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.

Pre-employment screening of latent tuberculosis infection among healthcare workers using tuberculin skin test and QuantiFERON-TB Gold test at a tertiary care hospital in Saudi Arabia

“…In Saudi Arabia, little is known about the agreement of TST and IGRAs results among HCWs. However, a recent study reported 75.5% (Ä = 0.34) agreement between TST and QFT-G results among 200 dialysis patients with a positive TST rate of 13% and positive QFT-G rate of 32.5% [26]. Another study reported 90.9% (Ä = 0.46) agreement between TST and T-SPOT among 44 kidney donors and 60.15% (Ä = 0.07) agreement between the two tests among 133 hemodialysis patients, with 40% of them having discordant results between TST and T-SPOT [27].…”

Prevalence of Latent Mycobacterium Tuberculosis Infection (LTBI) in Saudi Arabia; Population based survey

“…Obviously, this data did not reflect the major changes that have happened in socioeconomic standards and TB management in Saudi Arabia in the last three decades. Additionally, the impact of using QFT-GIT in estimating LTBI prevalence and ARTI has never been adequately examined in a population-based sample in Saudi Arabia (Balkhy et al, 2016;Al Jahdali et al, 2013;Al Wakeel et al, 2015). The objective of the current study was to calculate recent estimates of the prevalence of LTBI and ARTI in a Saudi population-based sample.…”

Tuberculosis among Chronic Hemodialysis Patients: A Senegalese Single Center Experience

“…In our series TST was negative in 76% of cases, this result corroborates those found by several authors, its negativity reflects the state of anergy secondary to lower CMI [3] [22] did not find a significant difference between the two tests. However, other authors have demonstrated the superiority of IGRAs tests compared to the TST in sensitivity and specificity [13] [23].…”