APC RESISTANCE UNIVERSITY
ABOUT ACTIVATED PROTEIN C RESISTANCE
During the last years, publications have suggested that the APC resistance phenotype is a risk factor for venous thrombosis, irrespective of the FV Leiden mutation1. The Coatest® APC™ Resistance and Coatest® APC™ Resistance V kits measure different entities, and hence both are included in the thrombophilia screening panel in a number of well-respected laboratories.
Since APC resistance was first detected in 1993, Chromogenix and DiaPharma have been leaders in APC resistance diagnostics. The Coatest® APC™ Resistance test was a revolution in coagulation testing. In order to allow for APC resistance analysis of plasma from patients on oral anticoagulant or heparin therapy, a modification of the original APC resistance test was developed. While Coatest® APC™ Resistance kits detect APC resistance phenotype regardless of it cause, Coatest® APC™ Resistance V kits exclusively detect inherited APC Resistance due to mutations in the Factor V gene. This assay variant not only gives unsurpassed sensitivity for the FV:Q506 mutation, but also strongly reduces the influence of pre-analytical variations and is not influenced by heparin or warfarin. Compared to PCR analysis, Coatest® APC™ Resistance V is a more cost effective test for the Factor V mutation and provides a quicker turn-around time.
Furthermore, recent publications have described laboratory testing algorithms for Activated Protein C Resistance that include a screening test for APC resistance2. Since the genetic tests for FV Leiden are much more costly and labor intensive than the clot-based screening assay, the clot-based test using FV deficient plasma is the preferred method2. Because the screening assay shows sensitivity and specificity values approximating 100%, it can be used to determine if further analysis at the genetic level is necessary. Using Coatest® APC™ Resistance V to screen patients will save the laboratory both time and money.With these APC resistance screening tests, DiaPharma can offer the optimal combination of phenotypic and genotypic information for clinical decision-making. Please contact us today to learn more at 1-800-447-3846 or email@example.com.
Algorithm for the diagnosis of the Factor V Leiden mutation and Activated Protein C Resistance
Activated Protein C Resistance UNIVERSITY
Activated Protein C Resistance Frequently Asked Questions
Activated Protein C Resistance Abstracts & References
PRODUCTS FOR ACTIVATED PROTEIN C
For in vitro diagnostic use
Determinations (Coatest APC Resistance): 80-160 (automated)
Determinations (Coatest APC Resistance V): 80-160 (automated)
Determinations (Coatest APC Resistance VS): 40-80 (automated)
Description (Coatest APC Resistance V & VS)
An APTT-based kit for the screening of factor-V-related APC resistance. The high sensitivity and specificity of the test for the factor V:Q506 mutation is obtained by prediluting the sample plasma with an excess of V-DEF Plasma bioreagent. The test design makes it possible to discriminate between heterozygous and homozygous factor V genotypes. It also allows for analysis of plasma from patients on heparin or oral anticoagulant therapy. High discrimination between genotypes with 100% sensitivity for FV:Q506. Reduces need for PCR determination. Applicable to anticoagulant treated patients.
Description (Coatest APC Resistance)
An APTT-based assay for the detection of the APC resistance phenotype, i.e. the poor anticoagulant response to activated protein C (APC). The test result (APC ratio) gives an estimation of the anticoagulant function in vivo and provides information on the thrombotic risk associated with inherited and acquired APC resistance. Detects the APC resistance phenotype regardless of its cause. Detects both inherited and acquired APC resistance.
Measurement principle (Coatest APC Resistance V & VS)
One volume of plasma is prediluted with four volumes of V-DEF Plasma. The dilution is then incubated with the APTT reagent for a standard period of time. Coagulation is triggered by the addition of CaCl2 in the absence and presence of exogenous APC and the time for clot formation is recorded.
Measurement principle (Coatest APC Resistance)
Plasma is incubated with the APTT reagent for a standard period of time. Coagulation is initiated by the addition of CaCl2 in the absence and presence of APC and the time for clot formation is recorded.
Reagents and Stability when opened
|Reagent||Units APC V||Units APC VS||Units APC||Expiration / Temperature|
|V-DEF Plasma||4 × 4 mL||2 × 4 mL||n/a||8 hours at 15-25°C, 24 hours at 2-8°C, 3 months at -20°|
|CCaCl2||1 × 8 mL||2 × 2 mL||2 × 2 mL||1 week at 15-25°C, 1 month at 2-8°C|
|APTT Reagent||1 × 16 mL||2 × 4 mL||2 × 4 mL||1 week at 15-25°C, 1 month at 2-8°C|
|APC/CaCl2||4 × 2 mL||2 × 2 mL||2 × 2 mL||8 hours at 15-25°C, 5 days at 2-8°C, 3 months at -20°C|
|Control level 1||1 × 1 mL||1 × 1 mL||n/a||6 hours at 15-25°C, 3 months at -20°C|
|Control level 2||1 × 1 mL||1 × 1 mL||n/a||6 hours at 15-25°C, 3 months: -20°C|
FV:Q506 Mutation Screening
The Coatest APC Resistance V method was used for analysis of plasma from various sample categories.
A complete discrimination was obtained between normal and mutated factor V genotypes. OAC = Oral Anticoagulant Therapy.