Usefulness of bronchial reactivity analysis in the diagnosis of bronchial asthma in patients with bronchial hyperresponsiveness

AbstractWe examined the usefulness of some bronchial reactivity indices to identify bronchial asthma in patients with airway hyperresponsiveness.Eighty-eight consecutive patients with positive response to histamine bronchial challenge (⩾20% fall in FEV1) were included in the study. Dose–response curves were characterised by their sensitivity (PD20) and reactivity. Dose–response slope, continuous index of responsiveness (CIR) and bronchial reactivity index (BRI) with respect to baseline and post-diluent baseline values were determined as reactivity indices. The clinical diagnosis remaining in the case history 2 years after the bronchial challenge was considered the definitive diagnosis.Asthmatic patients had higher baseline BRI (12.121±0.412 vs. 11.615±0.201; P