文摘
Concern exists about whether or not multiplex assays are sensitive enough to detect subtle yet biologically relevant changes in circulating concentrations of inflammatory biomarkers such as interleukin (IL)-6 in healthy humans. We tested two different multiplex kits (human Magnetic Luminex Performance Assay, R&D Systems [Minneapolis, MN]; and human Cytokine/Chemokine Magnetic Bead Panel, Millipore [Billerica, MA]) to detect IL-6 concentration changes versus a high sensitivity (HS)-ELISA (R&D Systems) in plasma collected from eighteen healthy adults (mean age 35.3 [SD = 8.88]) (10 women) before and 90 and 210 min after the start of an acute laboratory psychosocial stressor, the Trier Social Stress Test (TSST). Multiplexes were completed per manufacturer instructions and analyzed using a MAGPIX (Luminex, Austin, TX). For the R&D multiplex, IL-6 was detected in all samples and values were associated with concentrations determined by HS-ELISA (r = 0.81, p < 0.001). For the Millipore multiplex, IL-6 was detected in only 83% of the samples and values were not correlated with those determined by HS-ELISA (p = 0.46). To examine associations between IL-6 responses to the TSST we computed areas under the curve (AUCs) using the trapezoidal method. AUCs were positively correlated between the R&D multiplex and HS-ELISA (r = 0.83, p = 0.001), but not between the Millipore multiplex and HS-ELISA. These results suggest that certain multiplex assays may be able to detect changes in plasma concentrations of IL-6 as a result of TSST challenge.