ORGANIZING PNEUMONIA FOLLOWING PULMONARY TRANSPLANTATION AND THE DEVELOPMENT OF OBLITERATIVE BRONCHIOLITIS

Twelve patients receiving lung transplants between 1988 and 1992 who d eveloped clinical and histological features of obliterative bronchioli tis (OB) were compared with a group of 13 patients with good stable lu ng function (FEV(1) more than 80% of predicted). Histological features of 180 biopsies were studied from the first postoperative year in ord er to assess whether any were associated with the development of OB. C linically and histologically defined pulmonary rejection occurring aft er the first month was more frequent in OB patients (P=0.03). Organizi ng pneumonia that was associated with acute rejection but not with non viral infection was also seen more frequently in OB patients (P=0.003) . When all available lung transplant recipients surviving beyond 18 mo nths were included in analyses, organizing pneumonia in the first year was associated with an increased relative risk of developing OB of 2. 26 (95% CL 1.19-4.29), and the occurrence of coexistent organizing pne umonia and pulmonary rejection gave a relative risk for OB of 6.33 (95 % CL 1.61-24.94). An increased incidence of histologically defined org anizing pneumonia in OB patients has not been described previously. Fu rthermore the coexistence of organizing pneumonia with pulmonary rejec tion in the first year posttransplantation is a strong predictive fact or for the development of OB.