Soluble triggering receptor expressed on myeloid cells and the diagnosis of pneumonia

N Engl J Med. 2004 Jan 29;350(5):451-8. doi: 10.1056/NEJMoa031544.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Biomarkers / analysis
  • Bronchoalveolar Lavage Fluid / chemistry*
  • Bronchoalveolar Lavage Fluid / immunology
  • Community-Acquired Infections / diagnosis
  • Cytokines / analysis
  • Diagnosis, Differential
  • Female
  • Humans
  • Logistic Models
  • Lung Diseases, Fungal / diagnosis
  • Male
  • Membrane Glycoproteins*
  • Middle Aged
  • Myeloid Cells
  • Pneumonia / diagnosis
  • Pneumonia / etiology
  • Pneumonia, Bacterial / diagnosis*
  • Pneumonia, Bacterial / immunology
  • Pneumonia, Bacterial / therapy
  • Prospective Studies
  • ROC Curve
  • Receptors, Immunologic / analysis*
  • Respiration, Artificial*
  • Sensitivity and Specificity
  • Severity of Illness Index
  • Triggering Receptor Expressed on Myeloid Cells-1


  • Biomarkers
  • Cytokines
  • Membrane Glycoproteins
  • Receptors, Immunologic
  • TREM1 protein, human
  • Triggering Receptor Expressed on Myeloid Cells-1