Laboratory Medicine Program

Heparin-Induced Thrombocytopenia (HIT) IgG Antibody Test
(HIT, anti-PF4 antibodies, HIT IgG)

Clinical Decription:
Heparin induced thrombocytopenia (HIT) is an uncommon complication of unfractionated heparin prophylaxis associated with thrombocyopenia and rarely arterial or venous thrombosis.

Method: Chemiluminescent ; Acustar

Component Tests Used: SRA (Serotonin Release Assay) upon authorization

Reference Ranges Used:
< 1.00 U/mL Positive

Specimen Type: Citrated plasma
Collected In: 3.2% Sodium Citrate
Volume: 2 x 1.0 mL (minimum: 2 x 1.0 mL)

Shipping: Send frozen on dry ice.

Special Instructions: Patient should be fasting, if possible. The specimen must be double-centrifuged to obtain a platelet-poor plasma specimen (Plt <10x10E9/L): 1. Immediately centrifuge specimen at 1500xG for 10 minutes. 2. Separate the plasma from the platelet/buffy coat and transfer into a clean plastic tube. 3. Centrifuge the separated plasma at 1500xG for an additional 10 minutes. 4. Transfer 1.0 to 2.0 mL of the double-centrifuged plasma into a clean plastic tube, leaving approx. 200uL for discard. 5. Freeze plasma aliquot immediately for storage. Maintain frozen for shipping and handling.

Testing Schedule(s): Requires Lab Approval, Monday through Friday 0900-1500 hrs.

Turnaround Time: determined on an individual basis

For more information, call 416.340.5227 or 1.866.865.5227