Comparative evaluation of innovative diagnostic tests for latent and active TВ infection in children

Abstract

The results of three new tests based on antigens CFP-10 аnd ESAT-6 were studied in 50 children: intradermal Diaskintest and tests in vitro QUANTIFERON and Tubinferon. Diaskintest and Tubinferon are developed and produced in the Russian Federation. QUANTIFERON test is performed by Cellestis (Australia). 20 children had active TB, 22 children had latent TB infection, and 8 were not infected by M. tuberculosis. It has been established that while the frequency of coincidence of the results is high (66 %), in some situations, tests may react differently and give additional information when used together in difficult diagnostic cases. In vitro tests were more sensitive compared with Diaskinintest in immunopathological conditions. Tubinferon test had higher sensitivity in latent TB infection (40.9 %) compared to Diaskintest (22.7 %) and QUANTIFERON test (31,8 %), but lower sensitivity in developed tuberculosis - 60, 80 and 85 % respectively. All three tests are more informative in TB disease than in latent TB infection. An important advantage of the Tubinferon test is the ability to evaluate in vitro postvaccinal allergy, due to presence of the sample with the tuberculin. This can be used in the differential diagnostic between tuberculosis and generalized BCG infection, including children with HIV. Mantoux test may be more effective then Diaskintest in children who was not vaccinated with BCG. Tubinferon test system deserves wide clinical application, further study and development.