Mesenchymal stromal cells for prevention and treatment of graft-versus-host disease: successes and hurdlesIntrona, Martino; Rambaldi, AlessandroCurrent Opinion in Organ Transplantation: February 2015 - Volume 20 - Issue 1 - p 72–78 doi: 10.1097/MOT.0000000000000158 STEM CELL TRANSPLANTATION: Edited by Giuseppe Remuzzi Abstract Author Information 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. USC Ematologia, Azienda Ospedaliera Papa Giovanni XXIII, Bergamo, Italy Correspondence to Martino Introna, Centro di Terapia Cellulare ‘G. Lanzani’, via Garibaldi 11/13, 24124 Bergamo, Italy. Tel: +39 035 227 8636; fax: +39 035 227 8674; e-mail: email@example.com Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.