Abstract:
Background/Objectives: According to the World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC), an estimated 3-6% of people suffer from post-COVID condition or syndrome (PCS). A subset meets the diagnostic criteria for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Studies have reported that SARS-CoV-2 proteins or RNA can persist after acute infection in serum or tissues, but their role in PCS is unclear.
Methods: Here, SARS-CoV-2 spike protein was analyzed in the serum of 121 PCS patients with predominant fatigue and exertional intolerance, of whom 72 met diagnostic criteria for ME/CFS, 37 post-COVID recovered healthy controls, and 32 pre-pandemic healthy controls.
Results: Spike protein was detected in the serum of 11% of recovered controls, 2% of PCS patients, and 14% of ME/CFS patients between 4 and 31 months after SARS-CoV-2 infection, but not in pre-pandemic samples. The occurrence and concentration of spike protein did not correlate with infection or vaccination timepoints. In ME/CFS patients, spike protein presence was not associated with the severity of symptoms or functional disability. In 5 out of 22 patients who under-went immunoglobulin depletion, spike protein levels were reduced or undetectable after treatment, indicating binding to immunoglobulins.
Conclusions: In summary, this study identified serum spike protein in a subset of patients but found no association with ME/CFS.
Source: Fehrer A, Sotzny F, Kim L, Kedor C, Freitag H, Heindrich C, Grabowski P, Babel N, Scheibenbogen C, Wittke K. Serum Spike Protein Persistence Post COVID Is Not Associated with ME/CFS. J Clin Med. 2025 Feb 8;14(4):1086. doi: 10.3390/jcm14041086. PMID: 40004616. https://www.mdpi.com/2077-0383/14/4/1086 (Full text)