AUTHOR=Carrère-Kremer Séverine , Kolia-Diafouka Pratt , Pisoni Amandine , Bolloré Karine , Peries Marianne , Godreuil Sylvain , Bourdin Arnaud , Van de Perre Philippe , Tuaillon Edouard 

TITLE=QuantiFERON-TB Gold Plus Assay in Patients With Latent vs. Active Tuberculosis in a Low Incidence Setting: Level of IFN-γ, CD4/CD8 Responses, and Release of IL-2, IP-10, and MIG

JOURNAL=Frontiers in Microbiology

VOLUME=Volume 13 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.825021

DOI=10.3389/fmicb.2022.825021

ISSN=1664-302X

ABSTRACT=Objectives. We analyzed results of the QuantiFERON Glod Plus assay (QFT) and cytokine patterns associated with Active tuberculosis (ATB) among patients with positive QFT. 

Methods. Hundred-ninety-five patients QFT-positive, 24 had an ATB and 171 a LTBI. IFN-γ secretion was analyzed relatively to IL-2, IP-10 and MIG secretion, and compared between two sets of peptide antigens (tube 1 - CD4+ T cell stimulation; tube 2 - CD4+/CD8+ T cell response). 

Results. Higher IFN-γ response were measured in the ATB group (p=0.0089). There was a lower ratio of tube 1/tube 2 IFN-γ concentrations in the ATB group (p = 0.0009), and a median (IQR) difference between the two sets of -0.82 IU/ml (-1.67 to 0.18) vs -0.07 IU/ml (-0.035 to 0.11, p<0.0001), in the ATB group compared to the LTBI group, respectively. In addition, patients with low ratios of IL-2/IFN-γ, IP-10/ IFN-γ, and MIG/IFN-γ were much more likely to have ATB. 

Conclusion. High level of IFN-γ secretion, preferential IFN-γ response in tube 2, and impaired capacity of IL-2, IP-10, and MIG release relatively to IFN-γ secretion were associated with ATB. These features of T cell response may be helpful in low prevalence settings to suspect ATB in patients tested positive for IGRA.