Table 4

 Biomarkers selected for analysis

Pathobiological function
The biomarkers were selected from clusters statistically associated with the diagnosis of COPD and thought to have known or potential significance in the pathobiology of COPD.
AR, amphiregulin; BDNF, brain-derived neurotrophic factor; βNGF, β-nerve growth factor; IFNγ, interferon γ; IL, interleukin; IL-1ra, interleukin 1 receptor antagonist; IL-2Rγ, interleukin 2 receptor gamma; I-TAC, interferon γ-inducible T cell α chemoattractant; MCP-1, monocyte chemotactic protein 1; MIP-1β, macrophage inflammatory protein 1β; MMP-9, matrix metalloproteinase 9; MPIF-1, myeloid progenitor inhibitory factor 1; PAI-II, plasminogen activator inhibitor II; TGFα, transforming growth factor α; TIMP-1, tissue inhibitors of metalloproteinases 1; TNFα, tumour necrosis factor α; TNF R1, tumour necrosis factor receptor I; VEGF, vascular endothelial growth factor.
ChemoattractantsI-TAC, eotaxin-2, MPIF-1, MCP-1, MIP-1β, IL-8, PARC
InflammationIL-15, IL-1ra, IL-17, TNFα, TNF R1, IFNγ, IL-12 p40, IL-2Rγ
Destruction and repairTGFα, VEGF, AR, BDNF, βNGF, MMP-9, TIMP-1
Novel markersPAI-II, prolactin