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| Primary Name |
Protein S Functional |
| Synonym |
Protein S activity |
| Synonym |
-- |
| Contraction |
PS |
| Contraction |
-- |
| Contraction |
-- |
| UAB Procedure Number |
2500380 |
| CPT Code |
85306 |
| Specimen |
Collect one (1) blue-stopper tube (3.2% sodium citrate), filled to specified volume. Do not underfill or overfill. |
| Specimen Management |
Centrifuge blue-stopper tube within one (1) hour of collection, separate plasma and test or quick-freeze at -70°C. |
| Specimen Accepted |
Daily including weekends |
| Times Available |
0730-1600 |
| Test Performed |
Two days a week |
| Available Stat? |
-- |
| Description |
When the functional PS level is consistently decreased, the patient may have a congenital deficiency. Chronic PS deficiency confers a 2- to 11-fold risk of venous thrombosis. Acquired PS deficiency occurs in a number of inflammatory conditions, during pregnancy, following a thrombotic episode, and in liver disease. Protein S production is decreased during Coumadin (warfarin) therapy. The protein S assay should be ordered at least 10 days after a thrombotic event or after termination of Coumadin therapy. When the INR is >1.7 the protein S order is canceled. |
| Reference Interval |
65%-140% |
| Critical Value |
-- |
| Therapeutic Range |
-- |
| Follow-up Test |
If the functional PS assay indicates a deficiency, total and free protein S antigen assays and the C4B binding protein immunoassay may be used to distinguish among qualitative and quantitative disorders. |
| Associated With |
Venous thrombosis |
| Associated With |
Arterial thrombosis |
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