Immunoadsorption in Patients With Chronic Fatigue Syndrome Including Patients With Post-COVID-19 CFS

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a severely debilitating condition with a varying prevalence of 0.3 - 3% and markedly restricts activity and function of patients. They experience severe fatigue even after minimal exercise or mental activity, together with a myriad of further symptoms such as cognitive impairment, poor sleep quality, muscle and joint pain, or headache. With the pandemic situation, ME/CFS related to post-acute COVID-19 syndrome (PACS) is becoming a raising issue. According to the WHO (in February 2022), there are more than 423 million confirmed cases of COVID-19 worldwide and a large proportion of patients discharged from hospital are suffering from persistent symptoms (Carfi et al., 2020; Davis et al., 2020). The etiology and the mechanisms leading to the typical chronic course of ME/CFS or the pathophysiology of PACS are not fully understood. There is increasing evidence that a post-viral autoimmune reaction with the presence of autoantibodies targeting different neuronal tissues is involved in the pathogenesis. This is a double-blinded, randomized, sham-controlled immunoadsorption (IA) study in patients with chronic fatigue syndrome (CFS) including patients with CFS related to post-acute COVID-19 syndrome (PACS-CFS). Primary endpoint of the study is clinical improvement 3 months after the completion of immunoadsorption (IA) quantified using the change from baseline of the Chalder Fatigue Scale (range 0-33). Patients are randomized 2:1 in order to provide therapy to as many patients as possible. During the screening period, all patients are tested for the presence of autoantibodies in blood and cerebrospinal fluid (CFS). A comprehensive characterization by CFS specific questionnaires, quality of life questionnaires (PROMIS), cognitive and neuropsychological testing (MOCA, CANTAB) is performed, and each patient is offered to receive an optional cranial MRI before and after immunoadsorption. Depending on the clinical phenotype, electromyography and pulmonary function testing will be done. We use established hand strength and finger tapping devices as well as an accelerometer to objectify clinical improvement. Patients are hospitalized for 9-12 days receiving IA 5 times every other day. Directly after completion of IA as well as at month 1, 3 and 6 there are followup visits. The study will help to better understand disease mechanisms and thereby allow (hopefully biomarker associated) characterization of patients benefitting from such a costly but safe and often highly efficient therapy.