title: Soluble triggering receptor expressed on myeloid cells in sputum of patients with community-acquired pneumonia or pulmonary tuberculosis: a pilot study.
abstract: Soluble triggering receptor expressed on myeloid cells (s-TREM-1) is upregulated on the surface of inflammatory cells in the presence of bacterial infections, apparently excluding those due to Mycobacterium tuberculosis. Therefore, sputum concentrations of s-TREM-1 may be of value in distinguishing bacterial pneumonia from pulmonary tuberculosis (PTB) in patients with respiratory infections. The current pilot study was designed to evaluate whether s-TREM-1 concentrations measured in the sputum of patients with suspected community-acquired pneumonia (CAP) allowed differentiation of those patients with PTB from other causes of pneumonia and to correlate s-TREM-1 with CURB-65, a marker of disease severity. Soluble s-TREM-1 concentrations were measured in sputum samples from patients admitted to a tertiary hospital with CAP or PTB by means of an ELISA procedure. Soluble-TREM-1 was readily detectable and quantifiable in sputum samples from patients with both CAP and PTB, with concentrations of 234±47 and 178±36 pg/ml respectively, but did not differ significantly between the two groups. However, patients with PTB had significantly lower leukocyte counts, 9±1.3 vs 15±1.4 × 10(9)/l compared with those without PTB. Interestingly, sputum s-TREM-1 concentrations correlated significantly with the CURB-65 pneumonia severity score calculated at the time of admission. Soluble-TREM-1 expression is upregulated in patients with both CAP and PTB, but does not differentiate between these two conditions. Sputum concentrations of s-TREM-1 may predict the severity of disease in patients with CAP.
authors.affiliation: Department of Internal Medicine, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa. grtintinger@gmail.com
authors.forename: G R
authors.initials: GR
authors.lastname: Tintinger
authors.forename: J J
authors.initials: JJ
authors.lastname: van der Merwe
authors.forename: H
authors.initials: H
authors.lastname: Fickl
authors.forename: P
authors.initials: P
authors.lastname: Rheeder
authors.forename: C
authors.initials: C
authors.lastname: Feldman
authors.forename: R
authors.initials: R
authors.lastname: Anderson
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000150:complications; D015415:Biomarkers / Q000032:analysis; D017714:Community-Acquired Infections / Q000175:diagnosis; D005260:Female; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis*; D009169:Mycobacterium tuberculosis / Q000472:pathogenicity; D022423:Myeloid Cells / Q000737:chemistry; D010865:Pilot Projects; D018410:Pneumonia, Bacterial / Q000175:diagnosis* / Q000382:microbiology; D011971:Receptors, Immunologic / Q000032:analysis*; D013183:Sputum / Q000737:chemistry* / Q000382:microbiology; D000073871:Triggering Receptor Expressed on Myeloid Cells-1; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000382:microbiology
chemical_list: D015415:Biomarkers; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; C408842:TREM1 protein, human; D000073871:Triggering Receptor Expressed on Myeloid Cells-1