Sputum neutrophil count after bronchial allergen challenge is related to peripheral blood neutrophil chemotaxis in asthma patients

Objective

The aim of this study was to estimate relations between sputum neutrophilia and the chemotactic activity of peripheral blood neutrophils after the bronchial allergen challenge in asthma patients.

Materials and methods

Fifteen patients with allergic asthma (AA), 13 patients with allergic rhinitis (AR), all sensitized to Dermatophagoides pteronyssinus, and 8 healthy subjects (HS) underwent bronchial challenge with D. pteronyssinus. Sputum and peripheral blood collection were performed 24 h before, 7 and 24 h after the bronchial challenge. Cell counts were determined by the May-Grünwald-Giemsa method. Neutrophil chemotaxis was analyzed by a flow cytometer; IL-8 levels were measured by ELISA.

Results

Sputum neutrophil count and peripheral blood neutrophil chemotaxis of patients with AA were greater 7 and 24 h after the challenge compared with the baseline values and patients with AR and HS (P < 0.05). Moreover, a significant correlation was found between the neutrophil count in sputum and IL-8 levels, and the chemotactic activity of peripheral blood neutrophils 24 h after the bronchial challenge only the patients with AA (P < 0.05).

Conclusions

Increased sputum neutrophil count was found to be associated with an enhanced chemotactic activity of peripheral blood neutrophils during allergen-induced late-phase airway inflammation in patients with allergic asthma.