title: Tissue plasminogen activator as a novel diagnostic aid in acute pulmonary embolism.
abstract: BACKGROUND
  We evaluated the diagnostic efficacy of tissue plasminogen activator (tPA), using an enzyme-linked immunosorbent assay (ELISA) and compared it with an ELISA D-dimer (VIDAS D-dimer) in acute pulmonary embolism (PE).
  
  
  METHODS
  We studied 127 consecutive outpatients with clinically suspected PE. The diagnosis of PE was based on a clinical probability pretest for PE and a strict protocol of imaging studies. A plasma sample to measure the levels of tPA and D-dimer was obtained at enrollment. Diagnostic accuracy for tPA and D-dimer was determined by the area under the receiver operating characteristic (ROC) curve. Sensitivity, specificity, predictive values, and the diagnostic utility of tPA with a cutoff of 8.5 ng/mL and D-dimer with a cutoff of 500 ng/mL, were calculated for PE diagnosis.
  
  
  RESULTS
  PE was confirmed in 41 patients (32 %). Areas under ROC curves were 0.86 for D-dimer and 0.71 for tPA. The sensitivity/negative predictive value for D-dimer using a cutoff of 500 ng/mL, and tPA using a cutoff of 8.5 ng/mL, were 95 % (95 % CI, 88-100 %)/95 % (95 % CI, 88-100 %) and 95 % (95 % CI, 88-100 %)/94 %), respectively. The diagnostic utility to exclude PE was 28.3 % (95 % CI, 21-37 %) for D-dimer and 24.4 % (95 % CI, 17-33 %) for tPA.
  
  
  CONCLUSIONS
  The tPA with a cutoff of 8.5 ng/mL has a high sensitivity and negative predictive value for exclusion of PE, similar to those observed for the VIDAS D-dimer with a cutoff of 500 ng/mL, although the diagnostic utility was slightly higher for the D-dimer.
authors.affiliation: Hospital Universitario Príncipe de Asturias, Universidad de Alcalá de Henares, Neumología, Madrid, Spain.
authors.forename: Julio
authors.initials: J
authors.lastname: Flores
authors.affiliation: Hospital Universitario Ramón y Cajal, Servicio de Hematología y Hemoterapia, Madrid, Spain.
authors.forename: Angel
authors.initials: A
authors.lastname: García-Avello
authors.affiliation: Hospital Universitario Príncipe de Asturias, Universidad de Alcalá de Henares, Neumología, Madrid, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: Alonso
authors.affiliation: Hospital Universitario Príncipe de Asturias, Universidad de Alcalá de Henares, Neumología, Madrid, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Ruíz
authors.affiliation: Hospital Universitario Príncipe de Asturias, Universidad de Alcalá de Henares, Neumología, Madrid, Spain.
authors.forename: Olga
authors.initials: O
authors.lastname: Navarrete
authors.affiliation: Hospital Universitario Príncipe de Asturias, Servicio de Radiodiagnóstico, Madrid, Spain.
authors.forename: Concepción
authors.initials: C
authors.lastname: Alvarez
authors.affiliation: Hospital Universitario Príncipe de Asturias, Servicio de Medicina Interna, Madrid, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Lozano
authors.affiliation: Hospital Universitario Príncipe de Asturias, Universidad de Alcalá de Henares, Fundación para la Investigación Biomédica, Madrid, Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Arribas
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D003952:Diagnostic Imaging; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011655:Pulmonary Embolism / Q000097:blood / Q000175:diagnosis* / Q000201:enzymology; D012372:ROC Curve; D015203:Reproducibility of Results; D010959:Tissue Plasminogen Activator / Q000097:blood*
chemical_list: D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D; C067262:PLAT protein, human; D010959:Tissue Plasminogen Activator
keywords: D-dimer; Pulmonary embolism diagnosis; diagnostic utility; tPA; tissue plasminogen activator