Quantifying Soluble Plasma Cytokines

The soluble plasma cytokines were quantified using the Luminex multiplex platform (Luminex, Austin TX) as described previously.^{10 (link)} Briefly, the analytes were quantified using the Luminex multiplex platform with custom-developed reagents (R&D Systems, Minneapolis, MN), as described in detail^{43 (link)} or single-plex ELISA (R&D Systems, Minneapolis, MN). The quantified analytes were read on MAGPIX^® instrument and the raw data was analyzed using the xPONENT^® software. Analytes quantified using single-plex ELISA were read using optical density. Values outside the lower limit of detection were imputed using 1/3 of the lower limit of the standard curve for analytes quantified by Luminex and 1/2 of the lower limit of the standard curve for analytes quantified by ELISA.