[Membranous and respiratory bronchiole disease in patients with normal air-flow and mild air-flow limitation].

In order to evaluate the role of membranous (MB) and respiratory bronchioles (RB) in patients with normal and mild airflow limitation, we quantitatively assessed the pathological change of MB, RB and alveoli in the pathological specimens of 42 patients who required surgery for removal of a solitary pulmonary nodule. We also measured the destructive index (DI), to evaluate the destruction of alveolar walls. High resolution CT scan and pulmonary function tests were performed within 1 month of resection. Results of the pulmonary function tests correlated with pathological changes of RB better than with MB. Significant correlation between the emphysema score of resected lung and the pathological change of MB and RB was observed. There was also significant correlations between the CT score or DI and RB changes. However, there was no significant correlation between the CT score or DI and the change of MB. There were significant differences between smokers and nonsmokers in the results of pulmonary function test, pathological changes of RB and severity of emphysema. We postulate that RB is responsible for subtle functional abnormalities in the early stages of chronic obstructive pulmonary disease.