The limited and inadequate availability of
organs from human donors has resulted in the utilisation
of xenografts as an alternative tool. Nevertheless,
hyperacute rejection (HAR) following xenograft
determines the loss of the transplanted organ. The
“primum movens” is the activation of the complement
pathway mediated by the binding of natural xenogenic
antibodies to the endothelium of the graft, followed by
the lysis of the endothelial cells with subsequent
oedema, thrombosis and necrosis of the transplanted
organ. In this work we describe morphological and
biomolecular observations of isolated human-decay
accelerating factor (h-DAF, CD55) transgenic pig hearts,
after perfusion for four hours with human blood. H-DAF
is a membrane glycoprotein inhibiting the complement
activation in humans. We describe considerably reduced
damages in transgenic hearts, compared to controls. The
cardiac function resulted preserved. Our data are in
agreement with what was already shown by other groups
using different experimental models. In conclusion, we
encourage the use of new sources of transgenic animals,
pointing out the importance of morphological analysis in
evaluation of xenograft