Bronchial biopsy and reactivity in patients with chest tightness relieved with bronchodilator

It has been hypothesized that some patients with chest tightness of unknown origin can be successfully treated with a bronchodilator and that they should be diagnosed with chest pain variant asthma. We conducted a prospective study to characterize newly diagnosed patients with chest tightness relieved with bronchodilator use and without characteristic bronchial asthma attacks.

Eleven patients were registered following recurrent positive responses of chest tightness to inhalation of a ß₂-agonist. These patients underwent assessments of airway responsiveness to methacholine, bronchial biopsy and bronchial lavage under fiber-optic bronchoscopy before receiving treatment.

For the patients with chest tightness relieved with bronchodilator use, the bronchial biopsy specimens exhibited significant increases in lymphocyte and macrophage infiltration (p < 0.05) and no significant increase in eosinophils (p = 0.2918) compared with the control subjects. The bronchial responsiveness to methacholine was increased in two of the patients with chest tightness, and it was not increased in seven; in addition, increased percentages of eosinophils were detected in bronchial lavage fluid (5% or more) from two patients, but no increase was detected in eight patients.

We suspect that the chest tightness was induced by airway constriction in these patients, but further study is necessary to validate this hypothesis. We propose that the chest tightness relieved with bronchodilator use was attributed to airway constriction resulting from inflammation with lymphocytes and macrophages and/or that the chest tightness was directly attributed to airway inflammation. This clinical trial is registered at www.umin.ac.jp (UMIN13994 and UMIN 16741).