Mycobacteria-induced secretion of cytokines and chemokines in healthcare workers with apparent resistance to infection with <i>Mycobacterium tuberculosis</i>.

Cytokines and chemokines in PBMC supernatants (stimulated with Mtb and BCG), plasma and supernatants from Quantiferon-TB PLUS assay (Nil and TB1 stimulated) after incubation for 16-20 hours. Concentrations were measured by Luminex using the ProcartaPlex Human Monitoring Panel 65-plex panel (Invitrogen™) according to manufacturers' instructions. Biological samples were collected from individuals with latent TB infection (LTBI, IGRA+ &amp; TST+), people with resistance to Mtb infection (Resisters, IGRA- &amp; TST-) and people with previous but successfully treated TB. IGRA+ for IFN-gamma level &gt;0.35IU/mL; IGRA- for IFN-gamma &lt;0.35IU/mL; TST+ for induration &gt;10mm and TST- for induration &lt;10mm