Comparative performance of QuantiFERON-TB Gold versus skin test with tuberculosis recombinant allergen (Diaskintest) among patients with suspected pulmonary tuberculosis in Russia.

Background: The early identification of Mycobacterium tuberculosis infection can prevent tuberculosis (TB) transmission. A skin test with a tuberculosis recombinant allergen (Diaskintest) is a new method for identification that has been implemented in Russia. This study was performed to compare the performances of Diaskintest and QuantiFERON-TB Gold (QFT) in adults and children with suspected TB in Moscow, Russia.

Methods: Adults (n=85) and children (n=96) were tested using Diaskintest and QFT. Concordance and comparative analyses were performed.

Results: Diaskintest and QFT were concordant in 84% of adults and 90% of children (overall concordance 87%, κ>0.6, K>0.5). The concordance between QFT, Diaskintest, and the final diagnosis was good in adults (86% and 81%, respectively) and moderate in children (77% and 79%, respectively). In adults, QFT had a higher sensitivity for detecting TB than Diaskintest (82% and 68%, respectively); in children, Diaskintest was more sensitive (73% and 65%, respectively). In patients with a confirmed TB diagnosis, negative Diaskintest/QFT results were associated with low disease activity. Combined Diaskintest/QFT results identified TB patients with higher sensitivity and specificity than each test separately.

Conclusions: Diaskintest is a low-cost diagnostic tool that shows a test positivity rate similar to QFT and can be used in combination with QFT as an adjunctive test for TB diagnosis.