Recent progress in haploidentical transplantation: is this the optimal choice for alternative donor transplantation?

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?

Background

Haploidentical donor stem cell transplantation (HID-SCT) based on antithymocyte globulin (ATG) for graft-versus-host disease (GVHD) prophylaxis had achieved a similar incidence of chronic graft-versus-host disease (cGVHD) with human leukocyte antigen (HLA)-matched sibling donor stem cell transplantation (MSD-SCT). However, bronchiolitis obliterans syndrome (BOS), which serves as pulmonary cGVHD, was rarely compared between HID and MSD transplantation.

Methods

One thousand four hundred five patients with hematologic malignancies who underwent allogeneic SCT were enrolled in this retrospective study. Based on donor type, we divided the patients into three groups: HID, MSD, and match unrelated donor (MUD) groups. The cumulative incidences and risk factors of BOS were analyzed.

Results

The 5-year cumulative incidence of BOS was 7.2% in the whole population. HID transplantation had a lower 5-year cumulative incidence of BOS than MSD transplantation (4.1% vs. 10.0%, p < 0.001) and a similar incidence with MUD transplantation (4.1% vs. 6.2%, p = 0.224). The 5-year cumulative incidence of BOS was lower in the ATG group than that in the non-ATG group in both the whole and MSD populations (4.6% vs. 11.2%, p < 0.001, and 4.1% vs. 11.2%, p = 0.042, respectively). The 5-year incidence of BOS in mixed grafts [peripheral blood stem cell (PBSC) plus bone marrow] group was also lower than that in the PBSC group (4.2% vs. 9.1, p = 0.001). Multivariate analysis showed that HID, ATG, and mixed grafts were protective factors for BOS [odds ratio (OR) 0.3, 95% CI 0.2–0.6, p < 0.001; OR 0.3, 95% CI 0.2–0.7, p = 0.001; OR 0.3, 95% CI 0.1–0.8, p = 0.013], and acute graft-versus-host disease (aGVHD) and cGVHD were independent risk factors for BOS (OR 2.1, 95% 1.1–4.3, p = 0.035; OR 10.1, 95% CI 4.0–25.0, p < 0.001).

Conclusions

HID transplantation had a lower incidence of BOS than MSD transplantation, which might be associated with ATG and mixed grafts.

Pediatric acute myeloid leukemia patients with KMT2A rearrangements: a single-center retrospective study

PURPOSE

Pediatric acute myeloid leukemia (AML) with KMT2A rearrangements has a very different prognosis. Poor outcomes cannot be avoided even after hematopoietic stem cell transplantation. In order to investigate the prognosis and efficacy, we conducted a retrospective analysis.

PATIENTS AND METHODS

We retrospectively analyzed a total of 32 children with KMT2A rearrangements AML treated in our hospital between January 2015 and February 2021.

RESULTS

The proportion of patients with KMT2A-rearranged in the medium-risk group of overall survival (OS) and event-free survival (EFS) was 100%. No differences in OS, EFS and cumulative incidence of relapse (CIR) were detected between the haploidentical hematopoietic stem cell transplantation (haplo-HSCT) and full matched HSCT (P = 0.289, P = 0.303, P = 0.303). Acute graft-versus-host disease (aGVHD) was often detected in the haplo-HSCT cohort, while full matched HSCT had no obvious aGVHD, assessed as≤1 grade (P < 0.05). Patients in the medium-risk pediatric group could acquire 100% OS and EFS only after chemotherapy. There was no significant difference in OS, EFS and CIR between full matched HSCT and haploidentical transplantation in pediatric AML with KMT2A rearrangements, but full matched HSCT seemed to have a lower death rate. The severity of aGVHD in the full matched HSCT was less than that in the haploidentical transplantation group.

CONCLUSION

The primary choice of donor can be HLA-matched sibling donors or matched unrelated donors for children with AML with KMT2A rearrangements, and the secondary choice can be haploid donors.

Psychosocial outcomes of parents in pediatric haploidentical transplant: parental hematopoietic cell donation as a double-edged sword

Parents are increasingly used as donors for their child's haploidentical hematopoietic cell transplant, creating a dual role for parents that may increase the stress of caring for their ill child. Empiric research on the psychological adjustment of parental donors is lacking. We conducted a retrospective survey of parents (n = 136) whose child underwent transplant with a parental donor or a matched-unrelated donor, including both donor and nondonors, and both parents of survivors and bereaved. All parents completed standardized measures of quality of life, depression, anxiety, post-traumatic stress, and life satisfaction. Bereaved parents also completed measures of their grief response, while parents of survivors completed measures of the parent-child relationship. The overall sample reported psychological functioning near normative levels, but bereaved parents demonstrated significantly poorer outcomes across all measures. The effect of donor status differed by transplant outcome: for parents of survivors, donors reported better mental health than nondonors, but amongst bereaved parents, donors fared more poorly than nondonors. Bereaved donors reported greater difficulties with grief than nondonors. Results suggest that serving as donor can be a double-edged sword, acting as a protective factor when there is a successful outcome but a significant risk factor when the child does not survive.

Successful Salvage Haploidentical Bone Marrow Transplantation in a Child With Hemophagocytic Lymphohistiocytosis, When the Previously Matched Unrelated Donor Tested Positive for SARS-CoV-2 on the Day of Stem Cells Collection

The coronavirus disease 2019 pandemic has made us adjust our standards and cope with unpredictable circumstances affecting the whole world, including the medical field.

A 2-year-old boy diagnosed with X-linked lymphoproliferative disease type 2 with concomitant positive polymerase chain reaction test for Epstein-Barr virus–DNA was admitted to our transplant ward. His treatment scheme had to be modified at the last moment because of a donor disqualification due to a positive polymerase chain reaction result for severe acute respiratory syndrome coronavirus 2 just before the apheresis. We decided to perform salvage haploidentical bone marrow transplant from the patient's mother because it was the only possible option. Now, in a 5-month observation period after the hematopoietic stem cell transplantation, our patient is in good general condition. His case convinced us to redirect our approach to transplant procedure preparation. Following the European Group of Blood and Marrow Transplantation recommendations, we use cryopreserved apheresis materials to ensure the availability of stem cell products before the start of a conditioning regimen.

Prevention and Treatment of Acute Graft-versus-Host Disease in Children, Adolescents, and Young Adults

Acute graft-versus-host disease (GVHD) continues to be a major cause of morbidity and mortality after allogeneic hematopoietic cell transplant (HCT) in pediatric patients (ie, children and adolescent and young adults) and limits broader application of the therapy. Pediatric HCT patients have faced major obstacles to access clinical trials that test new agents for GVHD prevention and treatment. According to a recent search, only 6 clinical trials of interventions for prevention or treatment of acute GVHD were conducted specifically in pediatric patients in the United States over the past decade, with 8 internationally. In this review, we summarize the studies that were performed and specifically enrolled and reported on pediatric patients after allogeneic HCT and provide a listing of studies currently under way.