This session will include a brief discussion of platelet refractoriness and indications for matched platelets as well as a description of the common methods used for HLA antibody testing and platelet crossmatching and the issues in interpreting and correlating the results. One speaker will discuss the results of a group of serum samples sent to several laboratories asked to test for HLA antibodies, identify antibodies that they would consider in selecting platelet donors appropriate for each case, perform platelet crossmatches on their own selected donor platelets and describe their protocol for platelet selection. A final speaker will present current practice and outcome data for HLA-matched and crossmatched platelet products. The session will close with Q&A.