title: Interferon gamma and interferon gamma inducible protein-10 in detecting tuberculosis infection.
abstract: OBJECTIVE
  This study aimed to compare the levels of TB-antigen specific Interferon gamma (IFN-γ) and IFN-γ inducible protein (IP)-10 in culture of whole blood samples from healthy controls (HC) and healthy household contacts (HHC).
  
  
  METHODS
  A total of 386 study subjects, which included 186 HC and 200 HHC, were recruited. QuantiFERON-TB Gold in-tube (QFT-IT) assay was employed to measure IFN-γ levels. IP-10 levels were measured in the supernatants collected from QFT-IT tubes. Tuberculin skin test was also performed.
  
  
  RESULTS
  The levels of TB antigen specific IFN-γ and IP-10 were significantly higher in HHC compared to HC. There was no significant difference observed between positivity of QFT-IT and IP-10 in HC and HHC. The positivity of TST was significantly lower in subjects <17 year, when compared to IP-10 (p<0.005). The reduced cut-off point 0.22IU/ml significantly increased the positivity of QFT-IT among children with high risk for latent TB infection (LTBI).
  
  
  CONCLUSIONS
  Measurement of TB antigen specific IFN-γ and IP-10 can be potential markers for the detection of LTBI.
authors.affiliation: Department of Immunology, National Institute for Research in Tuberculosis, Mayor V.R. Ramanathan Road, Chetput, Chennai, Tamil Nadu, India.
authors.forename: Basirudeen
authors.initials: B
authors.lastname: Syed Ahamed Kabeer
authors.forename: Paulkumaran
authors.initials: P
authors.lastname: Paramasivam
authors.forename: Alamelu
authors.initials: A
authors.lastname: Raja
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000942:Antigens, Bacterial; D015415:Biomarkers; D002478:Cells, Cultured; D054357:Chemokine CXCL10 / Q000032:analysis* / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000032:analysis* / Q000378:metabolism; D059425:Interferon-gamma Release Tests; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D014374:Tuberculin Test; D014376:Tuberculosis / Q000175:diagnosis*; D055815:Young Adult
chemical_list: D000942:Antigens, Bacterial; D015415:Biomarkers; C114753:CXCL10 protein, human; D054357:Chemokine CXCL10; C573415:IFNG protein, human; D007371:Interferon-gamma