Inflammatory response following intra-articular injection of decellularized porcine amnion/chorion in horses.
Authors: Cormier Kamille V, Fontenot Robin L, Eddy Alison, Williams Matthew L, Wills Robert W, Jumper William Isaac, Mochal-King Cathleen A
Journal: Veterinary surgery : VS
Summary
# Editorial Summary: Inflammatory Response to Decellularised Porcine Amnion/Chorion in Equine Joints Decellularised porcine amnion/chorion suspension (dPACLS) has emerged as a potential biologic therapeutic for joint disease, but its safety profile in equine intra-articular applications required investigation. Researchers injected either 50 mg (high dose) or 5 mg (low dose) of dPACLS into one radiocarpal joint of 10 horses, with the contralateral joint receiving saline as control, then monitored systemic and synovial inflammatory markers alongside clinical lameness for 168 hours. Both dose groups triggered elevated synovial fluid nucleated cell counts at 24 and 48 hours post-injection; however, the high-dose group demonstrated substantially greater inflammatory burden, with significantly elevated synovial fluid serum amyloid A (SAA) throughout the study period, persistent systemic SAA elevation at all timepoints except 168 hours, and three horses developing lameness with elevated cell counts at the study endpoint. The authors concluded that dPACLS is not suitable for intra-articular use at either tested dose, as the material provoked a clinically evident inflammatory response that outweighed any potential therapeutic benefit—an important consideration for practitioners evaluating novel biologics for joint pathology.
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Practical Takeaways
- •Decellularized porcine amnion/chorion suspension is not suitable for intra-articular use in horses at the doses tested (5-50 mg), as it triggers significant joint inflammation and potential lameness.
- •If considering any biologic joint injection, dose matters critically—the 10-fold difference between groups produced markedly different inflammatory responses, suggesting careful dose optimization is essential.
- •Monitor treated joints closely for at least 7 days post-injection; persistent lameness with elevated joint fluid cell counts may indicate an ongoing inflammatory reaction requiring intervention.
Key Findings
- •High-dose dPACLS (50 mg) induced significantly greater synovial fluid and systemic SAA elevation compared to low-dose (5 mg) and saline controls.
- •Both treatment groups showed elevated synovial fluid nucleated cell counts at 24 and 48 hours post-injection, indicating acute inflammatory response.
- •Three of five high-dose horses developed clinical lameness with persistent elevated synovial cell counts at 168 hours post-injection.
- •Systemic SAA remained elevated in high-dose group at all timepoints through 96 hours, while low-dose group showed no systemic elevation at any timepoint.