The SOLID Platelet Study

Platelet transfusion can be a life-saving procedure in preventing or treating serious bleeding in patients who have low and/or dysfunctional platelets. Treatment of blood cancer and other blood diseases, as well as bone marrow transplantation, is not possible without platelet transfusion support. Unfortunately, 15- 25% of chronically transfused patients platelet counts will stop responding to these transfusions, putting them at risk for serious bleeding complications. The development of human leukocyte antigen (HLA) antibodies is responsible for 4- 8% of this platelet transfusion refractoriness. The presence of HLA antibodies is a clinical complication that is generally managed by the selection of products that are negative for the antigens for which the patient has antibodies. Often, for patients with chronic and ongoing need, this selection is facilitated by targeted recruitment of donors with known HLA types (i.e., types that lack antigens cognate to the patients known antibodies and are thus predicted to be compatible). However, for very broadly HLA- alloimmunized patients, compatible products may be exceedingly scarce or completely unavailable, precluding the ability to consistently provide products the patient will likely increment from. This research protocol is designed to evaluate the efficacy of a 4-hour continuous infusion of single donor, apheresis platelets in overcoming both alloimmune-mediated and non-alloimmune-mediated platelet refractoriness. We hypothesize that when we transfuse patients over a long duration, who have platelet refractoriness, the platelet counts will increase to higher numbers for an extended period of time in the peri-transfusion period when compared to shorter transfusion intervals.