Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a severe multi-systemic disease characterized by debilitating fatigue that is not relieved by rest. The causes of the disease are still largely unexplained, and no causative treatment is currently available. Changes in the immune response are considered as fundamental in the development of ME/CFS. Thus, we aimed to evaluate the immunological profile of ME/CFS patients in a retrospective data analysis. As part of the routine workup for ME/CFS patients, a differential blood count, leukocyte subtyping, and quantification of immunoglobulins and IgG subclasses, as well as a complement analysis, was performed. Out of 262 ME/CFS patients, 64.9% had a reduction or deficiency in at least one of the listed immune parameters. In contrast, 26.3% showed signs of immune activation or inflammation. A total of 17.6% of the ME/CFS patients had an unclassified antibody deficiency, with IgG3 and IgG4 subclass deficiencies as the most common phenotypes. Reduced MBL (mannose-binding lectin) levels were found in 32% of ME/CFS patients, and MBL deficiency in 7%. In summary, the present results confirmed the relevance of immune dysfunction in ME/CFS patients underlining the involvement of a dysfunctional immune response in the disease. Thus, immune parameters are relevant disease biomarkers, which might lead to targeted therapeutic approaches in the future.

中文翻译：

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患有肌痛性脑脊髓炎/慢性疲劳综合征的奥地利患者队列中免疫失调的评估

肌痛性脑脊髓炎/慢性疲劳综合征 (ME/CFS) 是一种严重的多系统疾病，其特征是无法通过休息缓解的虚弱疲劳。该病的病因在很大程度上仍无法解释，目前尚无有效的治疗方法。免疫反应的变化被认为是 ME/CFS 发展的基础。因此，我们旨在通过回顾性数据分析评估 ME/CFS 患者的免疫学特征。作为 ME/CFS 患者常规检查的一部分，进行了差异血细胞计数、白细胞亚型、免疫球蛋白和 IgG 亚类的定量以及补体分析。在 262 名 ME/CFS 患者中，64.9% 的患者至少有一项所列免疫参数降低或缺乏。相比之下，26.3% 的人表现出免疫激活或炎症的迹象。共有 17.6% 的 ME/CFS 患者存在未分类的抗体缺陷，其中 IgG3 和 IgG4 亚类缺陷是最常见的表型。在 32% 的 ME/CFS 患者中发现 MBL（甘露糖结合凝集素）水平降低，在 7% 中发现 MBL 缺乏。总之，目前的结果证实了 ME/CFS 患者免疫功能障碍的相关性，强调了疾病中功能失调的免疫反应的参与。因此，免疫参数是相关的疾病生物标志物，可能会导致未来有针对性的治疗方法。目前的结果证实了 ME/CFS 患者免疫功能障碍的相关性，强调了功能失调的免疫反应与疾病的相关性。因此，免疫参数是相关的疾病生物标志物，可能会导致未来有针对性的治疗方法。目前的结果证实了 ME/CFS 患者免疫功能障碍的相关性，强调了功能失调的免疫反应与疾病的相关性。因此，免疫参数是相关的疾病生物标志物，可能会导致未来有针对性的治疗方法。