HEPARIN INDUCED THROMBOCYTOPENIA ANTIBODY w/ REFLEX to SRA

Message

Please send serum and plasma in separate transfer tubes then freeze.

Test Code

HITRS

Alias/See Also

205631; PF4

CPT Codes
86022

Includes

If positive, this test will automatically reflex to a Serotonin Release Assay (SRA).

Preferred Specimen

1 Blue tube (Sodium Citrate), centrifuge and aliquot (transfer) plasma into a transfer tube, freeze
1 Gold tube (SST), centrifuge and aliquot (transfer) serum into a transfer tube, freeze

Minimum Volume

1 mL in each transfer tube

Other Acceptable Specimens

None

Instructions

Centrifuge for complete separation of blood and plasma from blue tube; serum from gold tube. Plasma and serum should be removed within 1 hour from collection and placed in separate transfer tubes. Indicate the specimen type on each transfer tube (plasma) or (serum). Freeze both transfer tubes and send frozen.

Transport Container

Standard transport tubes

Transport Temperature

Frozen

Specimen Stability

15-30°C up to 4 hours
-20°C up to 6 months - frozen plasma is the preferred sample type
- Note: Up to two (2) freeze/thaw cycles will be accepted

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

The following conditions will result in a rejected specimen:

Plasma samples at room temp >4 hours
Clotted
Hemolyzed

Methodology
Qualitative immunoturbidimetric

Setup Schedule

M, Tu, W, Th, F, Sa, Su

Report Available

Within 24 hours of receipt at the performing laboratory.

Reference Range

Negative

Clinical Significance

HIT antibody testing is used to aid in the diagnosis of heparin induced thrombocytopenia. Testing should be used in conjunction with the patient’s 4Ts score for pretest probability. See below for additional information.

Heparin Induced Thrombocytopenia (HIT) occurs when Unfractionated and Low Molecular Weight Heparin treatments cause an autoimmune reaction which will trigger antibodies to activate platelets and initiate the formation of blood clots, resulting in venous and/or arterial thrombosis. PF4-H antibody is the most critical antibody in patients with HIT. Its high affinity for heparin forms an immunocomplex with the drug which then leads to platelet activation. Determining the risk of HIT can prevent unnecessary changes in anticoagulant therapy in most HIT-suspected cases. This can be done by performing a clinical assessment of HIT using the 4Ts score.** If the 4Ts score yields a score between 5 and 8, follow up with HIT-Ab testing. If the HIT-Ab testing is positive, the test will be confirmed with a Serotonin Release Assay (SRA) to confirm the diagnosis of HIT.

Performed By
Alverno Laboratories

Performing Laboratory
Alverno Central Lab
NHMC (Hematology, IL Coag)

Additional Information
Heparin Induced Thrombocytopenia
Reflex Serotonin Release Assay

Last Updated: December 21, 2023

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.