Does the Relationship Between Microelements (Copper, Zinc and Selenium) and Proinflammatory Proteins (IL-6, IL-8 and Tissue Factor) Have Diagnostic Value in Equine Medicine?

Some correlations between serum Cu, Zn and Se and cytokines have been reported in humans. Especially, the Cu:Zn ratio corresponded with inflammation. To date, relationships between microelements and proinflammatory proteins are poorly understood in horses. The aim of the study was to evaluate whether Cu, Zn and Se may influence turnover of IL-6, IL-8 and tissue factor (TF) in breeding and working horses. Blood samples obtained from 66 horses were analysed. There were 37 pregnant broodmares of different breeds, 13 barren broodmares and 16 race Thoroughbred horses. Serum Cu, Zn and Se concentration was determined using the gas flame atomic absorption spectrometry (GFAAS) method. Plasma IL-6, IL-8 and TF concentration was determined by the ELISA method. A coefficient correlation was carried out to compare the values of microelements studied with IL-6, IL-8 and TF using Pearson's test. The values of IL-6 correlated significantly positively with Se and Cu:Zn ratio, IL-8 correlated positively with Cu and Cu:Zn ratio and negatively with Zn, and TF correlated positively with Cu, Cu:Zn ratio and Se. The Cu:Zn ratio varies significantly between horses, with high values occurring in horses with high levels of proinflammatory proteins, which may indicate the presence of a subclinical inflammatory process. The high variability of TF in the studied groups gives hope for the use of its determination in laboratory diagnostics of horses.