ABSTRACT
Since lung transplantation became a reality 25 years ago, improvements in lung preservation, surgical techniques and post-operative management have improved the 1 -year patient survival to almost 80%. Beyond the first year, though, bronchiolitis obliterans (BO), considered a form of chronic allograft rejection, has become a major threat to survival since it affects up to 50 to 60% of patients who survive five years after transplantation and more than half of these patients will eventually succumb to it within the next few years. Treatment for BO includes augmented immunosuppression with boluses of parenteral corticosteroids in addition to adjusting the immunosuppression regi men either by increasing the dose of the drugs being use or switching to other immunosuppressant s within the same class. The addition of other drugs like methotrexate, or newer agents like sirolimus have also being used. Aerosolized cyclosporine is a promising therapeutic alter native but its role in preventing or treating BO remains to be defined. Other strategies include using cytolytic therapy against T-lymphocytes, total lymphoid irradiation and photopheresis. To date none of these strategies have proven conclusively effective in preventing or treating an established BO. The major problem with the available data is that it is spread across too many transplant centers in the form of small, non controlled, non randomized studies which make interpretation of results very difficult. Large multicenter and well designed trials will be essential to advance our understanding of the complex pathophysiology of this condition and to find an effective therapy against BO.
