Is clinical effect of autologous conditioned serum in spontaneously occurring equine articular lameness related to ACS cytokine profile?
Authors: Marques-Smith Patrick, Kallerud Anne S, Johansen Grethe M, Boysen Preben, Jacobsen Anna M, Reitan Karoline M, Henriksen Mia M, Löfgren Maria, Fjordbakk Cathrine T
Journal: BMC veterinary research
Summary
# Editorial Summary: Autologous Conditioned Serum and Cytokine Profiles in Equine Lameness Autologous conditioned serum has become a popular biological treatment for equine joint disease, yet the wide variation in its bioactive component concentrations between individual preparations raises questions about consistency and efficacy. This Norwegian study examined 47 harness racehorses with naturally occurring low-grade articular lameness treated with three intra-articular ACS injections over six weeks, investigating whether specific cytokine and growth factor profiles (interleukin-1 receptor antagonist, insulin-like growth factor-1, and transforming growth factor-beta) correlated with clinical response. Clinical responders—those demonstrating sound trot-up and ≥50% improvement in flexion test scores two weeks post-treatment—showed no significant association between their clinical outcome and the measured cytokine concentrations, though initial lameness severity was an important predictor of response. The findings suggest that whilst ACS may benefit horses with low-grade articular lameness, the mechanism does not appear to depend on IL-1Ra, IGF-1 and TGF-β levels alone, indicating either that other constituents drive efficacy, that response is multifactorial, or that current biomarker measurement may not capture the relevant biological activity. For practitioners, this underscores the need for continued outcome tracking and suggests that standardising ACS production based solely on these three factors may not optimise clinical results.
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Practical Takeaways
- •ACS preparations vary significantly in their bioactive content between horses, which may explain variable clinical responses to treatment
- •Standardizing or measuring cytokine profiles in ACS could help predict which horses are likely to respond to intra-articular injection
- •Baseline lameness grade and treatment timing appear relevant to clinical outcomes with biological joint treatments
Key Findings
- •Large inter-individual differences exist in cytokine and growth factor content of autologous conditioned serum (ACS) preparations
- •Clinical response to intra-articular ACS injection was evaluated using lameness grading and flexion tests at 2 weeks post-treatment
- •Association analysis examined relationships between ACS cytokine profile (IL-1Ra, IGF-1, TGF-β) and clinical outcome in harness racehorses with articular lameness