Small airways function in pulmonary sarcoidosis.

Closing volume and maximal expiratory flow-volume curves were performed in a group of 25 patients with pulmonary sarcoidosis in stages I and II and with normal spirographic results. Although the mean values of these tests were mostly within the limits of predicted values, 48% of the patients had an increased slope of the alveolar plateau and 40% had decreased maximal expiratory flow at low lung volumes. Abnormal test results were found even in patients with normal static lung compliance. Our results suggest that functional abnormalities in small airways may occur early in the course of sarcoidosis.