QuantiFERON-TB Gold In-Tube test for diagnosis of latent tuberculosis (TB) infection in solid organ transplant candidates: a single-center study in an area endemic for TB Z. Ahmadinejad, F. Azmoudeh Ardalan, M. Razzaqi, S. Davoudi, A. Jafarian. QuantiFERON-TB Gold In-Tube test for diagnosis of latent tuberculosis (TB) infection in solid organ transplant candidates: a single-center study in an area endemic for TB. Transpl Infect Dis 2013: 15: 90–95. All rights reserved Abstract: Background. The prevalence of Mycobacterium tuberculosis in transplant recipients is estimated to be 50 times higher than in the general population, with a mortality rate of around 40%. Diagnosis and treatment of latent tuberculosis (TB) infection (LTBI) is an essential strategy for TB control. In this study we compared the QuantiFERON-TB Gold In-Tube test (QFT) with the tuberculin skin test (TST) for detection of LTBI in solid organ transplant (SOT) candidates. Patients and methods. Between March 2008 and September 2011, 187 transplant candidates, who were referred to the transplant clinic of Imam-Khomeini Hospital, were enrolled in the study. Patients were screened for LTBI with both QFT and TST. Twenty-three patients (12.3%) were excluded for failure to follow up. Concordance between the 2 tests, and variables associated with test discordance were assessed. Results. The mean age of patients was 40 years (range: 11–65) and male-to-female ratio was 1.2 (88/76). TST and QFT were positive in 26 (15.9%) and 33 (20.1%) patients, respectively. Five cases (3.1%) had indeterminate QFT. Overall agreement between QFT and TST was about 80% (k = 0.32, P-value = 0.0001). Conclusion. Considering the fair overall agreement between the 2 tests, and greater ease of the QFT from the patient’s point of view, QFT is recommended for detection of LTBI in SOT candidates. Z. Ahmadinejad 1 , F. Azmoudeh Ardalan 2 , M. Razzaqi 3 , S. Davoudi 1 , A. Jafarian 4 1 Department of Infectious Diseases, Imam-Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran, 2 Department of Pathology, Imam-Khomeini Complex Hospital, Tehran University of Medical Sciences, Tehran, Iran, 3 Iranian Tissue Bank Research & Preparation Center, Tehran University of Medical Sciences, Tehran, Iran, 4 Department of Surgery, Imam-Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran Key words: QuantiFERON-TB Gold In-Tube; tuberculin skin test; latent tuberculosis infection; solid organ transplantation Correspondence to: Zahra Ahmadinejad, MD, Department of Infectious Disease, Imam-Khomeini Hospital, Keshavarz Blvd, Tehran, Iran Tel: +98 21 66581598 Fax: +98 21 66581598 E-mail: ahmadiz@tums.ac.ir Received 21 February 2012, revised 16 July 2012, accepted for publication 25 July 2012 DOI: 10.1111/tid.12027 Transpl Infect Dis 2013: 15: 90–95 About 8.8 million (8.5–9.2) new cases of tuberculosis (TB) were diagnosed in 2010 and the number of people who died from TB reached 1.4 million in that year (1). The rate of TB among solid organ transplant (SOT) recipients is approximately 50-fold higher than in the general population (2, 3), and the use of immunosup- pressants leads to higher mortality rate among these patients of up to 40% (4, 5). Two tests are available for diagnosing latent TB infection (LTBI): the tuberculin skin test (TST), which is still recommended by Amer- ican Society of Transplantation as the preferred screen- ing test in transplant candidates (6), and the QuantiFERON-TB Gold In-Tube test (QFT), which was approved by the U.S. Food and Drug Administra- tion in 2005. Despite widespread use of the TST, it is not reliable as a gold standard (2). Interoperator variability in performing and reading the TST, the requirement for 2 patient visits within 48–72 h, and false-positive results arising from non-tuberculous mycobacteria and Bacillus Calmette-Gue ´rin (BCG) vaccination are some of the limitations of the TST (2, 6–8). The QFT is based on the cell-mediated immune response against a set of industrial peptides similar to Mycobacterium tuberculosis (MTB) proteins, i.e., early secretory antigenic target-6 (ESAT-6), culture filtrate protein-10 (CFP-10), and TB7.7 (1, 9). In addition, 90 © 2012 John Wiley & Sons A/S Transplant Infectious Disease, ISSN 1398-2273