season in both groups of AD patients.

Elevated liver enzymes are commonly observed among adult-onset Still's disease (AOSD), but severe acute liver failure is extremely rare. Although severe acute liver failure associated with AOSD poses a life-threatening condition, the appropriate treatment is unclear. Some case reports have demonstrated the efficacy of high-dose prednisolone (PSL) and cyclosporin A (CyA), although the adverse effects of CyA led certain patients to cease its use. Therefore, an alternative treatment option is crucial, and thus far, there have been no reports of tocilizumab (TCZ) being used for this severe phenotype. Here, we report the first case of successful treatment using TCZ as maintenance therapy for severe ALF associated with AOSD. Following initial treatment with high-dose PSL and CyA, our case was switched to TCZ due to CyA-related side effects including alopecia and tremors. Our case highlights TCZ as a potential option for maintenance therapy of this severe condition.

Familial Mediterranean Fever (FMF) is the most common hereditary autoinflammatory disease, characterized by recurrent fever, arthritis, rash, and serositis, and is caused by mutations in the MEFV gene coding for the pyrin protein. The primary treatment goal is to prevent acute attacks and minimize subclinical inflammation to avoid secondary amyloidosis with colchicine as the first-line treatment. However, 10-20% of patients are colchicine-resistant or intolerant. While the therapeutic potential of IL-6 inhibitors such as tocilizumab (TCZ) has been suggested, the detailed serum cytokine profiles after TCZ treatment in patients with FMF remain largely unexplored. This study focused on a sub-analysis of a clinical trial evaluating TCZ in patients with colchicine-resistant FMF (crFMF). We analyzed the serum cytokine profiles at 0, 2, 4, 8, 12, 16, 20, and 24 weeks in the TCZ and placebo groups. Our findings revealed a decrease in serum C-X-C motif chemokine ligand 1 and vascular endothelial growth factor levels in the TCZ group at week 4 compared to baseline, which persisted until week 24, indicating the potential of TCZ to manage crFMF by modulating specific inflammatory cytokines. Further research is required to confirm these findings and optimize the treatment strategies for FMF.

X-linked NF-κB essential modulator (NEMO) deficiency is a primary immunodeficiency characterized by combined immunodeficiency and ectodermal dysplasia. Monocytes from the patients demonstrate a severely impaired response to tissue necrosis factor or lipopolysaccharide, whereas hyper-inflammation is found in some patients. Juvenile myelomonocytic leukemia (JMML) is a pediatric malignancy caused by hypersensitivity to granulocyte-macrophage colony-stimulating factor (GM-CSF) and aberrant RAS signaling activation. Patients with JMML demonstrate characteristic manifestations such as splenomegaly, monocytosis and the presence of myeloid or erythroid precursors in the peripheral blood. Here, we present the case of a male infant with ectodermal dysplasia, bacterial septicemia, Pneumocystis pneumonia, severe inflammation and transient manifestations mimicking JMML. Genetic analysis revealed a deep intronic germline variant of IKBKG. Full-length IKBKG cDNA and NEMO protein expression were almost inexistent. Peripheral mononuclear cells (PBMCs) from the patient showed increased RAS signaling activation with GM-CSF or Phorbol 12-myristate 13-acetate without the RAS-associated gene variant, although the increased RAS signaling activation in induced-pluripotent stem cell-derived myeloid lineage and bone marrow-derived mesenchymal cells was not evident. The patient with NEMO deficiency demonstrated JMML-like manifestation and severe inflammation. PBMCs of the patient demonstrated increased RAS signaling activation with unknown pathophysiology.

We compared different antineutrophil cytoplasmic antibody (ANCA) detection methods using a predominantly myeloperoxidase (MPO)-ANCA-associated vasculitis cohort. Stored sera from 147 patients with untreated ANCA-associated vasculitis (AAV), including microscopic polyangiitis and granulomatosis with polyangiitis (n = 115 and 32, respectively), and 124 disease controls were tested for P-ANCA and C-ANCA with immunofluorescence (IIF), and for MPO-ANCA and proteinase 3 (PR3)-ANCA with different antigen-specific immunoassays: direct enzyme-linked immunosorbent assay (ELISA), chemiluminescent enzyme immunoassay (CLEIA), third-generation fluorescent enzyme immunoassay (FEIA), and latex turbidimetrical immunoassay (LTIA). In addition, MPO-ANCA and PR3-ANCA titers were calibrated using certified reference materials (CRMs). The sensitivities and specificities for AAV diagnoses were 95% and 94% (IIF), 86% and 98% (ELISA), 93% and 94% (CLEIA), 92% and 96% (FEIA), and 68% and 88% (LTIA). Dual IIF/antigen-specific immunoassay testing reduced diagnostic accuracies from 94% to 93%. The quantitative agreement between ANCA levels measured using CLEIA and FEIA and calibrated using CRMs was not good. In conclusion, this study demonstrated the high performance of antigen-specific immunoassays for AAV diagnosis in a predominantly MPO-ANCA-associated vasculitis cohort and suggested that the benefit of dual IIF/antigen-specific immunoassay testing is limited. Standardizing ANCA measurements using different immunoassays was difficult, even when using CRMs.