Multiplex analysis of pro-inflammatory cytokines in serum of Actinobacillus pleuropneumoniae-infected pigs

•A CBA 3-plex assay was successfully validated for use in porcine serum samples.•Serum of A. pleuropneumoniae-infected pigs was analyzed for TNF-α, IL-1β and IL-6.•Increased levels were observed for all 3 cytokines.•Maximal concentrations of TNF-α and IL-6 were recorded at 12 h and at 10 h.•A similar concentration-time profile was observed for IL-6 with CBA and ELISA.

Porcine pleuropneumonia is a severe respiratory disease caused by Actinobacillus (A.) pleuropneumoniae. The aim of the present study was to analyze serum samples of A. pleuropneumoniae-infected pigs for TNF-α, IL-1β and IL-6 using a cytometric bead array (CBA) 3-plex assay and additionally for IL-6 using ELISA.The CBA 3-plex assay was successfully validated for use in serum. The limits of detection varied between 0.012 and 0.333 ng/mL, and the inter- and inter-assay coefficients of variation were < 5% and < 10%, respectively.Increased levels were observed for all 3 cytokines following experimental infection with A. pleuropneumoniae. Mean peak concentrations of TNF-α and IL-6 were recorded at 12 h and at 10 h p.i., respectively. For IL-6, similar concentration-time profiles were observed with CBA and ELISA.It is proposed that this immuno-assay can be applied for the screening of immunomodulatory properties of drugs and vaccine adjuvants in infection, inflammation and vaccination.