Interferon-γ release assays for the diagnosis of latentMycobacterium tuberculosisinfection: a systematic review and meta-analysis

Abstract

We conducted a systematic review and meta-analysis to compare the accuracy of the QuantiFERON-TB1 Gold In-Tube (QFT-G-IT) and the T-SPOT1.TB assays with the tuberculin skin test (TST) for the diagnosis of latent Mycobacterium tuberculosis infection (LTBI).The Medline, Embase and Cochrane databases were explored for relevant articles in November 2009. Specificities, and negative (NPV) and positive (PPV) predictive values of interferon-c release assays (IGRAs) and the TST, and the exposure gradient influences on test results among bacille Calmette-Guérin (BCG) vaccinees were evaluated.Specificity of IGRAs varied 98-100%. In immunocompetent adults, NPV for progression to tuberculosis within 2 yrs were 97.8% for T-SPOT1.TB and 99.8% for QFT-G-IT. When test performance of an immunodiagnostic test was not restricted to prior positivity of another test, progression rates to tuberculosis among IGRA-positive individuals followed for 19-24 months varied 8-15%, exceeding those reported for the TST (2-3%). In multivariate analyses, the odd ratios for TST positivity following BCG vaccination varied 3-25, whereas IGRA results remained uninfluenced and IGRA positivity was clearly associated with exposure to contagious tuberculosis cases.IGRAs may have a relative advantage over the TST in detecting LTBI and allow the exclusion of M. tuberculosis infection with higher reliability.

Latent tuberculous screening of recent migrants attending language classes: a cohort study and cost analysis

“…the positive predictive values, PPV). Diel et al 12 performed a metaanalysis of published studies. Four studies met the inclusion/exclusion criteria, two of which were in an HIV+ cohort.…”

“…Given the heterogeneity in the study populations and methods used, and the dependence of PPV on LTBI prevalence in the population tested, we chose a pragmatic value between the pooled PPVs reported in 18 and the range of PPVs from the two meta-analyses 12,18 , taken as 5%-14.6%, with a mean of 10%. However, this value needs to be taken with caution, given the uncertainties discussed here, and the lower rates reported in some other studies e.g.…”

Testy IGRA w Diagnostyce Zakażenia Prątkami Gruźlicy w Wybranych Sytuacjach Klinicznych

“…Testy IGRA służą do wykrywania LTBI i są wykorzystywane najczęściej w badaniu osób, które miały kontakt z chorymi prątkującymi, a także u chorych kwalifikowanych do leczenia biologicznego inhibitorami TNF-α [7,12,13]. Rekomendacje dotyczące stosowania testów IGRA i próby tuberkulinowej TST do diagnostyki LTBI różnią się w poszczególnych krajach.…”

Interferon-γ release assays for the diagnosis of latentMycobacterium tuberculosisinfection

“…We thank O. Moran Mendoza for his comment on the joint systematic review and meta-analysis on the role of interferon-c release assays (IGRAs) for the diagnosis of latent infection with Mycobacterium tuberculosis by the Tuberculosis Network European Trials Group (TBNET) and the European Centre for Disease Prevention and Control (ECDC) [1]. O. Moran Mendoza highlights the as-yet limited knowledge about the positive predictive values of IGRAs for the development of tuberculosis, a standpoint that is also expressed in the new European Union guidance on the use of IGRAs in support of the diagnosis of tuberculosis [2].…”