The value of skin allografts in the evaluation of the rejection of liver allotransplants in pigs.

Abstract

In accordance with other researchers,we found that skin allografts in unrelated pigs are usually rejected within 5–10 days of grafting, and that the allografts of porcine liver are particularly well-tolerated without immunosuppressive therapy. Other researchers also report that skin or kidney allografts from the same donor performed simultaneously with liver transplantation enjoy immunosuppressive effects caused by liver allografts. Our findings on skin allografts from the same donor performed simultaneously with liver allografts show that: (a) skin grafts always break down after a set time, in the same way as those not associated with liver transplantation, and (b) skin grafts do not interfere with the rejection of liver allografts. These findings did not change even under the following experimental conditions: in the orthotopic or heterotopic liver transplantation, and with blood transfusions from the donor only; from the donor and another source or, finally, from an entirely different source. We have also proved that a previously transplanted skin graft is capable, when a second skin graft is transplanted simultaneously with a liver allograft from the same donor, of sensitizing the subject, causing a second-set phenomenon of the subsequent skin graft and a first-set phenomenon, or an aggressive rejection of the liver. These findings confirm once more the particular tolerance of pigs to orthotopic liver allografts without immunosuppressive therapy between subjects immunologically competent, and seem to deny the ability of liver allografts to protect the tissues of the donor itself.