Sample type: Clotted blood
Test name: HIT a.k.a. Heparin Induced Thrombocytopenia PF4 antibodies
Condition / Indication: Requested when there is a high clinical suspicion of HIT. This is usually indicated by the 4T score. HIT typically develops 4 to 14 days following treatment with unfractionated heparin (UFH), however, low molecular weight heparin (LMWH), or, more rarely, fondaparinux have been shown to also cause HIT. In HIT heparin-dependent IgG antibodies bind to platelet factor 4 and activates platelets resulting in thrombocytopenia and/or thrombosis.
Special precautions & notes: Requesting for HIT is now available on ICE. If urgent please phone ahead of your request. An example 4T score calculator can be found below.
Referred outside NBT for analysis? Yes
Turnaround time: 1 day for urgent requests otherwise 5 days.
Referral location: NHS Blood and Transplant, Filton, North Bristol Park, Northway, Filton, Bristol BS34 7QH