Haploidentical versus Cord Blood Transplantation in Pediatric AML. A Retrospective Outcome Analysis on Behalf of the Pediatric Subcommittee of GETH (Grupo Español de Trasplante Hematopoyético).

Haploidentical stem cell transplantation (Haplo-SCT) and cord blood transplantation (CBT) are both effective alternative treatments in patients suffering from acute myeloid leukemia (AML) and lacking a matched HLA donor. In the last years, many centers have abandoned CBT procedures mostly due to concern about poorer immune recovery compared with Haplo-SCT. We conducted a retrospective multicenter study comparing the outcomes using both alternative approaches in AML. A total of 122 transplants (86 Haplo-SCTs and 36 CBTs) from 12 Spanish centers were collected from 2007 to 2021. Median age at hematopoietic stem cell transplantation (HSCT) was 7 years (0.4-20). Thirty-nine patients (31.9%) showed positive minimal residual disease (MRD) at HSCT and a previous HSCT was performed in 37 patients (30.3%). The median infused cellularity was 14.4 × 106/kg CD34+ cells (6.0-22.07) for Haplo-SCT and 4.74 × 105/kg CD34+ cells (0.8-9.4) for CBT. Median time to neutrophil engraftment was 14 days (7-44) for Haplo-SCT and 17 days (8-29) for CBT (P = .03). The median time to platelet engraftment was 14 days (6-70) for Haplo-SCT and 43 days (10-151) for CBT (P < .001). Graft rejection was observed in 13 Haplo-SCTs (15%) and in 6 CBTs (16%). The cumulative incidence of acute graft versus host disease (GvHD) grades II-IV was 54% and 51% for Haplo-SCT and CBT, respectively (P = .50). The cumulative incidence of severe acute GvHD (grades III-IV) was 22% for Haplo-SCT and 25% for CBT (P = .90). There was a tendency to a higher risk of chronic GvHD in the Haplo-SCT group being the cumulative incidence of 30% for Haplo-SCT and 12% for CBT (P = .09). The cumulative incidence of relapse was 28% and 20% for Haplo-SCT and CBT, respectively (P = .60). We did not observe statistically significant differences in outcome measures between Haplo-SCT and CBT procedures: 5-year overall survival (OS) was 64% versus 57% (P = .50), 5-year disease-free survival (DFS) 58% versus 57% (P = .80), GvHD-free and relapse-free survival (GFRFS) 41% versus 54% (P = .30), and cumulative incidence of transplant-related mortality (TRM) 14% versus 15% (P = .80), respectively. In the multivariate analysis, MRD positivity and a disease status >CR1 at the time of HSCT were significantly associated with poorer outcomes (P < .05). In conclusion, our study supports that both haploidentical and cord blood transplantation show comparable outcomes in pediatric AML patients. We obtained comparable survival rates, although CBT showed a trend to lower rates of chronic GvHD and higher GFRFS, demonstrating that it should still be considered a valuable option, particularly for pediatric patients.

Diagnosis, treatment, and surveillance of Diamond-Blackfan anaemia syndrome: international consensus statement.

Diamond-Blackfan anaemia (DBA), first described over 80 years ago, is a congenital disorder of erythropoiesis with a predilection for birth defects and cancer. Despite scientific advances, this chronic, debilitating, and life-limiting disorder continues to cause a substantial physical, psychological, and financial toll on patients and their families. The highly complex medical needs of affected patients require specialised expertise and multidisciplinary care. However, gaps remain in effectively bridging scientific discoveries to clinical practice and disseminating the latest knowledge and best practices to providers. Following the publication of the first international consensus in 2008, advances in our understanding of the genetics, natural history, and clinical management of DBA have strongly supported the need for new consensus recommendations. In 2014 in Freiburg, Germany, a panel of 53 experts including clinicians, diagnosticians, and researchers from 27 countries convened. With support from patient advocates, the panel met repeatedly over subsequent years, engaging in ongoing discussions. These meetings led to the development of new consensus recommendations in 2024, replacing the previous guidelines. To account for the diverse phenotypes including presentation without anaemia, the panel agreed to adopt the term DBA syndrome. We propose new simplified diagnostic criteria, describe the genetics of DBA syndrome and its phenocopies, and introduce major changes in therapeutic standards. These changes include lowering the prednisone maintenance dose to maximum 0·3 mg/kg per day, raising the pre-transfusion haemoglobin to 9-10 g/dL independent of age, recommending early aggressive chelation, broadening indications for haematopoietic stem-cell transplantation, and recommending systematic clinical surveillance including early colorectal cancer screening. In summary, the current practice guidelines standardise the diagnostics, treatment, and long-term surveillance of patients with DBA syndrome of all ages worldwide.

