QuantiFERON-TB Gold Plus Test as a parameter of Mycobacterium tuberculosis detection

Background: Latent tuberculosis infection (LTBI) is a state of persist immune response to Mycobacterium tuberculosis ( M. tuberculosis ) antigens without any clinical evidence of active tuberculosis. A new progress and inovation in diagnostics of latent tuberculosis, more specific and susceptible than tuberculin skin test, are Interferon Gamma Release Assay, Quanti FERON-TB test, in vitro blood tests used to detect immune response to TB proteins, by measuring interferon gamma (IFN-γ( in whole blood from persons infected with M. tuberculosis . The aim of this retrospective study was to determinate the role of QuantiFERON-TB Gold Plus (QFT – Plus test) test in diagnostics of LTBI evaluating the results from inpatients and outpatiens. Methods: This was a retrospective study where blood samples were collected from 1 st of January to 31 st of December 2016 in the Microbiological Laboratory of General Hospital Tesanj. Samples were performed from inpatients and outpatients in Zenica-Doboj Canton. Full blood from patients aged from 1 to 95 years was collected in four, special QFT plus blood test tubes and tested with QFT – Plus test. Results: The study involved 159 patients who were tested with QFT-Plus test. Gender distribution of positive data (30.82 %) showed prevalence of males (59.18 %). The most common diagnosis of positive data was infiltratio pulmonum (49 %). Sensitivity of QFT – Plus test was 91.67 % and test showed specificity of 73.79 %. Conclusion: Our research showed that QFT – Plus test can be helpful, as a supplement, but it can not be the main parameter in diagnostics of tuberculosis. If the test is positive, it is necessary to observe all other clinical findings to complete the diagnosis.