P-selectin glycoprotein ligand-1 (PSGL-1) is up-regulated on leucocytes from patients with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterized by a dysregulated recruitment of circulating leucocytes into the lung which is associated with the onset and progress of the disease. P-selectin glycoprotein ligand-1 (PSGL-1) is expressed on leucocytes and plays an essential role in primary leucocyte-endothelial cell adhesive contacts. The present study investigated if PSGL-1 is up-regulated on leucocytes of COPD patients. Peripheral blood samples were collected from COPD patients as well as controls (smoking, nonsmoking volunteers) and subjected to analysis of PSGL-1 expression on leucocytes, i.e. neutrophils, eosinophils, monocytes and lymphocytes by flow cytometry. No significant difference was observed between healthy nonsmoking and healthy smoking control subjects. In contrast, PSGL-1 expression was found to be significantly increased on the surface of all four leucocyte populations in COPD patients compared to both control groups. The finding that PSGL-1 surface expression is up-regulated on leucocytes of COPD patients as compared to leucocytes of controls suggests PSGL-1 as a potential target for anti-inflammatory treatment.