LUNG-FUNCTION ASSOCIATED WITH HISTOLOGICALLY DIAGNOSED ACUTE LUNG REJECTION AND PULMONARY INFECTION IN HEART-LUNG TRANSPLANT PATIENTS

A group of 34 heart-lung transplant patients were studied with serial pulmonary function measuremens, chest radiographs, and transbronchial biopsies from the time of surgery. These investigations were carried out routinely at 3 and 6 months and then unnually after transplantation as well as on clinical suspicion of acute lung rejection or infection. A total of 61 transbronchial biopsies and concurrent lung function and chest radiogaphs were obtained. Of the biopsies, 30 (49.2%) showed histologic evidence of lung rejection, 12 (19.7%) demonstrated various opportunistic infections, and 19 (31.1%) were normal. Compared to during episodes of normal biopsies, FEV1 decreased significantly with lung rejection (p < 0.001) and with infection (p < 0.01). Vital capacity (VC) and DL(CO) also fell with these acute lung complications. Using histologic diagnosis as a standard, lung function testing had a sensitivity of 86% in detecting lung rejection in the first 3 months postoperation and 75% in the subsequent period. Its sensitivity for detecting lung infection was 75%. Although not distinguishing between these two complications, lung function had specificity of 84% for detecting occurrence of an acute lung complication. Chest radiographs, although of similar sensitivity in the first 3 months postsurgery, had a sensitivity of only 19% for rejection in subsequent months and 58% for infection. Its specificity was 100%. Lung function testing changes in a predictable fashion with lung rejection and infection, offers an improvement over chest radiographs, and provides a quantitative measurement to aid the decision of when to undertake transbronchial lung biopsy.