title: Soluble triggering receptor expressed on myeloid cells-1 for diagnosing empyema.
abstract: BACKGROUND
  Studies have shown that soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) is upregulated by microbial products in the bronchoalveolar lavage fluid, and cerebrospinal fluid of patients with pneumonia and bacterial meningitis, respectively. Our goal was to evaluate whether sTREM-1 in pleural fluid can distinguish pleural empyema from postthoracotomy-related pleural effusion and effusions of other etiologies.
  
  
  METHODS
  Patients who presented with pleural effusion were identified through laboratory records. In addition to routine biochemical markers, differential white blood cells, cytology, Gram stain, and pleural fluid culture, pleural fluid sTREM-1 was measured by enzyme-linked immunosorbent assay using a commercial kit (R&D Systems, Minneapolis, MN).
  
  
  RESULTS
  Eighty-nine patients were included in the study: 17 with empyema, 7 simple parapneumonic effusion, 18 transudate, 12 postthoracotomy pleural effusion, 22 malignancy, 1 connective tissue disease, and 12 with undetermined effusion. Mean levels of sTREM-1 were significantly higher in empyema than in postthoracotomy pleural effusion (687 +/- 479 pg/mL vs 34 +/- 81 pg/mL, p < 0.0001, respectively) and in effusions of other etiologies (15 +/- 54 pg/mL, p < 0.0001). A cutoff value of 114 pg/mL for pleural sTREM-1 achieved a sensitivity of 94% and a specificity of 93% in differentiating empyema from pleural effusions of other etiologies. The area under the receiver operating characteristic curve for pleural effusion sTREM-1 as a predictor for empyema was 0.966.
  
  
  CONCLUSIONS
  Our findings suggest that sTREM-1 in the pleural fluid can potentially assist clinicians in the differentiation of bacterial from nonbacterial pleural effusion, particularly in postthoracotomy pleural effusion.
authors.affiliation: Infectious Diseases Unit, Tel Aviv University, Petah-Tiqwa, Israel. bishara@netvision.net.il
authors.forename: Jihad
authors.initials: J
authors.lastname: Bishara
authors.forename: Elad
authors.initials: E
authors.lastname: Goldberg
authors.forename: Shai
authors.initials: S
authors.lastname: Ashkenazi
authors.forename: Yael
authors.initials: Y
authors.lastname: Yuhas
authors.forename: Zmira
authors.initials: Z
authors.lastname: Samra
authors.forename: Milton
authors.initials: M
authors.lastname: Saute
authors.forename: Hila
authors.initials: H
authors.lastname: Shaked
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000032:analysis; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003937:Diagnosis, Differential; D004653:Empyema / Q000175:diagnosis* / Q000473:pathology; D004797:Enzyme-Linked Immunosorbent Assay; D005122:Exudates and Transudates / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis / Q000378:metabolism*; D008875:Middle Aged; D022423:Myeloid Cells / Q000378:metabolism / Q000473:pathology; D010996:Pleural Effusion / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology; D016066:Pleural Effusion, Malignant / Q000175:diagnosis / Q000473:pathology; D011336:Probability; D011971:Receptors, Immunologic / Q000032:analysis / Q000378:metabolism*; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D013908:Thoracotomy / Q000009:adverse effects* / Q000379:methods; D000073871:Triggering Receptor Expressed on Myeloid Cells-1; D055815:Young Adult
chemical_list: D015415:Biomarkers; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; C408842:TREM1 protein, human; D000073871:Triggering Receptor Expressed on Myeloid Cells-1