FIGURE 3.

Serum levels of extracellular matrix (ECM) molecules are altered during acute exacerbations of COPD (AECOPD). a) Serum levels of collagen and elastin turnover products increase during AECOPD compared with stable COPD and drop to stable state levels at 14 days follow-up [2, 5]. b) Serum levels of hyaluronic acid and heparan sulfate increase during AECOPD compared with stable COPD and remain at high levels at 14 days follow-up [4, 106]. Serum levels of chondroitin sulfate decrease during AECOPD compared with stable COPD and remain at low levels at 14  days follow-up [106].