title: Can interferon-gamma or interferon-gamma-induced-protein-10 differentiate tuberculosis infection and disease in children of high endemic areas?
abstract: BACKGROUND
  Diagnosis of childhood tuberculosis (TB) is difficult in high TB burden settings. Interferon-gamma-induced protein 10 (IP10) has been suggested as a marker of TB infection and disease, but its ability to differentiate the two conditions remains uncertain.
  
  
  OBJECTIVE
  To describe Interferon-gamma (INFγ) and IP10 expression in children with TB infection and disease and controls to assess their potential to differentiate latent and active TB.
  
  
  METHODS
  This was a cross sectional study of 322 1-15 years old children with symptoms of TB (28 confirmed, 136 probable and 131 unlikely TB), 335 children in contact with adults with pulmonary TB and 156 community controls in Southern Ethiopia. The Tuberculin Skin Test (TST) and Quantiferon-In-Tube (QFT-IT) were performed. INFγ and IP10 were measured in plasma supernatants.
  
  
  CONCLUSIONS
  Children with confirmed and probable TB and contacts were more likely to have TST+ (78.6%, 59.3% and 54.1%, respectively) than children with unlikely TB (28.7%) and controls (12.8%) (p<0.001). Children with confirmed TB (59.3%) and contacts (44.7%) were more likely to have INFγ+ than children with probable (37.6%) or unlikely TB (28.1%) and controls (13.1%) (p<0.001). IP10 concentrations were higher in INFγ+ children independently of TST (p<0.001). There was no difference between IP10 concentrations of children with confirmed TB and contacts (p = 0.8) and children with and without HIV (p>0.1). INFγ and IP10 can identify children with TB infection and disease, but cannot differentiate between the two conditions. HIV status did not affect the expression of IP10.
authors.affiliation: Liverpool School of Tropical Medicine, Liverpool, United Kingdom.
authors.forename: Mohammed Ahmed
authors.initials: MA
authors.lastname: Yassin
authors.forename: Roberta
authors.initials: R
authors.lastname: Petrucci
authors.forename: Kefyalew Taye
authors.initials: KT
authors.lastname: Garie
authors.forename: Gregory
authors.initials: G
authors.lastname: Harper
authors.forename: Isabel
authors.initials: I
authors.lastname: Arbide
authors.forename: Melkamsew
authors.initials: M
authors.lastname: Aschalew
authors.forename: Yared
authors.initials: Y
authors.lastname: Merid
authors.forename: Zelalem
authors.initials: Z
authors.lastname: Kebede
authors.forename: Amin Ahmed
authors.initials: AA
authors.lastname: Bawazir
authors.forename: Nabil Mohamed
authors.initials: NM
authors.lastname: Abuamer
authors.forename: Luis Eduardo
authors.initials: LE
authors.lastname: Cuevas
mesh_terms: D000293:Adolescent; D000328:Adult; D054357:Chemokine CXCL10 / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003937:Diagnosis, Differential; D004797:Enzyme-Linked Immunosorbent Assay; D058872:Epidemics; D005002:Ethiopia / Q000453:epidemiology; D005260:Female; D006801:Humans; D007223:Infant; D007371:Interferon-gamma / Q000097:blood*; D008297:Male; D012372:ROC Curve; D012016:Reference Values; D014374:Tuberculin Test; D014376:Tuberculosis / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control*; D014397:Tuberculosis, Pulmonary / Q000453:epidemiology
chemical_list: C114753:CXCL10 protein, human; D054357:Chemokine CXCL10; D007371:Interferon-gamma