title: Soluble triggering receptor on myeloid cells-1 is expressed in the course of non-infectious inflammation after traumatic lung contusion: a prospective cohort study.
abstract: BACKGROUND
  The triggering receptor expressed on myeloid cells-1 (TREM-1) is known to be expressed during bacterial infections. We investigated whether TREM-1 is also expressed in non-infectious inflammation following traumatic lung contusion.
  
  
  METHODS
  In a study population of 45 adult patients with multiple trauma and lung contusion, we obtained bronchoalveolar lavage (BAL) (blind suctioning of 20 ml NaCl (0.9%) via jet catheter) and collected blood samples at two time points (16 hours and 40 hours) after trauma. Post hoc patients were assigned to one of four groups radiologically classified according to the severity of lung contusion based on the initial chest tomography. Concentration of soluble TREM-1 (sTREM-1) and bacterial growth were determined in the BAL. sTREM-1, IL-6, IL-10, lipopolysaccharide binding protein, procalcitonin, C-reactive protein and leukocyte count were assessed in blood samples. Pulmonary function was evaluated by the paO2/FiO2 ratio.
  
  
  RESULTS
  Three patients were excluded due to positive bacterial growth in the initial BAL. In 42 patients the severity of lung contusion correlated with the levels of sTREM-1 16 hours and 40 hours after trauma. sTREM-1 levels were significantly (P < 0.01) elevated in patients with severe contusion (2,184 pg/ml (620 to 4,000 pg/ml)) in comparison with patients with mild (339 pg/ml (135 to 731 pg/ml)) or no (217 pg/ml (97 to 701 pg/ml)) contusion 40 hours following trauma. At both time points the paO2/FiO2 ratio correlated negatively with sTREM-1 levels (Spearman correlation coefficient = -0.446, P < 0.01).
  
  
  CONCLUSIONS
  sTREM-1 levels are elevated in the BAL of patients following pulmonary contusion. Furthermore, the levels of sTREM-1 in the BAL correlate well with both the severity of radiological pulmonary tissue damage and functional impairment of gas exchange (paO2/FiO2 ratio).
authors.affiliation: Clinic of Anaesthesiology, Intensive Care Medicine and Pain Therapy, University Hospital Frankfurt am Main, Theodor Stern Kai 7, 60590 Frankfurt am Main, Germany. tobias.bingold@googlemail.com
authors.forename: Tobias M
authors.initials: TM
authors.lastname: Bingold
authors.forename: Barbara
authors.initials: B
authors.lastname: Pullmann
authors.forename: Sven
authors.initials: S
authors.lastname: Sartorius
authors.forename: Emanuel V
authors.initials: EV
authors.lastname: Geiger
authors.forename: Ingo
authors.initials: I
authors.lastname: Marzi
authors.forename: Kai
authors.initials: K
authors.lastname: Zacharowski
authors.forename: Heimo
authors.initials: H
authors.lastname: Wissing
authors.forename: Bertram
authors.initials: B
authors.lastname: Scheller
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D003288:Contusions / Q000150:complications / Q000000981:diagnostic imaging / Q000378:metabolism*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000209:etiology / Q000378:metabolism*; D055370:Lung Injury / Q000150:complications / Q000000981:diagnostic imaging / Q000378:metabolism*; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism*; D011446:Prospective Studies; D011859:Radiography; D011971:Receptors, Immunologic / Q000378:metabolism*; D012720:Severity of Illness Index; D013997:Time Factors; D000073871:Triggering Receptor Expressed on Myeloid Cells-1
chemical_list: D015415:Biomarkers; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; C408842:TREM1 protein, human; D000073871:Triggering Receptor Expressed on Myeloid Cells-1