Abstract # 1844 A high-sensitivity magnetic multiplex assay detects changes in plasma concentrations of interleukin-6 induced by the Trier Social Stress Test

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, RD 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 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.