- Percentage of inhibition of memory T cell response (by IFN-gamma ELISPOT) and/or naïve T cell response (by MLR) versus donor antigens higher than 15-20% in patients receiving peri-transplant MSC infusion as compared to patients receiving the immunosuppressive therapy alone, in the context of normal immune responses versus third party antigens, mitogens (PHA) and recall antigens (mumps, pertussis).