Zusammenfassung: Myalgische Enzephalomyelitis/Chronisches Fatigue-Syndrom (ME/CFS) ist eine schwere, chronische Multisystemerkrankung, die je nach Ausprägung zu erheblichen körperlichen und kognitiven Einschränkungen, zum Verlust der Arbeitsfähigkeit bis hin zur Pflegebedürftigkeit einschließlich künstlicher Ernährung und in sehr schweren Fällen sogar zum Tod führen kann. Das Ziel dieses D-A-CH-Konsensusstatements ist es, 1) den aktuellen Wissensstand zu ME/CFS zusammenzufassen, 2) in der Diagnostik die kanadischen Konsensuskriterien (CCC) als klinische Kriterien mit Fokus auf das Leitsymptom post-exertionelle Malaise (PEM) hervorzuheben und 3) vor allem im Hinblick auf Diagnostik und Therapie einen Überblick über aktuelle Optionen und mögliche zukünftige Entwicklungen aufzuzeigen. Das D-A-CH-Konsensusstatement soll Ärzt:innen, Therapeut:innen und Gutachter:innen dabei unterstützen, Patient:innen mit Verdacht auf ME/CFS mittels adäquater Anamnese und klinisch-physikalischen Untersuchungen sowie der empfohlenen klinischen CCC zu diagnostizieren und dabei die präsentierten Fragebögen sowie die weiteren Untersuchungsmethoden zu nutzen. Der Überblick über die zwei Säulen der Therapie bei ME/CFS, Pacing und die symptomlindernden Therapieoptionen sollen nicht nur Ärzt:innen und Therapeut:innen zur Orientierung dienen, sondern auch Entscheidungsträger:innen aus der Gesundheitspolitik und den Versicherungen darin unterstützen, welche Therapieoptionen bereits zu diesem Zeitpunkt bei der Indikation „ME/CFS“ von diesen erstattbar sein sollten.

Myalgic encephalomyelitis/chronic fatigue (ME/CFS) is a post-infectious, chronic disease that can lead to severe impairment and, even, total disability. Although the disease has been known for a long time, and has been coded in the ICD since 1969 (G93.3), medical research has not yet been able to reach a consensus regarding its physiological basis and how best to treat it. Against the background of these shortcomings, psychosomatic disease models have been developed and psychotherapeutic treatments have been derived from them, but their empirical testing has led to sobering results. According to the current state of research, psychotherapy and psychosomatic rehabilitation have no curative effect in the treatment of ME/CFS. Nevertheless, we see numerous patients in practices and outpatient clinics who suffer severely as a result of their illness and whose mental well-being and coping strategies would benefit from psychotherapeutic help. In this article, we outline a psychotherapeutic approach that serves this need, taking into account two basic characteristics of ME/CFS: firstly, the fact that ME/CFS is a physical illness and that curative treatment must therefore be physical; and secondly, the fact that post exertional malaise (PEM) is a cardinal symptom of ME/CFS and thus warrants tailored psychotherapeutic attention.

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.

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex disease characterized by profound fatigue, post-exertional malaise (PEM), and neurocognitive dysfunction. Immune dysregulation and gastrointestinal symptoms are commonly observed in ME/CFS patients. Despite affecting approximately 0.89% of the general population, the underlying pathophysiological mechanisms remain poorly understood. This study aimed to elucidate the relationship between immunological characteristics and intestinal barrier function in ME/CFS patients. ME/CFS patients were stratified into two groups based on their immune competence. After documentation of detailed medical records, serum and plasma samples were collected for the assessment of inflammatory immune mediators and biomarkers for intestinal barrier integrity by ELISA. We found reduced complement protein C4a levels in immunodeficient ME/CFS patients suggesting a subgroup-specific innate immune dysregulation. ME/CFS patients without immunodeficiencies exhibit a mucosal barrier leakage, as indicated by elevated levels of Lipopolysaccharide-binding protein (LBP). Stratifying ME/CFS patients based on immune competence enabled the distinction of two subgroups with different pathophysiological patterns. The study highlights the importance of emphasizing precise patient stratification in ME/CFS, particularly in the context of defining suitable treatment strategies. Given the substantial health and socioeconomic burden associated with ME/CFS, urgent attention and research efforts are needed to define causative treatment approaches.

Background: Post‐COVID Syndrome (PCS) is the term for a condition with persistent symptoms in a proportion of COVID‐19 patients after asymptomatic, mild, or severe disease courses. Numbers vary, but the current estimate is that after COVID‐19 approximately 10% develop PCS. The aim of our study was to evaluate the impact of SARS‐CoV‐2 infection on the gastrointestinal (GI) tract and associations with the development of PCS with fatigue, post‐exertional malaise (PEM), orthostatic dysregulation, autonomous dysregulation, and/or neurocognitive dysregulation.Methods: By combining medical record data from a prospective observational study with symptom analysis before, during, and after SARS‐CoV‐2 infection, we aimed to identify potential risk factors and predictive markers for PCS. Additionally, we analyzed blood, saliva, and stool samples from this well‐characterized PCS patient cohort to biologically validate our findings.Results: We identified significant associations between pre‐existing GI complaints and the development of PCS Fatigue. PCS patients showed higher LBP/sCD14 ratios, lower IL‐33 levels, and higher IL‐6 levels compared to control groups. Our results highlight the critical role of the GI tract in PCS development of post‐viral Fatigue.Conclusion: We propose that the viral infection disrupts pathways related to the innate immune response and GI barrier function, evidenced by intestinal low‐grade inflammation and GI barrier leakage. Monitoring GI symptoms and markers before, during, and after SARS‐CoV‐2 infection is crucial for identifying predictive clinical phenotypes in PCS. Understanding the interaction between viral infections, immune responses, and gut integrity could lead to more effective diagnostic and treatment strategies, ultimately reducing the burden on PCS patients.

Background/Objectives: Growing evidence suggests that mast cell activation (MCA) may contribute to Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), a debilitating disorder characterized by persistent fatigue and post-exertional malaise (PEM). Particularly in relation to orthostatic intolerance (OI), including postural orthostatic tachycardia syndrome (POTS), this study aimed to investigate the prevalence and clinical relevance of MCA in an Austrian ME/CFS patient cohort. Methods: Two data sets were analyzed. The CCCFS data set, a comprehensive, patient-centered online questionnaire consisting of 687 filled surveys, focuses on patient stratification. Self-reported clinical features, disease progression, and treatment responses were analyzed. Preliminary findings were validated in a second, retrospective study, analyzing data of 383 Austrian ME/CFS patients with regard to MCA involvement and OI. Results: Among followed-up ME/CFS patients, MCA prevalence increased over the disease course, with up to 25.3% meeting the criteria for clinically relevant MCA. ME/CFS patients with Mast Cell Activation Syndrome (MCAS) and OI reported symptom alleviation significantly more often following mast cell-targeted treatment than those without MCAS (p < 0.0001). With regard to IF-channel inhibitors, ME/CFS patients diagnosed with MCAS responded more frequently than those without MCAS (p = 0.076), while no significant differences were observed in response to beta blockers (p = 0.637). In both cohorts, OI, particularly POTS, was significantly more common in patients with MCA involvement. Conclusions: MCA appears to be a frequent and clinically relevant comorbidity in ME/CFS and is associated with a higher prevalence of OI, particularly POTS. Stratifying patients based on MCA involvement may support personalized treatment approaches and improve clinical outcomes.