Functional and biochemical inflammatory responses to low-dose intra-articular recombinant equine IL-1β: a pilot study.
Authors: Korac Lindsay, St George Lindsay, MacNicol Jennifer, McCrae Persephone, Jung L, Golestani N, Karrow Niel, Cánovas Angela, Pearson Wendy
Journal: Frontiers in veterinary science
Summary
# Editorial Summary: Low-dose IL-1β as a Model for Subclinical Joint Inflammation in Horses Researchers at this institution developed a pilot model to investigate early-stage joint inflammation by injecting small doses of recombinant equine interleukin-1β (reIL-1β) into the intercarpal joints of three horses in a crossover design, collecting synovial fluid at intervals up to 24 hours post-injection alongside objective gait analysis using inertial measurement units (IMUs). The 50 ng dose produced a significant rise in synovial prostaglandin E₂ (PGE₂) at 6 and 12 hours, whilst the 75 ng dose elevated PGE₂ at all timepoints measured, yet neither dose substantially altered nitric oxide or glycosaminoglycan (cartilage turnover marker) concentrations. Notably, the higher dose induced measurable asymmetry in poll motion (MinDiff) during the same timeframe, with PGE₂ concentration correlating positively with gait asymmetry metrics (ρ = 0.35). This model reliably induces a mild, transient inflammatory state without causing overt clinical dysfunction, potentially offering equine practitioners and researchers a refined tool for studying subclinical synovitis and validating novel therapeutics whilst maintaining rigorous ethical standards in animal research.
Read the full abstract on PubMed
Practical Takeaways
- •This pilot work demonstrates that early joint inflammation can be detected via synovial biomarkers and IMU gait analysis before clinical lameness becomes obvious—potentially enabling earlier intervention in natural joint disease
- •The correlation between PGE2 and upper-body asymmetry metrics suggests inertial measurement units may be useful objective tools for detecting subclinical inflammatory responses in clinical practice
- •This experimental model may help validate new anti-inflammatory therapies for early-stage joint disease, but results from n=3 horses require validation in larger studies before applying findings
Key Findings
- •50 ng reIL-1β increased synovial prostaglandin E2 (PGE2) at 6 and 12 hours post-injection; 75 ng increased PGE2 at all time points measured
- •75 ng reIL-1β significantly increased poll MinDiff (upper-body asymmetry) at 6 and 12 hours, correlating positively with PGE2 concentration (ρ = 0.35, p < 0.05)
- •Neither dose significantly elevated nitric oxide or glycosaminoglycan levels, indicating a mild inflammatory response without cartilage degradation biomarkers
- •Low-dose intra-articular reIL-1β produces transient, mild synovitis detectable by biochemical markers and subtle gait asymmetry without overt lameness