Binding of the heterogenous antiplatelet antibody to megakaryocytes in vivo

Abstract

Flow cytometric analysis was done for the detection of rabbit anti-guinea pig platelet antibody on guinea pig platelets and megakaryocytes. Antiserum, absorbed by guinea pig erythrocytes, was intraperitoneally administered.
Antibody-binding to platelets was strongly detected 1.5 and 3h after injection of 2ml/kg body weight of antibody followed by severe thrombocytopenia after 3h. Apparent antibody-binding to megakaryocytes obtained by centrifugal elutriation was detected 12 and 36h later. The number of megakaryocytes was not changed. Injection of 0.4ml/kg of antibody caused mild thrombocytopenia with manifest antibody-binding to platelets, and no apparent binding to megakaryocytes.
These findings suggest that platelet-associated antibody caused thrombocytopenia and that serum antibody reached to megakaryocytes. But small amount of antibody had different attitude on antibody-binding to platelets and megakaryocytes.