MSC is safe and compatible
Compatibility - Donor MMSCs do not react with the patient's immune system, so they can be administered to any patient. This is due to the presence of a special protein on the surface of MMSCs, MHC-1. There are no reported cases of immune incompatibility with donor MMSCs during their therapeutic use.
Is there a risk of rejection?
Donor (allogeneic) mesenchymal multipotent stromal cells (MMSCs) do not react with the immune system and, therefore, do not pose a risk of allergic reactions or rejection.
MMSCs possess one important property: the ability to actively interact with and modify the activity of virtually all cells of the immune system (IS), creating an immunotolerant environment for both the MMSCs themselves and surrounding cells and tissues.
Their immunomodulatory properties allow MMSCs to be considered a safe means of overcoming pathological inflammatory processes and ensuring immune tolerance during organ transplantation and autoimmune diseases. MMSCs are capable of influencing immune system cells both directly and indirectly (through other immune cells). MMSCs exert their immunomodulatory effects through various mechanisms, including the secretion of soluble factors and cell-cell interactions with target cells.
Safety. MMSCs are unable to proliferate or transform in the body. They have only a paracrine effect – they produce growth factors, signaling molecules, etc., which reduce inflammation and activate regeneration. The use of this type of stem cell began in 1996, and as of 2020, no adverse events have been reported.
Is there a risk of cancer?
In 2013, a group of European scientists published a long-term safety study of MMSC infusion procedures used to treat orthopedic conditions. Between 1990 and 2006, 1,873 patients were treated with bone marrow-derived MMSCs. Patients were followed from the time of their first injection in 1990 until December 31, 2011, or the earliest date of death. This long period (an average of 12.5 years, ranging from 5 to 22 years) helped monitor the potential development of cancer. The primary outcome was to assess the risk of tumor development at sites treated with MMSCs. A secondary outcome was to assess the risk of cancer diagnosis at sites not treated with the cells. After reviewing 7,306 MRI images and 52,430 X-rays from 1,873 patients, not a single tumor was detected at sites treated with MMSCs.
The study showed no increased risk of cancer development over a mean follow-up period of 12.5 years.
There is no rational reason for this fear, other than that of an entirely different cell type (embryonic stem cell), which, although named the same (stem cell), can cause teratomas – hence the confusion!