Outcome of Children Developing Grade III-IV Acute Graft-Versus-Host Disease after Allogeneic Hematopoietic Stem Cell Transplantation

Acute graft versus host disease (aGvHD) remains one of the major causes of procedure-related morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). Information on the outcome of pediatric patients experiencing this complication is limited. We conducted a retrospective registry-based analysis on children who developed grade III-IV acute GVHD and were reported to the European Blood and Marrow Transplantation (EBMT) registry. Included in the study were children below age of 18 years who were transplanted between 2004 and 2016 (n=28109). Of these children, 1968 experienced grade III-IV acute GvHD: 1370 were had malignancies, while 598 were affected by a non-malignant disorder (NMD). Median year at HSCT was 2009 for patients with malignancies and 2010 for patients with NMD. In this latter group, as expected, the median age at HSCT was lower (5.8 years), in comparison with those affected by malignancies (9 years). The donor was an HLA-identical sibling in 576 cases and an unrelated donor in 895 cases. Umbilical cord blood (UCB) was employed in 282 cases, while a relative other than a compatible sibling in 215 cases. Overall, 1075 patients were given bone marrow (BM), while 598 received peripheral blood stem cells (PBSC). A fully myeloablative conditioning regimen has been employed in 94% of patients with malignancies in comparison with 75% of children with NMD. As a post-transplant pharmacological GvHD prophylaxis, a different strategy of immune suppressive treatment have been used: it consisted in the association of Cyclosporine-A (CSA) and Methotrexate in 40%, CSA alone in 30% and CSA plus Mycophenolate mofetil in 10% of patients. Grade III aGvHD occurred in 1383 patients (70%), while grade IV aGvHD was diagnosed in 585 (30%). Chronic GvHD occurred in 48.2% and 49.3% of patients with malignant and NMD, respectively. It was extensive in 262 (26.8%) patients with malignancies and in 111 (28%) children affected by NMD. Within patients with malignancies, the 2-year Kaplan-Meyer probability of overall survival (OS) was 65.7% (confidence interval 95, 63 - 68.4). In this group, the cumulative incidence of non-relapse mortality (NRM) was 23.1%. Notably, the occurrence of GvHD was responsible of death in 228 patients (CI 14.5%). In the NMD cohort, the 2-year Kaplan-Meyer probability of overall survival (OS) was 67.8% (confidence interval 95, 63.8 - 71.9). Sixty-one patients died to GvHD, being the 2-year cumulative incidence of GvHD-related mortality 19%. These data indicate that the occurrence of grade III-IV aGVHD is associated with a dismal outcome also in pediatric patients. The main cause of fatality is represented by NRM, while leukemia recurrence affected outcome of a lower number of children. Thus, strategies aimed at preventing this immune-mediated complication and at optimizing its treatment are desirable

Allogeneic Stem Cell Transplantation From HLA-Mismatched Donors for Pediatric Patients with Acute Lymphoblastic Leukemia Treated According to the 2003 BFM and 2007 International-BFM Studies: Impact of Disease Risk on Outcomes.

Summary Rational Allogeneic HSCT is beneficial for pediatric patients with relapsed or (very) high-risk ALL in remission. A total of 1115 consecutive patients were included in the ALL SCT 2003 BFM study and the ALL SCT 2007-International study and were stratified according to relapse risk (Standard vs. High vs. Very High Risk of Relapse) and donor type (Matched Sibling vs. Matched Donor vs. Mismatched Donor). Patients and methods A total of 148 patients (60% male, median age 8.7 years; B-cell precursor ALL: 75%) were transplanted from MMD, which was defined as either less than 9/10 HLA-compatible donors or less than 5/6 unrelated cord blood after myelo-ablative conditioning regimen (TBI-based: 67%) for HRR (n=42) or VHRR disease (n=106). The stem cell source was either BM (n=31), unmanipulated PBSCs (n=28), T-cell ex vivo depleted PBSCs (n=59) or cord blood (n=25). The median follow-up was 5.1 years. Results The 4-year OS and EFS was 56±4% and 52±4%, respectively, for the entire cohort. Patients transplanted from MMD for HRR disease obtained remarkable 4-y OS and EFS values of 82±6% and 80±6%, respectively, while VHRR patients obtained values of 45±5% and 42±5% (p Conclusion HSCT with a mismatched donor is feasible in pediatric ALL patients but leads to inferior results compared to HSCT with better matched donors, at least for patients transplanted for VHRR. The results are strongly affected by disease status. The main cause of treatment failure is still relapse, highlighting the urgent need for interventional strategies after HSCT for patients with residual leukemia before and/or after transplantatio

The impact of donor type on the outcome of pediatric patients with very high risk acute lymphoblastic leukemia. A study of the ALL SCT 2003 BFM-SG and 2007-BFM-International SG

