Study objectives: Eosinophils and neutrophils play
major roles, respectively, in the pathogenesis of asthma and COPD, and
it is well recognized that levels of these cells in peripheral blood
are increased in relation to their pulmonary involvement. However, the
relation between peripheral blood cell counts of the other major
leukocyte groups and these lung diseases or markers of allergy or
airflow obstruction is less clear. We have therefore investigated the
association between peripheral blood levels of eosinophils,
neutrophils, basophils, monocytes, and lymphocytes and the occurrence
of chronic respiratory symptoms, atopy, lung function, and bronchial
hyperresponsiveness, and the modifying effect of age, in adults.
Design: A cross-sectional general population study.
Setting: Data on > 2,000 British adults, who originally
participated in a study of diet and lung health, were analyzed using
multiple linear and logistic regression to adjust for potential
confounders, including age, sex, and smoking history.
Results: We found that, like eosinophils, the peripheral
basophil count was increased in relation to asthma and associated
symptoms, and to airway hyperreactivity and increased total IgE, but
differed from eosinophils in that basophils were unrelated to atopy.
Monocytes were predominantly associated with symptoms indicative of
obstructive airway disease, in similar relation to neutrophils, but
both of these leukocyte counts were also increased in asthma patients
in older age groups. Lymphocyte counts were unrelated to any objective
or subjective marker of disease.
peripheral blood cell counts reflect pulmonary involvement of these
leukocyte groups, basophils and monocytes may play a distinct role in
the pathogenesis of allergic and nonallergic respiratory