Circulating Anticoagulant (Inhibitor)

Message
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.


Test Code
CIRINH


Alias/See Also
70909
Incubated Mixing studies


CPT Codes
85610; 85730; 85670 (Possible Reflexes 85611; 85732x6)

Includes
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


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


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


Instructions
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.


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


Transport Temperature
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 (


Specimen Stability
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


Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
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.


Methodology
Clotting

Setup Schedule
Monday - Friday
SCOAG


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


Limitations
Anti-coagulant medications


Clinical Significance
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.


Performing Laboratory
CompuNet Clinical Laboratories, LLC
2308 Sandridge Drive
Moraine, Ohio 45439


Last Updated: November 19, 2021


The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.