Chromogenix Coatest® APC™ Resistance Control Plasma Level 1

Chromogenix Coatest® APC™ Resistance Control Plasma Level 1 is for control of accuracy when using Chromogenix Coatest® Activated Protein C Resistance (APC R) assay kits.

Packaging

Chromogenix Coatest® APC™ Resistance Control Plasma Level 1 (C822650), 5 x 1 ml, is a lyophilized preparation of citrated human plasma.

Stability

6 hours at 20-25°C, 6 hours at 2-8°C or 3 months at -20°C or below. The frozen reagent should be thawed at 37°C and gently mixed before use. Do not refreeze.

Background

Protein C, a part of the natural anticoagulant system, is a vitamin K-dependent protein zymogen (molecular weight=62,000 da) that is synthesized in the liver and circulates at a plasma concentration of approximately 5 mcg/mL. Protein C is activated to activated protein C (APC) via proteolytic cleavage by thrombin bound to thrombomodulin, an endothelial cell surface membrane protein. APC downregulates the procoagulant system by proteolytically inactivating procoagulant factors Va and VIIIa. Protein S, another vitamin K-dependent coagulation protein, catalyzes APC inactivation of factors Va and VIIIa. APC interacts with and proteolyses factors V/Va and VIII/VIIIa at specific APC binding and cleavage sites, respectively. Resistance to activated protein C (APC resistance) is a term used to describe abnormal resistance of human plasma to the anticoagulant effects of human APC. APC resistance is characterized by a reduced anticoagulant response of patient plasma after adding a standard amount of APC. For this assay, the activated partial thromboplastin time clotting test fails to prolong significantly after the addition of APC.

The vast majority of individuals with familial APC resistance have a specific point mutation in the procoagulant factor V gene (1691G-A, factor V Leiden) encoding for a glutamine (Q) substitution for arginine (R)-506 in the heavy chain of factor V (factor V R506Q). This amino acid change alters an APC cleavage site on factor V such that factor V/Va is partially resistant to inactivation by APC. The carrier frequency for the factor V Leiden mutation varies depending on the population.

The Chromogenix Coatest® APC™ Resistance Control Plasmas can be used with Coatest APC Resistance cat # K823120 (823120), Coatest APC Resistance V cat # K823120 (823120) and Coatest APC Resistance VS cat # K823138 (823138) kits.

Procedure

Reconstitute each vial with 1.0 ml deionized water, filtered through 0.22 µm or NCCLS type II water1. Allow to stand at room temperature for 30 minutes. Swirl gently before use.

Different clotting times will be obtained with different types of instruments depending on the clot detection principle.