C

Repeated platelet transfusions can lead to allo-immunization against donor class I HLA antigens, producing platelet-refractoriness. Providing platelets that are HLA-matched (ideally apheresis single-donor units matched for the patient’s HLA type) circumvents the antibody-mediated destruction and yields the highest post-transfusion count increment [Karlström, 2019, PMID 30575964; Schmidt, 2019, PMID 30285067].