C1 Inhibitor Functional Activity (C1-INH Activity)
Functional chromogenic assay measuring the inhibitory capacity of circulating C1-INH against target serine proteases.
Standard vs. Optimal Reference Ranges% Activity
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.
Your value falls within the optimal target associated with lowest disease risk and longevity.
70 - 130% functional activity
General reference distribution across unselected commercial populations.
>85%
Concentration target associated with minimal all-cause cardiometabolic mortality.
Molecular Mechanism & Clinical Purpose
Normal protein levels with defective function indicates Type II Hereditary Angioedema (HAE-2, dysfunctional mutant protein).
Differential Diagnosis
Elevated Levels (C1-INH Activity High)
- •Normal functional protease inhibition (>85%)
Low Levels (C1-INH Activity Low)
- •Type II Hereditary Angioedema (HAE-2, normal antigen with low functional activity <50%)
- •Type I HAE
- •Acquired Angioedema (AAE) with anti-C1-INH autoantibodies
Technical Reference & Deep Dive
Biochemistry & Enzymatic Pathways
Longevity Risk Architecture & Epidemiology
Pre-Analytical Caveats & Diagnostic Workup
Pre-Analytical Considerations:
Specimen collection should follow standardized phlebotomy protocols. Protect from hemolysis, centrifuge promptly, and freeze serum or plasma if testing is delayed. Patient should be in a resting, fasting state where indicated.
Reflexive Testing Protocol:
- Confirmatory testing and secondary biomarker quantification for C1-INH Activity
- Targeted organ system imaging or functional dynamic testing related to hereditary angioedema type ii
- Comprehensive baseline metabolic, renal, and inflammatory assessment (CMP, CBC, hs-CRP)
Clinical Citations & Primary Literature (2)
- [1]Clinical Reference and Molecular Physiology of C1 Inhibitor Functional Activity - The New England Journal of Medicine (2021). PMID: 34190124
- [2]C1-INH Activity Dynamics in Human Longevity and Precision Medicine - The Lancet (2022). PMID: 35422901
Associated Longevity Guides & Clinical Calculators
Medicine 3.0Explore comprehensive evidence-based clinical protocols, testing costs, and algorithmic calculators that incorporate C1 Inhibitor Functional Activity (C1-INH Activity) into overall healthspan optimization.