The effects of regular inhaled formoterol and budesonide on preformed Th-2 cytokines in mild asthmatics

Abstract

In a recent placebo-controlled study in mild atopic asthmatics, we observed a significant decrease in eosinophils in the bronchial submucosa, after 2 months of treatment with inhaled formoterol and budesonide. Biopsy material from each treatment group; formoterol (24μg bid), budesonide (400μg b.i.d.) and placebo has been further assessed to investigate the role of Th-2 cytokines by immunohistochemistry using Mabs to eosinophils as an index of inflammation, IL-4 and IL-5. Treatment with formoterol significantly reduced the number of eosinophils (EG2+) in the submucosa and epithelium, but this was not paralleled by changes in cytokine immunoreactivity. In contrast, treatment with budesonide significantly reduced both the number of eosinophils (EG2+) and immunoreactivity for IL-4 and IL-5 in the submucosa. Thus, while budesonide has effects on cytokines involved in eosinophil recruitment this explanation does not apply to the eosinopaenia observed with the long-acting β2 adrenoreceptor agonist formoterol.