The Vascularization of Skin Autografts and Homografts

Transfer of Delayed Hypersensitivity to Skin Homografts With Leukocyte Extracts in Man*

“…The average time of onset for the rejection of first set grafts was established to be 8 to 12 days, and four to six days for the accelerated rejection of subsequent grafts. This is based upon earlier (39)(40)(41) as well as current observations.…”

“…The greater the genetic differences (i.e., the less the number of tissue transplantation antigens shared) between the individuals studied, the more abrupt and intense will be the reaction of one to a graft from the other. This consideration, coupled with the fact that the experimental demonstration of the individual specificity of homograft responses has not been as extensively studied in man (39)(40)(41)43) as in animal species (4, 6, 7, 10, 11), introduces inescapable variables for the type of experimental observation reported in this study. Nevertheless, since the effects of transfer on the test grafts have been judged as significant only in terms of their relation to the behavior of control grafts on the same recipient, it is felt that the bearing of such variables on the observations reported, although not eliminated entirely, has been greatly diminished.…”

“…diameter) and a full-thickness skin graft excised (39). The graft was placed on gauze saturated with normal saline and the undersurface freed of subcutaneous tissue.…”

“…Microscopic appearance of graft rejection. The method of stereomicroscopic observation of the graft capillaries devised by Taylor and Lehrfeld (42) and adapted to man has been used throughout this study; it has been described in detail elsewhere (39). With this method, the ultimate macroscopic rejection of the skin graft is predicted by the microscopic changes, which include cessation of capillary blood flow, intracapillary thrombosis and extravasation of blood into the graft.…”

“…Using these criteria, it had been determined earlier, in an experimental study of the homograft rejection phenomena in human skin (39), that the average time of rejection of first set grafts is 10 to 12 days, whereas a second graft from the same donor to the same recipient, if applied two to three weeks later, will be rejected in an accelerated fashion (four to six days), as a manifestation of actively acquired homograft sensitivity, specifically directed against the tissues of that particular donor (40).…”