Protein S Activity - Machaon Diagnostics

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Protein S Activity

Justification

Reduced protein S may be seen in warfarin therapy, pregnancy, use of oral contraceptives, DIC, acute thrombosis, HIV, nephrotic syndrome, liver disease and L-asparaginase chemotherapy. Congenital or acquired deficiency of protein S is also a risk factor for venous thromboembolism (VTE). Protein S is a Vitamin K-dependent plasma protein synthesized in the liver. Activated protein S acts as a cofactor to protein C, greatly potentiating its anticoagulant function.

STAT: < 24 hours (7 days a week)

Clot-based

Draw Tube: Blue Top

Sample Type: Citrated Plasma

Specimen Requirements

	Sample Type	Volume Required	Minimum Volume	Stability
PREFERRED	Citrated Plasma	1mL	0.5mL	Frozen (-20C): 2 weeks Frozen (-80C): 6 months
ALTERNATIVE	-	-	-	-

REJECTION CRITERIA	Thawed in transit, refrozen or clotted sample
SPECIAL INSTRUCTIONS	-

General Information

METHODOLOGY	Clot-based
STAT TAT	< 24 hours (7 days a week)
STAT TAT Performance	> 90% of results released in 24 hours 7 days a week
ROUTINE TAT	< 3 days (M-F)
ALTERNATIVE NAMES	PS
DESCRIPTION	The principle of the Protein S Activity assay is based upon the cofactor activity of protein S which enhances the anticoagulant action of activated protein C. This enhancement is reflected by the prolongation of the clotting time of a system enriched with factor Va which is a physiological substrate for activated protein C.
LIMITATIONS	-
NORMAL RANGE	68-136%
ASSOCIATED TESTING	-
REFERENCES	-
SAMPLE REPORT	Upon request
NEW YORK STATE APPROVED	Yes

Test Codes

ORDER CODE	P3100
CPT CODE	85306
LOINC CODE	27822-6