APC-resistance as measured by a Textarin time assay: comparison to the APTT-based method

Area of Science:

• Hematology
• Coagulation Science
• Molecular Diagnostics

Background:

• Protein C is crucial for anticoagulation, regulating blood coagulation by degrading factors V and VIII.
• Activated Protein C Resistance (APC-Resistance) is a thrombophilia risk factor, often caused by the factor V Leiden mutation.
• Existing APC-Resistance tests have limitations in sensitivity and specificity.

Purpose of the Study:

• To evaluate a novel Textarin time assay for detecting APC-Resistance.
• To compare the Textarin assay's performance against the standard APTT-APC-Resistance test.
• To assess the Textarin assay's correlation with the genotypic factor V Leiden abnormality.

Main Methods:

• Developed a Textarin time assay utilizing Textarin, a factor V-dependent prothrombin activator from snake venom.
• Evaluated the Textarin assay in normal subjects and patient cohorts including those with factor V Leiden, oral anticoagulation, and heparin therapy.
• Compared Textarin assay results with APTT-APC-Resistance test outcomes and factor V Leiden genotype.

Main Results:

• The Textarin assay demonstrated high sensitivity and specificity for identifying APC-Resistance.
• Phenotypic APC-Resistance detected by the Textarin assay showed a stronger correlation with the factor VR506Q genotype than the APTT-APC-Resistance test.
• The Textarin assay proved effective across various patient populations, including those on anticoagulation therapy.

Conclusions:

• The Textarin time assay is a sensitive and specific diagnostic tool for APC-Resistance.
• This novel assay offers improved accuracy in identifying APC-Resistance compared to the APTT-APC-Resistance method.
• The Textarin assay provides a valuable alternative for diagnosing APC-Resistance and its association with thrombophilia.