Combined Detection of IFN-γ and Lymphocyte Subsets with Activation Indicators in the Clinical Application of Mycobacterium Tuberculosis Infection at Different Times

The immune status of mycobacterium tuberculosis (MTB) infection is essential for the diagnosis and treatment of this disease. In this work, we aim to evaluate the clinical significance of the combination of serum IFN-γ, IGRAs (Interferon-Gamma Release Assay), lymphocyte subset with activation indicators detection in active and latent tuberculosis infection patients. For this study, anticoagulant whole blood were collected from 45 active tuberculosis (AT group), 44 latent tuberculosis (LT group) and 32 healthy controls (HCs group). The serum IFN-γ and IGRAs detected by chemiluminescence, and the percentage of lymphocyte subsets and activated lymphocytes detected by flow cytometry. The results showed combined IGRAs, serum IFN-γ and NKT cells not only has good diagnostic efficiency for the AT, but also provides a laboratory diagnostic method to distinguish AT from LT. Activation indicator of CD3(+)HLA-DR(+)T and CD4(+)HLA-DR(+)T can effectively distinguish LT from HCs. While combined CD3(+)T, CD4(+)T, CD8(+)CD28(+)T, Treg and CD16(+)CD56(+)CD69(+) cells can distinguish AT from HCs. This study showed combined direct detection of serum IFN-γ and IGRAs as well as lymphocyte subsets with activation indicators which may provide laboratory basis for the diagnosis and differential diagnosis of active and latent MTB infection.