Study: Variable outcomes of stem cell injections for knee osteoarthritis

Knee osteoarthritis (KOA) affects more than one in ten individuals over 40 years old, leading to diminished mobility and diminished quality of life. Although stem cell injections have been promoted as a potential treatment, there remains a lack of clear evidence regarding their efficacy. The high variability in treatment outcomes is largely due to the source of mesenchymal stromal cells (MSCs) utilized in injections.

These cells can be sourced from various tissues like fat or bone marrow, and their quality and therapeutic potential can differ significantly among patients.

To address this variability, researchers from the Schroeder Arthritis Institute conducted a long-term follow-up of a Health Canada-approved phase I/IIa clinical trial involving twelve patients who received MSC injections derived from their own bone marrow. At the 12-month mark, six patients were classified as responders, experiencing at least a 20% improvement in both pain and knee mobility scores. At the 24-month follow-up, the majority of these responders maintained their positive results.

The team further investigated the characteristics of MSCs from both responders and nonresponders. They found that MSCs from responders exhibited a more potent anti-inflammatory effect and better regulation of immune cell reactivity compared to those from nonresponders. Additionally, 14 microRNAs, which play a role in regulating gene expression in cells, were identified as having varying quantities in the MSCs of responders versus nonresponders.

These findings suggest that laboratory tests on cultured MSCs could potentially predict their therapeutic potency, allowing for the selection of MSCs with enhanced efficacy for clinical use in KOA patients. However, the researchers emphasize the need for larger, controlled clinical trials to validate these findings and corroborate the potential of potency-based cell selection in the treatment of knee osteoarthritis.