Platelet adherence and phagocytosis. A method for the detection of platelet antibodies.
An assay was developed to identify platelet antibodies based on the adherence and phagocytosis of sensitized platelets by blood monocytes. Platelets obtained from normal HLA-typed donors were labeled with carboxyfluorescein diacetate (COFDA), fixed in paraformaldehyde, and sensitized with antibody. T cell-depleted mononuclear cells (MNCs) were mixed with antibody-sensitized platelets. Following an incubation phase, monocytes were isolated by adherence to glass tissue culture slides. Phagocytosis and adherence were evaluated by fluorescence microscopy. Thirteen of 18 donor-specific HLA antibodies and four of six sera from patients with chronic immune thrombocytopenic purpura enhanced platelet uptake. This assay was useful in detecting allo- and autoantibodies directed against platelets and may be valuable in investigating the pathophysiology of macrophage-mediated platelet destruction.
D001792:Blood Platelets / Q000166:cytology* / Q000276:immunology; D002448:Cell Adhesion; D005452:Fluoresceins; D006801:Humans; D008722:Methods; D010587:Phagocytosis; D013921:Thrombocytopenia / Q000097:blood / Q000209:etiology / Q000276:immunology
D005452:Fluoresceins