Immunological studies on bronchial secretion. II. Antibodies against bronchial secretion in systemic lupus erythematosus and asthmatic patients.

Bronchial secretion was tested by double gel-diffusion with sera from 100 asthmatic patients, 72 systemic lupus erythematosus patients, 29 patients with other diseases and 31 normal individuals. Positive gel-diffusion reactions were observed only in the sera from two patients with S.L.E. Sera from 100 asthmatic patients, 29 non-allergic patients and 31 normal individuals, tested with bronchial secretion by the passive haemagglutination and inhibition test, showed only three positive reactions with sera from asthmatic patients. Two problems were discussed: the immunological relationship between antigenic determinants found in the sputum and serum in S.L.E. patients; and the possibility that the bronchial secretion being reabsorbed might act as an auto-antigen.