Platelets are indicated in patients with low platelet counts (thrombocytopenia) to prevent bleeding (prophylactic) or to stop bleeding (therapeutic).
~ 50% of platelets concentrates (PC) are transfused to patients with severe thrombocytopenia after chemotherapy for leukemia or cancers where patients have recurrent needs. Surgery is also a frequent indication, especially cardiac surgery.
In 2013, 4.7 million PC have been administered in Europe and the USA.
Currently, the only source of platelets is from human blood donation.
PC must be stored at room temperature to be functional. The risk of bacterial contamination limits the storage duration to 5 days.
Immune factors and viral/bacterial contamination can lead to lack of efficacy (refractoriness, i.e. insufficient post-transfusion platelet increment) or safety issues.