Increased anti-nucleocapsid secretory IgA and consumption of complement component 3 in post-COVID syndrome patients
By
Zhiwen Hai
Weihua Yang
Azam Ghazi
Amalia Buitrago
Patricia Marín-García
Isabel G Azcárate
Alba González-Escalada
Nineth Rossi
Javier Benítez-Cruz
Iván Estévez-Benito
Agustín Tortajada
José R. Regueiro
José M. Bautista
Narcisa Martinez-Quiles
May 14, 2026
Clinical Scorecard: Elevated Secretory IgA Against Nucleocapsid and Complement Component 3 Consumption in Patients with Post-COVID Syndrome
At a Glance
Category Detail
Condition Post-COVID Syndrome Key Mechanisms Immune dysregulation involving elevated anti-Nucleocapsid sIgA and complement component C3 consumption. Target Population Patients recovering from COVID-19 experiencing persistent symptoms. Care Setting Clinical settings focusing on post-viral syndromes.
Key Highlights
Increased anti-Nucleocapsid sIgA in post-COVID syndrome patients compared to controls. Reduced C3 levels indicating ongoing complement activation. Anti-Nucleocapsid IgG levels do not correlate with sIgA levels. C3 levels can effectively discriminate between patients and controls. Salivary anti-Nucleocapsid IgA and C3 consumption may serve as biomarkers. Guideline-Based Recommendations
Diagnosis
Consider elevated anti-Nucleocapsid sIgA and C3 levels for diagnosing post-COVID syndrome. Management
Targeted therapies may be developed focusing on complement system dysregulation. Monitoring & Follow-up
Regular assessment of anti-Nucleocapsid sIgA and complement levels in post-COVID patients. Risks
Potential for ongoing immune dysregulation and long-term health impacts. Patient & Prescribing Data
Individuals with post-COVID syndrome.
Further validation of biomarkers needed for effective treatment strategies.
Clinical Best Practices
Monitor immune response parameters in post-COVID patients. Evaluate complement system activity in patients with persistent symptoms. Related Resources & Content
