Cytokine concentrations and responses measured with an in-house MMIA.

<p>Median background cytokine concentrations (Nil, pg/mL) and cytokine responses (pg/mL) to phytohemagglutinin (Mitogen Response), early secreted antigenic target-6 (ESAT-6 Response), culture filtrate protein 10 (CFP-10 Response), TB7.7 (TB7.7 Response), and combinations of these <i>M. tuberculosis</i> (<i>Mtb</i>) antigens (ESAT-6+CFP-10 Response and ESAT-6+CFP-10+TB7.7 Response) are listed with ranges in parentheses. Cytokine concentrations were measured with an in-house multiplexed microsphere-based immunoassay (in-house MMIA) for patients with culture-confirmed tuberculosis (patients) and subjects at low-risk of <i>Mtb</i> exposure (controls). For concentrations that were designated “out of range” by Bio-Plex Manager software, low values are reported as 0 and high values are reported as the upper limit of the standard curve multiplied by the dilution factor (25,000 pg/mL). Responses were calculated by subtracting the background cytokine concentration in plasma from blood incubated with saline (Nil) from the cytokine concentration in plasma from blood incubated with mitogen or <i>Mtb</i> antigens. N = 6 for patients and N = 10 for controls unless indicated (*n = 6). <i>P</i> values were calculated by Mann-Whitney U Rank Sum test comparing cytokine concentrations or responses for patients with controls. Significant differences (<i>p</i><0.05) are indicated in <b>bold type</b>.