Lentivirus-mediated gene therapy corrects ribosomal biogenesis and shows promise for Diamond Blackfan anemia.

This study lays the groundwork for future lentivirus-mediated gene therapy in patients with Diamond Blackfan anemia (DBA) caused by mutations in ribosomal protein S19 (RPS19), showing evidence of a new safe and effective therapy. The data show that, unlike patients with Fanconi anemia (FA), the hematopoietic stem cell (HSC) reservoir of patients with DBA was not significantly reduced, suggesting that collection of these cells should not constitute a remarkable restriction for DBA gene therapy. Subsequently, 2 clinically applicable lentiviral vectors were developed. In the former lentiviral vector, PGK.CoRPS19 LV, a codon-optimized version of RPS19 was driven by the phosphoglycerate kinase promoter (PGK) already used in different gene therapy trials, including FA gene therapy. In the latter one, EF1α.CoRPS19 LV, RPS19 expression was driven by the elongation factor alpha short promoter, EF1α(s). Preclinical experiments showed that transduction of DBA patient CD34+ cells with the PGK.CoRPS19 LV restored erythroid differentiation, and demonstrated the long-term repopulating properties of corrected DBA CD34+ cells, providing evidence of improved erythroid maturation. Concomitantly, long-term restoration of ribosomal biogenesis was verified using a potentially novel method applicable to patients' blood cells, based on ribosomal RNA methylation analyses. Finally, in vivo safety studies and proviral insertion site analyses showed that lentivirus-mediated gene therapy was nontoxic.

Spanish registry of hemoglobinopathies and rare anemias (REHem-AR): demographics, complications, and management of patients with ß-thalassemia.

INTRODUCTION: The increase in the number of patients with hemoglobinopathies in Europe in recent decades highlights the need for more detailed epidemiological information in Spain. To fulfil this need, the Spanish Society of Pediatric Hematology and Oncology (SEHOP) sponsored the creation of a national registry of hemoglobinopathies known as REHem-AR (Spanish Registry of Hemoglobinopathies and Rare Anemias). Data from the transfusion-dependent (TDT) and non-transfusion-dependent (NTDT) ß-thalassemia cohorts are described and analyzed. METHODS: We performed an observational, multicenter, and ambispective study, which included patients of any age with TDT and NTDT, registered up to December 31, 2021. RESULTS: Among the 1741 patients included, 168 cases of thalassemia were identified (103 TDT and 65 NTDT-patients). Survival at 18 years was 93% for TDT and 100% for NTDT. Regarding management, 80 patients with TDT (77.7%) and 23 patients with NTDT (35.4%) started chelation treatment during follow-up, with deferasirox being the most widely used. A total of 76 patients within the TDT cohort presented at least 1 complication (73.8%), the most frequent being hemosiderosis and osteopenia-osteoporosis. Comparison of both cohorts revealed significant differences in the diagnosis of hepatic hemosiderosis (p = 0.00024), although these were not observed in the case of cardiac iron overload (p = 0.27). DISCUSSION: Our registry enabled us to describe the management of ß thalassemia in Spain and to analyze the morbidity and mortality of the cohorts of patients with TDT and NTDT. Complications related to iron overload in TDT and NTDT account for most of the morbidity and mortality of the disease, which is associated with a considerable social, psychological, and economic impact, although cardiac, osteopathy and endocrinological complications requiring more attention. The convenience and simplicity of online registries make it possible to homogenize variables and periodically update data, thus providing valuable information on these diseases.