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    CD4(+) T cells of myasthenia gravis patients are characterized by ıncreased IL-21, IL-4, and IL-17A productions and higher presence of PD-1 and ICOS
    (Frontiers Media SA, 2020) Çebi, Merve; Durmuş, Hacer; Aysal, Fikret; Özkan, Berker; Engin Gül, Gizem; Çakar, Arman; Hocaoğlu, Mehmet; Mercan, Metin; Yentur, Sibel Penbe; Tütüncü, Melih; Yayla, Vildan; Akan, Onur; Doğan, Öner; Parman, Yeşim; Saruhan-Direskeneli, Güher
    Myasthenia gravis (MG) is an autoimmune disease mediated by autoantibodies predominantly against the acetylcholine receptor (AChR). Specific T cell subsets are required for long-term antibody responses, and cytokines secreted mainly from CD4(+) T cells regulate B cell antibody production. The aim of this study was to assess the differences in the cytokine expressions of CD4(+) T cells in MG patients with AChR antibodies (AChR-MG) and the effect of immunosuppressive (IS) therapy on cytokine activity and to test these findings also in MG patients without detectable antibodies (SN-MG). Clinically diagnosed AChR-MG and SN-MG patients were included. The AChR-MG patients were grouped as IS-positive and -negative and compared with age- and sex-matched healthy controls. Peripheral blood mononuclear cells were used for ex vivo intracellular cytokine production, and subsets of CD4(+) T cells and circulating follicular helper T (cTfh) cells were detected phenotypically by the expression of the chemokine and the costimulatory receptors. Thymocytes obtained from patients who had thymectomy were also analyzed. IL-21, IL-4, IL-10, and IL-17A productions in CD4(+) T cells were increased in AChR-MG compared to those in healthy controls. IS treatment enhanced IL-10 and reduced IFN-gamma production in AChR-MG patients compared to those in IS-negative patients. Increased IL-21 and IL-4 productions were also demonstrated in SN-MG patients. Among CD4(+) T cells, Th17 cells were increased in both disease subgroups. Treatment induced higher proportions of Th2 cells in AChR-MG patients. Both CXCR5(+) and CXCR5(-) CD4(+) T cells expressed higher programmed cell death protein 1 (PD-1) and inducible costimulatory (ICOS) in AChR-MG and SN-MG groups, mostly irrespective of the treatment. Based on chemokine receptors on CXCR5(+)PD-1(+) in CD4(+) T (cTfh) cells, in AChR-MG patients without treatment, the proportions of Tfh17 cells were higher than those in the treated group, whereas the Tfh1 cells were decreased compared with those in the controls. The relevance of CXCR5 and PD-1 in the pathogenesis of AChR-MG was also suggested by the increased presence of these molecules on mature CD4 single-positive thymocytes from the thymic samples. The study provides further evidence for the importance of IL-21, IL-17A, IL-4, and IL-10 in AChR-MG. Disease-related CD4(+)T cells are identified mainly as PD-1(+) or ICOS+ with or without CXCR5, resembling cTfh cells in the circulation or probably in the thymus. AChR-MG and SN-MG seem to have some similar characteristics. IS treatment has distinctive effects on cytokine expression.
  • Küçük Resim
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    Evaluation of laboratory findings, clinical features and rates of diagnosis of patients admitted to outpatient clinic of pediatric neurology with neuromuscular manifestations
    (Dr. Behcet Uz Pediatric Hospital, 2020) Aksu Uzunhan, Tuğçe; Ertürk, Biray; Özyavuz Çubuk, Pelin; Uyanık, Bülent; Ayaz, Akif; Akan, Onur; Özdemir, Taha Reşid
    Objective: Our aim is to evaluate how many patients with neuromuscular manifestations get a definite diagnosis and which methods are used in the pathway to diagnosis as well as to assess patient characteristics.Methods: Patients aged 0-18 years old with neuromuscular manifestations (e.g., weakness, hypotonia, creative kinase elevation) who were admitted to Okmeydani Training and Research Hospital between January 2017 and July 2019 were included. Retrospectively, patient demographics, clinical signs, laboratory tests, diagnoses, clinical follow-up were recorded.Results: Forty-five patients aged 67.8 +/- 59.6 months were included in the study. Thirteen (29%) patients were female, and 32 (71%) were male. Creatine kinase levels were increased in 26 (58%) patients (median: 3211 IU/L). Twenty-four patients underwent electromyography; seven patients had neuropathy and nine patients muscular pathologies. Three (0.07%) patients underwent muscle biopsy and had nonspecific myopathic changes. Twenty-six (58%) patients out of 45 had a definite diagnosis, and 21 of these diagnoses were genetically confirmed. Seven patients had been subjected to next generation sequencing, and five of these were diagnosed with dystrophinopathy, hypokalemic periodic paralysis, mental retardation autosomal dominant type 9, Ullrich muscular dystrophy, and calpainopathy. Altogether, the most common diagnoses were dystrophinopathy, spinal muscular atrophy, and chronic inflammatory demyelinating polyneuropathy.Conclusion: After a patient history is taken, a physical examination is conducted, and serum creotine kinase levels are measured, establishment of diagnosis is possible through targeted genetic tests for diseases like dystrophinopathy. However, for patients who cannot be diagnosed with this approach, neuromuscular panels and whole exome sequencing can provide a diagnosis.