1991 Volume 2 Issue 2 Pages 136-142
Anti-human GPIIb/IIIa mouse monoclonal antibodies, NNKY2-11 and NNKY2-18, reacted with platelets of dogs, cats and monkeys as well as humans. These antibodies inhibited the platelet aggregations of humans and animals in vitro. In this report, we injected NNKY2-11 and NNKY2-18 intravenously into dogs and examined the effects of the monoclonal antibodies on dog platelets in vivo. When 100μg/kg of NNKY2-11 (IgG2a) were injected into dogs, platelet aggregation was inhibited partially and no change in circulating platelet counts occurred. When 200-300μg/kg of the antibody was infused, the number of circulating platelets decreased rapidly to the level of 5, 000/μl, followed by the recovery to the original level in a time-dependent fashion. Infusion of NNKY2-18 (IgG 1) also caused the partial inhibition of aggregation and the decrease of platelet counts similarly. When NNKY2-11-F (ab′) 2 was injected into dogs, platelet aggregation was inhibited similarly to intact IgG, and thrombocytopenia was observed. When NNKY2-11-Fab was injected, a slight inhibition of aggregation was obtained, but thrombocytopenia was not observed.
