D-dimer as a potential biomarker for the progression of COPD

D-dimer is a manifestation of endogenous fibrinolytic activity and associated with inflammation process. Despite chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease characterized by a hypercoagulable state, D-dimer levels in COPD patients are still conflicting.

Forty-three participants were investigated at admission for an acute exacerbation of COPD, and reassessed when stable. Forty-three controls were matched for age, gender, body mass index, smoking index, comorbidities and medication use. Participants underwent pulmonary function and laboratory testing, including the measurements of D-dimer and high-sensitivity C-reactive protein (hsCRP).

The median of D-dimer was 2839 μg/l (IQR: 2078-4389 μg/l) and 1799 μg/l (IQR: 1205-2196 μg/l) in exacerbated and stable COPD patients respectively. The median of D-dimer in the control subjects was 433 μg/l (IQR: 369-456 μg/l). D-dimer level was significantly increased in stable COPD patients compared with healthy controls, and further increased in those patients with an acute exacerbation (both P<0.001). D-dimer was positively correlated with the well-known inflammatory marker hsCRP both in the exacerbated and stable phases of COPD (r=0.392 P=0.009 and r=0.411 P=0.006, respectively), and negatively correlated with FEV1% predicted and FEV1/FVC in stable COPD (r=-0.409 P=0.006 and r=-0.343 P=0.024, respectively).

D-dimer is increased in COPD patients, and could be considered as an inflammatory marker for the assessment of inflammation in the progression of COPD.