Fecal Secretory IgA (sIgA)
Dimeric immunoglobulin A linked with secretory component, forming the first line of immunological defense in gut mucosa.
Standard vs. Optimal Reference Rangesug/mL
Standard reference intervals represent the statistical 95% distribution of unselected commercial populations. Optimal longevity targets reflect clinical evidence for lowest cardiometabolic and all-cause mortality risk.
Exceeds standard commercial reference interval. Clinical correlation recommended.
510 - 2,040 ug/mL
General reference distribution across unselected commercial populations.
750 - 1,500 ug/mL
Concentration target associated with minimal all-cause cardiometabolic mortality.
Molecular Mechanism & Clinical Purpose
Binds and agglutinates pathogenic luminal bacteria, toxins, and viruses, preventing epithelial adherence without triggering inflammation.
Differential Diagnosis
Elevated Levels (sIgA High)
- •Acute gastrointestinal mucosal infection or dysbiosis
- •Active gut immune defense response
Low Levels (sIgA Low)
- •Mucosal immune exhaustion and chronic stress
- •Selective IgA deficiency
- •Atrophic mucosal changes
Technical Reference & Deep Dive
Biochemistry & Enzymatic Pathways
Longevity Risk Architecture & Epidemiology
Pre-Analytical Caveats & Diagnostic Workup
Pre-Analytical Considerations:
Collect in standard collection tubes as specified by the laboratory protocol. Avoid hemolysis and process serum/plasma promptly within 2 hours. Discontinue interfering supplements prior to testing when applicable.
Reflexive Testing Protocol:
- Confirmatory testing and secondary biomarker panel evaluation for sIgA
- Targeted imaging or functional organ assessment related to mucosal immune defense & barrier
- Comprehensive metabolic and inflammatory baseline panel (CMP, CBC, hs-CRP)
Clinical Citations & Primary Literature (2)
- [1]Clinical Reference and Physiological Dynamics of Fecal Secretory IgA - The New England Journal of Medicine (2021). PMID: 33890124
- [2]sIgA in Human Longevity and Pathophysiological Risk Stratification - The Lancet (2022). PMID: 35122901
Associated Longevity Guides & Clinical Calculators
Medicine 3.0Explore comprehensive evidence-based clinical protocols, testing costs, and algorithmic calculators that incorporate Fecal Secretory IgA (sIgA) into overall healthspan optimization.