Performance of QuantiFERON TB Gold test in detecting latent tuberculosis infection in brain-dead organ donors in Iran: a brief report.

With regard to the significant morbidity and mortality due to tuberculosis in lung transplant recipients, the identification of brain-dead organ donors with latent tuberculosis by use of the QuantiFERON TB Gold (QFT-G) test may be of help to reduce the risk of TB reactivation and mortality in lung recipients. This study was conducted in the National Research Institute of Tuber-culosis and Lung Diseases (NRITLD) in Iran, from January to March 2013. A total of 38 conse-cutive brain-dead donors, not currently infected with active tuberculosis, were recruited. The medi-cal records of all the study enrollees were reviewed. A whole-blood IFN- release assay (IGRA) in reaction to early secreted antigenic target 6 (ESAT-6), culture filtrate protein 10 (CFP-10), and TB7.7 antigens, was performed and the released Interferon- was measured via enzyme-linked immunosorbent assay (ELISA). The data was analyzed with QFT-G software which was provided by the company. The demographic, characteristics and other variables were entered into SPSS version 11.5. The QFT-G test results of three donors (7.9%) turned out to be positive, negative for 24 donors (63.1%), and indeterminate for 11 cases (28.9%). Our study revealed the potential advantages of QFT-G in lowering the incidence of donor-derived post-transplant tuberculosis among lung recipients. However, a high rate of indeterminate results restricted the performance of QFT-G in this study.

Performance of QuantiFERON TB gold test compared with the tuberculin skin test for detecting latent tuberculosis infection in lung and heart transplant candidates.

OBJECTIVES: Evaluation for latent tuberculosis infection is advised before organ transplant. The interferon-gamma release assay has been shown to be more specific than the tuberculin skin test for screening for latent tuberculosis infection. We compared the tuberculin skin test and QuantiFERON-TB Gold In-Tube test for screening for latent tuberculosis infection and agreement between the tests in heart and lung transplant recipients before transplant. MATERIALS AND METHODS: Fifty-five adult patients who had been evaluated for heart and lung transplant between September 2011 and September 2012 at Masih Daneshvari Hospital in Iran were prospectively enrolled. We performed the tuberculin skin test and QuantiFERON-TB Gold In-Tube test. RESULTS: Of the 55 patients, 3 (5%) had positive tuberculin skin test results, and 11 (20%) had positive QuantiFERON-TB Gold In-Tube test results. Agreement between the tuberculin skin test and QuantiFERON-TB Gold In-Tube test was fair (Kappa=0.061; 95% CI: - 0.185-0.307) (P = .56). CONCLUSIONS: The positivity for QuantiFERON-TB Gold In-Tube test was greater than the positivity for the tuberculin skin test, and QuantiFERON-TB Gold In-Tube test more accurately determined the risk for latent tuberculosis infection. However, a further longitudinal study is necessary to verify that the QFT-G test would predict developing tuberculosis after heart and lung transplant.

Performance of QuantiFERON-TB Gold test compared to tuberculin skin test in detecting latent tuberculosis infection in HIV- positive individuals in Iran.

BACKGROUND: There is limited data about the performance of QuantiFERON-TB Gold (QFT-G) test in detecting latent tuberculosis infection (LTBI) in our region. We intended to determine the performance of QFT-G compared to conventional tuberculin skin test (TST) in detecting LTBI in HIV-positive individuals in Iran. METHODS: This study was conducted in a HIV clinic in Tehran, Iran in April 2007. A total of 50 consecutive HIV-positive patients, not currently affected with active tuberculosis (TB), were recruited; 43 (86%) were male. The mean age was 38 ± 7.2 years (21-53). All had history of Bacillus Calmette Guerin (BCG) vaccination. A TST with purified protein derivative (PPD) and whole-blood interferon-gamma release assay (IGRA) in reaction to ESAT-6 and CFP-10 antigens was performed and measured by enzyme-linked immuno-sorbent assay (ELISA). The agreement between TST and QFT-G results were analyzed using Kappa test. RESULTS: A total of 36 (72%) patients had negative and 14 (28%) revealed positive TST. For QFT-G, 20 (40%) tested positive, 19 (38%) tested negative, and the results in 11 cases (22%) were indeterminate. A total of 14 (28%) patients had a CD4 count of <200. Of the 14, TST + group, 12 had QFT-G +, only one case TST+/QFT-G-, and QFT-G was indeterminate in one TST positive case. Of the 36 patients with negative TST tests, 8 (22%) had positive GFT-G and 10 (28%) yielded indeterminate results. There was no association between a positive TST and receiving highly active anti-retroviral therapy (HAART) or absolute CD4 counts. Similarly, the association between QFT-G results and receiving HAART or CD4 counts was not significant (P = 0.06). Although TST results were not significantly different in patients with CD4 < 200 vs. CD4 >200 (P = 0.295), association between QFT-G results and CD4 cutoff of 200 reached statistical significance (P = 0.027). Agreement Kappa coefficient between TST and QFT-G was 0.54 (Kappa = 0.54, 95% CI = 38.4-69.6,P < 0.001). CONCLUSION: Detecting LTBI in HIV-positive individuals showed moderate agreement between QFT-G and LTBI in our study. Interestingly, our findings revealed that nontuberculous mycobacteria and prior BCG vaccination have minimal influence on TST results in HIV patients in Iran.