MSCs are multipotent adult stem cells capable of differentiating into various cell types such as chondrocytes (cartilage cells). Additionally, they release bioactive molecules collectively known as the secretome, which help regulate inflammation, repair tissues, and promote joint regeneration.
Why use allogeneic cells?Homogeneity and youth: They come from young donors, giving them higher quality and regenerative capacity compared to cells derived from older or sick patients. Convenience: They are ready to use and do not require extraction or cultivation from the patient.This demonstrates advantages over autologous (patient-derived) cells, especially in older individuals or those with metabolic diseases (source: sciencedirect.com).
How do these cells act in the knee?
● Reduction of inflammation: They secrete molecules such as PGE2, IL‑10, and IDO that modulate the immune response, activating anti-inflammatory macrophages (M2 phenotype) and calming chronic inflammation.
● Cartilage protection and regeneration:
○ They promote chondrocyte survival through the HGF growth factor. (Cartilage cells live longer.)
○ They release exosomes with microRNAs that stimulate cartilage matrix synthesis and reduce its breakdown. (They improve the cartilage tissue environment and prevent further cell death.)
○ They enhance mitochondrial health and reduce oxidative stress in chondrocytes. (Reducing the stress on these cells and creating a better environment for them.)
○ They stimulate bone repair in the subchondral bone, reinforcing joint support.
Clinical EvidenceNumerous studies have shown promising results:
● Meta-analysis (2020): A review of 11 studies (558 patients) concluded that MSCs significantly reduce pain (VAS) and improve joint function (WOMAC), without increasing adverse events.Sources: aiche.onlinelibrary.wiley.com, sciencedirect.com, ncbi.nlm.nih.gov
● Randomized study with allogeneic MSCs (30 patients): Compared MSC injections to hyaluronic acid. The MSC group showed greater improvement in pain, function, and cartilage quality on MRI after one year.Source: mdpi.com
● Long-term studies using placenta-derived MSCs (allogeneic): Showed functional and structural cartilage improvements with no major complications, even up to 7 years post-injection.
● Recommended Dose: Doses ranging from 50M to 100M per session have shown significant improvement in the joint, often avoiding the need for additional sessions within the first year of treatment.
How do they delay surgery?
● Pain relief and functional improvement: Many patients reduce or stop painkillers and regain mobility within 6 to 12 months.
● Cartilage regeneration: Quantitative MRIs show increased cartilage thickness and quality.
● Prevention of complications and structural enhancement: By improving the subchondral bone and reducing inflammation, progressive joint damage is
slowed.This helps delay or even avoid the need for knee replacement, especially in intermediate stages of the disease.
Safety and Side EffectsStudies show high tolerance:
● No serious adverse effects have been reported following intra-articular injection of allogeneic MSCs.
● Some patients may experience mild fever or temporary knee discomfort, with no major consequences.
Conclusion
Allogeneic mesenchymal stem cells offer an innovative approach to treating knee osteoarthritis. They act through anti-inflammatory and regenerative mechanisms that:
● Relieve pain and improve mobility.
● Promote recovery of cartilage and subchondral bone.
● May delay joint replacement surgery.They are backed by clinical studies and scientific reviews. While research is ongoing, this therapy represents a safe and promising alternative for patients looking to avoid surgery.
Sources:
● https://www.sciencedirect.com/science/article/pii/S2214031X20300450?utm
● https://aiche.onlinelibrary.wiley.com/doi/10.1002/btm2.10701?utm
● https://pubmed.ncbi.nlm.nih.gov/25822648/
● https://josr-online.biomedcentral.com/articles/10.1186/s13018-023-04131-7?utm
