title: Expression of soluble triggering receptor expressed on myeloid cells-1 in childhood CF and non-CF bronchiectasis.
abstract: BACKGROUND
  Soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) is demonstrating promise as an inflammatory biomarker of acute infection in various pulmonary conditions; including community acquired pneumonia, ventilator associated pneumonia and non-tuberculous mycobacterial infection.
  
  
  BACKGROUND
  The expression of sTREM-1 has been poorly studied in all forms of bronchiectasis, both in the context of cystic fibrosis (CF) and non-cystic fibrosis bronchiectasis.
  
  
  METHODS
  Induced sputum samples were collected for sTREM-1 determination in children with HIV-associated bronchiectasis and CF-bronchiectasis. The presence or absence of an exacerbation was noted at study entry. Lung function parameters (FEV1, FVC, FEV1 /FVC, FEF(25-75)) were measured using the Viasys SpiroPro Jaeger Spirometer (Hoechberg, Germany).
  
  
  RESULTS
  A total of twenty-six children with HIV-associated bronchiectasis and seventeen with CF were included. With respect to sTREM-1, the levels were readily detected in both groups, but were significantly higher in children with HIV-associated bronchiectasis (1244.0 pg/ml (iqr 194.5; 3755.3 pg/ml) and 204.9  pg/ml (iqr 66.9; 653.6 pg/ml) P = 0.003. There was a positive correlation between sTREM-1 and IL-8 as well as sputum neutrophil elastase in the HIV-bronchiectasis group (r = 0.715 and r = 0.630), respectively both P < 0.005. sTREM-1 was not further increased in subjects presenting with an acute pulmonary exacerbation in the HIV-associated bronchiectasis and in CF participants (P = 0.971 and P = 0.481), respectively. In the CF group sTREM-1 strongly correlated with FVC% predicted and FEV1 % predicted (r = 0.950 and r = 0.954), both P < 0.005.
  
  
  CONCLUSIONS
  The pulmonary innate immune functions are over-active in HIV-associated bronchiectasis, with readily detected sTREM-1 values, which were higher than those in CF. sTREM-1 does not correlate with markers of HIV-disease activity but does correlate with markers of neutrophilic inflammation. In CF sTREM-1 has a negative correlation with pulmonary function parameters.
authors.affiliation: Division of Pulmonology, Department of Paediatrics and Child Health, Steve Biko Academic Hospital, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.
authors.forename: R
authors.initials: R
authors.lastname: Masekela
authors.forename: R
authors.initials: R
authors.lastname: Anderson
authors.forename: K
authors.initials: K
authors.lastname: de Boeck
authors.forename: M
authors.initials: M
authors.lastname: Vreys
authors.forename: H C
authors.initials: HC
authors.lastname: Steel
authors.forename: S
authors.initials: S
authors.lastname: Olurunju
authors.forename: R J
authors.initials: RJ
authors.lastname: Green
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000378:metabolism; D001987:Bronchiectasis / Q000378:metabolism*; D002648:Child; D003550:Cystic Fibrosis / Q000378:metabolism*; D005260:Female; D015658:HIV Infections / Q000378:metabolism; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism; D019272:Leukocyte Elastase / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000378:metabolism*; D013183:Sputum / Q000378:metabolism; D000073871:Triggering Receptor Expressed on Myeloid Cells-1
chemical_list: D015415:Biomarkers; D016209:Interleukin-8; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; C408842:TREM1 protein, human; D000073871:Triggering Receptor Expressed on Myeloid Cells-1; D019272:Leukocyte Elastase
keywords: biomarker; exacerbation; immunodeficiency; innate immunity