title: [Clinical usefulness of T-SPOT.TB test for the diagnosis of tuberculosis].
abstract: BACKGROUND
  Tuberculosis-specific ELISPOT assay (T-SPOT.TB, Oxford Immunotec, UK) is a test that detects interferon-gamma producing T-cells after stimulating patient's lymphocytes with two kinds of tuberculosis-specific antigens (ESAT-6 and CFP-10). We evaluated clinical usefulness of T-SPOT.TB test in Korean adults with intermediate burden of tuberculosis and high rate of BCG vaccination at birth.
  
  
  METHODS
  T-SPOT.TB test was performed in 79 patients and 64 healthy volunteers and these patients and volunteers were classified into four groups: group 1, patients with active tuberculosis (n=30); group 2, patients with not-active tuberculosis (n=27); group 3, patients without tuberculosis (n=24); group 4, healthy volunteers without tuberculosis history (n=62). Positive rates and average spot counts of T-SPOT.TB test were obtained among these groups.
  
  
  RESULTS
  Positive rates of group 1 (96.4%) and group 2 (92.3%) were higher than those of group 3 (31.6%) and group 4 (27.4%) (P<0.0001). The sensitivity deduced from group 1 and specificity deduced from group 4 of T-SPOT.TB test were 96.4% and 72.6%, respectively. The average spot counts of group 1 and 2 were higher than those of group 3 and 4 (P<0.001). There was a tendency of increasing positive rate with increasing age. Overall agreement between T-SPOT.TB test and tuberculin skin test was 63.8% (kappa=0.29).
  
  
  CONCLUSIONS
  T-SPOT.TB test would be a very useful screening and supplementary test for diagnosis of tuberculosis due to its high sensitivity. However, positive results of T-SPOT.TB should be cautiously interpreted because of high positivity in treated tuberculosis patients and healthy volunteers in Korea.
authors.affiliation: Department of Laboratory Medicine, Hallym University College of Medicine, Seoul, Korea. hskim0901@empal.com
authors.forename: Hyun Soo
authors.initials: HS
authors.lastname: Kim
authors.forename: Cheol Hong
authors.initials: CH
authors.lastname: Kim
authors.forename: Mina
authors.initials: M
authors.lastname: Hur
authors.forename: In Gyu
authors.initials: IG
authors.lastname: Hyun
authors.forename: Min Jeong
authors.initials: MJ
authors.lastname: Park
authors.forename: Wonkeun
authors.initials: W
authors.lastname: Song
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Park
authors.forename: Hee Jung
authors.initials: HJ
authors.lastname: Kang
authors.forename: Kyu Man
authors.initials: KM
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000942:Antigens, Bacterial / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D014376:Tuberculosis / Q000175:diagnosis*
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C117940:CFP-10 protein, Mycobacterium tuberculosis; C093276:ESAT-6 protein, Mycobacterium tuberculosis; D011933:Reagent Kits, Diagnostic; D007371:Interferon-gamma