Clinical follow-up of horses treated with allogeneic equine mesenchymal stem cells derived from umbilical cord blood for different tendon and ligament disorders

Background: Mesenchymal stem cells (MSCs) offer promise as therapeutic aids in the repair of tendon and ligament disorders in sport horses. Equine allogeneic MSCs derived from umbilical cord blood (eUCB-MSCs) can be obtained in a minimally invasive fashion with successful propagation of MSCs. Objective: The objective of this study was to determine the applicability and therapeutic effect of eUCB-MSCs on tendinitis of the superficial digital flexor tendon, desmitis of the suspensory ligament, tendinitis of the deep digital flexor tendon, and desmitis of the inferior check ligament in clinical cases. Methods: A retrospective clinical study was performed. At two equine clinics, 52 warmblood horses were treated with cultured eUCB-MSCs between 2009 and 2012. About 2-10 x 10(6) cells per lesion were administered. When a lesion was treated twice, the total amount could run up to 20 x 10(6) cells. Pearson's chi-squared test was used to compare the effect of the injured structure on the success rate, as well as the effect of the age of the horse. Results: Based on repeated examinations, 40 horses (77%) returned to work on the same or a higher level based on information provided by the owner. Neither the injured structure nor the age of the horse had a statistically significant influence on the result. Conclusion: Overall, the results of treatment of some tendon and ligament injuries with eUCB-MSCs in clinical cases are promising.