title: Microparticles in sputum of COPD patients: a potential biomarker of the disease?
abstract: 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.
  
  
  OBJECTIVE
  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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Medical and Surgical Sciences, Institute of Respiratory Diseases, University of Foggia, Foggia, Italy.
authors.forename: Donato
authors.initials: D
authors.lastname: Lacedonia
authors.affiliation: Department of Medical and Surgical Sciences, Institute of Respiratory Diseases, University of Foggia, Foggia, Italy.
authors.forename: Giovanna Elisiana
authors.initials: GE
authors.lastname: Carpagnano
authors.affiliation: Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy.
authors.forename: Teresa
authors.initials: T
authors.lastname: Trotta
authors.affiliation: Department of Medical and Surgical Sciences, Institute of Respiratory Diseases, University of Foggia, Foggia, Italy.
authors.forename: Grazia Pia
authors.initials: GP
authors.lastname: Palladino
authors.affiliation: Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy.
authors.forename: Maria Antonietta
authors.initials: MA
authors.lastname: Panaro
authors.affiliation: Department of Medical and Surgical Sciences, Institute of Respiratory Diseases, University of Foggia, Foggia, Italy.
authors.forename: Liugi Davide
authors.initials: LD
authors.lastname: Zoppo
authors.affiliation: Department of Medical and Surgical Sciences, Institute of Respiratory Diseases, University of Foggia, Foggia, Italy.
authors.forename: Maria Pia
authors.initials: MP
authors.lastname: Foschino Barbaro
authors.affiliation: Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Porro
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000032:analysis; D002452:Cell Count / Q000379:methods; D055252:Cell-Derived Microparticles / Q000473:pathology*; D004417:Dyspnea / Q000503:physiopathology; D005434:Flow Cytometry / Q000379:methods; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology; D012720:Severity of Illness Index; D013183:Sputum / Q000166:cytology*; D013223:Statistics as Topic
chemical_list: D015415:Biomarkers
keywords: COPD; lung; microparticles; sputum