Critical Considerations for Mesenchymal Stem Cell-based Therapies in Osteoarthritis and Spinal Cord Injury: A Narrative Review

Mesenchymal stem cells (MSCs) have been proposed as treatments for degenerative diseases, but clinical outcomes have been inconsistent. Here, we reviewed the ClinicalTrials.gov database and identified ~1,600 trials associated with MSC-based therapies; osteoarthritis (OA) and spinal cord injury (SCI) were most frequently investigated, but the reporting of results was consistently low (<7%). We next searched the PubMed database and identified 26 OA and 16 SCI published trials, which included studies from one or both databases. Our analysis identified a common set of factors that influenced therapeutic efficacy in both diseases, including MSC source, donor type, dose/route & frequency of administration, and patient variation. Of these, three factors were significant for improving efficacy. MSC quality is affected by age of the donor, and this is especially important when treating older OA patients with autologous MSCs. Phase of the disease is important, and both OA and SCI may benefit from early treatment, since MSCs can ameliorate inflammation and initiate tissue repair. MSC source is critical as allogenic MSCs are no longer considered "immune privileged", and autologous cells can differentiate and repair damaged tissue without immune interference. The results of this narrative literature review suggest that establishing a personal autologous MSC bank may be an essential component for achieving success with MSC-based therapies, since MSCs from this repository could be deployed early, ameliorate inflammation, and initiate repair of damaged tissues.