Survival and late effects of hematopoietic cell transplantation in patients with thalassemia major

Pediatric Transplant and Cellular Therapy Consortium RESILIENT Conference on Pediatric Chronic Graft-versus-Host Disease Survivorship after Hematopoietic Cell Transplantation: Part II. Organ Dysfunction and Immune Reconstitution Considerations for Children with Chronic Graft-versus-Host Disease after Hematopoietic Cell Transplantation

While highly morbid forms of chronic graft versus host disease (cGVHD) and severe late effects of allogeneic hematopoietic cell transplantation (HCT) can impact children and adults alike, unique considerations arise in pediatric cases regarding diagnosis, monitoring, treatment, and likelihood of resolution. As children can present with atypical features of cGVHD and with more significant disease due to inability to communicate symptoms, they may be at increased risk for highly morbid forms of cGVHD and incur greater subsequent late effects, which may be more pronounced in those with underlying chromosomal breakage syndromes, with higher prevalence in pediatric HCT recipients. The long-term effects of cGVHD and its therapies include impaired immune reconstitution, leading to increased risks of infection and secondary malignant neoplasms. However, children also have the greatest potential for full immune reconstitution, due to thymus recovery that could impact the timing of vaccination with respect to tolerance and restoration of optimal immunity. Developing strategies to mitigate the late effects incurred with, and as a result of, cGVHD is of critical importance. The working group recommends surveillance strategies for late effects in patients with cGVHD, increased utilization of emerging diagnostic tools, integration of monitoring for cGVHD treatment response, and development of new treatments and specifies aims of future research endeavors.

Special considerations in assisted reproductive technology for patients with hematologic disease

Populations with hematologic disorders seeking fertility care often present with a complex clinical picture, including disease-specific sequelae and comorbid conditions. Limited literature exists to help guide fertility clinics on the management of these patients, many of whom require multidisciplinary care coordination centered on patient-specific fertility goals. Thanks to advancements in life-prolonging therapies for hematologic disorders, growing numbers of affected individuals are seeking assisted reproductive technologies for family building. Thus, it is important to be aware of the unique considerations and risks of assisted reproductive technologies for these populations and develop evidence-based care guidelines to optimize outcomes.

Cardiac injury caused by iron overload in thalassemia

Cardiac iron overload affects approximately 25% of patients with β-thalassemia major, which is associated with increased morbidity and mortality. Two mechanisms are responsible for iron overload in β-thalassemia: increased iron absorption due to ineffective erythropoiesis and blood transfusions. This review examines the mechanisms of myocardial injury caused by cardiac iron overload and role of various clinical examination techniques in assessing cardiac iron burden and functional impairment. Early identification and intervention for cardiac injury and iron overload in β-thalassemia have the potential to prevent and reverse or delay its progression in the early stages, playing a crucial role in its prognosis.

Uniform Graft-versus-Host Disease Prophylaxis using Post-Transplantation Cyclophosphamide, Methotrexate, and Cyclosporine following Peripheral Blood Hematopoietic Stem Cell Transplantation from Matched and Haploidentical Donors for Transfusion-Dependent Thalassemia: A Retrospective Report from the Bone Marrow Failure Working Group of Hunan Province, China

