Geisinger Medical Laboratories Test Catalog
ANTITHROMBIN III ACTIVITY |
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ORDERING INFORMATION: |
Geisinger Epic Procedure Code: LAB1770 Geisinger Epic ID: 17587 | |
SPECIMEN COLLECTION |
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Specimen type: |
Platelet-poor plasma | |
Preferred collection container: |
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Alternate Collection Container: |
Other size blue-top (3.2% sodium citrate) tubes (e.g., 1.8 mL, 4.5 mL)
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Specimen required: |
1 mL | |
Special notes: |
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SPECIMEN PROCESSING |
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Specimen processing instructions: |
Centrifuge specimen immediately at designated time and speed to obtain platelet-poor plasma (<10,000/µL). Using a plastic pipette, carefully remove plasma from cells, avoiding platelet/buffy layer by leaving a thin layer of plasma on top the cells. The centrifuged plasma should be aliquoted (1 mL per aliquot) into clearly labeled polypropylene tubes. The number of tests ordered will determine the aliquots needed. Check the residual specimen for clot and if present discard sample and redraw specimen. If plasma is icteric, lipemic or hemolyzed a lab comment should be generated to notify staff. Freeze upright in non-thaw freezer. | |
Transport temperature: |
Frozen. | |
Specimen stability: |
Room temperature (plasma off cells): 8 hours Frozen (plasma) -20°C: 30 days Frozen (plasma) -70°C: 6 months |
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Rejection criteria: |
Clotted, hemolyzed, improperly filled tubes, improper anticoagulant ratio (HCT >55% and citrate not adjusted), refrigerated specimens, or stability exceeded. Note: Specimen suspected of thawing in transport, indicated by slant in aliquot or specimen in lid of tube, will have testing performed, and the comment “interpret results with caution as thawing suspected” added to results. | |
TEST DETAILS |
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Reference interval: |
80-120% | |
Additional information: |
Anticoagulation Impact on Coagulation Tests | |
CPT code(s): |
85300 | |
Note: The billing party has sole responsibility for CPT coding. Any questions regarding coding should be directed to the payer being billed. The CPT codes provided by GML are based on AMA guidelines and are for informational purposes only. | ||
Test includes: |
Antithrombin level | |
Methodology: |
Chromogenic |
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Synonyms: |
AT3 Antithrombin 3 Antithrombin
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Clinical significance: |
Antithrombin 3 (AT3) is a blood protein produced in the liver that naturally prevents clot formation. AT3 works with heparin to stop clot production mainly by inhibiting thrombin (factor IIa) and factor Xa. Low AT3 levels increase risk of blood clots in patients and decrease response to heparin therapy. AT3 levels are low during or immediately after a blood clot, in patients with kidney or liver disease, and during heparin therapy. | |
Doctoral Director(s:) |
Michelle Grant DO | |
Review Date: | 03/30/2023 |