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Microparticles in sputum of COPD patients: a potential biomarker of the disease?
Donato Lacedonia1, Giovanna Elisiana Carpagnano1, Teresa Trotta2
1Department of Medical and Surgical Sciences, Institute of Respiratory Diseases, University of Foggia, Foggia, Italy.
Background:
Microparticles (MPs) are small membrane vesicles of 0.1-1 µm which are released by cells following chemical, physical, and apoptotic stimuli. MPs represent more than a miniature version of the cell. Their composition and function depend not only on cellular origin, but also on stimuli. Chronic obstructive pulmonary disease (COPD) is a lung disease characterized by nearly irreversible lung destruction which results in airway limitation.
Purpose:
We investigated the presence and source of MPs in sputum of COPD patients to evaluate if changes in MP number and origin may reflect the pathophysiological conditions of disease and may serve as potential biomarkers for diagnostic and prognostic use.
Methods:
Induced sputum samples were collected from 18 male subjects and liquefied with Sputasol. MPs obtained were immunolabeled for leukocyte (CD11a), granulocyte (CD66b), monocyte-macrophage (CD11b), platelets and megakaryocytic cells (CD41), endothelial cells (CD31), and red blood cells (CD235ab) and analyzed by cytofluorimetry.
Results:
There was a negative correlation between CD31-MPs and forced expiratory volume in 1 second (R=-53, P<0.05) and CD66b-MP level was correlated with worse performance index of COPD such as the Body mass index airflow Obstruction, Dyspnea, and Exercise capacity (BODE); they were negatively correlated with 6-minute walking test: 0.65 and -0.64, respectively (P<0.05). CD235ab-MPs showed a negative correlation with body mass index (R=-0.86, P<0.05), while there was a positive correlation with dyspnea index (R=0.91, P<0.05).
Conclusion:
The main finding of this study was that MPs were detected in the sputum of patients affected by COPD. The phenotype of some of them was related to the main COPD parameters. These results suggest that MPs could be implicated in the pathogenesis of COPD.
Insights
Microparticles (MPs) in sputum may indicate disease severity in Chronic Obstructive Pulmonary Disease (COPD). These cell-derived vesicles show correlations with lung function and patient-reported symptoms, suggesting a role in COPD pathogenesis.
Area of Science:
- Pulmonary Medicine
- Cell Biology
- Biomarker Discovery
Background:
- Microparticles (MPs) are cell-derived vesicles released under various stimuli, reflecting cellular origin and condition.
- Chronic Obstructive Pulmonary Disease (COPD) is a progressive lung disease marked by irreversible airway limitation and lung destruction.
Purpose of the Study:
- To investigate the presence and cellular origin of MPs in COPD patient sputum.
- To determine if MP levels and phenotypes correlate with COPD severity and clinical parameters.
- To evaluate MPs as potential diagnostic and prognostic biomarkers for COPD.
Main Methods:
- Induced sputum samples were collected from 18 male COPD patients.
- MPs were immunolabeled for various cell types including leukocytes, granulocytes, monocytes, platelets, endothelial cells, and red blood cells.
- Flow cytometry (cytofluorimetry) was used to analyze MP phenotypes and quantities.
Main Results:
- MPs were detected in COPD sputum, with specific phenotypes correlating with disease severity.
- Endothelial cell-derived MPs (CD31-MPs) negatively correlated with forced expiratory volume in 1 second (FEV1).
- Granulocyte-derived MPs (CD66b-MPs) correlated with the BODE index and 6-minute walking test, while red blood cell-derived MPs (CD235ab-MPs) correlated with body mass index and dyspnea.
Conclusions:
- MPs are present in COPD sputum and their phenotypes are associated with key disease parameters.
- These findings suggest MPs may play a role in the pathogenesis of COPD.
- MPs in sputum represent a potential avenue for developing novel diagnostic and prognostic biomarkers for COPD.
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