Evaluation of heart-lung transplant recipients with prospective, serial transbronchial biopsies and pulmonary function studies.

The insidious development of obliterative bronchiolitis after heart-lung transplantation is thought to be due to rejection and possibly infection (cytomegalovirus). To evaluate further, we prospectively managed the last 16 consecutive heart-lung transplant recipients with serial transbronchial biopsies with lavage and pulmonary function studies as part of a surveillance protocol or as dictated by clinical presentation. A total of 123 transbronchial biopsies with lavage were performed, 77 for clinical indications (group I) and 46 for routine surveillance (group II). Results of 64 (83.1%) group I biopsies were positive for rejection or infection. Thirty-one of these biopsy specimens showed signs of rejection (29 in group I and two in group II), characterized by a perivascular mononuclear infiltrate, lymphocytic bronchiolitis, and occasionally alveolar septal mononuclear infiltrate. Forty-six serial pulmonary function tests were performed. The forced expiratory volume in 1 second (percent predicted), forced expiratory flow rate between 25% and 75% of the forced vital capacity (percent predicted), and arterial oxygen tension (millimeters of mercury) were significantly reduced from baseline values during rejection episodes: forced expiratory volume in 1 second, 75.7% +/- 20.1% versus 52.7% +/- 18.3% (p less than or equal to 0.05); forced expiratory flow rate between 25% and 75% of the forced vital capacity, 97.6% +/- 30.5% versus 49.8% +/- 22.3% (p less than or equal to 0.05); and arterial oxygen tension, 92.1 +/- 8.8 mm Hg versus 71.4 +/- 18.8 mm Hg (p less than or equal to 0.05). The fall in pulmonary function was reversible with pulse methylprednisolone. Asynchronous heart and lung rejection was documented. Of the 29 episodes of pulmonary rejection, 18 (62%) occurred asynchronously. Ten of the 16 (62%) heart-lung recipients had at least one episode of cardiac rejection. Thirteen of 16 (81%) had at least one episode of lung rejection. Serial transbronchial biopsies with lavage, as dictated by pulmonary function tests and clinical status, have guided early and more specific therapy directed against rejection and infection. With early detection, small airway dysfunction has been reversible.