Update on the Use of Mesenchymal Stem Cells and their Products in Hematopoietic Stem Cell Transplantation

Graft Versus Host Disease (GVHD) is a major limitation to the success of allogeneic Hematopoietic Stem Cell Transplantation (HSCT) as Steroid-Refractory (SR) acute GVHD carries poor prognosis due to the absence of an efficacious second-line therapy. Mesenchymal Stem Cells (MSCs) which have immunosuppressive, immunomodulatory, and regenerative properties may become a highly effective therapeutic modality for SR-GVHD in the near future. MSCs have already been approved to treat childhood SR-GVHD in Japan, and they have been conditionally licensed in New Zealand and Canada. It is expected that MSCs will be approved for the treatment of SR-GVHD in adults in Europe, North America, and other parts of the world within a few years. Utilization of the recently introduced techniques including the use of MSC products such as exosomes and Extracellular Vesicles (ECVs) instead of the parent MSCs, robotic manufacturing technology, and genetic engineering of MSCs will ultimately overcome the remaining obstacles facing the widespread utilization of MSCs and their products as therapeutics not only in HSCT but also in other medical fields. The aim of this review is to provide an update on the remarkable progress achieved in the use of MSCs and their products in the field of HSCT.