Serum biomarkers in patients with stable and exacerbated COPD-bronchiectasis overlap syndrome

Introduction: Bronchiectasis (B), commonly seen in patients with chronic obstructive pulmonary disease (COPD), is associated with exacerbations and predicts mortality.

Objectives: To differentiate patient groups with COPD-(B+) or COPD-(B-) and their exacerbations by using inflammatory markers.

Methods: Consecutive COPD patients were divided into two groups according to findings on high resolution thorax CT (HRCT) images using Smith and modified Reiff scores. Patients were prospectively followed for possible future exacerbations. Serum fibrinogen, C-reactive protein (CRP), soluble urokinase-type plasminogen activator receptor (suPAR) and Plasminogen activator inhibitor-1 (PAI-1) levels were studied during exacerbation and stable periods.

Results: Eighty-seven patients were included and (85 M, 2 F), mean aged was 68.1 ± 9 (46-87). HRCT confirmed bronchiectasis in 38 (43.7%) patients, most commonly in tubular form (89.4%) and in lower lobes. COPD-B(+) group had lower body mass index (P = 0.036), more advanced stage of disease (P = 0.004) and more frequent exacerbation (P = 0.01). The HRCT scores were correlated with exacerbation rate (r = 0.356, P < 0.05). Fibrinogen and CRP values were higher in exacerbation (P = 0.01, P = 0.013, respectively) especially in COPD-B(+) patients. suPAR and PAI-1 levels were also higher in COPD-B(+) patients although it was not statistically significant.

Conclusion: Bronchiectasis is common and causes frequent exacerbations in COPD. Identifying of COPD-B(+) phenotype by HRCT scoring systems has considerable importance for both therapeutic options and clinical outcome of the disease. In addition to fibrinogen and CRP, high serum levels of suPAR and PAI-1 suggest us their significant roles in increased systemic inflammation associated with coexisting of COPD and bronchiectasis.