Role of QuantiFERON®-TB Gold In-Tube in tuberculosis contact investigation: experience in a tuberculosis unit

• Published in: Infectious diseases (London, England) Vol. 47; no. 4; pp. 244 - 251
• Main Authors: Gonz lez-Moreno, Juan, García-Gasalla, Mercedes, Gállego-Lezaun, Cristina, Fernández-Baca, Victoria, Mir Viladrich, Isabel, Cifuentes-Luna, Carmen, Serrano Bujalance, Araceli, Salom Vallespir, Andrea, Payeras Cifre, Antoni
• Format: Journal Article
• Language: English
• Published: England Informa Healthcare 01.04.2015; Taylor & Francis
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Antitubercular Agents - therapeutic use; Child; Child, Preschool; Contact Tracing; Female; Humans; IGRA; Infant; Infant, Newborn; Interferon-gamma Release Tests - methods; Interferon-gamma Release Tests - standards; Latent Tuberculosis - diagnosis; Latent Tuberculosis - drug therapy; Latent Tuberculosis - epidemiology; Male; Middle Aged; Prospective Studies; QuantiFERON-TB -Gold In-Tube; Reproducibility of Results; Tuberculin Test; tuberculosis; Young Adult; tuberculosis; QuantiFERON-TB -Gold In-Tube; IGRA
• ISSN: 2374-4235; 2374-4243
• DOI: 10.3109/00365548.2014.987813

Abstract Background: Interferon-γ release assays (IGRAs) are increasingly used for the diagnosis of latent tuberculosis infection (LTBI). Because of the lack of a gold standard for the diagnosis of LTBI, IGRAs are compared to the tuberculin skin test (TST) and yield conflicting results. We assessed the usefulness of an IGRA test, QuantiFERON®-TB Gold In-Tube (QFT-G-IT), for diagnosing LTBI compared with TST in the setting of a contact screening study. Methods: A prospective comparison between the QFT-G-IT and the TST in TB contact subjects in a low TB burden area was conducted sequentially between January 2006 and December 2012. Results: A moderate concordance between the two tests (κ = 0.44 for TST cut-off of 5 mm and κ = 0.56 for TST cut-off of 15 mm) was found. A better agreement was shown in younger contacts and in non-vaccinated contacts when using a TST of 15 mm. Independent risk factors for a TST+/QFT-G-IT- discordance were history of BCG vaccination and age between 31 and 59 years. Discordance was also more frequent using a TST cut-off value of 5 mm. QFT-G-IT+/TST- was infrequent and was found in older contacts. Conclusions: Based on our data, we cannot recommend the use of QFT-G-IT as the only test to rule out LTBI, especially in older patients.