Progression of obliterative airway disease occurs despite the removal of immune reactivity by retransplantation

0 BLITERATIVE bronchiolitis (OB) has emerged as the main cause of long-term morbidity and mortality following lung transplantation.’ However, the mechanisms of lung injury which lead to OB are poorly understood. Our laboratory has developed a novel model of obliterative airway disease (OAD) in which rat tracheal allografts, but not isografts, heterotopically implanted into the greater omentum, develop lesions by day 28 that are histologically similar to those seen in clinical OB.2*’ In this study, we determined the degree of alloimmune response required to initiate the development of OAD.