Allogenic mesenchymal stem cells as a treatment for equine degenerative joint disease: a pilot study.

This research studied the safety and efficacy of using allogenic mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP) in treating degenerative joint disease in horses. It found that this treatment, particularly when MSCs were chondrogenic induced, helped horses return to work with few adverse effects.

Study Overview

• The study was conducted to evaluate the safety and report the clinical outcome of using allogenic, immature or chondrogenic induced MSCs in combination with PRP as a treatment for degenerative joint disease in 165 horses. The intention was to augment the relatively scant body of research on large-scale animal studies of this cell-based therapy.

Methodology

• MSCs and PRP were isolated from a 6-year-old donor horse. These were then transplanted in their untreated state or after chondrogenic induction into degenerated joints of 165 horses. Different types of joints were treated, including the stifle (30 horses), fetlock (58 horses), pastern (34 horses), and coffin (43 horses).
• The safety of the procedure was monitored through a clinical evaluation of the horses. The clinical outcomes were categorized into four groups based on the horse’s abilities post-treatment: failure to return to work (score 0), rehabilitation (score 1), return to work (score 2), and return to previous level (score 3).
• Outcomes were assessed after six weeks or at 18 weeks for horses that returned for long-term follow-up.

Results

• Of the 165 horses treated, only three (1.8%) showed moderate flare reactions within a week after treatment, but these reactions had no long-term effects.
• For horses treated with native MSCs, 45% returned to work after six weeks. This figure rose to 60% for those treated with chondrogenic induced MSCs.
• After 18 weeks, 78% of the horses treated with native MSCs and 86% of those treated with chondrogenic induced MSCs had returned to work.
• Although not statistically significant, higher average scores were observed with chondrogenic induced MSCs compared to native MSCs. The odds ratio was 1.47 in the short term and 1.24 in the long term.
• Interestingly, a higher percentage of horses treated for lower limb joints returned to work after chondrogenic induced MSC treatment. However, the opposite trend was observed for stifle joints.

Conclusion

• The successful return to work for a large number of horses treated with both native MSCs and chondrogenic induced MSCs suggests that this cell-based therapy may be a viable approach for treating degenerative joint disease in horses.
• The lack of significant adverse effects demonstrates the relative safety of the procedure.
• Given the somewhat varying results between treatment for stifle and lower limb joints, more protracted follow-up data would be beneficial to confirm the sustainability of these results.