Immune responsiveness to inhaled antigens: local antibody production in the respiratory tract in health and lung diseases.

The pulmonary defence mechanism in summer type hypersensitivity pneumonitis induced by Trichosporon cutaneum was investigated. We have studied the antibody response to fungal antigens in sera and bronchoalveolar lavage (BAL) fluids from patients with summer type hypersensitivity pneumonitis, bird fancier's lung, interstitial pneumonia associated with collagen vascular disease (INT-PNE), and from normal volunteers. Antigens extracted from fungi frequently isolated from home environments were used in ELISA to detect IgG and IgA antibodies in sera and BAL fluids. The results of the present study show that antibody titre in the respiratory tract to a variety of fungi from home environments is modulated by ongoing pulmonary inflammation, and that antibody production against inhaled antigens is altered by pulmonary inflammation resulting from diverse pathogenesis. This study concludes that the preexisting pulmonary inflammatory disease alters antibody production in the respiratory tract in response to inhaled fungi, and that the type of alteration depends in part on the etiology of the preexisting disease.