Zoetis Inc. has announced findings from new research conducted by the University of Pennsylvania New Bolton Center. The study1 compared quantities of alpha-2-macroglobulin (A2M); immunomodulatory cytokines, including IL-1β, IL-1Ra, IL-4, IL-6, IL-10, IL-17a, and TNF-α; and the growth factor TGF-β1 in the outputs of four commercially available orthobiologics: Pro-Stride APS, Restigen PRP, Alpha2EQ and Arthrex ACP using blood samples from six healthy horses.

Photo showing the dynamics of a horse's legs in action.
This study is important as it highlights differences in some of the major cytokines and proteins we think about when managing joint disease in horses.
© 2018 by Somogyvari New window.
Results indicated that both Pro-Stride APS and Restigen PRP devices may be more effective in modulating inflammation and promoting healing than the other devices tested. Key findings included:
- Both Pro-Stride and Restigen produced high levels of IL-1ra. The ratio of IL-1Ra to IL-1β needed to promote joint health is 100:1 or greater; only Pro-Stride APS and Restigen PRP exceeded this threshold while Alpha 2EQ and Arthrex ACP did not. Interestingly, IL-1ra levels in Alpha2EQ and Arthrex ACP were below the level of detection.
- Pro-Stride produced a significantly higher concentration of A2M than Alpha2EQ.
- Levels of TGF- β1, a protein important for cartilage maintenance and repair, were significantly higher in Pro-Stride, Restigen and Arthrex, compared to Alpha2EQ.
- No significant differences were found in the concentrations of IL-1β, IL-4, IL-6, IL-10 and IL-17a between devices.
“Our priority at Zoetis is to provide veterinarians with scientifically backed products they can confidently use to safely and effectively treat their equine patients,” said Dr. Nathan Voris, Director of Equine Technical Services at Zoetis. “This new study highlights the value of our Pro-Stride and Restigen devices and adds to the industry’s base of knowledge around the differences between available orthobiologic options. Studies like this help veterinarians and horse owners make informed decisions for their horse.”
“It is important for us as equine veterinarians to gain understanding of what makes up the orthobiologics we use.” explains Kyla Ortved, DVM, PhD, DACVS, DACVSMR, Associate Professor of Large Animal Surgery, University of Pennsylvania School of Veterinary Medicine. “Although a significant amount of work is still required to fully understand all the options we have available, we felt this study was important as it highlights differences in some of the major cytokines and proteins we think about when managing joint disease.”
These findings back up previous research2, which also found that the Pro-Stride and Restigen devices produced more platelet-derived growth factors and white-blood-cell-derived anti-inflammatory cytokines in the cellular output, as well as a significantly higher concentration of A2M than the final plasma output of Alpha2EQ.2
Zoetis’ Pro-Stride and Restigen devices are comprehensive therapies for the management and treatment of osteoarthritis and soft tissue injuries. Pro-Stride and Restigen, together with CenTrate® BMA (equine bone marrow aspirate device), make up Zoetis’ family of regenerative medicine devices to help veterinarians manage equine lameness.
Learn more about the regenerative medicine device portfolio here. Contact your local Zoetis Equine specialist or call 1-888-ZOETIS1 with questions.
References
- Barot D, Usimaki A, Linardi R et al. Equine autologous blood-based products contain variable quantities of transforming growth factor-β1, interleukin-1 receptor agonist, and α2-macroglobulin. AJVR. Jan 30, 2025. DOI: https://doi.org/10.2460/ajvr.24.11.0363
- Ortved, KF, Alward, L, Cowles, B, et al. Use of quantitative mass spectrometry-based proteomics and ELISA to compare the alpha 2 macroglobulin concentration in equine blood-based products processed by three different orthobiologic devices. Front. Vet. Sci. 2024;11. DOI: https://doi.org/10.3389/fvets.2024.1335972
Press release by Amy Sales