Purpose of review: The aim of the present review was to give a critical opinion on the use of mesenchymal stromal cells (MSCs) to treat or to prevent graft-versus-host disease (GVHD).
Recent findings: The first part includes a summary of the many clinical trials published so far either to prevent or to treat GVHD in recipients of haematopoietic stem cell transplantation. We discuss in more detail a comparison in a subgroup of studies, including our own clinical work, which have in common the use of the platelet lysate to expand the MSCs from bone marrow origin.In the second part, we describe a few crucial elements of the biology of the GVHD and the biology of the MSCs themselves, showing their possible role in the immune modulation and in the inflammation in several in-vivo experimental models.
Summary: The complexity of the clinical condition that is the object of the trials and the paucity of information on the mechanisms of action in vivo of MSCs at different anatomical sites and in different times of the development of the disease preclude at the moment the identification of a strong rationale for MSC therapeutic schedule. Moreover, the typical development of GVHD requires different time points of clinical evaluation than those previously generally utilized in studies conducted on MSCs.