A specific assay for anti-HLA antibodies: application to platelet donor selection.
Alloimmunization to donor class I HLA antigens represents a major obstacle to successful platelet transfusion therapy. It is desirable to distinguish alloimmunization from nonimmunologic causes of poor platelet survival to assess the need for HLA-matched, single-donor platelets. We describe a new in vitro assay for anti-HLA antibodies and report its application to the problem of platelet crossmatching. In contrast to previously described crossmatch techniques, the immunobead assay is specific for anti-HLA antibodies. The assay was used to evaluate 51 single-donor platelet transfusions given to seven patients from 35 different donors. Recipient plasma was assayed for antibodies directed against HLA antigens present on donor platelets. A one-hour posttransfusion corrected count increment of greater than or equal to 7,500 was considered a successful outcome. Twenty-nine of 33 (87.9%) transfusion episodes associated with a negative immunobead assay had successful outcomes. The four unsuccessful transfusions were associated with potential nonimmunologic causes of poor platelet survival. Only two of 18 (11.1%) episodes associated with a positive assay had successful outcomes. Only one unsuccessful transfusion episode was associated with a negative immunobead assay and a positive radiolabeled antiglobulin test result, which suggested that isolated alloantibodies to antigens other than class I HLA antigens are not a common cause of platelet refractoriness. Platelets stored in suspension at 4 degrees C or frozen in liquid nitrogen were found suitable for crossmatch testing.
Millard
F E
FE
Department of Internal Medicine, US Naval Hospital, San Diego, CA 92134.
Tani
P
P
McMillan
R
R
D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000032:analysis*; D001781:Blood Component Removal; D001782:Blood Donors; D001792:Blood Platelets / Q000276:immunology; D016026:Bone Marrow Transplantation; D005260:Female; D006680:HLA Antigens / Q000276:immunology*; D006801:Humans; D007938:Leukemia / Q000276:immunology / Q000628:therapy*; D007945:Leukemia, Lymphoid / Q000276:immunology / Q000628:therapy; D015470:Leukemia, Myeloid, Acute / Q000276:immunology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D017713:Platelet Transfusion; D010983:Plateletpheresis
D001323:Autoantibodies; D006680:HLA Antigens