Detection of <i>M. tuberculosis</i> DNA in peripheral blood mononuclear cells of tuberculosis contacts does not associate with blood RNA signatures for incipient tuberculosis

Human exposure to Mycobacterium tuberculosis (Mtb) is thought to result in a spectrum of outcomes including bacillary clearance, quiescent Mtb infection, incipient tuberculosis, subclinical tuberculosis and active tuberculosis [1]. Incipient tuberculosis - defined as a prolonged asymptomatic phase of early disease preceding clinical presentation as active disease [2] – may be distinguished from quiescent Mtb infection by detection of host gene expression signatures in blood, whose presence associates with increased risk of progression to active TB [3]. We and others have previously reported detection of Mtb DNA in CD34-positive peripheral blood mononuclear cells (PBMC) of asymptomatic TB-exposed adults with normal chest radiographs [4–6]. Footnotes This manuscript has recently been accepted for publication in the European Respiratory Journal . It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJ online. Please open or download the PDF to view this article. Conflict of Interest: A. Versi has nothing to disclose. Conflict of interest: STR has a pending patent in relation to detection of M. tuberculosis infection in peripheral blood. MN and ARM hold a patent in relation to blood transcriptomic biomarkers of tuberculosis. MN reports grants from the Wellcome Trust during conduct of the study. All other authors have no competing interests to declare. The views expressed are those of the authors and not necessarily those of the United Kingdom Medical Research Council or the United Kingdom Department of Health.