A COMPARISON OF THE PERFORMANCE OF PIG HEARTS PERFUSED WITH PIG OR HUMAN BLOOD USING AN EX-VIVO WORKING HEART MODEL

The pathophysiology of xenograft hyperacute rejection is still poorly understood although it is believed to involve complement fixation to v ascular endothelium, probably as a result of-the presence of naturally occurring anti-species antibodies. Hyperacute rejection of pig hearts by human blood was studied in an ex-vivo working heart model. Cardiac performance and immunological reactions occurring in the perfusing bl ood were studied. Stroke work performed by pig hearts perfused with hu man blood and their survival (median 47 min: n = 10) was significantly reduced compared to survival (median 158 min: n = 10) and stroke work performed by pig hearts perfused with pig blood. Decomplementation of human blood resulted in improved performance and duration of the acti on (median survival > 240 min: n = 10) of hearts. Quantitative differe nces were seen in complement fixation between the groups. Our data dem onstrate the central role of complement in the destruction of pig-to-m an xenografts.