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Updated: Oct 17, 2026
A Pre-Clinical Model of Synovitis Using Ex vivo Human Synovial Tissue with Preserved Function and Architecture
Published on: March 20, 2026
Multimodal characterization of equine synovitis: Correlation between arthroscopic, histopathological, and biomarker
A Charbonnel1, C Thorin2, S Allain3
1Department of Surgery, Equine Clinic, ONIRIS, National College of Veterinary Medicine, Food Science and Engineering, Nantes, France.
Background:
Endoscopy and synovial membrane histology are complementary modalities for evaluating synovial inflammation. Cytokine involvement in non-septic arthritis is well documented but remains poorly characterized in septic synovitis.
Aims/Objectives:
This study aimed to characterize the inflammatory cytokine profile associated with septic and non-septic synovitis and assess correlations among endoscopic, histological, and synovial fluid biomarker findings.
Methods:
Three groups were defined: horses undergoing elective or therapeutic endoscopy (Group 1, n=26), horses with confirmed septic synovitis (Group 2, n=25; 20 underwent endoscopic evaluation), and horses with perisynovial injuries without synovial involvement (Group 3, n=19). Synovial fluid was analysed for cell count, total protein, neutrophil percentage, and cytokine concentrations. Endoscopic and histological scores were assigned in Groups 1 and 2. Statistical analyses included non-parametric, correlation tests, and principal component analysis (PCA).
Results:
Endoscopic and histological scores were significantly higher in Group 2 than in Group 1 (P=.004 and P=.006, respectively). Synovial fluid cellularity was significantly higher in Group 2 (median, 19,000 cells/µL; IQR, 11,800-81,930; P<.001). IL-1β, IL-6, TNF-α, and IL-10 concentrations were significantly higher in Group 2 than in Groups 1 and 3, with IL-6 reaching a median concentration of 1,416.51 (IQR, 645.49-5,225.84) in Group 2. These four cytokines contributed most strongly to group discrimination in the PCA.
Conclusion:
Combining endoscopic and histological evaluation with cytokine profiling provided a more comprehensive assessment of septic synovitis. IL-1β, IL-6, TNF-α, and IL-10 emerged as promising biomarkers of synovial sepsis.