Role of Innate Immunity in Initiation and Progression of Osteoarthritis, with Emphasis on Horses.
Authors: Estrada McDermott Juan, Pezzanite Lynn, Goodrich Laurie, Santangelo Kelly, Chow Lyndah, Dow Steven, Wheat William
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Osteoarthritis in horses is increasingly recognised as a multifactorial inflammatory disease rather than a simple mechanical breakdown, with innate immune dysfunction playing a central role in both initiating and perpetuating cartilage damage. Synovial macrophages emerge as critical orchestrators of joint inflammation—capable of both amplifying and suppressing the low-grade inflammatory cascade depending on local and systemic signals—making them key targets for intervention. The review synthesises evidence from human research, experimental OA models, and equine clinical studies to demonstrate how acute trauma, chronic overload, and age-related changes can trigger this aberrant immune response, which then sustains itself through continuous cartilage destruction even after the initial insult has resolved. Understanding this immunological basis for OA progression has direct implications for practitioners, shifting the therapeutic focus beyond pain management and joint support towards immune modulation strategies that can interrupt the inflammatory cycle and potentially alter disease trajectory. The authors examine existing immune-modulatory treatment options and their mechanisms, providing a framework for evidence-based selection of therapeutics that target synovial inflammation rather than simply treating symptoms.
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Practical Takeaways
- •OA requires individualized management based on its specific etiology (trauma, overuse, or degenerative), as it is not a single disease—tailor prevention and treatment accordingly.
- •Anti-inflammatory treatments targeting macrophage activity and innate immunity may offer better long-term outcomes than approaches that only address acute inflammation symptoms.
- •Understanding immune modulation in OA can help practitioners select from various therapeutic options (including novel immunotherapies) based on individual horse response and disease stage.
Key Findings
- •Osteoarthritis is a multifactorial disease initiated by acute trauma, repetitive overload, or age-related spontaneous development, not a single disease entity.
- •Macrophages in synovium and synovial fluid are key regulators of innate immunity in OA, capable of both stimulating and suppressing joint inflammation.
- •The innate immune system perpetuates low-grade inflammation leading to sustained cartilage injury and destruction in OA pathogenesis.
- •Multiple therapeutic immune modulatory options are available for OA management with varying mechanisms of action.