New approaches for immunosuppression.

New approaches for experimental immunosuppression have been reviewed. These include the following: 1) cyclosporin A, a metabolite from fungus that suppresses multiplying but not resting T and B lymphocytes and can be used in pulsed manner with interspersed drug-free periods; 2) total lymphoid irradiation (transplantation tolerance in rats has been achieved by pretransplant radiation); 3) thoracic duct drainage, which is being revived following its demonstrated effectiveness in the treatment of some autoimmune disease; 4) hyperbaric oxygen (HBOX). We have found that HBOX 2 1/2 ATA for five hours daily depresses cell-mediated immunity in mice and that this can be reversed by intravenous administration of autologous macrophages.