Safety assessment of equine allogeneic tenogenic primed mesenchymal stem cells in horses with naturally occurring tendon and ligament injuries.

Abstract

BACKGROUND: Mesenchymal stem cells provide a valuable treatment option in orthopedic injuries in horses. OBJECTIVES: The aim of this study was to evaluate the hematological, biochemical, immunological and immunomodulatory parameters following intralesional treatment with tenogenic primed equine allogeneic peripheral blood-derived mesenchymal stem cells (tpMSCs) in client-owned horses with naturally occurring superficial digital flexor tendon (SDFT) and suspensory ligament (SL) injuries. METHODS: The immunogenicity and immunomodulatory capacities of tpMSCs were assessed in a modified mixed lymphocyte reaction, including peripheral blood mononuclear cells (PBMCs) of 14 horses with SDFT and SL injuries after treatment with tpMSCs. In a second study, 18 horses with SDFT and SL injuries received either an intralesional injection with tpMSCs (&#x2009;=&#x2009;9) or no treatment (&#x2009;=&#x2009;9). RESULTS: The tpMSCs did not provoke a cellular immune response (&#x2009;<&#x2009;0.001) and were able to immunomodulate stimulated T lymphocytes (&#x2009;<&#x2009;0.001). Therapeutic use of tpMSCs did not result in relevant hematologic or biochemical abnormalities. MAIN LIMITATIONS: Both studies had a small sample size. No statistical analyses were performed in the second study. Fibrinogen was only analyzed in a single horse prior to treatment. CONCLUSION: Co-incubation of tpMSCs and PBMCs of horses that have been previously exposed to tpMSCs did not elicit a cellular immune response and tpMSCs were able to immunomodulate stimulated T lymphocytes. Intralesional treatment with tpMSCs did not provoke abnormal changes in hematological and biochemical parameters.