Diagnostic Performance of a Cytokine and IFN-γ–Induced Chemokine mRNA Assay after Mycobacterium tuberculosis–Specific Antigen Stimulation in Whole Blood from Infected Individuals

Abstract

Interferon (IFN)-γ release assays have limited sensitivity and cannot differentiate between active tuberculosis (TB) disease and latent TB infection (LTBI). Numerous cytokines and regulator factors have been implicated in the pathogenesis and control of Mycobacterium tuberculosis infection. Additional cytokines and chemokines associated with M. tuberculosis infection may improve the performance of IFN-γ release assays. We developed a real-time RT-PCR TaqMan assay for targeting levels of eight human targets [IFN-γ, tumor necrosis factor (TNF)-α, IL-2R, IL-4, IL-10, CXCL9, CXCL10, and CXCL11] and evaluated the assay with three different study groups. Results showed that the sensitivity of TNF-α, IL-2R, and CXCL10 in the active pulmonary tuberculosis (PTB) group was 96.43%, 96.43%, and 100%, respectively. The sensitivity of IL-2R and CXCL10 in the latent tuberculosis infection group was 86.36% and 81.82%, respectively. Statistical results showed that TNF-α and CXCL9 were the best individual markers for differentiating between the PTB, LTBI, and non-TB groups. For optimal sensitivity and differentiation of M. tuberculosis infection status, the simultaneous detection of multiple targets was attempted. The combination of IFN-γ, TNF-α, and IL-2R, and the combination of TNF-α, IL-2R, CXCL9, and CXCL10 showed the best performance for detecting active PTB (both 100% positivity) and LTBI (86.36% and 81.82% positivity, respectively). These results imply that the combination of suitable markers is useful in efficiently diagnosing TB and differentiating M. tuberculosis infection status.

High IFN-γ Release and Impaired Capacity of Multi-Cytokine Secretion in IGRA Supernatants Are Associated with Active Tuberculosis

“…Lower IL-2/IFN-γ secretion [7,26] and a relative shift from IL-2 towards IFN-γ production were determined in ATB compared to LTBI or successfully treated TB subjects [5–7,25,26]. Similar observations were also made with other Th1 related cytokines, IP-10, MIG, TNF-α [5,7]. Analysis of T cell response against ESAT-6/CFP-10 at single cell level using flow cytometry were also in line with these results [13,15,27–29].…”

Unique Chemokine Profiles of Lung Tissues Distinguish Post-chemotherapeutic Persistent and Chronic Tuberculosis in a Mouse Model

“…Therefore, to more accurately distinguish between these two stages, the selective combination of immune response genes has been under study. Among them, the protein levels of CXCL10 (IP-10; Tonby et al, 2015; Wergeland et al, 2015; Xiong et al, 2016; regulated under IFN-γ) and levels of mRNA Kim et al, 2015 or protein (Jeong et al, 2015; Lee et al, 2015a) for CXCL9, CXCL10, and CXCL11 have been pointed out by other researchers. These studies were mostly performed with blood mononuclear cells after stimulation with Mtb-specific antigens.…”

Gene network in pulmonary tuberculosis based on bioinformatic analysis

“…Previous study confirmed that five genes (IFN-γ, TNF-α, IL-2R, CXCL9, and CXCL10) could be used for the detection of Mtb infection, including active PTB disease and LTB. The sensitivity of each gene was above to 80% [17]. The gene network profile provided more potential for diagnostic biomarkers selection.…”