PFA-200 (Platelet Function Analysis)
| Category | Haematology >> Specialised Coagulation Services |
|---|---|
| Test background |
Platelet function is initially assessed using the PFA-200 analyser which offers quantitative assessment of platelet function at high shear as whole blood is forced through an aperture coated with either collagen/epinephrine or collagen/ADP agonists. The test is measured as aperture closure time (CT) in seconds for each COL/EPI and COL/ADP cartridge. The PFA is sensitive to platelet function defects such as Glanzmann’s Thrombasthaenia and Bernard-Soulier Syndrome as well as disorders of von Willebrand factor, though sensitivity is reduced when VWD Type I is included. Aspirin or aspirin-like platelet defects are associated with a significantly prolonged COL/EPI closure time. |
| Clinical Indications |
Screening for Platelet Dysfunction: To assess abnormal platelet function in patients with a history of easy bruising, prolonged bleeding (e.g., epistaxis, menorrhagia), or unexplained bleeding tendencies. Assessment of Drug Effects: To monitor the effects of antiplatelet medications (e.g., aspirin) or other drugs that may impair platelet function. Monitoring the therapeutic effect of drug treatments such as DDAVP. Preoperative Screening: To identify patients at risk of excessive bleeding during surgery due to platelet or vWF abnormalities. |
| Reference range | Closure Times: Collagen/Epinephrine: 75 – 165 seconds |
| Sample & container required | Adults - 2 x 2.7 mL sodium citrate (pale blue top) Paediatrics – 2 x 1.8 mL sodium citrate (pale blue top) |
| Turnaround time | 4 hours |
| Notes | Samples will be rejected if under/over-filled, clotted or haemolysed. The test is not advised if the platelet count is below 100 x 109/L and may be rejected. Please do not send the samples via pod system. Sample must be hand delivered immediately after collection possibly within 30 minutes. This test is not under the scope of UKAS accreditation. |