Serum proteomics links the cardiorespiratory biomarkers CTRC, OSM, and MMP-10 to exacerbation severity and number in patients with COPD

During exacerbations, patients with chronic obstructive pulmonary disease (COPD) are at risk for severe cardiovascular disease (CVD). Despite this, the available literature on systemic biomarkers of CVD during exacerbations is limited. In the present study, a proteomic approach was used to assess alterations in the concentrations of 177 biomarkers of CVD and inflammation in serum samples from 26 long-term smokers (LTS) with mild-to-severe COPD (GOLD stage 1–3) and chronic bronchitis (COPD-CB) but no allergy. These patients were followed for 60 weeks, and they all provided paired samples during stable disease and exacerbations. Serum samples from ten healthy non-smokers (HNS) and ten LTS without COPD or CB constituted controls. Of all the proteins analyzed, only chymotrypsin C (CTRC), oncostatin M (OSM), and matrix metalloproteinase 10 (MMP-10) displayed significantly altered concentrations during exacerbations in the COPD-CB group. Here, the concentrations of CTRC and OSM correlated with exacerbation severity, CRP, blood leukocytes, and other cardiovascular biomarkers. In contrast, the concentration of MMP-10 during stable disease correlated with blood eosinophil counts and exacerbation numbers. Finally, the concentrations of OSM and MMP-10 during stable disease correlated with blood leukocytes and tobacco load, respectively. Our study suggests that CTRC, OSM, and MMP-10 bear potential as cardiorespiratory biomarkers in patients with COPD and CB. Collectively, these biomarkers display substantial alterations during exacerbations and correlate with the severity and number of exacerbations. These results motivate prospective studies to determine the clinical utility of CTRC, OSM, and MMP-10 in assessing cardiorespiratory risk in patients with COPD.