title: Osteopontin is upregulated in malignant and inflammatory pleural effusions.
abstract: OBJECTIVE
  Osteopontin (OPN) is an important mediator of inflammation and cancer progression. In the present study, we asked whether pleural fluid (PF) and serum OPN concentrations differed between patients with pleural effusions of different aetiologies, and whether assessment of OPN levels was useful for diagnostic purposes.
  
  
  METHODS
  One hundred and nine consecutive patients with pleural effusions of different aetiologies were recruited prospectively during daily clinics. OPN levels were measured by ELISA.
  
  
  RESULTS
  PF OPN levels were 10-fold higher in exudates than in transudates and were significantly correlated with markers of pleural inflammation and vascular hyper-permeability, such as PF/serum LDH or protein ratios, PF protein and PF vascular endothelial growth factor levels. Patients with malignant pleural effusions had higher PF and lower serum OPN concentrations than those with benign disease. The diagnostic accuracies of PF and PF/serum OPN for malignancy were 71.5% (95% CI: 64-80) and 70.6% (95% CI: 62-80), respectively.
  
  
  CONCLUSIONS
  OPN levels were elevated in exudative pleural effusions, as compared with the levels in blood or transudative pleural effusions. While PF and PF/serum OPN were higher in patients with malignancies, the diagnostic accuracy of the tests was not sufficient to permit routine use in clinical practice.
authors.affiliation: Applied Biomedical Research and Training Center Marianthi Simou., Department of Critical Care & Pulmonary Services, General Hospital 'Evangelismos', School of Medicine, University of Athens, Athens.
authors.forename: Charalampos
authors.initials: C
authors.lastname: Moschos
authors.forename: Ilias
authors.initials: I
authors.lastname: Porfiridis
authors.forename: Ioannis
authors.initials: I
authors.lastname: Psallidas
authors.forename: Androniki
authors.initials: A
authors.lastname: Kollintza
authors.forename: Georgios T
authors.initials: GT
authors.lastname: Stathopoulos
authors.forename: Spyros A
authors.initials: SA
authors.lastname: Papiris
authors.forename: Charis
authors.initials: C
authors.lastname: Roussos
authors.forename: Ioannis
authors.initials: I
authors.lastname: Kalomenidis
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008171:Lung Diseases / Q000150:complications / Q000175:diagnosis / Q000378:metabolism*; D008175:Lung Neoplasms / Q000150:complications / Q000175:diagnosis / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D053495:Osteopontin / Q000378:metabolism*; D010996:Pleural Effusion / Q000209:etiology / Q000378:metabolism*; D016066:Pleural Effusion, Malignant / Q000175:diagnosis / Q000209:etiology / Q000378:metabolism*; D010997:Pleural Neoplasms / Q000150:complications / Q000175:diagnosis / Q000378:metabolism*; D011014:Pneumonia / Q000150:complications / Q000175:diagnosis / Q000378:metabolism; D011446:Prospective Studies; D014376:Tuberculosis / Q000150:complications / Q000175:diagnosis / Q000378:metabolism; D055815:Young Adult
chemical_list: D015415:Biomarkers; D014408:Biomarkers, Tumor; D053495:Osteopontin