immunosuppression /-səpresh″ən/ [L, immunis + supprimere, to press down] , 1. the administration of agents that significantly interfere with the ability of the immune system to respond to antigenic stimulation by inhibiting cellular and humoral immunity. Corticosteroids; cytotoxic drugs, including antimetabolites and alkylating agents; antilymphocytic antibodies; and irradiation may produce immunosuppression. Immunosuppression may be deliberate, such as in preparation for bone marrow or other transplantation to prevent rejection by the host of the donor tissue, or incidental, such as often results from chemotherapy for the treatment of cancer. 2. an abnormal condition of the immune system characterized by markedly inhibited ability to respond to antigenic stimuli. −immunosuppressed, adj.
