Serum Spike Protein Persistence Post COVID Is Not Associated with ME/CFS

Area of Science:

• Immunology
• Virology
• Infectious Diseases

Background:

• Post-COVID condition (PCS) affects 3-6% of individuals, with some meeting criteria for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).
• The persistence of SARS-CoV-2 components, such as spike protein, after acute infection is suspected but its role in PCS remains unclear.

Purpose of the Study:

• To investigate the presence and potential role of SARS-CoV-2 spike protein in the serum of patients with post-COVID condition, particularly those with ME/CFS.
• To determine if spike protein levels correlate with symptom severity or functional impairment in ME/CFS patients.

Main Methods:

• Serum samples from 121 PCS patients (72 with ME/CFS), 37 recovered controls, and 32 pre-pandemic controls were analyzed for SARS-CoV-2 spike protein.
• Spike protein presence, concentration, and correlation with clinical data were assessed. Immunoglobulin depletion was performed on a subset of patients.

Main Results:

• Serum spike protein was detected in 11% of recovered controls, 2% of PCS patients, and 14% of ME/CFS patients, months post-infection.
• Spike protein presence did not correlate with time since infection/vaccination, symptom severity, or functional disability in ME/CFS patients.
• Immunoglobulin depletion reduced or eliminated detectable spike protein in 5 of 22 patients, suggesting it binds to immunoglobulins.

Conclusions:

• Serum spike protein was identified in a minority of post-COVID condition patients, including those with ME/CFS.
• The study found no association between the presence of serum spike protein and the diagnosis or severity of ME/CFS.
• Findings suggest spike protein may be bound by immunoglobulins in some individuals, but its direct role in ME/CFS pathogenesis requires further investigation.