Diagnosis of latent tuberculosis infection in children with the useof different immunological methods

Abstract

Introduction: IGRA-tests – are modern methods for diagnosis of latent TB infection. Positive results of these tests are associated with the process of active reproduction of M. tuberculosis. One method among IGRA-tests is ELISPOT, it came to practice in 2004. ELISPOT was licensed in Russia in 2012, but results of ELISPOT among children are not presented in publications.Diaskintest(DST) – immunological skin test with TB antigens ESAT-6 and CFP-10. Objective: To compare results of ELISPOT and DST in diagnosis of latent TB infection among children. Materials and methods: 159 patients from 2 to 14 years old were examined and included in open study at children9s department during 2014-2016. All patients were vaccinated by BCG and have positive results of tuberculin skin test. 62 children(39%) have concomitant allergic diseases.Diagnostic complex included: clinical signs, immunological (ELISPOT,DST) and X-rays methods. Results: Among 159 children tested, 9(5.7%) have positive ELISPOT results, 2(1.3%) – indeterminate results, 148(93.0%) – negative results. Results of DST were as follows: positive – in 24(15.1%) children, doubtful – 7(4.4%), negative – 128(80.5%). 2 children who have positive results of ELISPOT and DST were diagnosed with tuberculosis of intrathoracic lymph nodes by X-rays methods. Results of DST and ELISPOT were comparable in 86.2%. 13 children with positive results and 7 – with doubtful results of DST have negative results of ELISPOT, all these children have concomitant allergic diseases. Conclusions: Results of DST and ELISPOT are comparable. ELISPOT should be used for the diagnosis of latent TB infection in children with allergic pathology.