Thread by @LenaFaust1

Our new systematic review and meta-analysis in @TheLancetInfDis on diagnostic performance of newer skin tests for #tuberculosis infection compared to TST and IGRA: a quick tweetorial! @LeleRangaka @cdenki @McGill_TB @UCLTB @StopTB @FINDdx
authors.elsevier.com/c/1drDZ5E-UoV4…

With an estimated 2 billion ppl w/ #TBinfection (TBI) worldwide, TBI screening is important for TB control - but, scalability of commonly-used TBI tests is limited (eg. high cost of IGRAs, low specificity of TST),making it a priority to evaluate the dx performance of newer tests

We included studies reporting on the performance of index tests alone or with a comparator. 37 studies were included in qualitative synthesis, (29 evaluating Diaskintest, 5 C-Tb, 2 EC-skintest, and 1 DPPD) and 22 in quantitative analyses (15 Diaskintest, 5 C-Tb, 2 EC).

These newer skin-based tests are specific to M.tb antigens, with C-Tb, Diaskintest & EC using recombinant ESAT-6 & CFP-10, and the DPPD test based on DPPD, a recombinant protein unique to M.Tb. Performance of these newer tests has until now not yet been systematically reviewed.

Head-to-head comparisons of index tests vs TST & IGRA was possible in 9 studies. Key results on sensitivity and specificity of index tests in head-to-head studies: (various sensitivity analyses available in supplement)

So, newer skin-based tests may perform similarly to IGRA/TST, but given varying study quality & lack of data on some outcomes, further studies needed that use @WHO framework for eval of tests & evaluate implementation-relevant outcomes(cost-effectiveness, feasibility, access..)