Adoptive Immunotherapies After Allogeneic Hematopoietic Stem Cell Transplantation in Patients With Hematologic Malignancies

•How adoptive immunotherapies can help to manage the complications after hematopoietic stem cell transplantation (HSCT).•Strategies aiming at maximizing tumor-specific cytotoxic T-lymphocyte, regulatory T-cell, natural killer cell, cytokine-induced killer cell, and γδ T-cell efficacies to treat the graft-versus-host disease or relapse occurring after allogeneic HSCT are gathered in this review.•We focused our attention on the cross-talk between regulatory T cells and natural killer cells after HSCT.

Hematopoietic stem cell transplantation (HSCT) is the only curative therapy for patients with chemotherapy-resistant hematologic malignancies that are usually fatal in absence of treatment. Hematopoietic stem cell transplantation is associated with significant early and late morbidity and mortality. Graft-versus-host disease, infections, and relapse are the most important causes of mortality after HSCT. Until now, these complications have been managed mainly with pharmacological drugs, but in some situations, this approach clearly shows its limit. As such, there is a significant need for novel therapies for the treatment of complications after allogeneic HSCT. In this review, the currently available adoptive immunotherapies offering an alternative in case of treatment failure of HSCT complications will be described. The results of the main clinical trials based on immune cell infusion will be discussed and the strategies aiming at maximizing cytotoxic T-lymphocyte, regulatory T-cell, natural killer cell, cytokine-induced killer cell, and γδ T-cell efficacies in the context of immunotherapy approaches after allogeneic HSCT in patients with hematologic malignancies will be gathered.