title: Usefulness of the QuantiFERON TB-2G test for the differential diagnosis of pulmonary tuberculosis.
abstract: OBJECTIVE
  We prospectively evaluated the usefulness of the QuantiFERON TB-2G (QFT-2G) compared to that of tuberculin skin test (TST) as a supportive method of diagnosing pulmonary tuberculosis (TB) without invasive examinations.
  
  
  METHODS
  The subjects were 90 patients who required differentiation of pulmonary TB clinically and for whom a definitive diagnosis could not be obtained after admission. The final clinical diagnosis of TB infection in 28 patients and non-TB infection in 62 patients was established using bronchoscopic procedures.
  
  
  RESULTS
  In patients with TB infection, the positive response rate on QFT-2G (79%) was significantly higher than that on TST (57%). The QFT-2G negative rate (5%) was significantly lower than that on TST (48%) in patients with non-TB infection. For QFT-2G test, there was a positive response in 25 patients, a negative response in 49, and indeterminate findings in 16. Of the two patients with a false-negative result on QFT-2G, one had pulmonary TB during immunosuppressive treatment and one had pulmonary tuberculoma. Of the three non-TB patients with a positive result on QFT-2G, two had pneumonia and one had pulmonary mycosis. Four TB patients with an indeterminate result on QFT-2G included two elderly patients and two immunocompromised patients.
  
  
  CONCLUSIONS
  We could confirm the usefulness of the QFT-2G test compared to TST in patients requiring a differential diagnosis between pulmonary TB and other pulmonary diseases in this series. Therefore, we recommend the QFT-2G test as one of the useful noninvasive diagnostic examinations for pulmonary TB.
authors.affiliation: Division of Respiratory Diseases, Department of Medicine, Kawasaki Medical School, Kurashiki, Japan. yoshihiro@med.kawasaki-m.ac.jp
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Kobashi
authors.forename: Keiji
authors.initials: K
authors.lastname: Mouri
authors.forename: Shinichi
authors.initials: S
authors.lastname: Yagi
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Obase
authors.forename: Minoru
authors.initials: M
authors.lastname: Fukuda
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Miyashita
authors.forename: Mikio
authors.initials: M
authors.lastname: Oka
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005260:Female; D006403:Hematologic Tests; D006801:Humans; D007371:Interferon-gamma / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014374:Tuberculin Test; D014397:Tuberculosis, Pulmonary / Q000097:blood* / Q000175:diagnosis*
chemical_list: D007371:Interferon-gamma