Review of Immunosuppression for Lung Transplantation

The currently used standard triple-drug immunosuppressive regimen with cyclosporine (CSA), azathioprine, and prednisone fails to prevent acute and chronic rejection in most lung transplant recipients. The incidence of acute and chronic rejection is significantly higher in clinical lung transplantation than for any other solid organ graft. 34 , 95 Five years after lung transplantation, the incidence of the bronchiolitis obliterative syndrome (BOS), a disease entity that most likely reflects a form of chronic rejection, is presently approximately 50%. 20 , 95 With severe limitations in organ supply, retransplantation cannot be considered a feasible option and BOS therefore is the primary direct and indirect cause of patient mortality. 70 The development of novel approaches to current immunosuppression therefore is an important unmet clinical need. Among all the new immunosuppressant agents that have been recently approved for clinical use or are being actively studied in the laboratory, four stand out—tacrolimus (FK506), sirolimus (rapamycin), mycophenolate mofetil, and leflunomide (and its malononitriloamide analogues). The following review provides information on these novel compounds and alternative means to control rejection and educates the reader on their current use and future development.