title: [CLINICAL UTILITY OF T-SPOT.TB ASSAY WITH T-Cell Xtend REAGENT FOR ACTIVE TUBERCULOSIS DIAGNOSIS IN THE FIELD TEST AT OUR HOSPITAL].
abstract: BACKGROUND
  T-SPOT.TB (T-SPOT), an interferon-gamma release assay, has shown promise as a diagnostic tool for active tuberculosis (TB), and its use is expanding. Addition of the T-Cell Xtend (TCX) reagent may allow delayed processing, and this characteristic is important for using this test in the field. However, limited data is available on the usefulness of T-SPOT with TCX as a field test for diagnosing active TB.
  
  
  OBJECTIVE
  To investigate the clinical utility of T-SPOT with TCX and the risk factors for a false-negative result in patients with active TB.
  
  
  METHODS
  A total of 57 patients with active TB who underwent the T-SPOT test with TCX prior to treatment were enrolled between May 2013 and May 2015. One patient with an indeterminate result for T-SPOT was excluded; therefore, the data of 56 patients were eventually included in the final analysis. The basic characteristics and clinical findings were compared between the true-positive and false-negative T-SPOT groups.
  
  
  RESULTS
  Of the 56 patients, 40 (71.4%), 13 (23.2%), 3 (5.4%) had true-positive, false-negative, and borderline T-SPOT results, respectively. This study did not reveal any significant risk factors for a false-negative T-SPOT result.
  
  
  CONCLUSIONS
  In this clinical study, the proportion of patients with a false-negative result for T-SPOT with TCX for active TB was higher than that reported previously. Therefore, careful interpretation of a negative result for T-SPOT with TCX is necessary, regardless of the patient's background.
authors.forename: Kenji
authors.initials: K
authors.lastname: Nemoto
authors.forename: Shuji
authors.initials: S
authors.lastname: Oh-ishi
authors.forename: Masato
authors.initials: M
authors.lastname: Taguchi
authors.forename: Kentaro
authors.initials: K
authors.lastname: Hyodo
authors.forename: Jun
authors.initials: J
authors.lastname: Kanazawa
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Miura
authors.forename: Takio
authors.initials: T
authors.lastname: Takaku
authors.forename: Shingo
authors.initials: S
authors.lastname: Usui
authors.forename: Kenji
authors.initials: K
authors.lastname: Hayashihara
authors.forename: Takefumi
authors.initials: T
authors.lastname: Saito
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006779:Hospitals, Public; D006801:Humans; D059425:Interferon-gamma Release Tests; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes / Q000276:immunology*; D014376:Tuberculosis / Q000175:diagnosis* / Q000276:immunology