title: Booster phenomenon of QuantiFERON-TB Gold after prior intradermal PPD injection.
abstract: METHODS
  University medical school in Japan.
  
  
  OBJECTIVE
  To clarify the influence of prior intradermal purified protein derivative (PPD) injection on QuantiFERON-TB Gold (QFT-G).
  
  
  METHODS
  Ninety-seven sixth-year university medical students aged 20-29 years concurrently underwent QFT-G and tuberculin skin test (TST). The first negative QFT-G and the first TST <15 mm were followed by a second QFT-G one month later.
  
  
  RESULTS
  Five of the 97 (5%) subjects tested positive for the first QFT-G. Thirty-three underwent a second QFT-G, five of whom (15%) turned positive, demonstrating the booster phenomenon of QFT-G.
  
  
  CONCLUSIONS
  Prior intradermal PPD injection may boost QFT-G. Further studies of the diagnostic significance and immunological mechanisms of this phenomenon are needed. For clinical application, especially during contact screening, QFT-G should be evaluated while keeping in mind the possible influence of prior PPD intradermal injection.
authors.affiliation: Division of Control and Treatment of Infectious Diseases, Chiba University Hospital, Chiba, Japan. igari@faculty.chiba-u.jp
authors.forename: H
authors.initials: H
authors.lastname: Igari
authors.forename: A
authors.initials: A
authors.lastname: Watanabe
authors.forename: T
authors.initials: T
authors.lastname: Sato
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000276:immunology; D015331:Cohort Studies; D004196:Disease Outbreaks / Q000517:prevention & control; D005260:Female; D006801:Humans; D007117:Immunization, Secondary; D015994:Incidence; D007271:Injections, Intradermal; D007371:Interferon-gamma / Q000097:blood* / Q000276:immunology; D007564:Japan / Q000453:epidemiology; D008297:Male; D008403:Mass Screening / Q000379:methods; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D011933:Reagent Kits, Diagnostic; D018570:Risk Assessment; D012577:Schools, Medical; D012680:Sensitivity and Specificity; D013337:Students, Medical; D014373:Tuberculin; D014374:Tuberculin Test / Q000379:methods*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial; D011933:Reagent Kits, Diagnostic; D014373:Tuberculin; D007371:Interferon-gamma