Allogeneic HSCT represents the only potentially curative treatment for very high risk (VHR) ALL. Two consecutive international prospective studies, ALL-SCT-(I)BFM 2003 and 2007 were conducted in 1150 pediatric patients. 569 presented with VHR disease leading to any kind of HSCT. All patients >2 year old were transplanted after TBI-based MAC. The median follow-up was 5 years. 463 patients were transplanted from matched donor (MD) and 106 from mismatched donor (MMD). 214 were in CR1. Stem cell source was unmanipulated BM for 330 patients, unmanipulated PBSC for 135, ex vivo T-cell depleted PBSC for 62 and cord-blood for 26. There were more advanced disease, more ex vivo T-cell depletion, and more chemotherapy based conditioning regimen for patients transplanted from MMD as compared to those transplanted from MSD or MD. Median follow up (reversed Kaplan Meier estimator) was 4.99 years, median follow up of survivals was 4.88, range (0.01–11.72) years. The 4-year CI of extensive cGvHD was 13 ± 2% and 17 ± 4% (p = NS) for the patients transplanted from MD and MMD, respectively. 4-year EFS was statistically better for patients transplanted from MD (60 ± 2% vs. 42 ± 5%, p < 0.001) for the whole cohort. This difference does not exist if considering separately patients treated in the most recent study. There was no difference in 4-year CI of relapse. The 4-year NRM was lower for patients transplanted from MD (9 ± 1% vs. 23 ± 4%, p < 0.001). In multivariate analysis, donor-type appears as a negative risk-factor for OS, EFS, and NRM. This paper demonstrates the impact of donor type on overall results of allogeneic stem cell transplantation for very-high risk pediatric acute lymphoblastic leukemia with worse results when using MMD stem cell source

Despite mutation acquisition in hematopoietic stem cells, JMML-propagating cells are not always restricted to this compartment

Juvenile myelomonocytic leukemia (JMML) is a rare aggressive myelodysplastic/myeloproliferative neoplasm of early childhood, initiated by RAS-activating mutations. Genomic analyses have recently described JMML mutational landscape; however, the nature of JMML-propagating cells (JMML-PCs) and the clonal architecture of the disease remained until now elusive. Combining genomic (exome, RNA-seq), Colony forming assay and xenograft studies, we detect the presence of JMML-PCs that faithfully reproduce JMML features including the complex/nonlinear organization of dominant/minor clones, both at diagnosis and relapse. Further integrated analysis also reveals that although the mutations are acquired in hematopoietic stem cells, JMML-PCs are not always restricted to this compartment, highlighting the heterogeneity of the disease during the initiation steps. We show that the hematopoietic stem/progenitor cell phenotype is globally maintained in JMML despite overexpression of CD90/THY-1 in a subset of patients. This study shed new lights into the ontogeny of JMML, and the identity of JMML-PCs, and provides robust models to monitor the disease and test novel therapeutic approaches

GSTM1 and GSTT1 double null genotypes determining cell fate and proliferation as potential risk factors of relapse in children with hematological malignancies after hematopoietic stem cell transplantation.

PURPOSE This study aimed to retrospectively evaluate the genetic association of null variants of glutathione S-transferases GSTM1 and GSTT1 with relapse incidence in children with hematological malignancies (HMs) undergoing busulfan (BU)- containing allogeneic hematopoietic stem cell transplantation (HSCT) and to assess the impact of these variants on BU-induced cytotoxicity on the immortalized lymphoblastoid cell lines (LCLs) and tumor THP1 GST gene-edited cell models. METHODS GSTM1- and GSTT1-null alleles were genotyped using germline DNA from whole blood prior to a conditioning BU-based regimen. Association of GSTM1- and GSTT1-null variants with relapse incidence was analyzed using multivariable competing risk analysis. BU-induced cell death studies were conducted in GSTs- null and non-null LCLs and CRISPR-Cas9 gene-edited THP1 leukemia cell lines. RESULTS Carrying GSTM1/GSTT1 double null genotype was found to be an independent risk factor for post-HSCT relapse in 86 children (adjusted HR: 6.52 [95% Cl, 2.76-15.42; p = 1.9 × 10-5]). BU-induced cell death preferentially in THP1GSTM1(non-null) and LCLsGSTM1(non-null) as shown by decreased viability, increased necrosis and levels of the oxidized form of glutathione compared to null cells, while GSTT1 non-null cells showed increased baseline proliferation. CONCLUSION The clinical association suggests that GSTM1/GSTT1 double null genotype could serve as genetic stratification biomarker for the high risk of post-HSCT relapse. Functional studies have indicated that GSTM1 status modulates BU-induced cell death. On the other hand, GSTT1 is proposed to be involved in baseline cell proliferation

Low Body Mass Index Is Associated with Increased Risk of Acute GVHD after Umbilical Cord Blood Transplantation in Children and Young Adults with Acute Leukemia: A Study on Behalf of Eurocord and the EBMT Pediatric Disease Working Party

