Mediators of immediate-type hypersensitivity in sputum from patients with chronic bronchitis and asthma.

Mediators of immediate-type hypersensitivity were studied in the sputum of patients with chronic bronchitis. The same mediators were also measured in early-onset, skin-test-positive asthmatics, in late-onset, skin-test-negative asthmatics, and in patients with bronchial carcinoma, bronchiectasis, and pneumonia. Sputum eosinophilia was a feature of bronchitics and asthmatics, whereas raised blood eosinophil levels were found only in the early-onset, skin-test-positive asthmatics. Histamine and IgE were present in considerable amounts in the sputum of bronchitics and early-onset, skin-test-positive asthmatics. Smaller amounts were found in the other groups. The sputum in all the groups contained material giving an "S.R.S (slow-reacting substance) like" induced contraction of the guinea pig ileum. "Classical" S.R.S.-A., determined by arylsulphatase IIB susceptibility, was present only in bronchitics and both types of asthmatics. Since the bronchitics were, in general, skin-test negative and had normal concentrations of circulating IgE and eosinophils, it is suggested that the findings in the sputum indicate an element of local immediate-type (type I) hypersensitivity in bronchitis although its significance for pathogenesis is not known.