Humoral responses to pig-to-baboon cardiac transplantation: Implications for the pathogenesis and treatment of acute vascular rejection and for accommodation

Academic Article

Abstract

  • Organs transplanted between phylogenetically-disparate species, such as from the pig into the primate, are subject to hyperacute and acute vascular rejection. Hyperacute rejection of a porcine organ by a primate is thought to be initiated by the binding of xenoreactive natural antibodies to GalĪ±1- 3Gal expressed on the endothelial lining of blood vessels in the xenograft. The factor(s) which initiates acute vascular rejection is uncertain; however, there is some evidence implicating xenoreactive antibodies. The nature of the humoral response which might contribute to acute vascular rejection of a porcine organ was investigated in baboons which received a porcine cardiac xenograft plus immunosuppression with methylprednisolone, azathioprine, and cyclosporine. Following rejection and surgical removal of the xenografts, the serum concentration of xenoreactive antibodies increased in untreated animals but in immunosuppressed animals was similar to the concentration in preimmune serum. The antibodies in the sensitized recipients were specific for GalĪ±1- 3Gal (70-95%) and other determinants (5-30%). However, cross-blocking studies showed that, following xenotransplantation, the immunosuppressed baboons had no detectable IgM or IgG directed against 'new' endothelial antigens. These results indicate that antibodies made by immunosuppressed individuals in response to xenotransplantation are much like xenoreactive natural antibodies and suggest that acute vascular rejection might in some cases be addressed by therapeutic strategies aimed at those antibodies.
  • Authors

    Published In

  • Human Immunology  Journal
  • Digital Object Identifier (doi)

    Author List

  • McCurry KR; Parker W; Cotterell AH; Weidner BC; Lin SS; Daniels LJ; Holzknecht ZE; Byrne GW; Diamond LE; Logan JS
  • Start Page

  • 91
  • End Page

  • 105
  • Volume

  • 58
  • Issue

  • 2