Detection of platelet antibodies using the platelet migration inhibition assay.
We evaluated the usefulness of the Platelet Migration Inhibition (PMI) assay in detecting antibody to platelets in patients receiving platelet transfusions. Forty-one PMI assays were performed on pretransfusion sera from 19 patients. After each transfusion, each patient was evaluated clinically and by transfusion response for alloimmunization. Prevalence of antiplatelet antibody, the predictive value of positive and negative results, and efficiency of the PMI assay were calculated. The 41 PMI assays yielded true-positive, true-negative, false-positive, and false-negative results of 18, 14, 5, and 4, respectively. The sensitivity and specificity of the PMI assay were calculated at 81.8% and 73.7%. The PMI assay was comparable in sensitivity and specificity to immunofluorescence and superior to platelet aggregation and lymphocytotoxicity for detecting platelet (inhibition) antibodies. This test is simple and less costly than immunofluorescence; however, it lacks speed and efficiency for crossmatching purposes. It is useful as a clinical test in screening potential platelet pheresis donors and patients receiving platelet transfusions every other day. It may prove useful in research as a functional test to understand alloimmunization and restricted alloimmunization.
D001792:Blood Platelets / Q000276:immunology*; D001803:Blood Transfusion; D002464:Cell Migration Inhibition; D005069:Evaluation Studies as Topic; D005188:False Negative Reactions; D005189:False Positive Reactions; D006801:Humans; D007518:Isoantibodies / Q000302:isolation & purification*; D017713:Platelet Transfusion
D007518:Isoantibodies