Peripheral blood eosinophil counts and bronchial responsiveness

Abstract

Bronchial responsiveness (histamine PC20) and peripheral blood eosinophil counts were measured in 23 asthmatic subjects, of whom 14 were atopic and nine non-atopic. In the group as a whole there was an inverse correlation between baseline eosinophil count and histamine PC20 (r = -0.71; p < 0.001). For atopic subjects a relationship between eosinophil count and histamine PC20 was observed (r = -0.74; p < 0.01), but there was no correlation between eosinophil count and baseline FEV1 or baseline FEV1 and histamine PC20. For the non-atopic subjects a similar relationship between eosinophil count and histamine PC20 was seen (r = -0.68; p < 0.05) and a less significant inverse correlation between baseline eosinophil count and baseline FEV1 (r = -0.65; p < 0.05). These results show a relationship between eosinophil count and non-specific bronchial responsiveness in both atopic and non-atopic asthma.