First independent evaluation of QuantiFERON-TB Plus performance

Tuberculosis elimination requires an effective strategy to diagnose and treat people infected with Mycobacterium tuberculosis who would otherwise be at high risk of developing and transmitting active disease [1, 2]. The diagnostic tools for latent tuberculosis infection (LTBI) are the tuberculin skin test (TST) and the T-cell interferon-γ release assays (IGRAs). Two IGRAs are commercially available, QuantiFERON-TB Gold In-Tube (QFT-GIT) (Qiagen, Hilden, Germany) and T-SPOT.TB (Oxford Immunotec, Abingdon, UK). Compared to the TST, IGRAs offer operational advantages and higher specificity in the bacille Calmette–Guérin (BCG)-vaccinated population [3], and they are at least as sensitive for LTBI [4]. However, IGRAs have limitations: reduced sensitivity in children and immunocompromised subjects, including HIV-infected individuals [3, 4]; failure to discriminate between active tuberculosis and LTBI; and poor correlation with the risk of progression to active disease [3]. QuantiFERON-TB Plus improves sensitivity for active TB and maintains high specificity among unvaccinated controls <http://ow.ly/XjYPK> The authors thank the study subjects for their generous participation, and G. Pellicciotta, P. Erba and I. Mascherona (IRCCS San Raffaele Scientific Institute, Health Care Staff Protection Unit, Milan, Italy) for their valuable support in control enrolment.