MSCs in pediatric hematopoietic stem cell transplantation

Hematopoietic stem cell transplantation (HSCT) is an accepted treatment for some children with certain life-threatening conditions such as malignant diseases, immune deficiency, inborn errors of metabolism, bone marrow failure syndromes, and hemoglobinopathies. The introduction of alternative donor population such as cord blood and haploidentical transplantations has resulted in this treatment becoming more readily available. Inherent risks with alternative donor sources are mainly immune- mediated complications, with graft rejection or graft failure and graft-versus-host disease (GVHD) as main obstacles. Mesenchymal stromal cells (MSCs) through cell-to-cell interactions, production of growth factors, and secretion of matrix proteins play a vital role in the regulation of hematopoiesis and exhibit a wide range of immunomodulatory and anti-inflammatory properties in vitro and in vivo. Use of MSCs in phase I/II clinical studies with HSCT in children indicates that their infusion is safe and effective in preventing graft failure after T-cell-depleted allogeneic HSCT from an HLA-disparate relative as well as in rescuing patients with severe, steroid-refractory GVHD.