Although the survival of patients with transfusion-dependent thalassemia (TD-TM) is reportedly inferior after haploidentical hematopoietic stem cell transplantation (HSCT), the heterogeneity of transplantation approaches in studies suggests the need to assess the effect of conditioning regimen on matched and haploidentical transplantation outcomes. A novel post-transplantation cyclophosphamide (PTCy)-based approach for patients with TD-TM undergoing haploidentical HSCT was reported in our prior study. Here we aimed to retrospectively evaluate the real-world efficacy and safety of graft-versus-host disease (GVHD) prophylaxis in patients with TD-TM after HSCT from matched donors and haploidentical donors (HIDs). In this retrospective multicenter study, among 238 patients with TD-TM who underwent HSCT, 160 underwent peripheral blood HSCT, using uniform GVHD prophylaxis with PTCy, methotrexate, and cyclosporine, at member centers of the Bone Marrow Failure Working Group of Hunan Province between 2019 and 2023. The median age of the cohort at transplantation was 6 years (95% confidence interval [CI], 6 to 7 years). The 160 donors included 99 (61.9%) haploidentical family members, 13 matched sibling donors, and 48 matched or mismatched unrelated donors. The engraftment rate was 98.8% (95% CI, 96.1% to 97.7%). HSCT from HIDs had a lower risk of mixed chimerism (HR, .078; P = .022). Within 100 days after transplantation, 31 patients (19.6%; 95% CI, 14.0% to 26.3%) had grade II-IV acute GVHD (aGVHD), 9 of whom had grade III-IV aGVHD (5.7%; 95% CI, 2.9% to 10.1%). HIDs were significantly associated with a higher risk of grade II-IV aGVHD (HR, 3.973; P = .009). Nineteen patients (11.9%; 95% CI, 7.6% to 17.6%) developed late aGVHD after a median of 516 days (95% CI, 407 to 709 days). Twenty-six patients (16.5%; 95% CI, 11.3% to 22.8%) exhibited any 1 of the diagnostic, distinctive, or atypical features of chronic GVHD (cGVHD) according to the 2014 National Institutes of Health (NIH) criteria after a median of 690 days (95% CI, 496 to 902 days). Among these 26 patients, 7 had NIH-defined cGVHD, 14 had only 1 distinctive sign with no histologic evidence, and 5 had only atypical cGVHD signs. Of the 26 patients, 5 were classified with overlap syndrome. Of 21 patients classified with NIH-defined and potential cGVHD, 3 had moderate cGVHD and 1 had severe cGVHD. Logistic regression analyses identified that grade II-IV aGVHD independently predicted subsequent cGVHD (HR, 3.920; P = .006). The rates of cGVHD were similar in the matched donor and HID groups. Thalassemia-free survival (TFS) and event-free survival (EFS) were 97.5% (95% CI, 94.2% to 99.2%) and 90.6% (95% CI, 85.4% to 94.4%), respectively, after a median of 690 days (95% CI, 496 to 902 days). TFS rates were similar in the matched donor and HID groups (P = .549). The EFS rate was significantly higher in the matched donor group compared to the HID group (P = .033). Our study suggests that when PTCy-based uniform GVHD prophylaxis is administered, HSCT from matched donors and HIDs results in a low incidence of severe GVHD and treatment-related mortality with satisfactory survival.

Safety and effectiveness of controlled ovarian stimulation and oocyte retrieval during prepubertal and peripubertal period

PURPOSE

Is it safe and effective to perform controlled ovarian stimulation (COS) and oocyte retrieval (OR) in prepubertal and peripubertal patients?

METHODS

In this retrospective cohort study, data of 20 pre-/peripubertal patients who underwent COS and OR for the purpose of oocyte cryopreservation (OC) between 2008 and 2023 were reviewed. Following COS, all OR procedures were performed transabdominally using a vaginal ultrasound probe. Ovarian reserve was assessed by serum FSH, LH, estradiol, AMH, and antral follicle counts (AFC) in all subjects. All mature oocytes were vitrified.

RESULTS

Mean age of the patients was 15.05 ± 1.87, mean AMH was 0.84 ± 0.8 ng/ml, mean FSH was 6.39 ± 3.95 IU/L, mean estradiol was 61.6 ± 51.9 pg/ml, mean LH was 4.69 ± 3.46 IU/L, and mean AFC was 5.5 ± 5.82. Among the patients, 12 had regular menstrual cycle, 5 had irregular menstrual cycle, whereas 3 patients still did not have their menarche yet. The indications for OC were as follows: primary ovarian insufficiency (n = 7), ovarian surgery for ovarian tumors (n = 5) or ovarian torsion (n = 1), mosaic Turner syndrome (n = 2), acute lymphoblastic leukemia (n = 1) anaplastic B-cell lymphoma (n = 1), Ewing's sarcoma (n = 1), Noonan syndrome (n = 1), and Thalassemia (n = 1). The mean number of oocytes retrieved, MII oocytes frozen, and maturation rate were 5.11 ± 5.0, 3.92 ± 4.48, and 75.1 ± 25.6%, respectively. Stepwise linear regression analysis demonstrated a positive correlation between AFC and number of total oocytes retrieved and number of MII oocytes. In the case diagnosed with Noonan syndrome, all 7 retrieved oocytes were MI and all frozen at MI phase. No patient had any complication related to COS or OR.

CONCLUSION

Even though number of the enrolled subjects is limited and mean AMH is lower in our cohort, we demonstrated that performing COS and OR is safe in pre-/peripubertal patients. If required, transabdominal route can be performed in this age group for OR. AFC appears as a prognostic factor for stimulation outcome in this age group. Pediatric patients or young adolescents at risk for primary ovarian insufficiency should not be discouraged from utilizing OC.

