Current Trends in Transplantation of Patients with Hematological Malignancies

Hematopoietic stem cell transplantation (HSCT) is widely used to treat hematological malignancies and nonmalignant hematological disorders. Many advances have been made in improving the success of bone marrow transplantation. However, lack of available matched related or matched sibling donors has posed a significant challenges to the availability and proper utilization of hematopoietic stem cell transplantation in patients with hematological malignancies. The rising availability of alternative donors, particularly haploidentical donors (HIDs), has propelled the rapid rise of allo-HSCT. The aim of this review is to highlight and evaluate the recent advances in the development of HSCT, focusing mainly on the selection of suitable hematopoietic stem cell donors, HID-HSCT and some current advances in the use of umbilical cord blood cells as an alternative graft source. Haplo-HSCT has shown a promising result and better outcomes due to the number of advantages, including a wide range of stem cell sources, increased GVL effects, improved immunologic reconstitution, and positive clinical outcomes. In the near future, haplo-HSCT is likely to be considered as a better option for patient donor selection particularly in AML patients while HLA matching is unlikely to be the most important factor in AML patient donor selection.  In addition, the use of umbilical cord blood cells has shown a promising role as an alternative source of HSCT even with other available sources such as bone marrow and peripheral blood. Other transplantation procedures, such as T-cell depletion allografts, Post-transplant cyclophosphamide (PTCY), G-CSF-mobilized allografts, and antithymocyte globulin, have contributed to significant improvements in haplo-HSCT outcomes in recent decades.