Mesenchymal stem cell therapy for knee osteoarthritis: 5years follow-up of three patients

AimOsteoarthritis is a degenerative joint disease characterized by the destruction of joint cartilage. Mesenchymal stem cells (MSCs) are found in low numbers in normal cartilage, mainly in the superficial layer, acting as repairing agents. In OA, MSCs are seen in larger numbers, but act chaotic and are unable to repair the cartilage. The synovial membrane becomes inflamed and interacts with the cartilage. Transplanted MSC have the ability to normalize them, redirecting them to their normal function. In a preliminary study, we showed that MSC could improve knee OA in four patients at 6months. This report shows their long-term follow-up at 5years. MethodsOne patient was lost to follow-up at 2years and three were followed for 5years. They were aged 55, 57, 65 and 54years, and had moderate to severe knee osteoarthritis. The worse knee of each patient was injected with 8-9x10(6) MSC. ResultsAs previously reported, all parameters improved in transplant knees at 6months (walking time, stair climbing, gelling pain, patella crepitus, flection contracture and the visual analogue score on pain). Then, they started gradually to deteriorate, but at 5years they were still better than at baseline. PGA (Patient Global Assessment) improved from baseline to 5years. The better knee at baseline (no MSC), continued its progression toward aggravation and at 5years became the worse knee. ConclusionTransplant knees were all in a rather advanced stage of OA. Earlier transplantation may give better results in long-term follow-up. This is what future studies have to demonstrate.