Comparative evaluation of gamma interferen tests in vitro for detection of cell-mediated immune response to recombinant Mycobacterium Tuberculosis antigens in detection of tuberculosis infection

Introduction. Laboratory methods based on the detection of T-cell sensitization are widely used to diagnose tuberculosis infection. These tests belong to the interferon gamma release assay (IGRA) group and play an important role in the diagnosis of latent tuberculosis infection, as well as serving as an alternative to traditional intradermal testing. IGRA tests utilize a single principle but employ different approaches in conducting and analyzing research data. A detailed understanding of these approaches can help select the optimal test system and increase its clinical significance. This study aims to compare and characterize the test systems available for immunological cell-mediated diagnosis of tuberculosis in Russia. Materials and Methods. To compare IGRA tests available in Russia, we selected the following: T-SPOT.TB, QuantiFERON-TB Gold Plus, and TB-Feron IGRAs. We analyzed their performance in terms of sensitivity, specificity, and accuracy, as well as the cost and availability of each test. We conducted a literature review on the aforementioned tests and their applications in clinical practice. We also consulted experts in the field to gain a deeper understanding of the nuances of each test system. Based on our findings, we formulated recommendations for selecting the most appropriate test for a given patient, taking into account factors such as cost, availability, and clinical relevance. Each test was conducted on 24 patients with a confirmed diagnosis of active tuberculosis, 16 patients with latent tuberculosis infection, and 10 healthy individuals. Results. The study revealed that for the active tuberculosis group (n=24), 19 patients had a positive test result using T-SPOT, while 19 patients had a positive QuantiFERON result, and 13 patients had a positive TB-Feron result. For the latent tuberculosis group (n=16), 15 patients showed a positive T-SPOT result, 14 patients showed a positive QuantiFERON, and 14 patients showed a positive TB-Feron test. In the healthy group, all patients tested negative for tuberculosis using all three test systems. Conclusion. Overall, the study confirms the convergence of immunoassay tests for latent tuberculosis, as well as the advantage of using short-chain Mycobacterium tuberculosis antigens in the diagnosis of active TB.