Measurement of procalcitonin in saliva of pigs: a pilot study.

Abstract

BACKGROUND: Procalcitonin (PCT) is a widely used biomarker of sepsis in human medicine and can have potential applications in the veterinary field. This study aimed to explore whether PCT could be measured in the saliva of pigs and whether its concentration changes in sepsis. Therefore, a specific assay was developed and analytically validated, and changes in PCT concentration were evaluated in two conditions: a) in an experimental model of sepsis produced by the administration of lipopolysaccharide (LPS) to pigs (n&#x2009;=&#x2009;5), that was compared with a model of non-septic inflammation induced by turpentine oil (n&#x2009;=&#x2009;4), and b) in healthy piglets (n&#x2009;=&#x2009;11) compared to piglets with meningitis (n&#x2009;=&#x2009;20), a disease that usually involves sepsis and whose treatment often requires large amounts of antibiotics in farms. RESULTS: The assay showed coefficients of variation within the recommended limits and adequate linearity&#xa0;after serial sample dilutions. The method's detection limit was set at 68&#xa0;&#x3bc;g/L, and the lower limit of quantification was 414&#xa0;&#x3bc;g/L. In the LPS experiment, higher concentrations of PCT were found after 24&#xa0;h in the animals injected with LPS (mean&#x2009;=&#x2009;5790&#xa0;&#x3bc;g/L) compared to those treated with turpentine oil (mean&#x2009;=&#x2009;2127&#xa0;&#x3bc;g/L, P&#x2009;=&#x2009;0.045). Also, animals with meningitis had higher concentrations of PCT (mean&#x2009;=&#x2009;21515&#xa0;&#x3bc;g/L) than healthy pigs (mean&#x2009;=&#x2009;6096&#xa0;&#x3bc;g/L, P value&#x2009;<&#x2009;0.0001). CONCLUSIONS: According to these results, this assay could be potentially used as a tool for the non-invasive detection of sepsis in pigs, which is currently a topic of high importance due to antibiotic use restriction.