Heparin Induced Thrombocytopenia (HIT) is the development of a thrombocytopenia in patients on heparin therapy. This is an immune mediated disorder in which heparin binds to Platelet Factor 4. These antibodies can bind to the Fc receptor on platelets leading to platelet activation.
Tube
05 (CP) – Citrate
Availability
24/7
Additional information
This test should only be requested after prior discussion with the haematology medical team. This HIT screen acts as a negative predictive indicator for the presence of HIT. A serum sample is required so any positive results can automatically be referred on to Royal Hallamshire Hospital, Sheffield (for confirmation by specific IgG antibody analysis) without having to recall the patient for re-bleeding.
PLEASE NOTE from October 2025 this test will be replaced by the an IgG specific PF4-H assay performed by an Acustar analyser.
Send to
Specialist Coagulation
Centre for Laboratory Medicine
St James University Hospital
Beckett Street
Leeds LS9 7TF
Contact
Collection Con
1x Citrate tube (Blue) filled to line AND 1 x Serum Gel (Gold) sample.
Samples must be processed within 6 hours of being taken.
Sample Storage
Citrated plasma. Must be processed or plasma frozen within 6 hours of collection.
Sample REQ
Blood
Ref. Range (Male)
<1.0
Ref. Range (Female)
<1.0
Ref. Range (Paed)
<1.0
Ref. Range Notes
Critical telephone values: All results will be phoned to the coagulation registrar or haematology registrar on call (out of hours)
Units
IU/dL
IP Acute TAT
2 hours