It included an aPTT-based APCR assay with dilution in factor V-deficient plasma (Coatest APC Resistance
V assay, Chromogenix), on a Star Evolution analyzer, and an FVL DNA assay (Invader assay, Hologic, Boston, Massachusetts).
Prothrombotic workups including protein C activity, protein S activity, antithrombin III level, APC resistance
, lupus anticoagulant, anticardiolipin antibodies, factor VIII inhibitor screening, and factor V Leiden defect were all negative, except for heterozygous mutation for prothrombin G20210A; the d-dimer level was normal 0.14 mcg/mL (0-0.5) and coagulation tests revealed low FVIII levels.
and third generation contraceptives.
is a common risk factor for thrombosis, and between 20% and 60% of thrombophilic patients suffer from some form of APC resistance
determined the prevalence of APC resistance
in 100 patients .
All assessments were reported to be within normal physiological limits except for the APC resistance
assay, which was reported low at 0.7 (normal 2.0-4.0 L).
"Our excellent HemosIL and Chromogenix reagent product line offers a broad spectrum of diagnostic tests, including assays for the detection of APC resistance
and factor V Leiden mutations.
(16) Tests ordered should include Factor V Leiden (APC resistance
), protein S deficiency, protein C deficiency, antithrombin as say, Prothrombin G20210A mutation, factor VIII activity, homocysteine level, and Lupus anticoagulant.
This finding is in agreement with the fact that patients with the FV-Leiden mutation show APC resistance
* APC Resistance
(functional test for Factor V Leiden)
(24) reported that the presence of LA was significantly associated with acquired APC resistance
(APC-R) in patients with SLE.
Low levels of protein S activity in factor V depleted plasma used in APC resistance