Multicenter Clinical Trial for the Evaluation of Mesenchymal Stem Cells From Adipose Tissue in Patients With Chronic Graft Versus Host Disease.

The main purpose of this trial is to assess the safety and feasibility of treatment with two-dose infusion of allogeneic mesenchymal stem cells from adipose tissue expanded in vitro in patients undergoing haematopoietic stem cell transplantation (HSCT, who have developed chronic and extensive graft versus host disease (GVHD). Mesenchymal stem cells (MSCs) express low levels of HLA class I molecules, and do not express class II molecules neither CD40, CD80 and CD86, being unable to induce proliferation of allogeneic lymphocytes. In addition, MSCs inhibit lymphocyte proliferation by inhibiting cell division and maintaining these cells in a quiescent state. This supports the hypothesis that MSCs are universal suppressors.