AUTHOR=Carlier Stephanie , Depuydt Eva , Van Hecke Lore , Martens Ann , Saunders Jimmy , Spaas Jan H. 

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

JOURNAL=Frontiers in Veterinary Science

VOLUME=11

YEAR=2024

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2024.1282697

DOI=10.3389/fvets.2024.1282697

ISSN=2297-1769

ABSTRACT=<sec id="sec1"><title>Background</title><p>Mesenchymal stem cells provide a valuable treatment option in orthopedic injuries in horses.</p></sec><sec id="sec2"><title>Objectives</title><p>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.</p></sec><sec id="sec3"><title>Methods</title><p>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 (<italic>n</italic> = 9) or no treatment (<italic>n</italic> = 9).</p></sec><sec id="sec4"><title>Results</title><p>The tpMSCs did not provoke a cellular immune response (<italic>p</italic> &lt; 0.001) and were able to immunomodulate stimulated T lymphocytes (<italic>p</italic> &lt; 0.001) <italic>in vitro</italic>. Therapeutic use of tpMSCs did not result in relevant hematologic or biochemical abnormalities.</p></sec><sec id="sec5"><title>Main limitations</title><p>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.</p></sec><sec id="sec6"><title>Conclusion</title><p>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.</p></sec>