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

PLoS One. 2016 Sep 7;11(9):e0162137. doi: 10.1371/journal.pone.0162137. eCollection 2016.

Abstract

Interferon gamma (IFN-γ) release assays (IGRAs) detect Mycobacterium tuberculosis (Mtb) infection regardless of the active (ATB) or latent (LTBI) forms of tuberculosis (TB). In this study, Mtb-specific T cell response against region of deletion 1 (RD1) antigens were explored by a microbead multiplex assay performed in T-SPOT TB assay (T-SPOT) supernatants from 35 patients with ATB and 115 patients with LTBI. T-SPOT is positive when over 7 IFN-γ secreting cells (SC)/250 000 peripheral blood mononuclear cells (PBMC) are enumerated. However, over 100 IFN-γ SC /250 000 PBMC were more frequently observed in the ATB group compared to the LTBI group. By contrast, lower cytokine concentrations and lower cytokine productions relative to IFN-γ secretion were observed for IL 4, IL-12, TNF-α, GM-CSF, Eotaxin and IFN-α when compared to LTBI. Thus, high IFN-γ release and low cytokine secretions in relation with IFN-γ production appeared as signatures of ATB, corroborating that multicytokine Mtb-specific response against RD1 antigens reflects host capacity to contain TB reactivation. In this way, testing cytokine profile in IGRA supernatants would be helpful to improve ATB screening strategy including immunologic tests.

MeSH terms

  • Adult
  • Aged
  • Antigens, Bacterial / metabolism
  • Bacterial Proteins / metabolism
  • Female
  • Humans
  • Interferon-gamma / metabolism*
  • Interferon-gamma Release Tests / methods*
  • Latent Tuberculosis / diagnosis
  • Leukocytes, Mononuclear / metabolism
  • Male
  • Middle Aged
  • Odds Ratio
  • Reagent Kits, Diagnostic
  • Tuberculosis / immunology*

Substances

  • Antigens, Bacterial
  • Bacterial Proteins
  • ESAT-6 protein, Mycobacterium tuberculosis
  • Reagent Kits, Diagnostic
  • Interferon-gamma

Grants and funding

This work was supported by the INSERM DHOS grant (AFSSAPS n° 2010-A00422-37) and by CHRU Montpellier. SCK was funded by the Fondation de France. The INSERM DHOS grant (AFSSAPS n°2010-A00422-37) did not provide any support in the form of salaries for authors, and did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The Fondation de France provided support in the form of salaries for SCK.