Neutrophil adhesion and complement inhibition prolongs survival of cardiac xenografts in discordant species

Hyperacute rejection results in rapid destruction of a discordant cardiac xenograft and is characterized by antibody deposition, complement activation, and platelet aggregation. The importance of neutrophils is unclear. Complement inhibition prolongs discordant cardiac xenograft survival. The purpose of this experiment was to determine the relative roles of complement and neutrophils. Selective inhibition of complement and neutrophil adhesion was used in a guinea pig-to-Lewis rat cardiac heterotopic xenotransplant model. NPC 15669 (N-[9H-(2,7-dimethylfluorenyl-9-methoxy)carbonyl]-L-leucine), a member of a new class of antiinflammatory agents termed leumedins, specifically prevents recruitment of neutrophils at inflammatory foci by inhibiting upregulation of the CD11b.