PROLONGATION OF LUNG XENOGRAFT SURVIVAL IN RATS WITH A SHORT-COURSE OF DEOXYSPERGUALIN AND CYCLOSPORINE-A

The efficacy of 15-deoxy-spergualin (DSG), cyclosporin A (CyA), and sp lenectomy - alone or in combination - in prolonging the survival of co ncordant lung xenotransplants was studied in the hamster-to-rat model. In the untreated group, rejection occurred within 3 days, with an ele vation of lymphocytotoxic antibody titers. The rejected lung revealed that ED1+ cells were more prevalent than MRC OX8+ cells in the perivas cular infiltrates. In the DSG group, the antibody response was suppres sed and median survival increased to 7.5 days. The rejected lungs demo nstrated a highly significant depression in ED1+ cellular infiltration and a moderate MRC OX8+ cellular infiltration. When maintenance CyA w as combined with a short course of DSG, survival dramatically increase d to beyond 100 days. There were no deposits of IgM, IgG, or C3 or of any cell infiltrate in the grafts of two animals sacrificed 107 and 11 9 days post-transplantation. We conclude that initial treatment with D SG combined with continuous CyA can suppress acute rejection in the ha mster-to-rat lung xenograft model, resulting in longterm graft surviva l.