Increased anti-nucleocapsid secretory IgA and consumption of complement component 3 in post-COVID syndrome patients - PubMed
3 hours ago
- #complement system
- #biomarkers
- #post-COVID syndrome
- Post-COVID syndrome patients show increased anti-Nucleocapsid secretory IgA (sIgA) in saliva.
- These patients have reduced levels of complement component C3, suggesting ongoing complement activation and consumption.
- Levels of C4 were decreased but not significantly, and total hemolytic activity (CH50) was similar to controls.
- In recently reinfected fully vaccinated patients, serum anti-Nucleocapsid IgG negatively correlates with factor H and CH50.
- No differences were found in circulating immune complexes between patient and control groups.
- Regression analysis indicates C3 levels can efficiently discriminate patients from controls, with improved power when combined with anti-Nucleocapsid sIgA.
- Elevated salivary anti-Nucleocapsid sIgA does not correlate with serum anti-Nucleocapsid IgG, reflecting different temporal dynamics.
- Findings suggest salivary anti-Nucleocapsid IgA and C3 consumption may be candidate biomarkers for post-COVID syndrome.
- The complement system is implicated as a key dysregulated component in post-COVID syndrome pathophysiology, potentially targetable for therapies.