title: Usefulness of two interferon-γ release assays for rheumatic disease.
abstract: BACKGROUND
  The aim of this study was to evaluate the performance of two interferon-γ release assays (IGRA), QuantiFERON-TB Gold In-Tube (QFT-GIT) and T-SPOT.TB, for pediatric patients with rheumatic disease in Japan and to analyze the frequencies of indeterminate test results with these kits.
  
  
  METHODS
  An IGRA was performed in 108 patients <20 years old in order to exclude tuberculosis infection at the time of first application of or change of biological agents and immunosuppressants in Yokohama City University Hospital.
  
  
  RESULTS
  None of the 108 patients tested had active tuberculosis during the 50 month observation period. Indeterminate results of QFT-GIT and T-SPOT.TB tests were obtained in 9.9% and in 0% of cases, respectively. Indeterminate results were obtained significantly more frequently in patients on prednisolone >0.5 mg/kg and in patients with active underlying disease. Use of biologicals and other immunosuppressants had no effect on these measurements.
  
  
  CONCLUSIONS
  IGRA are very useful for excluding tuberculosis infection in patients with rheumatic disease before starting new immunosuppressant therapy. Furthermore, the T-SPOT.TB test was suitable for evaluating latent tuberculosis infection even under immunosuppression, when TB tests are generally hard to perform.
authors.affiliation: Department of Pediatrics, Yokohama City University Hospital, Kanagawa, Japan.
authors.forename: Tomo
authors.initials: T
authors.lastname: Nozawa
authors.affiliation: Department of Pediatrics, Yokohama City University Medical Center, Kanagawa, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Mori
authors.affiliation: Department of Pediatrics, Yokohama City University Hospital, Kanagawa, Japan.
authors.forename: Kenichi
authors.initials: K
authors.lastname: Nishimura
authors.affiliation: Department of Pediatrics, Yokohama City University Hospital, Kanagawa, Japan.
authors.forename: Nodoka
authors.initials: N
authors.lastname: Sakurai
authors.affiliation: Department of Pediatrics, Yokohama City University Hospital, Kanagawa, Japan.
authors.forename: Masako
authors.initials: M
authors.lastname: Kikuchi
authors.affiliation: Department of Pediatrics, Yokohama City University Hospital, Kanagawa, Japan.
authors.forename: Ryoki
authors.initials: R
authors.lastname: Hara
authors.affiliation: Department of Pediatrics, International University of Health and Welfare Atami Hospital, Shizuoka, Japan.
authors.forename: Shumpei
authors.initials: S
authors.lastname: Yokota
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007223:Infant; D007231:Infant, Newborn; D059425:Interferon-gamma Release Tests / Q000379:methods*; D008297:Male; D012189:Retrospective Studies; D012216:Rheumatic Diseases / Q000150:complications* / Q000188:drug therapy; D014376:Tuberculosis / Q000150:complications / Q000175:diagnosis*; D055815:Young Adult
chemical_list: D007166:Immunosuppressive Agents
keywords: biological; children; immunosuppressant; interferon-γ release assay; tuberculosis