Comparison of efficacy between HLA6/6- and HLA3/6-matched haploidentical hematopoietic stem cell transplant in T-cell-replete transplants between parents and children

[Chinese expert consensus on the diagnosis and treatment of acute graft-versus-host disease after hematopoietic stem cell transplantation (2024)]

Despite the continuous improvement in the efficacy of allogeneic hematopoietic stem cell transplantation (allo-HSCT), acute graft-versus-host disease (GVHD) remains a major complication and cause of death. In recent years, with the emergence of new drugs for the prevention and treatment of acute GVHD and the update of a series of clinical studies, there have been varying degrees of changes in the routine prevention and treatment regimens for acute GVHD. Based on the main research achievements and the accumulation of clinical experience in this field in recent years, this consensus further updates the "The Consensus on Allogeneic Hematopoietic Stem Cell Transplantation for Hematological Diseases in China-Acute Graft-Versus-Host Disease (2020) .

Th2 polarization in target organs is involved in the alleviation of pathological damage mediated by transplanting granulocyte colony-stimulating factor-primed donor T cells

Acute graft-versus-host disease (aGVHD) is caused by allo-activated donor T cells infiltrating target organs. As a regulator of immune function, granulocyte colony-stimulating factor (G-CSF) has been demonstrated to relieve the aGVHD reaction. However, the role of G-CSF-primed donor T cells in specific target organs is still unknown. In this study, we employed a classical MHC-mismatched transplantation mouse model (C57BL/6 into BALB/c) and found that recipient mice transplanted with G-CSF-primed T cells exhibited prolonged survival compared with that of the PBS-treated group. This protective function against GVHD mediated by G-CSF-primed donor T cells was further confirmed by decreased clinical and pathological scores in this aGVHD mouse model, especially in the lung and gut. Moreover, we found that T cells polarized towards Th2 cells and regulatory T cells were increased in specific target organs. In addition, G-CSF treatment inhibited inducible co-stimulator (ICOS) expression and increased the expression of tolerance-related genes in recipient mice. Our study provides new insight into the immune regulatory effects of G-CSF on T cell-mediated aGVHD, especially for its precise regulation in GVHD target organs.

Influence of the degree of donor bone marrow hyperplasia on patient clinical outcomes after allogeneic hematopoietic stem cell transplantation

This study evaluated the influence of the degree of donor bone marrow (BM) hyperplasia on patient clinical outcomes after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Twelve patients received allo-HSCT from hypoplastic BM donors between January 2010 and December 2017. Forty-eight patients whose donors demonstrated BM hyperplasia were selected using a propensity score matching method (1:4). Primary graft failure including poor graft function and graft rejection did not occur in two groups. In BM hypoplasia and hyperplasia groups, the cumulative incidence (CI) of neutrophil engraftment at day 28 (91.7% vs. 93.8%, P=0.75), platelet engraftment at day 150 (83.3% vs. 93.8%, P=0.48), the median time to myeloid engraftment (14 days vs. 14 days, P=0.85) and platelet engraftment (14 days vs. 14 days, P=0.85) were comparable. The 3-year progression-free survival, overall survival, CI of non-relapse mortality and relapse were 67.8% vs. 71.7% (P=0.98), 69.8% vs. 77.8% (P=0.69), 18.5% vs. 13.6% (P=0.66), and 10.2% vs. 10.4% (P=0.82), respectively. In multivariate analysis, donor BM hypoplasia did not affect patient clinical outcomes after allo-HSCT. If patients have no other suitable donor, a donor with BM hypoplasia can be used for patients receiving allo-HSCT if the donor Complete Blood Count and other examinations are normal.

Comparison of the clinical outcomes of hematologic malignancies after myeloablative haploidentical transplantation with G-CSF/ATG and posttransplant cyclophosphamide: results from the Chinese Bone Marrow Transplantation Registry Group (CBMTRG)

This study compared G-CSF/ATG and PTCy in myeloablative haploidentical hematopoietic stem cell transplantation (haplo-HSCT) for hematologic malignancies between January 2013 and March 2018 reporting to the Chinese Bone Marrow Transplantation Registry Group (CBMTRG). For each PTCy, G-CSF/ATG subjects (1:4) were selected using the nested case-pair method. In total, 220 patients including 176 in G-CSF/ATG group and 44 in PTCy group were analyzed. The incidences of 30-day neutrophil engraftment (88.6% vs. 96.6%, P=0.001), 90-day platelet engraftment (84.1% vs. 94.2%, P=0.04), the median time to neutrophil engraftment (17 days vs. 12 days, P=0.000) and platelet engraftment (22 days vs. 17 days, P=0.001) were significantly inferior in PTCy group. The incidences of grades 2-4 and 3-4 acute graft-versus-host disease (GVHD), chronic GVHD and severe chronic GVHD were comparable. Among G-CSF/ATG and PTCy groups, the 3-year progression-free survival, overall survival, cumulative incidences of nonrelapse mortality and relapse was 74.3% vs. 61% (P=0.045), 78.3% vs. 65.2% (P=0.039), 12% vs. 27.3% (P=0.008), and 14.9% vs. 11.7% (P=0.61), respectively. G-CSF/ATG can achieve better engraftment, PFS and OS, and lower incidence of NRM compared to PTCy in myeloablative haplo-HSCT for hematologic malignancies.