DETECTION AND DIFFERENTIATION OF PLATELET-SPECIFIC ANTIBODIES BY FLOW-CYTOMETRY - THE BEAD-MEDIATED PLATELET ASSAY

BACKGROUND: Platelet-reactive antibodies cause a number of clinical di sorders. The detection and differentiation of these antibodies are pre requisites for the adequate treatment of these disorders. The bead-med iated platelet assay described here enables the detection and differen tiation of platelet-bound antibodies by the use of flow cytometry STUD Y DESIGN AND METHODS: The bead-mediated platelet assay is based on the isolation of human platelet glycoproteins by using flow cytometric st andardization beads after the incubation of typed platelets with human sera. The specificity and sensitivity of this assay were tested with five sera, each containing a known platelet-reactive antibody. The mon oclonal antibody-specific immobilization of platelet antigens assay wa s used as a reference test. RESULTS: The bead-mediated platelet assay was able to determine the glycoprotein specificity of the antibody wit hout cross-reactions in every case. In serial dilution tests, the bead -mediated platelet assay was able to detect the antibodies at higher d ilutions than the monoclonal antibody-specific immobilization of plate let antigen assay. Total test time was 3.5 hours. CONCLUSION: The bead -mediated platelet assay is a fast and reliable method for the detecti on and differentiation of platelet-reactive antibodies.