Predictive value of cross‐matching for transfusion of platelet concentrates to alloimmunized recipients

Abstract

Compatibility tests in which donor platelets were tested with recipient sera were performed retroactively after 64 transfusions of platelets from 59 unrelated donors to 10 alloimmunized patients. Techniques used were serotonin release, aggregometry, platelet factor 3 release, and lymphocytotoxicity, each of which has been advocated as a means of testing donor-recipient platelet compatibility. Although "false positive" reactions were few (positive crossmatch but satisfactory transfusion response), "false negative" reactions (negative crossmatch but poor transfusion response) were unacceptably high (43% by lymphocytotoxicity, 60% by serotonin release, 76% by platelet factor 3 release, and 83% by aggregometry). We conclude that current methods of detecting isosensitization to platelet alloantigens are less satisfactory than HLA phenotyping in selecting unrelated platelet donors for an alloimmunized patient population.

HLA antibody formation within the HLA‐A1 crossreactive group in multitransfused platelet recipients

“…Although a positive lymphocytotoxicity crossmatch predicted a poor post-transfusion platelet count increment in this and other studies [ 14,151, other investigators have noted that acceptable increments may occur in the face of a positive crossmatch [ 16,171. Possible explanations for these false-positive crossmatches include variations in the expression of certain HLA antigens, such as HLA-B8 and -B12, on platelets but not lymphocytes [ 181 and possibly the presence of autoreactive antilymphocyte antibodies that are unimportant with respect to platelet transfusion responses [ 191.…”

Intravascular and total body platelet equilibrium in healthy volunteers and in thrombocytopenic patients transfused with single donor platelets

“…Since the first report using CCI and HLA matched platelets in refractory patients [6], refractoriness has been primarily associated with alloimmunization [2,7,10]. Although other etiologies were recognized for causing poor responses [2], we distinguished immune vs. non-immune refractoriness [11].…”

“…They are the predicted platelet count increment (PPCI) [4,5], the corrected count increment (CCI) [6], and the percent recovery [7] based on platelet counts pre-and post-transfusion, blood volume, dose of platelets, and a splenic pooling factor [4][5][6][7]. They are the predicted platelet count increment (PPCI) [4,5], the corrected count increment (CCI) [6], and the percent recovery [7] based on platelet counts pre-and post-transfusion, blood volume, dose of platelets, and a splenic pooling factor [4][5][6][7].…”

In vitro Tests for Platelet Compatibility

“…Filip et al [32] retrospectively evaluated the lymphocytotoxicity test as a platelet cross match procedure and found a false-negative rate of 43% and false-positive rate of 17% with unrelated donor-patient pairs; HLA matching proved superior. Further, simple demonstration of platelet antibody might not result in a shortened platelet life span, since Shulman et al [33] have estimated that 500-1,000 antibody molecules must be bound to each platelet in order for platelet survival to be impaired.…”