2026/07/29 by Luma N. F. Max, Kara A. Brown, Sarah E. Struble +3
paper · doi:10.2460/javma.26.02.0080
Abstract Objective To quantify the effects of high-intensity laser therapy (HILT) on the concentration of key immunomodulatory cytokines and growth factors in equine platelet-rich plasma (PRP) and autologous protein solution (APS). We hypothesized that HILT treatment of PRP and APS in vitro would increase the concentration of cytokines and growth factors compared to untreated controls. Methods Whole blood was collected from 6 adult horses housed at the University of Pennsylvania in March 2025 and processed into PRP or APS using commercially available systems (Zoetis). Platelet-rich plasma and APS samples were divided into control or HILT-exposed groups and placed in multiwell plates. High-intensity laser therapy was applied with a class IV laser (Smart RLT Sport) at a wavelength of 1064 nm, mean power output of 20 W, pulse energy of 1,300 mJ, pulse duration of 65 milliseconds, and frequency of 10 Hz for 10 seconds. Concentrations of immunomodulatory cytokines, including TGF-β1 and PDGF-BB, were quantified with multiplex bead-based immunoassays and ELISA following a single freeze-thaw cycle. Results HILT exposure did not significantly increase or decrease concentrations of the measured cytokines and growth factors in either product. Conclusions These findings suggested that HILT, as applied to equine PRP and APS in vitro, neither enhances nor decreases the release of select cytokines and growth factors. Clinical Relevance Results from this study will help inform the rational integration of HILT with blood-based orthobiologics in the treatment of equine soft tissue injuries.