Optimizing Allogeneic Grafts in Hematopoietic Stem Cell Transplantation

Abstract

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is widely used in the treatment of hematological diseases. It is well known that allogeneic grafts play a key role in predicting transplantation prognosis. Hematopoietic stem cells (HSCs) are a functional part of grafts and are capable of reconstructing hematopoiesis and immunity, but purified HSCs have not been identified or isolated to date. In clinical practice, allogeneic grafts have been optimized to improve transplantation outcomes. The optimized grafts are considered to engraft successfully, reconstruct immunity rapidly, and exert a graft-vs-leukemia (GVL) effect without causing severe graft-vs-host disease (GvHD). In the last several decades, considerable efforts have been made in searching for optimized grafts based on different graft manipulation approaches and different graft sources. Currently, there is no uniform standard for optimized grafts in allogeneic transplantation. In the future, sorting out the cellular elements responsible for the effects of allo-HSCT might be a research direction for further optimization of grafts. In this review, we propose the concept of optimized grafts and summarize the recent advances made in the process of optimizing grafts.

Haploidentical donor stem cell transplantation had a lower incidence of bronchiolitis obliterans syndrome compared with HLA-matched sibling donor transplantation in patients with hematologic malignancies: Benefit from ATG?

“…A new finding in this study was that patients receiving mixed grafts had a lower risk of BOS than those who received PBSC grafts. This might be associated with lower incidences of GVHD in patients receiving mixed grafts ( 40 , 41 ).…”

MetaGut: Insights into gut microbiomes in stem cell transplantation by comprehensive shotgun long-read sequencing

“…Allogeneic hematopoietic stem cell transplantation (alloHSCT) is a potentially curative treatment for patients with high-risk hematological malignancies encompassing acute myeloid leukemia, high-risk myelodysplastic syndromes (MDS), and lymphoid leukemia (Rafiee et al 2021, Xu and Huang 2021). It is well-established that the gut bacteriome has an influence on the outcome of alloHSCT, including the occurrence of adverse events such as graft-versus-host-disease (GvHD) or life-threatening infections.…”

DNA methylation of hematopoietic stem/progenitor cells from donor peripheral blood to patient bone marrow: implications for allogeneic hematopoietic stem cell transplantation

“…This last one can include myeloablative, non-myeloablative and reduced intensity conditioning and it is essential in eradicating the primary cause of disease, facilitating donor cell engraftment and avoiding transplant rejection via immunosuppression [ 2 ]. Allograft stem cell source is mainly represented by bone marrow (BM)- and mobilized peripheral blood (mPB)-derived cells; moreover, an alternative source consists in umbilical cord blood [ 3 , 4 ]. In general, selection of HSPC origin is closely related to donor availability, patient’s age, disease and other clinical characteristics [ 5 , 6 ].…”

“…However, in the last years, mPB-HSCT significantly increased, accounting for 70% of adult and 30% of children transplants [ 7 ], probably due to an easy sourcing of HSPCs, a rapid engraftment of cells and their possible use in non-ablative regimens [ 4 , 8 ]. Despite the great progress made in recent years including refinement of donor selection, adverse reactions, such as graft-versus-host disease (GvHD), infections and relapse of the underlying disease, still represent a major cause of mortality in transplanted patients [ 5 ].…”