Multiplex analysis of cytokines and chemokines in human serum was performed by using the 17 cytokine Bio-Plex ProHuman Cytokine Assay (BioRad) run on the Luminex 200 system according to the manufacturer's instructions with the exception that a proprietary BioRad assay dilution buffer was modified to contain reagents demonstrated to reduce the effects of heterophilic antibodies in multiplex immunoassays as previously described 21 (link). Data processing was performed by using Bio-Plex Manager 5.0, and analyte concentrations (in picograms per milliliter) were interpolated from standard curves.