THE RELATIONSHIP BETWEEN DYSPNEA PERCEPTION AND BLOOD EOSINOPHIL COUNT IN ALLERGIC ASTHMA

Abstract

Introduction. In addition to the many factors that can affect perception of the dyspnea, airway inflammation also has a significant effect.The most important inflammatory cells in the pathogenesis of allergic asthma are eosinophils, which causes inflammation of the respiratory tract, manifested by increased bronchial reactivity. Unfortunately, the relationship between the dyspnea perception and eosinophils count in peripheral blood in allergic asthma has not been yet adequately investigated. Aim. To evaluate the association between the dyspnea perception and blood eosinophil count before and after the bronchial allergen challenge in patients with allergic asthma. Methodology. Eleven allergic asthma patients (mean age 31.8±9.3 years) with normal lung function and free of inhaled steroids were examined. All patients underwent bronchial challenges with methacholine and Dermatophagoides pteronyssinus (D. pteronyssinus) allergen. Dyspnea perception was evaluated using the Borg Scale to calculate a perception score at a 20% decrease in FEV1 during allergen challenge test PS20A. Eosinophils from peripheral blood were evaluated before and 24 h after bronchial allergen challenge. Results. Mean dyspnea perception during allergen challenge test (PS20A) was 2.97±2.31. The mean blood eosinophil count before allergen inhalation challenge test was 0.36±0.25×109/l, after provocation test it significantly increased up 0.51±10×0.219/l (p = 0.046). Statistically significant relationships were found between PS20A and eosinophil count in peripheral blood before (R = -0.651, p = 0.030) and 24 h after allergen challenge (R = -0.607, p = 0.048). Conclusions. The inverse relationship between PS20A and eosinophil count before and after allergen D. pteronyssinus challenge test was determined. In this way, when systemic eosinophilic inflammation is developing, the dyspnea perception is deteriorating, which can be a risk factor for a severe allergic asthma exacerbation.