Biomarkers of latent TB infection

Abstract

For the last 100 years, the tuberculin skin test (TST) has been the only diagnostic tool available for latent TB infection (LTBI) and no biomarker per se is available to diagnose the presence of LTBI. With the introduction of M. tuberculosis-specific IFN-γ release assays (IGRAs), a new area of in vitro immunodiagnostic tests for LTBI based on biomarker readout has become a reality. In this review, we discuss existing evidence on the clinical usefulness of IGRAs and the indefinite number of potential new biomarkers that can be used to improve diagnosis of latent TB infection. We also present early data suggesting that the monocyte-derived chemokine inducible protein-10 may be useful as a novel biomarker for the immunodiagnosis of latent TB infection.

Keywords::

• biomarker
• diagnosis
• ESAT-6
• IGRA
• IP-10
• latent tuberculosis infection
• prevention
• TB

Financial & competing interests disclosure

Morten Ruhwald and Pernille Ravn have received funding from the Lundbeck foundation (Copenhagen, Denmark), the Danish Lung Association (Copenhagen, Denmark), the University of Copenhagen (Denmark), Danida (Copenhagen, Denmark) and the Capital Region of Copenhagen (Denmark). Morten Ruhwald and Pernille Ravn are registered inventors on a patent filed by the University of Copenhagen disclosing IP-10 as a diagnostic biomarker for TB. Pernille Ravn has received a consultant fee from Cellestis in 2007 and is holding a 3-year research grant from the Danish Council for Independent Research – Medical Sciences (FSS) (Copenhagen, Denmark). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.