Comparing the Diagnostic Performance of QFT-Plus to Other Tests of Latent Tuberculosis Infection: A Systematic Review and Meta-analysis.

Background We conducted this review to compare the sensitivity, specificity, reproducibility, and predictive ability of QFT-Plus with that of QFT-GIT (QIAGEN, Hilden, Germany), T-SPOT.TB (Oxford Immunotec, Oxford, United Kingdom) and the tuberculin skin test (TST). Methods We searched MEDLINE, EMBASE, Web of Science, and the Cochrane Database of Systematic Reviews from January 2013 through May 2020. We included studies that compared QFT-Plus with at least one other LTBI test. We estimated sensitivity from studies of patients with active TB (as a surrogate) and specificity from studies of healthy individuals with very low-risk of LTBI. Three independent reviewers evaluated eligibility, extracted data, and assessed risk of bias. Results Compared with QFT-GIT, the sensitivity of QFT-Plus, in studies of patients with active tuberculosis, was 1.3% higher (95% CI: -0.3% to 2.9%), and in two studies of subjects with very low probability of LTBI, the specificity was 0.9% lower (CI, -2.4% to 0.6%). These differences were not statistically significant. The agreement between QFT-Plus and QFT-GIT was high, with a pooled Cohen's kappa statistic of 0.83 (95% CI, 0.79 to 0.88). In two studies, reproducibility of QFT-GIT and QFT-plus was similarly poor. All participants in the studies to estimate sensitivity were aged 15 and older, and only six were PLHIV. We found no studies to assess predictive ability. Conclusions QFT-Plus has very similar diagnostic performance as QFT-GIT. Further studies are needed to assess the sensitivity of QFT-Plus in immunocompromised subjects and younger children before concluding if this new version offers advantages.