title: Soluble triggering receptor expressed on myeloid cells and the diagnosis of pneumonia.
abstract: BACKGROUND
  The diagnosis and treatment of bacterial pneumonia in patients who are receiving mechanical ventilation remain a difficult challenge. The triggering receptor expressed on myeloid cells (TREM-1) is a member of the immunoglobulin superfamily, and its expression on phagocytes is specifically up-regulated by microbial products. The presence of soluble TREM-1 (sTREM-1) in bronchoalveolar-lavage fluid from patients receiving mechanical ventilation may be an indicator of pneumonia.
  
  
  METHODS
  We conducted a prospective study of 148 patients receiving mechanical ventilation in whom infectious pneumonia was suspected. A rapid immunoblot technique was used to measure sTREM-1 in bronchoalveolar-lavage fluid. Two independent intensivists who were unaware of the results of the sTREM-1 assay determined whether community-acquired pneumonia and ventilator-associated pneumonia were present or absent.
  
  
  RESULTS
  The final diagnosis was community-acquired pneumonia in 38 patients, ventilator-associated pneumonia in 46 patients, and no pneumonia in 64 patients. The presence of sTREM-1 by itself was more accurate than any clinical findings or laboratory values in identifying the presence of bacterial or fungal pneumonia (likelihood ratio, 10.38; sensitivity, 98 percent; specificity, 90 percent). In multiple logistic-regression analysis, the presence of sTREM-1 was the strongest independent predictor of pneumonia (odds ratio, 41.5).
  
  
  CONCLUSIONS
  In patients receiving mechanical ventilation, rapid detection of sTREM-1 in bronchoalveolar-lavage fluid may be useful in establishing or excluding the diagnosis of bacterial or fungal pneumonia.
authors.affiliation: Service de Réanimation Médicale, Hôpital Central, Nancy, France. s.gibot@chu-nancy.fr
authors.forename: Sébastien
authors.initials: S
authors.lastname: Gibot
authors.forename: Aurélie
authors.initials: A
authors.lastname: Cravoisy
authors.forename: Bruno
authors.initials: B
authors.lastname: Levy
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Bene
authors.forename: Gilbert
authors.initials: G
authors.lastname: Faure
authors.forename: Pierre-Edouard
authors.initials: PE
authors.lastname: Bollaert
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000032:analysis; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry* / Q000276:immunology; D017714:Community-Acquired Infections / Q000175:diagnosis; D016207:Cytokines / Q000032:analysis; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D016015:Logistic Models; D008172:Lung Diseases, Fungal / Q000175:diagnosis; D008297:Male; D008562:Membrane Glycoproteins; D008875:Middle Aged; D022423:Myeloid Cells; D011014:Pneumonia / Q000175:diagnosis / Q000209:etiology; D018410:Pneumonia, Bacterial / Q000175:diagnosis* / Q000276:immunology / Q000628:therapy; D011446:Prospective Studies; D012372:ROC Curve; D011971:Receptors, Immunologic / Q000032:analysis*; D012121:Respiration, Artificial; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D000073871:Triggering Receptor Expressed on Myeloid Cells-1
chemical_list: D015415:Biomarkers; D016207:Cytokines; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; C408842:TREM1 protein, human; D000073871:Triggering Receptor Expressed on Myeloid Cells-1