Endogenous glucocorticoids and antigen-induced acute and late phase pulmonary responses

Background Several studies suggest that endogenous glucocorticoids can damp en the severity of experimental allergic reactions in animals. Objective To investigate the influence that endogenous glucocorticoids have on the course of IgE-mediated pulmonary early and late phase reactions. Methods Twenty-one allergic asthmatic and six healthy control subjects unde rwent inhaled antigen challenge with measurements of plasma cortisol and co rtisone by gas chromatography-mass spectrometry. Results There were no differences between the asthmatic and control groups in the baseline levels of cortisol or cortisone. However, the asthmatic sub jects had significantly higher cortisol levels (67.2 +/- 8.6 vs 35.1 +/- 4. 5 ng/mL; P = 0.04) and had higher cortisol/ cortisone ratios (4.8 +/- 0.6 v s 3.0 +/- 0.2; P = 0.01) sh after challenge compared to the control subject s. Among the asthmatic subjects, those whose FEV1 recovered rapidly had hig her baseline levels of cortisol and those who displayed a late phase reacti on had lower levels of cortisol during the late phase period. Conclusion The results suggest that endogenous glucocorticoids may play a s ignificant role in the modulation of airway responses to antigen challenge, and that antigen challenge may induce cortisol production in allergic subj ects.