Systemic and SARS-CoV-2 specific Immune Disturbances in Individuals With Post-COVID Syndrome.

Area of Science:

• Immunology
• Infectious Diseases
• Post-COVID Conditions

Background:

• Post-COVID syndrome (PCS) presents persistent symptoms beyond 12 weeks post-SARS-CoV-2 infection.
• The precise immunological mechanisms driving PCS remain largely unknown.
• Understanding PCS pathophysiology is crucial for developing effective treatments.

Purpose of the Study:

• To investigate the immunological profile of individuals with Post-COVID syndrome.
• To compare immune responses in PCS patients versus healthy convalescent controls.
• To identify potential biomarkers for PCS.

Main Methods:

• Detailed immunological analyses were performed on 47 individuals with PCS and 25 controls.
• Immune phenotyping of T and B cell subsets was conducted.
• SARS-CoV-2-specific T cell responses were assessed using activation-induced marker (AIM) flow cytometry and tetramer staining for B cells. Cytokine levels were measured via Luminex platform.

Main Results:

• PCS patients showed reduced SARS-CoV-2 specific T cell responses (AIM+, CD8+) and lower IFNγ/IL2 cytokine levels.
• Non-virus specific T cell populations were comparable between PCS and control groups.
• PCS individuals exhibited increased activated B cells (CD19+) but not SARS-CoV-2 spike-specific B cells. Elevated plasma markers of vascular damage and inflammation were observed.

Conclusions:

• Persistent immune disturbances characterize PCS, including diminished SARS-CoV-2 specific T cell immunity and heightened B cell activation.
• Altered inflammatory and vascular biomarkers suggest underlying pathology in PCS.
• These findings contribute to understanding PCS mechanisms and may aid in biomarker discovery and therapeutic development.