Mediators of hypersensitivity in the sputum of young, symptomatic cigarette smokers.

We have measured the concentrations of mediators of hypersensitivity in the sputum of twenty-five young, symptomatic cigarette smokers who regularly expectorated and twenty-three matched non-smokers with a respiratory infection. The measurements included sputum and blood eosinophils, IgE, IgG, IgA and IgM and also sputum histamine. We found a significant increase of sputum histamine, and a higher sputum/serum ratio of IgE in smokers when compared to non-smokers. These findings support the view that the bronchial inflammatory response in smokers, as in chronic bronchitis, involves the participation of mediators of hypersensitivity.