scholarly journals Kinetics of a Tuberculosis-Specific Gamma Interferon Release Assay in Military Personnel with a Positive Tuberculin Skin Test

2010 ◽  
Vol 17 (6) ◽  
pp. 937-943 ◽  
Author(s):  
Sigrid E. van Brummelen ◽  
Anja M. Bauwens ◽  
Noël J. Schlösser ◽  
Sandra M. Arend

ABSTRACT Treatment of latent Mycobacterium tuberculosis infection on the basis of the tuberculin skin test (TST) result is inaccurate due to the false-positive TST results that occur after Mycobacterium bovis BCG vaccination or exposure to nontuberculous mycobacteria (NTM). Gamma interferon release assays (IGRAs) are based on M. tuberculosis-specific antigens. In a previous study among BCG-naïve military employees, a positive TST result after deployment was mostly associated with a negative IGRA result, suggesting exposure to NTM. Data regarding the kinetics of IGRAs are limited and controversial. The present study aimed to reassess the rate of false-positive TST results and to evaluate the kinetics of the Quantiferon TB Gold In-Tube assay (QFT-Git) in military personnel with a positive TST result. QFT-Git was performed at the time of inclusion in the study and was repeated after 2, 6, 12, and 18 or 24 months. Of 192 participants, 17 were recruits and 175 were screened after deployment (n = 169) or because of travel or health care work. Baseline positive QFT-Git results were observed in 7/17 (41.2%) and 12/174 (6.9%) participants, respectively. During follow-up, a negative QFT-Git result remained negative in 163/165 (98.8%) participants. Of 18 subjects with an initial positive QFT-Git result, reversion to a negative result occurred in 1/6 (16%) recruits, whereas it occurred in 8/12 (66%) subjects after deployment or with other risk factors (P = 0.046). The quantitative result was significantly lower in subjects with reversion than in those with consistent positive results (P = 0.017). This study confirmed a low rate of positive QFT-Git results among military personnel with a positive TST result after deployment, supporting the hypothesis of exposure to NTM. Reversion of the majority of initially low-positive QFT-Git results indicates that QFT-Git may be useful for the diagnosis of later reinfections.

2007 ◽  
Vol 14 (9) ◽  
pp. 1239-1241 ◽  
Author(s):  
Willeke P. J. Franken ◽  
Ben F. P. J. Koster ◽  
Ailko W. J. Bossink ◽  
Steven F. T. Thijsen ◽  
John J. M. Bouwman ◽  
...  

ABSTRACT We report a follow-up study of 29 subjects with negative tuberculin skin test (TST) results in association with positive gamma interferon release assay (IGRA) results, mainly due to responses to CFP-10 in the T-SPOT.TB assay, during a contact investigation. One year later, 12/29 subjects (41%) had converted to positive TST results in association with negative IGRA results.


2007 ◽  
Vol 15 (1) ◽  
pp. 168-171 ◽  
Author(s):  
Jose Domínguez ◽  
Juan Ruiz-Manzano ◽  
Malú De Souza-Galvão ◽  
Irene Latorre ◽  
Celia Milà ◽  
...  

ABSTRACT We evaluated the T-SPOT.TB and Quantiferon-TB Gold In tube (QFN-G-IT) tests for diagnosing Mycobacterium tuberculosis infection. T-SPOT.TB was more sensitive than QFN-G-IT in diagnosing both active and latent infection. Both gamma interferon tests were unaffected by prior Mycobacterium bovis BCG vaccination. Among children who were not BCG vaccinated but had a positive tuberculin skin test, QFN-G-IT was negative in 53.3% of cases, and T-SPOT.TB was negative in 50% of cases.


2014 ◽  
Vol 21 (4) ◽  
pp. 552-560 ◽  
Author(s):  
Leonardo Silva de Araujo ◽  
Fernanda Carvalho de Queiroz Mello ◽  
Nidai de Bárbara Moreira da Silva ◽  
Janaina Aparecida Medeiros Leung ◽  
Silvia Maria Almeida Machado ◽  
...  

ABSTRACTThe PstS1 antigen is highly immunogenic, principally when combined with CFP10 during both latent and active TB infection. In the present study, a selectedpstS1gene fragment was cloned, fused with CFP10, and expressed inEscherichia coli. The product [PstS-1(285-374):CFP10] was compared to the recombinant fused RD1 (region of deletion 1) protein (ESAT-6:CFP10) in detectingMycobacterium tuberculosisinfection in 108 recent contacts of pulmonary tuberculosis (TB) cases, considering a positive tuberculin skin test (TST) to be the baseline. The release of gamma interferon (IFN-γ) in 22-h whole-blood and 5-day lymphocyte stimulation assays primed with each antigen was determined. All contacts were clinically followed for up to 1 year, and 87% of the tuberculin skin test-positive (TSTpositive) patients accepted preventative treatment. Concerning the IFN-γ response to PstS-1(285-374):CFP10 in the 22-h and 5-day assays, a slight increase in contact-TSTpositivedetection was observed (23/54 and 26/54) compared to the level seen with the RD1 protein (18/54 and 24/54) whereas in the TSTnegativegroup, similarly lower numbers (≤5/48) of responders were achieved for both antigens, except for RD1 in the 5-day assay (8/48). By combining the IFN-γ responders to both antigens in the 5-day assays, slightly higher increases in positivity were found in the TSTpositive(32/54) and TSTnegative(10/48) groups. Two of 12 untreated TSTpositivecontacts progressed to active TB and were concordantly positive in all assays, except for one contact who lacked positivity in the RD1 5-day assay. We demonstrated for the first time that PstS-1(285-374):CFP10 slightly increased contact positivity and detection of active disease progression, suggesting its potential application as a TB infection marker.


2018 ◽  
Vol 39 (6) ◽  
pp. 750-752 ◽  
Author(s):  
Jeffrey M. Collins ◽  
Mary Hunter ◽  
Wanda Gordon ◽  
Russell R. Kempker ◽  
Henry M. Blumberg ◽  
...  

Following large declines in tuberculosis transmission the United States, large-scale screening programs targeting low-risk healthcare workers are increasingly a source of false-positive results. We report a large cluster of presumed false-positive tuberculin skin test results in healthcare workers following a change to 50-dose vials of Tubersol tuberculin.Infect Control Hosp Epidemiol 2018;39:750–752


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