call menu

Protein C Screening Test

A set of reagents for screening assessment of abnormalities in the protein C system (Protein C Screening Test) according to TU 9398-276-05595541-2009 is designed for screening evaluation of abnormalities in the protein C system in human blood plasma using the clotting method on all types of coagulometers.

The anticoagulant system of protein C (protein C, protein S, thrombomodulin, thrombin, protein C inhibitor) plays a crucial role in regulating the coagulation activity of blood plasma. The system primarily acts on inhibiting factors VIIIa and Va and inactivating plasminogen activator inhibitor (PAI-1). Dysfunctions in the system can lead to thromboses in various locations.

Method Principle: Incubation of normal plasma with an activator (Agkistrodon contortrix venom) induces the activation of endogenous protein C and protein S, resulting in prolonged clotting time of normal plasma in the activated partial thromboplastin time (APTT) test. Without the addition of the activator, the APTT of the same plasma remains unchanged.

In the plasma of individuals with a deficiency in the protein C system or the presence of mutant factor V (Leiden), the prolongation of APTT is less pronounced when the activator is added compared to normal plasma.

  • #

Kit Composition:
• APTT reagent, lyophilized (2 ml/vial) - 2 vials;
• APTT reagent with protein C activator, lyophilized (2 ml/vial) - 2 vials;
• Plasma calibrator, lyophilized (1 ml/vial) - 1 vial;
• 0.025 M calcium chloride solution (5 ml/vial) - 1 vial.

The kit is intended for 80 determinations.

Result Interpretation: The results of determining the activity of the protein C system are conventionally expressed as the Normalized Ratio (NR): In healthy individuals, NR is 1.0 ± 0.3 (M ± 2s). An NR value below 0.7 indicates significant abnormalities in the protein C system (functional deficiency or reduced synthesis of protein C, protein S) or the presence of mutant factor V (Leiden), resistant to the action of protein C.

Normal and pathological values of the Normalized Ratio should be monitored using control plasmas from NPO RENAM: Control plasma with normal and reduced levels of protein C (Plasma-Protein C) (code PFA-6/7).