New paradigms in the management of alloimmune refractoriness to platelet transfusions.
OBJECTIVE
Following transfusion or pregnancy, a significant number of patients develop antibodies to class I human leukocyte antigen. Some will exhibit platelet transfusion refractoriness, defined as inappropriately low platelet count increments after two or more consecutive transfusions. Unfortunately, failure of at least two products is required before an immunologic work-up is undertaken. Among those diagnosed with immune refractoriness, there is no standard method for identifying platelet products likely to be effective.


RESULTS
Recent advances in detection and identification of human leukocyte antigen antibody may permit pretransfusion screening of selected patients and provide guidance in choosing the optimal product. An approach more like that for red cell alloimmunized patients, in which one provides products guided solely by the antibody profile, is preferable to selection based on educated guesswork when human leukocyte antigen identical units are unavailable, and offers some advantages over platelet crossmatching.


CONCLUSIONS
This review presents a literature-based algorithm with which to approach the management of platelet refractory individuals, focusing on newer technology to maximize the post-transfusion yield of matched units. Strategies are presented that allow selection of more effective products for difficult, broadly alloimmunized individuals, including patients who have developed antibodies to human platelet antigens.
Vassallo
Ralph R
RR
University of Pennsylvania School of Medicine and American Red Cross Blood Services Heritage Division, Penn-Jersey Region, Philadelphia, Pennsylvania 19123, USA. vassallor@usa.redcross.org
D000017:ABO Blood-Group System / Q000276:immunology*; D001788:Blood Grouping and Crossmatching; D005260:Female; D006680:HLA Antigens / Q000276:immunology*; D006801:Humans; D017713:Platelet Transfusion; D011247:Pregnancy
D000017:ABO Blood-Group System; D006680:HLA Antigens