Evidence for boostingMycobacterium tuberculosis-specific IFN-γ responses at 6 weeks following tuberculin skin testing: Table 1—

To the Editors: We read with great interest the paper by Leyten et al. 1 in the present issue of the European Respiratory Journal , which assessed whether the tuberculin skin test (TST) might affect the results of the QuantiFERON®-TB Gold (QFT-G), a blood-based Mycobacterium tuberculosis -specific interferon-γ release assay (IFNGRA). This is an important topic in the UK with respect to the recently published National Institute for Clinical Excellence (NICE) guidelines 2 for the diagnosis and treatment of tuberculosis (TB). The guidelines state that if a suspected case of TB yields a negative initial TST then the subject should be re-tested at 6 weeks, at which point an IFNGRA may be used in conjunction with the TST. Experts within the field have previously been worried about the potential boosting effect of the TST on IFNGRA responses. However, to …