Allogeneic Versus Autologous Injectable Mesenchymal Stem Cells For Knee Osteoarthritis: Review And Current Status

Background: Osteoarthritis (OA) is the leading cause of joint disease in the United States. Conventional conservative interventions are often ineffective in providing long-term improvements in pain and function, and mesenchymal stem cell (MSC) therapy provides a promising treatment option. The traditional source of MSCs was of autologous origin; however, allogeneic MSC treatments are gaining popularity. Objectives: To review the current literature and perform a best evidence synthesis regarding the use of injectable allogeneic and autologous MSCs for the treatment of knee OA. Results: Although many studies were limited by sample size and lack of a control group, there were 19 studies that assessed injectable MSC therapy for knee OA, and most shown potential to improve pain and function. There were no studies that compared autologous versus allogeneic MSC injections, and only 1 study that compared adipose-derived versus bone marrow-derived MSC injections that showed significant improvements in pain and function but no significant differences between injection groups. Conclusions: MSC therapies in the treatment of knee OA are safe and have shown promising results but the available studies are limited. At this time, no definitive recommendations can be made regarding which MSC source to use. Allogeneic MSCs offer theoretical advantages over autologous MSCs, especially in ease of use and consistency of product, but there are concerns regarding cell viability and vitality, as well as the body's response to nonautologous products. Future clinical trials should focus on randomized head-to-head comparisons of MSC sources as well as the use of multiple injections for patients with knee OA.