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Updated: Aug 8, 2026
The Importance of Correct Protein Concentration for Kinetics and Affinity Determination in Structure-function Analysis
Published on: March 18, 2010
A modified functional global test to measure protein C, protein S activities and the activated protein C-resistance
D Gemmati1, M L Serino, G L Scapoli
1Centre for the Study of Haemostasis and Thrombosis, University of Ferrara, Italy.
Abstract:
Identifying a defect affecting the protein C/protein S (PC/PS) anticoagulant system, using a single global test, has recently become possible thanks to a new methodological approach based on the activation of endogenous plasma PC by Protac, derived from Agkistrodon Contortix snake venom (ACV). The introduction of a commercial test (ProC Global), ACV-based, provides a useful tool for the screening of thrombotic patients since the most frequent causes of inherited thrombophilia are found in the PC/PS system. The test provides information only on the global activity of the anticoagulant pathway but not on PC and PS activity or on the factor V related conditions (e.g., FV Leiden). The present study shows that by carrying out the test alternating the presence of PC-, PS-, or FV-deficient plasma and using appropriate amounts of ACV, it is possible to increase the specificity of the test to correctly evaluate respectively the PC or PS activities or the activated protein C resistance condition (APC-R). These simple modifications applied to the original commercial test allow to detect exactly, using a single, basic methodology, the principal defects affecting the PC/PS anticoagulant pathway. Furthermore, carrying out the tests on an automated coagulometer, in combination or not with the classic ProC Global assay, it is possible to use a unique reagent profile to simultaneously investigate in the same or different samples, the PC, PS, and APC-R defect.
Insights
A new method enhances the ProC Global test to specifically identify defects in protein C (PC) and protein S (PS) anticoagulant pathways. This allows for precise diagnosis of thrombophilia by detecting PC, PS, and activated protein C resistance (APC-R) defects.
Area of Science:
- Hematology
- Clinical Chemistry
- Molecular Diagnostics
Background:
- The protein C/protein S (PC/PS) anticoagulant system is crucial for hemostasis.
- Inherited thrombophilia is frequently linked to defects within the PC/PS system.
- Current global tests may not differentiate specific PC/PS pathway defects.
Purpose of the Study:
- To develop a modified assay for specific detection of PC, PS, and activated protein C resistance (APC-R) defects.
- To enhance the diagnostic specificity of an existing ACV-based global test.
- To enable precise identification of inherited thrombophilia causes within the PC/PS pathway.
Main Methods:
- Utilized Protac derived from Agkistrodon Contortix snake venom (ACV) for plasma activation.
- Modified the commercial ProC Global assay by incorporating PC-, PS-, or FV-deficient plasmas.
- Employed specific ACV concentrations to target individual components of the PC/PS system.
- Performed tests on an automated coagulometer for simultaneous analysis.
Main Results:
- Achieved increased specificity in detecting PC activity, PS activity, and APC-R.
- Demonstrated the ability to accurately identify principal defects in the PC/PS anticoagulant pathway.
- Enabled simultaneous investigation of PC, PS, and APC-R defects using a single reagent profile.
Conclusions:
- Simple modifications to the ACV-based assay allow precise diagnosis of PC/PS pathway defects.
- The enhanced methodology provides a versatile tool for screening thrombotic patients.
- This approach facilitates simultaneous assessment of multiple coagulation factors, improving diagnostic efficiency.
