[Membranous bronchiole diseases in patients without chronic air-flow limitation]

In order to investigate the relationship between pulmonary function and diseases involving membranous bronchioles (MB), we measured airway diameters and quantitated airway pathology scores in MB in 35 patients who required surgery for removal of a solitary nodule. The patients had FEV1 greater than 80% of the predicted value. Measurements of FEV1, nitrogen washout curve (delta N2/L), closing volume as a percentage of vital capacity (CV/VC%), and maximal flow rate at 50% of VC (V50) were made prior to the surgery. There were 21 smokers and 14 nonsmokers. There was 1.02 MB per cm2 of tissue. The mean internal diameter for MB cases was 0.55 +/- 0.05 mm. The total pathology scores for all MB cases were less than those found in North American populations. Inflammation scores were higher in patients with FEV1 less than 100% that of the predicted (p less than 0.05). FEV1 values correlated with goblet cell metaplasia (p less than 0.05). Tests specific for small airways did not correlate with the pathology scores in MB. We concluded. In 35 Japanese cases some diseases in MB were detected among cases whose average age was 59.5 years (42-78 yrs) and whose FEV1 was greater than 80% of the predicted value. The disease showed little effects of smoking and it was relatively minor in comparison with North American cases. This degree of abnormality is considered to be found in normal Japanese as well. It is supposed that an ordinary pulmonary function test would not reveal this abnormality in MB.