Comparison of the Cellular and Cytokine Profile of Autologous Protein Solution and Autologous Conditioned Serum in Healthy Horses

Introduction: Autologous protein solution (APS) or autologous conditioned serum (ACS) contain high concentrations of anti-inflammatory cytokines and growth factors meant to slow the catabolic degradation of articular cartilage in osteoarthritis (OA). This study evaluates the cellular composition and concentration of important cytokines and growth factors of APS and ACS.

Materials and Methods: Blood was collected from six healthy horses for processing of APS and ACS. Blood, APS, and ACS were analyzed for white blood cell (WBC), red blood cell (RBC), and platelet (PLT) concentration. ELISA analysis was performed for growth factor (TGF-β), as well as anti-inflammatory (IL-1Ra and sTNF-R1), and proinflammatory (IL-1β, TNF-α, and MMP-3) cytokines.

Results: ACS had significantly fewer WBCs, PLTs, and RBCs than APS. APS had significantly higher WBC and PLT concentration compared with baseline blood and ACS. No significant differences in IL-1β, IL-1Ra, TNFα, and MMP3 were observed between APS and ACS. Significantly higher concentrations of TGF-β (p = 0.024) and sTNF-R1 (p = 0.093) were measured in ACS compared with APS. When the ratio of IL-1β: IL-1Ra ratios were evaluated ACS (113.31 ± 78.98) produced a slightly higher mean ratio compared with APS (48.22 ± 78.98) but this difference was not significant (p = 0.2115).

Discussion/Conclusion: Despite significant varied cellular composition, only small differences were detected in the cytokine profiles of these products. Observed differences in clinical efficacy of these products may be related to other unmeasured proteins, as well as the type, and degree of joint pathology treated.

Acknowledgment: Project funded by the Birmingham Racing Committee and the Auburn University Department of Clinical Sciences.