Antigenic relationship between blood platelets and vascular endothelium.

S ENSITIZATION of animals with allogeneic blood platelets induces accelerated rejection of allogeneic skin as well as renal grafts.2 In the latter instance the histologic lesions of the rejected graft were described as primarily vascular. These as well as earlier observations have suggested that an antigenic relationship exists between blood platelets and vascular endothelium. The experiments to be reported here were undertaken with the objective of directly testing this possibility. Repeated injections of antigen derived from allogeneic aortic endothelium sensitized dogs to allogeneic blood platelets. This was demonstrated by a sharp reduction in the survival of allogeneic platelets in the circulation of the sensitized recipients.