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Activated Protein C Resistance

Primary Name	Activated Protein C Resistance
Synonym	Screen for factor V Leiden
Synonym	--
Contraction	APC resistance
Contraction	APCR
Contraction	--
UAB Procedure Number	2500700
CPT Code	85307
Specimen	* Collect one (1) blue-stopper tube (3.2% sodium citrate), filled to specified volume. Do not underfill or overfill. * If follow-up factor V Leiden mutation test is indicated, collect one (1) lavender-stopper tube (EDTA) whole blood. Do not centrifuge the lavender-stopper tube.
Specimen Management	* Centrifuge blue-stopper tube within one (1) hour of collection, separate plasma and test or quick-freeze at -70°C. * The lavender-stopper tube may be refrigerated up to 72 hours before shipping. Ship uncentrifuged overnight at ambient temperature or on wet ice.
Specimen Accepted	Daily including weekends
Times Available	0730 - 1600
Test Performed	Twice weekly
Available Stat?	Pathologist approval required.
Description	APC resistance is a thrombotic risk factor caused by the factor V Leiden mutation that is found in 3 to 8% of Caucasians. Factor V Leiden mutation confers a 3-fold increased risk of venous thrombosis. The APC resistance assay is performed as a screen before ordering the confirmatory factor V Leiden mutation assay.
Reference Interval	The lower limit of normal varies with test reagent lot number and can be obtained from the special coagulation laboratory. The report states normal or abnormal. When it is abnormal, the ratio is provided.
Critical Value	--
Therapeutic Range	--
Follow-up Test	Abnormal ratios are considered suggestive of factor V Leiden and the genetic test should be done for confirmation. The test will be done reflexively if a lavender-stopper tube has been provided.
Associated With	Venous thrombosis