Figure 1

Sputum cytospins from different subjects with asthma illustrate the heterogeneity of the airway inflammation. In the upper left panel, the predominant cells are macrophages with a normal neutrophil and eosinophil count; this cytospin cannot be distinguished from a sample from a healthy control (paucigranulocytic asthma ×100 original magnification); the upper right panel shows combined neutrophilic and eosinophilic inflammation (×400 original magnification); the lower left panel shows neutrophilic inflammation (×400 original magnification); and the lower right panel shows eosinophilic inflammation (×400 original magnification). Adapted from Brightling [98]. (Romanowsky stain.)