ACUTE LUNG INJURY IN LUNG ALLOGRAFTS

Background: Acute alveolar injury is a pathologic description of a non specific response of the lung to an acute injury. It has been our expe rience that acute alveolar injury may be seen in transbronchial biopsy and open lung biopsy specimens from patients who have successfully un dergone lung transplantation. Because no studies of the clinical signi ficance of acute alveolar injury in lung transplant recipients are ava ilable in the literature, we reviewed the impact of this pathologic fi nding in patients who underwent transplantation in the Toronto Lung Tr ansplant Program. Methods: From November 1983 through December 1992, w e retrospectively reviewed all transbronchial biopsies and open lung b iopsies performed in lung transplant recipients. Results: Of the 137 t ransplantations performed (53 single and 84 double) acute alveolar inj ury was observed in 21 single (34 of 173 transbronchial biopsy and 10 of 24 open lung biopsy) and 22 double (38 of 415 transbronchial biopsy and 3 of 11 open lung biopsy) lung transplantations. We sought to exp lain this finding on the basis of the concurrent clinical scenario. Ac ute alveolar injury occurred most commonly in association with infecti on (52%) followed by postoperative period (19%) and acute (16%) reject ion. Acute alveolar injury occurred as an isolated finding in 7% of pa tients. It occurred within the first 4 months after transplantation in 80% of cases. In 10 of 21 single lung transplantations and 12 of 22 d ouble lung transplantations, acute alveolar injury was seen at least t wice. However, no difference was found in mortality between such patie nts (6 of 10 single and 6 of 12 double lung transplantations) and pati ents with only one episode of acute alveolar injury.