title: Comparison of the tuberculin skin test and Quanti-FERON-TB Gold In-Tube (QFT-G) test for the diagnosis of latent tuberculosis infection in dialysis patients.
abstract: Dialysis patients are more likely than the general population to develop active tuberculosis (TB). In these patients, the availability of a highly sensitive and specific test to diagnose latent TB will ensure earlier treatment and decreased progression to active disease. In the current study, the Quanti-FERON-TB Gold In-Tube (QFT-G) test was compared with the tuberculin skin test (TST) for the diagnosis of latent tuberculosis infection (LTBI) among 200 hemodialysis patients and 15 confirmed TB disease cases in a tertiary care center in Saudi Arabia. Among the LTBI cases, 26 (13%) were TST positive, and 65 (32.5%) were positive by the QTF-G test, with an overall agreement between the 2 tests of 75.5% (k=0.34) being observed. Among the confirmed tuberculosis disease cases, none were positive by TST, and 10 (66.7%) were positive by the QTF-G test, resulting in an overall agreement of 33.3% (k=0). A comparison between the TST and the QTF-G test was performed based on the sensitivity, specificity, and area under the curve (AUC) obtained for the tests. The QTF-G test was more sensitive and less specific than the TST in predicting the confirmed TB disease cases. When we tested the correspondence of the AUC values between the 2 diagnostic modalities, the obtained p-value was 0.0003. In conclusion, the AUCs of the examined diagnostic modalities are significantly different in predicting LTBI and tuberculosis.
authors.affiliation: Department of Medicine, Pulmonary Division, King Saud Bin Abdulaziz University for Health Sciences, Saudi Arabia. Jahdalih@gmail.com
authors.forename: Hamdan
authors.initials: H
authors.lastname: Al Jahdali
authors.forename: Anwar E
authors.initials: AE
authors.lastname: Ahmed
authors.forename: Hanan H
authors.initials: HH
authors.lastname: Balkhy
authors.forename: Salim
authors.initials: S
authors.lastname: Baharoon
authors.forename: Fayez F
authors.initials: FF
authors.lastname: Al Hejaili
authors.forename: Ali
authors.initials: A
authors.lastname: Hajeer
authors.forename: Ziad
authors.initials: Z
authors.lastname: Memish
authors.forename: Salih
authors.initials: S
authors.lastname: Binsalih
authors.forename: Abdullah A
authors.initials: AA
authors.lastname: Al Sayyari
mesh_terms: D000368:Aged; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D059425:Interferon-gamma Release Tests / Q000379:methods*; D007674:Kidney Diseases / Q000628:therapy*; D055985:Latent Tuberculosis / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D006435:Renal Dialysis; D012529:Saudi Arabia; D012680:Sensitivity and Specificity; D014374:Tuberculin Test