The PROMPT study is now complete.

Chief investigator: Dr Lorna Williamson
Primary sponsor: NHSBT
Funder: NHSBT


In this study, we want to determine whether the activity/responsiveness of platelets given to stable patients with thrombocytopenia (low platelet numbers), affects patients’ platelet counts following transfusion.

We are also interested in investigating whether there is any change in the patient’s bleeding in the days after the platelet transfusion has been given. We will do this by randomising patients to receive a single platelet transfusion of either high or low responsiveness and monitoring the outcomes.

In addition we will collect the outcome data from some enrolled patients who are given a non-study transfusion of platelets so that we can compare the results to the study transfusions.

Study hypothesis

We hypothesise that platelet units produced from donors who have platelets that are high responders to ADP (adenosine di-phosphate) and CRP-XL will function differently from those collected from donors with low responsive platelets. This difference in function in vivo will manifest as more rapid splenic clearance of platelets from high responders from the circulation following transfusion to patients.

This double-blind, randomised, controlled trial will test this hypothesis by comparing platelet count increments (CI) following transfusion of one platelet unit derived from high or low responders into stable thrombocytopenic patients.

Study design

This will be a single-centre, randomised, double-blind, parallel-group study of platelet units of either high or low responsiveness in stable thrombocytopenic patients. Data will also be collected on consented patients who have received a non-trial platelet unit to provide more information on usual clinical outcomes in this patient group.


Anne M. Kelly, Stephen F. Garner, Theodora Foukaneli, Thomas R. Godec, Nina Herbert, Brennan C. Kahan, Alison Deary, Lekha Bakrania, Charlotte Llewelyn, Willem H. Ouwehand, Lorna M. Williamson, Rebecca A. Cardigan; The effect of variation in donor platelet function on transfusion outcome: a semirandomized controlled trial. Blood 2017; 130 (2): 214–220. doi:
View publication on Blood website