Hastening post-transplant immune reconstitution is a key challenge in HLA-haploidentical haematopoietic stem cell transplantation (HSCT). In experimental models of mismatched HSCT T regulatory cells (Tregs), when coinfused with conventional T cells (Tcons), favoured post-transplant immune reconstitution and prevented lethal GvHD. The present study evaluated the impact of early infusion of Tregs, followed by Tcons, on GvHD prevention and immunological reconstitution, in 28 patients with high risk haematological malignancies who underwent HLA-haploidentical HSCT. We show for the first time in humans that adoptive transfer of Tregs prevented GvHD in the absence of any post-transplant immunosuppression, promoted lymphoid reconstitution, improved immunity to opportunistic pathogens and did not weaken the Graft vs Leukaemia effect. This study provides evidence that Tregs are a conserved mechanism in human beings.
- Submitted October 6, 2010.
- Accepted December 14, 2010.
- Copyright © 2005 American Society of Hematology