Modification of xenograft response by selective plasmapheresis.

HYPERACUTE REJEcrION of human renal allografts in ABO compatible cases was first reported by TerasakU Kissmeyer-Nielson,~ Williams,3 and Starzl-l have further documented this problem, which has now been encountered in many active-transplant centers. Hyperacute rejection is initiated by preformed antidonor antibodies and may result in the destruction of the transplant within minutes of vasculariza-tion. A characteristic of this reaction is thrombotic occlusion of the microvascula-ture.~··;. The rejection of xenografts in widely divergent species, such as the pig to dog combination, is similar to hyperacute rejection in humans. Naturally occurring heterospecific antibodies apparently cause rejection of renal xenografts within 6-15 minutes. 6 The following experiments were designed to determine whether the xeno-graft response could be modified by selective plasmapheresis (SPF) , an electro-phoretic process which can extract gamma globulin from the circulating blood.