Immunosuppression

Immunosuppression refers to the deliberate reduction of immune system activity to prevent organ transplant rejection, manage autoimmune diseases, or achieve immunologic tolerance. It is commonly induced through pharmacological agents such as cyclosporine, azathioprine, corticosteroids, FK506, and rapamycin, which inhibit lymphocyte proliferation and activation, or via monoclonal antibodies, irradiation in transplant recipients, or natural immune deficiency states like HIV/AIDS where CD4+ T cells are depleted. Combination therapies are employed to balance efficacy against acute rejection with minimized toxicity, while specific immunosuppression can lead to antigen-induced tolerance. This strategy is essential in solid organ and bone marrow transplantation, as well as in treating various immune-mediated disorders.