Figure 2.

Proportion of donor plasma samples inside the assay quantification range for the Luminex (LMX) and Meso Scale Discovery (MSD) multiplex cytokine immunoassay kits. With the LMX system, all of the 19 shared cytokines were quantifiable in 100% of samples tested. Although the MSD assay had a LLoQ below that of the LMX assay for 17/19 (89) common analytes in earlier standard curve performance evaluations, this sensitivity did not directly translate to evaluating cytokines in human plasma samples. The MSD platform detected and quantified 7 of 19 analytes (37%) in 100% of plasma samples. The MSD assay detection/quantification rate for MIP-1α, IL-12p70, IL-1β, IL-17A, and IFN-γ in samples was 96%, 90%, 86%, 76%, and 75%, respectively. The MSD detection rate was <75% in the remaining 7 of 19 (37%) analytes, including a 0% detection rate for IL-21 and a 8% detection rate for IL-23.

Asterisks indicate significant differences for 11/19 analytes between MSD and LMX by Fisher Exact test, with “*” indicating P < .05, “**” indicating P < .01, and “***” indicating P < .001. No asterisk indicates mathematically similar detection frequencies between platforms for those cytokines.