PMC

Sputum inflammatory cells. Shown are box plots of % eosinophils and % neutrophils from sputum specimens. There was a wide range of values for both cell types in all sputum clusters. There are statistically significant differences among the four groups, (p=0.001 for eosinophils, p<0.0001 for neutrophils) with differentiation between clusters in contrast to blood inflammatory cells (see ). P values shown on graph are paired comparisons between two clusters of similar disease severity.

Sputum granulocyte patterns in the four clusters. Subjects were assigned into one of four possible patterns based on % sputum eosinophils (<2% or >=2%) and % sputum neutrophils (<40% or >=40%). All four granulocyte patterns are present in every cluster, but in general, as asthma severity increases (Clusters C and D), sputum neutrophils increase in nearly all subjects and sputum eosinophils persist in a third to half of these subjects despite increasing doses of inhaled and/or oral corticosteroids.