Umbilical Cord-Derived Mesenchymal Stromal Cells (MSCs) for Knee Osteoarthritis

Osteoarthritis (OA) is the most common form of arthritis and occurs as a result of the protective cartilage, found on the ends of the bones, degenerates over time. While OA can occur in any joint, it is most commonly found to occur in the hands, hips, spine, and knee.

An estimated 365 million people worldwide are currently living with some form of knee OA. Although there have been improvements in conventional treatment methods that have shown some benefit, there is no therapy or drug that can prevent or treat the development of OA in the knee.

Recent phase I/II trials using mesenchymal stromal cells (MSCs) derived from bone marrow (BM) and adipose tissue have demonstrated the feasibility, safety, and clinical and structural improvements in focal or diffuse disease.

Considering the findings of these phase I/II trials, Orrego et al. conducted this study to better assess the safety and efficacy of the intra-articular injection of single or repeated umbilical cord-derived (UC) MSCs in knee OA.

The target population of this study was individuals between the ages of 40-65 with symptomatic knee pain for at least 3 months with grade 1-3 Kellgren-Lawrence radiographic changes in the targeted knee, without meniscus rupture.  

The authors divided participants of this study into three specific groups, a control group which received intra-articular knee injections of hyaluronic acid (HA) at baseline and 6 months; the MCS-2 group, which received UC-MSCs at baseline and 6 months; and the MSC-1 group, who received UC-MSCs at baseline followed by placebo injection at 6 months. 

At the conclusion of this study’s 12 months follow-up period, Orrego et al. found that the group with repeated UC-MSC intra-articular injections, or MCS-2, experienced significant clinical changes in total WOMAC, pain component, and VAS when compared with the control group. The authors also found that only patients in the MSC groups experienced significant amelioration of pain and disability at 6 and 12 months. The authors also reported no safety signals were detected in the experimental groups as compared with the HA controls. 

Considering these findings, the authors conclude that the use of MSCs produces anti-inflammatory properties in response to tissue damage or inflammation that demonstrates suppressive effects on the maturation of dendritic cells, macrophages, Natural Killer, and cytotoxic T-lymphocytes.  

While these results appear promising, the authors point out that even if all MSC trials report a good safety record and improvements in cartilage quality, the use of autologous cell therapy does come with some limitations. Among these limitations include a dramatic decline of bone precursor cells when these cells are derived from bone marrow. Studies have also shown reduced chondrogenic activity of MSCs in cultures obtained from individuals with advanced forms of OA. For these reasons, and considering the findings in this study, the authors highlight that allogeneic sources of MSCs have been shown to express superior clonogenicity, migration, and paracrine capacities. 

The authors conclude that the repeated UC-MSC dose strategy utilized in this study led to a favorable safety profile and improved clinical results for the treatment of long-term pain in knee OA patients.

Source: Jose Matas, Mario Orrego, Diego Amenabar, Catalina Infante, Rafael Tapia-Limonchi, Maria Ignacia Cadiz, Francisca Alcayaga-Miranda, Paz L. González, Emilio Muse, Maroun Khoury, Fernando E. Figueroa, Francisco Espinoza, Umbilical Cord-Derived Mesenchymal Stromal Cells (MSCs) for Knee Osteoarthritis: Repeated MSC Dosing Is Superior to a Single MSC Dose and to Hyaluronic Acid in a Controlled Randomized Phase I/II Trial, Stem Cells Translational Medicine, Volume 8, Issue 3, March 2019, Pages 215–224, https://doi.org/10.1002/sctm.18-0053