Choice of immunoassay to evaluate porcine cytokine levels.

Background: In order to adequately monitor cytokines in experimental models, currently available methods and commercially available kits should be compared.

Aim: To compare the plasma and tissue concentrations of IL-1β, IL-6, IL-8, IL-10, and TNF as a measure of systemic inflammation in septic pigs.

Methods: Cytokines were quantified from blood and tissue samples obtained at 0, 60, 120, 180, and 240 min, and in postmortem biopsies of the liver, kidney, lung, heart, and spleen from 26 anesthetized landrace pigs. (24 with experimental sepsis, two sham controls). Porcine-specific ELISAs (R&D) and multiplex (9-plex from Thermo Fischer, 13-plex from Millipore) immunoassays were compared.

Results: The assays differed for the different cytokines and between blood and tissue. In blood, the highest concentration of TNF and IL-6 was in ELISA, IL-1β equal in ELISA and 13-plex, IL-8 in 13-plex and IL-10 in 9-plex. In tissue, the highest concentration of TNF and IL-1β was in ELISA, IL-6 and IL-8 in 13-plex and IL-10 in 9-plex.

Conclusion: The choice of analysis impacts the quantified cytokine responses in porcine models. ELISA and multiplex techniques supplement each other and our data suggest which assays to use for the quantification of the different cytokines.