- Appearance in the peripheral blood of regulatory T cells in a percentage higher than 80% in patients receiving peri-transplant MSC infusion as compared to patients receiving the immunosuppressive therapy alone and reversal of the inhibition of donor-specific immune response (evaluated by depletion of specific regulatory cells in ELISPOT and/or MLR assays) in a percentage higher than 50% in MSC-treated as compared with non MSC-treated patients.