Inhibition of human platelet function in vivo with a monoclonal antibody: with observations on the newly dead as experimental subject

The F(ab'>2 fragment of a monoclonal antibody to the plate-let glycoprotein Ilb/IIIa receptor (7E3) is a potent inhibitor of both in-vitro platelet aggregation and in-vivo platelet thrombus formation in animal studies. As a first step in as-sessing the potential of 7E3-F(ab'>2 a s an antithrombotic agent for use in humans, we administered 7E3-F(ab')2 intra-venously at increasing doses to a person who had just died and was being maintained on a respirator (neomort). At 0.1 and at 0.2 mg/kg body weight, 74 % and 92 % of the glyco-protein Ilb/IIIa receptors were blocked, respectively; adeno-sine-diphosphate-induced platelet aggregation was inhibited by 84 % and 100 % at these same doses. Platelet glycoprotein lb function remained intact, even at 0.6 mg/kg. Acute he-modynamic or hemorrhagic toxicity was not noted. This an-tibody fragment, a potent, immediate-acting inhibitor of platelet aggregation, may be of benefit in vaso-occlusive and thromboembolic disorders