TRANSFUSION MEDICINE AND IMMUNOHEMATOLOGY: Edited by Karina YazdanbakhshPlatelet transfusion for patients with platelet dysfunction: effectiveness, mechanisms, and unanswered questionsLee, Robert H.a,b; Kasthuri, Raj S.a,c; Bergmeier, Wolfganga,bAuthor Information aUNC Blood Research Center bDepartment of Biochemistry and Biophysics cDivision of Hematology, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA Correspondence to Wolfgang Bergmeier, 116 Manning Drive, 8212A MEJ bldg, Chapel Hill, NC 27599-7035, USA. Tel: +1 919 962 7331; e-mail: firstname.lastname@example.org Current Opinion in Hematology: November 2020 - Volume 27 - Issue 6 - p 378-385 doi: 10.1097/MOH.0000000000000608 Buy Metrics Abstract Purpose of review In this review, we discuss current clinical guidelines and potential underlying mechanisms regarding platelet transfusion therapy in patients at risk of bleeding, comparing management of patients with thrombocytopenia versus those with qualitative platelet disorders. Recent findings Platelet transfusion therapy is highly effective in managing bleeding in patients with hypoproliferative thrombocytopenia. Clinical trials have demonstrated that platelet transfusion can be used at a lower trigger threshold and reduced platelet doses, and may be used therapeutically rather than prophylactically in some situations, although additional data are needed. In patients with inherited platelet disorders such as Glanzmann's Thrombasthenia or those with RASGRP2 mutations, platelet transfusion may be ineffective because of competition between transfused and endogenous platelets at the site of vascular injury. Successful management of these patients may require transfusion of additional platelet units, or mechanism-driven combination therapy with other pro-hemostatic agents. In patients on antiplatelet therapy, timing of transfusion and inhibitor mechanism-of-action are key in determining therapeutic success. Summary Expanding our understanding of the mechanisms by which transfused platelets exert their pro-hemostatic function in various bleeding disorders will improve the appropriate use of platelet transfusion. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.