Selection of Platelet Apheresis Donors for Alloimmunized Patients by ELISA Platelet Crossmatch Versus HLA-Matching

Abstract

The development of platelet alloantibodies in multitransfused patients represents a major problem in platelet supportive therapy as 40-100% of patients with acute leukemia become alloimmunized during treatment [1,2]. Therefore, the provision of compatible platelets for alloimmunized patients is an important task for the blood transfusion service.Compatible platelet donors are usually selected based on HLA-matching between donor and recipient. Drawbacks of this approach are that 1) a large HLA-typed donor panel is required that needs continuous updating and is therefore very expensive; and 2) a significant percentage (13-31%) of HLA-matched platelet transfusions does not result in satisfactory post-transfusion platelet increments [3-6]. Another approach is to select platelet donors from the random donor population only using a platelet crossmatch test. This requires the availability of an assay for the detection of antiplatelet alloantibodies that is senstive,rapid and can be performed on preserved donor cell. The microplate platelet-ELISA meets these criteria [7]. Preliminary studies have indicated that the ELISA crossmatch allowed successful selection of compatible platelet donors from the random donor population [8]. Here, we describe our further experiences with platelet transfusions of ELISA crossmatch negative platelets into alloimmunized patients, comparing the results with those obtained from HLA-matched transfusions.