title: Platelet adherence and phagocytosis. A method for the detection of platelet antibodies.
abstract: 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.
mesh_terms: 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
chemical_list: D005452:Fluoresceins