title: Host cytokine responses induced after overnight stimulation with novel M. tuberculosis infection phase-dependent antigens show promise as diagnostic candidates for TB disease.
abstract: BACKGROUND
  We previously identified Mycobacterium tuberculosis (M.tb) antigen-induced host markers that showed promise as TB diagnostic candidates in 7-day whole blood culture supernatants. The aim of the present study was to evaluate the utility of these markers further, and cross-compare results with short-term antigen stimulated and unstimulated culture supernatants.
  
  
  METHODS
  We recruited 15 culture confirmed TB cases and 15 non-TB cases from a high-TB endemic community in Cape Town, South Africa into a pilot case-control study from an on-going larger study. Blood samples collected from study participants were stimulated with 4 M.tb antigens that were previously identified as promising (ESAT6/CFP10 (early secreted), Rv2029c (latency), Rv2032 (latency) and Rv2389c (rpf)) in a 7-day or overnight culture assay. Supernatants were also collected form the standard QuantiFERON In Tube (QFT-IT) test. The levels of 26 host markers were evaluated in the three culture supernatants using the Luminex platform.
  
  
  RESULTS
  The unstimulated levels of CRP, Serum amyloid P (SAP) and serum amyloid A (SAA) and ESAT-6/CFP-10 specific IP-10 and SAA were amongst the best discriminatory markers in all 3 assays, ascertaining TB with AUC of 72-84%. Four-marker models accurately classified up to 92%, 100% and 100% of study participants in the overnight, 7-day and Quantiferon culture supernatants, respectively, after leave-one-out cross validation.
  
  
  CONCLUSIONS
  Unstimulated and antigen-specific levels of CRP, SAA, IP-10, MMP-2 and sCD40L hold promise as diagnostic candidates for TB disease in short-term stimulation assays. Larger studies are required to validate these findings but the data suggest that antigen-specific cytokine production and in particular mutimarker biosignatures might contribute to future diagnostic strategies.
authors.affiliation: DST/NRF Centre of Excellence for Biomedical Tuberculosis Research and MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa.
authors.forename: Paulin N
authors.initials: PN
authors.lastname: Essone
authors.affiliation: DST/NRF Centre of Excellence for Biomedical Tuberculosis Research and MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa.
authors.forename: Novel N
authors.initials: NN
authors.lastname: Chegou
authors.affiliation: DST/NRF Centre of Excellence for Biomedical Tuberculosis Research and MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa.
authors.forename: Andre G
authors.initials: AG
authors.lastname: Loxton
authors.affiliation: DST/NRF Centre of Excellence for Biomedical Tuberculosis Research and MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa.
authors.forename: Kim
authors.initials: K
authors.lastname: Stanley
authors.affiliation: DST/NRF Centre of Excellence for Biomedical Tuberculosis Research and MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Kriel
authors.affiliation: DST/NRF Centre of Excellence for Biomedical Tuberculosis Research and MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa.
authors.forename: Gian
authors.initials: G
authors.lastname: van der Spuy
authors.affiliation: Department of Infectious Diseases, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Kees L
authors.initials: KL
authors.lastname: Franken
authors.affiliation: Department of Infectious Diseases, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Tom H
authors.initials: TH
authors.lastname: Ottenhoff
authors.affiliation: DST/NRF Centre of Excellence for Biomedical Tuberculosis Research and MRC Centre for Tuberculosis Research, Division of Molecular Biology and Human Genetics, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Stellenbosch University, Tygerberg, South Africa.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Walzl
mesh_terms: D000293:Adolescent; D000328:Adult; D000942:Antigens, Bacterial / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D016207:Cytokines / Q000097:blood*; D005260:Female; D006801:Humans; D059425:Interferon-gamma Release Tests; D008297:Male; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D010865:Pilot Projects; D012372:ROC Curve; D014397:Tuberculosis, Pulmonary / Q000097:blood* / Q000175:diagnosis / Q000276:immunology; D055815:Young Adult
chemical_list: D000942:Antigens, Bacterial; D015415:Biomarkers; D016207:Cytokines