Table 1.

FOOTPRINTS study participants: all enrolled subjects

Patient group	Rationale
383 patients with COPD, including: 123 patients with mild COPD* 130 patients with moderate COPD† 130 patients with severe COPD‡	Included to provide data on increased lung protease levels and the contribution that this may have on the development and progression of emphysema in the absence of A1ATD.
18 patients with COPD and A1ATD§	Included as they present with an earlier onset of emphysema and a faster decline in lung function, as well as a faster change in lung density.9
62 ex-smokers without airflow limitation	Included to provide a comparison for biomarkers between subjects with and without airflow limitation. Subjects were required to be healthy based on a complete medical history and to have: FEV1 ≥80% of predicted normal and post-bronchodilator. FEV1/forced vital capacity ≥lower limit of normal. A mean post DLCO ≥70% of predicted normal at visit 1.
Total enrolled: 463 subjects

*Defined as GOLD stage 1, FEV₁ ≥80% predicted.²⁵

†Defined as GOLD stage 2, FEV₁ ≥50–<80% predicted.²⁵

‡Defined as GOLD stage 3, FEV₁ ≥30–<50% predicted.²⁵

§Ddefined as having a diagnosis of COPD and a documented A1ATD of ZZ genotype prior to visit 2.

A1ATD, alpha1-antitrypsin deficiency; COPD, chronic obstructive pulmonary disease; DL_CO, diffusing capacity of the lungs for carbon monoxide; FEV₁, forced expiratory volume in 1 s; GOLD, Global Initiative for Chronic Obstructive Lung Disease; ZZ, ZZ allele.