Hematopoietic Stem Cell Transplantation in Children with Sickle Cell Disease and Thalassemia Major: A National Database Study

In patients with sickle cell disease (SCD) and beta-thalassemia major (TM), allogeneic hematopoietic stem cell transplantation (HSCT) was considered the only curative treatment option with a good survival rate. However, with the recent approval of gene therapies, more information is needed to understand the benefits and risks of these interventions. We performed a retrospective analysis of the Kids Inpatient Database to describe demographic features, short-term complications, and hospital charges of patients with SCD and TM treated with HSCT during 2006-2019 in the United States. The database was filtered using the International Classification of Diseases, 9th and 10th edition codes to identify children under 20 years of age with SCD or TM who underwent HSCT. A total of 513 children with SCD or TM who received HSCT were analyzed. The prevalence of HSCT per 1000,000 U.S. population increased from 0.31 in 2006 to 1.99 in 2019 (p < 0.001). The median age of children with SCD who underwent HSCT was 10 (6-15) years, and that for TM was 6 (3-11.5) years (p < 0.001). The combined mortality rate was 4% (2.4%-6.6%) but higher in the TM group. The length-of-stay and total charges were higher in the TM population (p < 0.01). This study provides national data on HSCT among hospitalized children with SCD and TM in the United States, demonstrating an increasing use of HSCT between 2006 and 2019. Although hospital mortality of HSCT in these conditions is low, it still represents a challenge, especially in TM patients.

Continuous and differential improvement in worldwide access to hematopoietic cell transplantation: activity has doubled in a decade with a notable increase in unrelated and non-identical related donors

Promoting access to and excellence in hematopoietic cell transplantation (HCT) by collecting and disseminating data on global HCT activities is one of the principal activities of the Worldwide Network for Blood and Marrow Transplantation, a non-governmental organization in working relations with the World Health Organization. HCT activities are recorded annually by member societies, national registries and individual centers including indication, donor type (allogeneic/autologous), donor match and stem cell source (bone marrow/peripheral blood stem cells/cord blood). In 2018, 1,768 HCT teams in 89 countries (6 World Health Organization regions) reported 93,105 (48,680 autologous and 44,425 allogeneic) HCT. Major indications were plasma cell disorders and lymphoma for autologous, and acute leukemias and MDS/MPN for allogeneic HCT. HCT numbers increased from 48,709 in 2007. Notable increases were seen for autoimmune diseases in autologous and hemoglobinopathies in allogeneic HCT. The number of allogeneic HCT more than doubled with significant changes in donor match. While HCT from HLA-identical siblings has seen only limited growth, HCT from non-identical related donors showed significant increase worldwide. Strongest correlation between economic growth indicator of gross national income/capita and HCT activity/10 million population was observed for autologous HCT (correlation coefficient [r]=0.79). HCT from unrelated donors showed strong correlation (r=0.68), but only moderate correlation was detected from related donors (r=0.48 for HLA-identical sibling; r=0.45 for other). The use of HCT doubled in about a decade worldwide at different speed and with significant changes regarding donor match as a sign of improved access to HCT worldwide. Although narrowing, significant gaps remain between developing and non-developing countries.

Exploring the bone marrow micro environment in thalassemia patients: potential therapeutic alternatives

Genetic mutations in the β-globin gene lead to a decrease or removal of the β-globin chain, causing the build-up of unstable alpha-hemoglobin. This condition is referred to as beta-thalassemia (BT). The present treatment strategies primarily target the correction of defective erythropoiesis, with a particular emphasis on gene therapy and hematopoietic stem cell transplantation. However, the presence of inefficient erythropoiesis in BT bone marrow (BM) is likely to disturb the previously functioning BM microenvironment. This includes accumulation of various macromolecules, damage to hematopoietic function, destruction of bone cell production and damage to osteoblast(OBs), and so on. In addition, the changes of BT BM microenvironment may have a certain correlation with the occurrence of hematological malignancies. Correction of the microenvironment can be achieved through treatments such as iron chelation, antioxidants, hypoglycemia, and biologics. Hence, This review describes damage in the BT BM microenvironment and some potential remedies.

Case report: Curing a rare, unstable hemoglobin variant Hb Bristol-Alesha using haploidentical hematopoietic stem cell transplantation

Unstable hemoglobinopathies are a rare, heterogeneous group of diseases that disrupt the stability of hemoglobin (Hb), leading to chronic hemolysis and anemia. Patients with severe phenotypes often require regular blood transfusions and iron chelation therapy. Although rare, studies have reported that hematopoietic stem cell transplantation (HSCT) seems to be an available curative approach in transfusion-dependent patients with unstable hemoglobinopathies. Here, we describe successful haploidentical HSCT for the treatment of an unstable Hb variant, Hb Bristol-Alesha, in a 6-year-old boy with severe anemia since early childhood. Two years after transplantation, he had a nearly normal hemoglobin level without evidence of hemolysis. DNA analysis showed complete chimerism of the donor cell origin, confirming full engraftment with normal erythropoiesis.