Liquid biopsy beyond of cancer: Circulating pulmonary cells as biomarkers of COPD aggressivity

Background: Pulmonary parenchymal destruction is consequence of Chronic Obstructive Pulmonary Disease (COPD), which results in degradation of the extracellular matrix and the appearance of peripheral pulmonary cells. The aim of this study is to demonstrate the feasibility of the detection and isolation of Circulating Pulmonary Cells (CPCs) in peripheral blood of patients with COPD. Methods: 17 COPD patients were enrolled in this prospective study to isolate CPCs. Peripheral blood samples for CPC analysis were processed using positive immunomagnetic methods combined with a double immunocytochemistry. Two antibodies, anti-cytokeratin and anti-CD44v6 were used to confirm the epithelial nature of the isolated cells and their lung origin respectively. Results: CK/CD44v6 positive CPCs were identified in 6 of 17 COPD patients (35.2% of the total) (range: 1-2 cells). No CPCs were detected in any of the 10 healthy volunteers. The COPD CPCs + patients showed a trend towards greater severity of the disease. Conclusions: This study suggest the feasibility to detect CPCs in peripheral blood of patients with COPD and its potential use as prognostic marker.