abs: In Vivo Effect of Cytokines After Repeated Intra-Articular Injections of Platelet Rich Plasma in Osteoarthritic Joints in Horses. Large Animal Residents' Forum
Evaluation of Anti-Inflammatory Properties and Growth Factor Release After Repeated Intra-Articular Injections of Leukocyte-Poor, Platelet-Rich Plasma in Horses with Early to Moderate Osteoarthritic Joints. Aguilar Miranda CM1, Riggs L2, Leise B2, McCauley C2. 1Atlantic Veterinary College, Charlottetown, PE, Canada; 2Louisiana State University, Baton Rouge, LA.
Platelet-Rich Plasma (PRP) has the potential benefit for osteoarthritis (OA) in horses. However, knowledge gaps exist over its cytokines influence after intra-articular injection. Our objective is to evaluate the long-term effect of repeated intra-articular injections of Leukocyte-Poor PRP (LP-PRP) in carpal joints with radiographic signs of OA. Eight healthy horses with bilateral grade 1 OA in both carpi were selected. In each horse, one radiocarpal joint was used as control (0.9% Sodium Chloride) and the contralateral joint treated (LP-PRP). At days 1, 7, and 21 synovial fluid (SF) was collected in both carpal joints, followed by their respective treatment. At days 51 and 81 only SF fluid was collected. At each time point, lameness was assessed and SF analyzed for hematology parameters and cytokine detection of IL-10, IL-13, IL-4, IL-1β, IL-6, TNF-α, and PDGF-ββ. Repeated injections of LP-PRP do not cause an increase in any inflammatory SF parameter. Similarly, no significance in lameness was observed from day 1 to day 51 (P = 0.625). No significant difference was detected in IL-10 (P = 0.155), IL-13 (P = 0.511), IL-4 (P = 0.659), or IL-1β (P = 0.387). IL-6, TNF-a, and PDGF-ββ were not detected in any time point. Repeated intra-articular injections with LP-PRP do not cause a long-term inflammation either improvement in lameness score. Our study provides further confirmation that PDGF- ββ cannot be detected after seven days of LP-PRP injection. A naturally occurring OA model in the horse is not a suitable model to compare the difference between treatments.