Circulating Anticoagulant (Inhibitor)

For Specimen Integrity during Extreme Weather see the “Lockbox Usage in Extreme Weather” document at the top of this page.

If unable to process and properly store specimens within 4 hours of collection then call CompuNet transportation for a STAT pick-up at (937) 297-8262 option 1.

This test needs a completed Anticoagulant Drug List submitted with the specimen. For a copy of the 2 page form click here




Samples must be received in the Special Coagulation department at the Sandridge location by 12:00pm for same day results.

CIRINH

70909
Incubated Mixing studies

PT
APTT
Thrombin Clotting Time (TCT)
Pathology Interpretation
Reflexes:
PT 1:1 mix (reflexes to this if PT is prolonged)
If APTT is prolonged then it will reflex to the following mixes and incubations:
     APTT 1:1 mix Immediate, 1 hour at 37⁰C, and 2 hours at 37⁰C
     APTT 1:4 mix Immediate, 1 hour at 37⁰C, and 2 hours at 37⁰C

5 plastic (2.7mL) completely filled 3.2% Sodium Citrate (light blue top) tubes

3 Frozen Capped aliquots of Sodium Citrate plasma (Polypropylene tubes recommended)

Use standard venipuncture and disposal techniques

Collect the required quantity of Sodium Citrate (light blue top) tubes.

If unable to process specimens within 4 hours of collection then call CompuNet transportation for a STAT pick-up at (937) 297-8262 option 1.

Sodium Citrate (light blue top) tube(s): Process immediately (stable only 4 hours), following instructions below:
Note: We recommend aliquot tubes to be made of polypropylene plastic as this material is safe to freeze at <-70oC.

1. Centrifuge capped Sodium Citrate (light blue top) tubes at 3000 rpm for 10 minutes, or at speed and time required to consistently produce Platelet Poor Plasma (<5/kmm3).

2. Carefully remove the plasma from all Sodium Citrate (light blue top) tubes; avoid disturbing the WBC/buffy coat, and combine all plasma into a plastic conical centrifuge tube.
Note: If the plasma shows any hemolysis, it must be recollected.

3. Centrifuge the plasma in the plastic conical centrifuge tube for a second time as in step 1.

4. In one smooth motion, carefully and quickly pour the centrifuged plasma into a second plastic conical centrifuge tube. A small amount of plasma along with a red cell button should remain on the bottom of the original conical tube if the pour was executed correctly.
Note: This quick-pour method prevents platelet transfer and contamination.

5. Aliquot at least 1mL of plasma into each aliquot tubes labeled “plasma.” Refer to the Minimum Volume" section above for the number of aliquots required per test.

6. Finally, place all aliquots into a <-20°C freezer within 4 hours.
Note: Aliquots must remain frozen until they are picked up by the CompuNet courier. Call CompuNet transportation department if frozen specimen boxes are needed.

Whole blood Sodium Citrate (light blue top) tubes
OR
Frozen - Capped aliquots of Sodium Citrate plasma (Polypropylene tubes recommended)

Room Temperature: Whole blood Sodium Citrate (light blue top) tubes
Refrigerated: Unacceptable for Sodium Citrate (light blue top) tubes whole blood or capped plasma aliquots
Frozen: Capped aliquots of Sodium Citrate plasma (

Room Temperature: Whole blood Sodium Citrate (light blue top) tubes < 4 hours
Refrigerated: Unacceptable for Sodium Citrate (light blue top) tubes whole blood or capped plasma aliquots
Frozen: Capped aliquots of Sodium Citrate plasma (Polypropylene tubes recommended) <30 days at <−20oC or <6 months at <−70oC

Rejected for hemolysis, clotted, improper fill, incorrect specimen type, thawed frozen aliquots, refrigerated plasma or blood, expired test tubes, >4 hours old if not processed into separated frozen plasma vials.

Monday - Friday
SCOAG

Same day testing if samples received by 12:00pm (noon);
1-3 days final report

Anti-coagulant medications

Circulating inhibitors, also known as circulating anticoagulants, can be divided into four groups. The first group inhibits clot formation, like heparin, warfarin and direct thrombin inhibitors that block the conversion of thrombin to fibrin clot formation. The second group blocks the interaction between coagulation factors and platelets and is characteristic of Lupus or Phospholipid Antibodies. The third group is a class of inhibitors that progressively inactivates individual coagulation factors, i.e. Factor VIII specifically. The fourth group is non-specific inhibitors that prolong coagulation screening assays. Inhibitors have been reported in patients with Hemophilia, autoimmune disorders, Rheumatoid Arthritis, pregnancy, postpartum, with antibiotic therapy and in normal individuals. Clinical appearance is confusing as presentation may be hemorrhagic and/or thrombotic.