Detection of latent tuberculosis infection in hemodialysis patients: Comparison between the quantiferon-tuberculosis gold test and the tuberculin skin test

Abstract

BackgroundTuberculosis (TB) remains an important cause of morbidity and mortality in hemodialysis (HD) patients. A gold standard for the diagnosis of latent tuberculosis infection (LTBI) is lacking.ObjectiveThe aim of this study was to compare the diagnostic utility of the QuantiFERON-Tuberculosis Gold (QFT-G) test with the tuberculin skin test (TST) in identifying LTBI in patients with end-stage renal disease (ESRD) on HD.Study designThe present study had a prospective design.Patients and methodsA total of 74 patients with ESRD on HD without active TB and other immunosuppressive conditions were tested for LTBI by the QFT-G test and the TST.ResultsLTBI, as estimated by the QFT-G test and TST, was detected in 35.1 and 13.5% of the HD patients, respectively; 37.8% of patients were positive for the QFT-G test and/or the TST. There was a poor agreement between QFT-G test and TST results in patients with ESRD on HD (QFT-G test vs. TST: κ=0.25, 95% confidence interval=0.12–0.37). TST was positive in 2.7% of patients when the QFT-G test was negative, and it was negative in 24.3% of patients when the QFT-G test was positive. There was no significant difference in duration of HD or creatinine levels between QFT-G-positive and QFT-G-negative patients (P=0.08 and 0.2, respectively). TST-positive patients had a significantly shorter duration of HD and lower creatinine levels than TST-negative patients (P=0.001 and 0.01, respectively).ConclusionIn patients with ESRD and on HD, LTBI cannot be simply ruled out with a negative TST result, but rather a QFT-G test is recommended. Screening and treatment of LTBI should be carried in dialysis patients, aiming to prevent progression to active TB and secondary infection of others.