Immunosuppression for the prevention and treatment of BOS

Over the past 3 decades, lung transplantation has evolved into a life-saving procedure for patients with end-stage lung disease. During this time, further development of biologic agents and newer immunosuppressive agents has continued to improve outcomes after transplantation. Although there is variability among centers regarding specific immunosuppressive medications, the overall approach to immunosuppressive regimens in lung transplantation is quite uniform and consists of a triple-drug immunosuppressive regimen that includes a calcineurin inhibitor, an antimetabolite, and corticosteroids (CS), with or without a biological agent as induction therapy. However, the discovery and continued development of new immunosuppressive agents that target novel immune pathways provide alternate therapeutic options for lung recipients with progressive decline in pulmonary function. The current goal of immunosuppression is to maintain allograft viability by preventing acute and chronic rejection while decreasing toxicities associated with immunosuppression. This chapter will review the current approach to immunosuppressive medications that are used in the maintenance of allograft stability and the prevention and treatment of bronchiolitis obliterans syndrome (BOS).