Circulating hematopoietic progenitor cells are decreased in COPD

Area of Science:

• Cardiovascular Biology
• Pulmonary Medicine
• Stem Cell Research

Background:

• Bone marrow progenitor cells are crucial for vascular repair.
• Emphysema is characterized by reduced alveolar capillary density and increased endothelial cell death.
• Circulating progenitor cell levels were hypothesized to be diminished in emphysema patients.

Purpose of the Study:

• Quantify circulating endothelial progenitor cells (EPCs) and hematopoietic progenitor cells (HPCs) in COPD patients.
• Correlate progenitor cell levels with COPD severity and emphysema presence.
• Assess progenitor cell function in COPD.

Main Methods:

• Isolated peripheral blood mononuclear cells from 61 COPD patients and 32 controls.
• Quantified EPCs (CD45dim CD34+) and HPCs (CD45+ CD34+ VEGF-R2+) via multi-parameter flow cytometry.
• Assessed progenitor cell function using cell culture assays and evaluated subjects with spirometry and CT scans.

Main Results:

• HPC levels were significantly lower in COPD subjects compared to controls.
• EPC levels were similar between COPD and control groups.
• Reduced HPC levels correlated with obstruction severity and were lowest in severe emphysema, independent of confounding factors. Endothelial cell colony-forming unit capacity was also reduced in COPD patients.

Conclusions:

• HPC levels are decreased in COPD and linked to emphysema phenotype and obstruction severity.
• Reduced HPCs may impair capillary endothelium maintenance, contributing to COPD pathogenesis.