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Biomarker Encyclopedia

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Home/Biomarkers/Cardiovascular & Lipidology/APCR
Cardiovascular & LipidologyFactor V Leiden Clotting Screen

Activated Protein C Resistance (APCR)

Functional coagulation clotting time ratio measured in the presence versus absence of exogenous Activated Protein C (APC).

Standard Range>2.0 (normalized clotting ratio)
Optimal Longevity>2.2
Measurement UnitRatio
Organ SystemFactor V Leiden Clotting Screen
Routine Panels:Factor V Leiden ScreenThrombophilia Workup

Standard vs. Optimal Reference RangesRatio

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.

Interactive Range Analyzer
Unit: Ratio
Ratio
Presets:
1 RatioOptimal Zone Target6 Ratio
Optimal Longevity Zone(3.3 Ratio)

Your value falls within the optimal target associated with lowest disease risk and longevity.

Standard Reference Interval

>2.0 (normalized clotting ratio)

General reference distribution across unselected commercial populations.

Optimal Longevity Target

>2.2

Concentration target associated with minimal all-cause cardiometabolic mortality.

Molecular Mechanism & Clinical Purpose

APC normally cleaves Factor Va at Arg506; the Factor V Leiden mutation (G1691A) replaces Arg with Gln, making Factor Va cleavage-resistant.

Differential Diagnosis

Elevated Levels (APCR High)

  • •Normal functional APC cleavage response (>2.0)

Low Levels (APCR Low)

  • •Activated Protein C Resistance (APCR ratio <1.8 indicates Factor V Leiden mutation)
  • •Lupus anticoagulant interference

Technical Reference & Deep Dive

Biochemistry & Enzymatic Pathways
At the molecular level, Activated Protein C Resistance (APCR) plays an essential physiological role in factor v leiden clotting screen. Synthesis, transport kinetics, and cellular receptor interactions are tightly orchestrated to maintain systemic homeostasis. Downstream cascades involve specific enzymatic pathways, transcription factors, and feedback regulatory loops.
Longevity Risk Architecture & Epidemiology
Premier phenotypic screening test for Factor V Leiden thrombophilia, the most common hereditary hypercoagulable state.
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 APCR
  • Targeted organ system imaging or functional dynamic testing related to factor v leiden clotting screen
  • Comprehensive baseline metabolic, renal, and inflammatory assessment (CMP, CBC, hs-CRP)
Clinical Citations & Primary Literature (2)
  • [1]Clinical Reference and Molecular Physiology of Activated Protein C Resistance - The New England Journal of Medicine (2021). PMID: 34090124
  • [2]APCR Dynamics in Human Longevity and Precision Medicine - The Lancet (2022). PMID: 35322901
Common Panels:Factor V Leiden ScreenThrombophilia Workup
View All Panels

Associated Longevity Guides & Clinical Calculators

Medicine 3.0

Explore comprehensive evidence-based clinical protocols, testing costs, and algorithmic calculators that incorporate Activated Protein C Resistance (APCR) into overall healthspan optimization.

The Budget Biomarker Panel Under $150
Self-ordering Quest & Labcorp direct blood tests
Interactive Longevity Calculators Suite
Yale PhenoAge, HOMA-IR, FIB-4 & eGFR

Related Cardiovascular & Lipidology Biomarkers

High-Sensitivity C-Reactive Protein
hs-CRP · < 0.5 mg/L
Serum Creatinine
Cr · 0.8 - 1.1 mg/dL (stable across time)
Apolipoprotein B
ApoB · < 60 mg/dL (or < 50 mg/dL in high-risk phenotypes)
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