Figure 1.

Neutrophil and lymphocyte counts and proportions stratified by GOLD (Global Initiative for Obstructive Lung Disease) spirometric stage. As GOLD stage increases, the relative proportions of peripheral neutrophils and lymphocytes increase and decrease, respectively ([A] COPDGene and [C] ECLIPSE [Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints]). This phenomenon is driven by an increase in absolute neutrophil count, whereas the absolute amount of lymphocytes remains relatively stable across GOLD stages ([B] COPDGene and [D] ECLIPSE). COPD = chronic obstructive pulmonary disease; NS = nonsmoker; PrISm = preserved ratio impaired spirometry (i.e., subjects with forced expiratory volume in 1 second [FEV₁]/forced vital capacity >0.7, but FEV₁ % predicted <80%).