Demographics of the Study Population and Biologic Samples1.

1Data are presented as mean ± standard deviation.2Smokers with “established COPD” defined by the GOLD criteria [31], [32]; the COPD smoker group included: GOLD I n = 9, GOLD II n = 11, and GOLD III n = 2.3B = black, W = white, O = other.4Pulmonary function testing parameters are given as % of predicted value with the exception of FEV1/FVC, which is reported as % observed; FVC - forced vital capacity, FEV1 - forced expiratory volume in 1 sec, TLC - total lung capacity, DLCO - diffusing capacity. For individuals with COPD, FVC, FEV1, and FEV1/FVC are post-bronchodilator values.5Small airway epithelium.6As a % of small airway epithelium recovered.