Plasma interleukin-6 concentration in Standardbred racehorses determined by means of a novel validated ELISA.

The research involves the development and validation of a new enzyme-linked immunosorbent assay (ELISA) for measuring plasma interleukin-6 (IL-6) concentration in Standardbred racehorses. After validation, this ELISA method was used to determine the plasma IL-6 concentration in a large group of Standardbred racehorses.

Development and Validation of ELISA Method

• The researchers developed a novel ELISA method using equine anti-IL-6 polyclonal antibody and the biotin-streptavidin chemical interaction to boost the assay’s sensitivity.
• The validation process tested the assay’s specificity, sensitivity, precision, and accuracy using both recombinant and endogenous proteins.
• The ELISA method showed minimal cross-reactivity with other human and equine cytokines, indicating high specificity.
• Tests conducted to determine assay precision and accuracy showed inter- and intra-assay precisions of ≤ 13.6% and ≤ 9.3%, respectively. The inter- and intra-assay accuracies were within ranges of ± 14.1% and ± 8.6%, respectively, for concentrations ranging from 78 to 5,000 pg/mL. The assay’s sensitivity was measured to be 18 pg/mL.

Determination of Plasma IL-6 Concentration in Standardbred Racehorses

• After successful validation, the researchers used the newly developed ELISA to measure the plasma IL-6 concentration levels in 319 Standardbred racehorses.
• Test results revealed significant variability in IL-6 concentration among the tested Standardbred racehorses. The range was from 0 to 193,630 pg/mL, with a mean of 6,153 pg/mL and a median of 376 pg/mL.
• A noteworthy finding was that the plasma IL-6 concentration was particularly high (>10,000 pg/mL) in 9.1% of the tested Standardbred racehorses, suggesting an area of study that could benefit from further investigation.

Conclusion

• The novel ELISA, validated in this study, was found to be effective and suitable for the quantification of IL-6 concentration in the plasma samples of equine.
• The research identified potential areas of future study, specifically the group of Standardbred racehorses with notably high plasma IL-6 concentration levels.