Cytokine profile influence equine ACS treatment results

Horses received 3 intra-articular injections of ACS administered at approximately 2-week intervals. Lameness evaluation consisting of a trot-up with subsequent flexions tests was performed at inclusion and approximately 2 weeks after the last treatment (re-evaluation); horses were classified as responders when there was no detectable lameness on trot-up and a minimum of 50% reduction in flexion test scores at re-evaluation. Association between clinical outcome (responders vs. non-responders) and age, lameness grades at inclusion (both initial trot-up and after flexion tests), treatment interval, follow-up time and the ACS content of IL-1Ra, IGF-1 and TGF-β was determined by regression modelling.

Results

Outcome analysis was available for 19 of 20 included horses; 11 responded to treatment whereas 8 did not. There was considerable inter-individual variability in cytokine/growth factor content of ACS, and in the majority of the horses, the level of IL-10, IL-1β and TNF-α was below the detection limit. In the final multivariate logistic regression model, ACS content of IGF-1 and IL-1Ra was significantly associated with clinical response (P = 0.01 and P = 0.03, respectively). No association with clinical response was found for the other tested variables.

Conclusions

The therapeutic benefit of ACS may be related to higher levels of IL-1Ra and IGF-1. Our study corroborates previous findings of considerable inter-individual variability of cytokine- and growth factor content in ACS.

Link to the publication

https://doi.org/10.1186/s12917-020-02391-7

Reference

Marques-Smith, P., Kallerud, A. S., Johansen, G. M., Boysen, P., Jacobsen, A. M., Reitan, K. M., Henriksen, M. M, Löfgren, M. & Fjordbakk, C. T. (2020). Is clinical effect of autologous conditioned serum in spontaneously occurring equine articular lameness related to ACS cytokine profile? BMC Veterinary Research, 16(1), 1-9.