Abstract Body mass index (BMI) may influence outcomes after allogeneic hematopoietic stem cell transplantation (HSCT). However, the impact of BMI on survival in children undergoing HSCT is not well defined, with conflicting results being reported on this issue. We analyzed 855 patients age 2 to 20 years with diagnosis of acute leukemia who underwent umbilical cord blood transplantation (UCBT) from 1990 to 2015. Patients were classified according to BMI as normal (fifth to 85th percentile), underweight (less than fifth percentile), overweight (85th to 95th percentile), and obese (>95th percentile) using growth charts for age and sex. All patients received single-unit UCBT after a myeloablative conditioning regimen. Diagnosis was acute lymphoblastic leukemia in 68% of the patients. Sixty-one percent of patients (n = 523) were in the normal BMI category, 11% (n = 96) were underweight, 16% (n = 137) overweight, and 12% (n = 99) obese. The cumulative incidence of grade II to IV acute graft-versus-host disease (aGVHD) was 35% (32% to 38%). According to pretransplantation BMI, aGVHD was 46% (33% to 59%) for underweight, 34% (31% to 42%) for normal, 36% (18% to 38%) for overweight, and 27% (15% to 37%) for obese ( P  = .04). In multivariate analysis, a BMI less than the fifth percentile was associated with higher incidence of acute grade II to IV GVHD compared with normal-BMI patients (hazard ratio,  1.61; 95% confidence interval, 1.15 to 2.26; P  = .006). Our results show that being underweight at the time of transplantation is associated with an increased risk of aGVHD, highlighting the importance of nutritional status before UCBT

Supportive Care During Pediatric Hematopoietic Stem Cell Transplantation : Prevention of Infections. A Report From Workshops on Supportive Care of the Paediatric Diseases Working Party (PDWP) of the European Society for Blood and Marrow Transplantation (EBMT)

Specific protocols define eligibility, conditioning, donor selection, graft composition and prophylaxis of graft vs. host disease for children and young adults undergoing hematopoietic stem cell transplant (HSCT). However, international protocols rarely, if ever, detail supportive care, including pharmaceutical infection prophylaxis, physical protection with face masks and cohort isolation or food restrictions. Supportive care suffers from a lack of scientific evidence and implementation of practices in the transplant centers brings extensive restrictions to the child's and family's daily life after HSCT. Therefore, the Board of the Pediatric Diseases Working Party (PDWP) of the European Society for Blood and Marrow Transplantation (EBMT) held a series of dedicated workshops since 2017 with the aim of initiating the production of a set of minimal recommendations. The present paper describes the consensus reached within the field of infection prophylaxis.Peer reviewe

Diagnosis and severity criteria for sinusoidal obstruction syndrome/veno-occlusive disease in adult patients: a refined classification from the European society for blood and marrow transplantation (EBMT).

peer reviewedSinusoidal obstruction syndrome, also known as veno-occlusive disease (SOS/VOD), is a potentially life-threatening complication that can develop after hematopoietic cell transplantation (HCT). A new definition for diagnosis, and a severity grading system for SOS/VOD in adult patients, was reported a few years ago on behalf of the European Society for Blood and Marrow Transplantation (EBMT). The aim of this work is to update knowledge regarding diagnosis and severity assessment of SOS/VOD in adult patients, and also its pathophysiology and treatment. In particular, we now propose to refine the previous classification and distinguish probable, clinical and proven SOS/VOD at diagnosis. We also provide an accurate definition of multiorgan dysfunction (MOD) for SOS/VOD severity grading based on Sequential Organ Failure Assessment (SOFA) score

Prognostic impact of Epstein-Barr virus serostatus in patients with nonmalignant hematological disorders undergoing allogeneic hematopoietic cell transplantation: the study of Infectious Diseases Working Party of the European Society for Blood and Marrow Transplantation

BackgroundIn patients with acute leukemia, lymphoma and chronic malignancies, donor and/or recipient Epstein-Barr virus (EBV) seropositive status increases the risk of development of chronic graft-versus-host disease (cGVHD) after allo-hematopoietic cell transplantation (allo-HCT), while it has no influence on other transplant outcomes. No data are available on the impact of EBV serostatus on transplant outcomes in patients with nonmalignant hematological disorders. ObjectiveWe analyzed the influence of the recipient's (R) and donor's (D) EBV serostatus on transplant outcomes (overall survival (OS); relapse-free survival (RFS); relapse incidence (RI); nonrelapse mortality (NRM); acute graft-versus-host disease (aGVHD); cGVHD) in patients with nonmalignant hematological disorders undergoing allo-HCT. Patients and MethodsA total of 2,355 allo-HCTs performed between 1997 and 2016 for acquired bone marrow failure or hemoglobinopathies were included in this retrospective Registry megafile Infectious Diseases Working Party of the European Society of Blood and Marrow Transplantation (IDWP-EBMT) study. ResultsArray ConclusionsAllo-HCT from EBV-seropositive versus EBV-seronegative donors are at 31% higher risk of cGVHD in patients with nonmalignant hematological disorders undergoing allo-HCT; however this difference is nonsignificant in multivariate analysis