Prolonged survival of human skin allografts following thermal injury.

We have studied the immune response of six patients admitted to the San Diego Regional Burn Treatment Center for treatment of major thermal injuries. Three of the patients retained skin allografts from unrelated donors for long periods (37, 47, and 67 days) while the remaining three rejected their grafts at 8, 10, and 12 days, respectively. Allograft survival appeared to be directly related to the immunosuppressive activity of patient sera on phytohemagglutinin-induced blastogenesis of normal lymphocytes in vitro. Survival did not appear to be related to patient lymphocyte number or reduced reactivity, nor was graft prolongation accompanied by reduced immunoglobulin production. Our work thus supports the hypothesis that spontaneous immunosuppression may be of importance in the clinical consequences of thermal injuries.