Clinical study of bronchial inhalation challenge in summer-type hypersensitivity pneumonitis induced by Trichosporon cutaneum

Abstract

To evaluate the methods and criteria of judgement for the bronchial antigen inhalation challenge test, the test was performed with culture filtrate antigen of serotype I and II of Trichosporon cutaneum in 18 patients with summer-type hypersensitivity pneumonitis from 15 families. The quantity of 15 mg of culture filtrate antigen was adequate, and had no side effects. In the tests, 17 of 18 patients showed a positive reaction to both or either, serotype of antigen. In 36 performances of inhalation, there were 21 positive reactions and 15 negative reactions. According to the criteria of judgment for inhalation challenge test, the positive response rates of observation items were 75% for symptoms and signs, and 51% for laboratory data. Items with a high positive rate were cough, crepitant rales, and decrease of PaO2. On the other hand, low positive rates were observed for decrease of DLco, VC and positive CRP. Items with both high sensitivity and high specificity were cough, crepitant rales and decrease of PaO2. The low positive rate of decreased DLco was due to insufficient improvement before inhalation challenge. It was concluded that our methods and criteria of judgment for bronchial inhalation challenge test are useful.