Successful long-term hematological and immunological reconstitution by autologous cord blood transplantation combined with post-transplant immunosuppression in two children with severe aplastic anemia

The state of the art in the treatment of severe aplastic anemia: immunotherapy and hematopoietic cell transplantation in children and adults

Acquired aplastic anemia (AA) is an immune-mediated bone marrow (BM) failure where marrow disruption is driven by a cytotoxic T-cell-mediated autoimmune attack against hematopoietic stem cells. The key diagnostic challenge in children, but also in adults, is to exclude the possible underlying congenital condition and myelodysplasia. The choice of treatment options, either allogeneic hematopoietic cell transplantation (alloHCT) or immunosuppressive therapy (IST), depends on the patient's age, comorbidities, and access to a suitable donor and effective therapeutic agents. Since 2022, horse antithymocyte globulin (hATG) has been available again in Europe and is recommended for IST as a more effective option than rabbit ATG. Therefore, an update on immunosuppressive strategies is warranted. Despite an improved response to the new immunosuppression protocols with hATG and eltrombopag, some patients are not cured or remain at risk of aplasia relapse or clonal evolution and require postponed alloHCT. The transplantation field has evolved, becoming safer and more accessible. Upfront alloHCT from unrelated donors is becoming a tempting option. With the use of posttransplant cyclophosphamide, haploidentical HCT offers promising outcomes also in AA. In this paper, we present the state of the art in the management of severe AA for pediatric and adult patients based on the available guidelines and recently published studies.

A multicentre trial of intensive immunosuppressive therapy combined with umbilical cord blood for the treatment of severe aplastic anaemia

Immunosuppressive therapy (IST) is an effective treatment regimen for severe aplastic anaemia (SAA) patients without HLA-identical donors. This study further compared the outcomes between IST and IIST-UCB in SAA on the basis of research shown that IST combined with umbilical cord blood infusion (IIST-UCB) treated effectively. A total of 123 patients from 11 hospitals in China were enrolled. Sixty-nine patients in IIST-UCB group were treated with ATG + CsA + CTX combined with cord blood, while 54 patients in IST group with ATG + CsA. The overall remission rates (ORRs), complete remission (CR) rates and partial response (PR) rates of IIST-UCB group and IST group at 3 months were 69.67% vs 51.85% (P = .045), 21.74% vs 3.7% (P = .004) and 47.83% vs 48.15% (P = .972), respectively. After 6 months of treatment, they were 76.81% vs 57.41% (P = .022), 37.68% vs 11.11% (P = .001) and 39.13% vs 46.30% (P = .425), respectively. After 1 year of treatment, they were 85.51% vs 61.11% (P = .002), 59.42% vs 25.93% (P = .000) and 26.09% vs 35.19% (P = .275), respectively. The ORRs and CR rates of IIST-UCB group were both significantly higher than IST group after 3 months, 6 months and 1 year of treatment. The neutrophil granulocyte, platelet and haemoglobin recovery times of IIST-UCB group were significantly shorter than IST group. Compared with standard IST, IIST-UCB as an effective therapy for SAA patients without HLA-identical donors accelerated the haematopoietic reconstitution, resulting in higher early CR rates.

Successful Bone Marrow Recovery After an Immunoablative Regimen With Autologous Cord Blood Transplant in a Child With Idiopathic Severe Aplastic Anemia: A Case Report

BACKGROUND

Aplastic anemia is a rare disease that manifests as bone marrow failure. The current treatment options include immunoablative therapy or allogeneic hematopoietic stem cell transplantation. We report a successful immunoablative regimen with autologous umbilical cord blood (auto-UCB) transplant in a 3-year-old boy with severe aplastic anemia.

CASE REPORT

The immunoablation procedure consisted of 5 × 3.75 mg/kg antithymocyte globulin (Thymoglobulin) (total 18.75 mg/kg), methylprednisolone for 4 days, and cyclosporine A. The patient received auto-UCB containing 0.3 × 10⁵ CD34⁺ cells per kilogram of body weight. Recovery of leukocyte count above 1000/μL was reached on post-transplant day +39, and recovery of granulocytes above 500/μL was reached on day +40. The final regular transfusions of packed red blood cells and platelet concentrate were performed on day +55. The complications that occurred in the post-transplant period were nausea, diarrhea, septic fever, and hepatic abscess formation. Post-transplant immunosuppression with cyclosporine A was discontinued 17.5 months after auto-UCB, and the patient remained in complete remission with normal blood counts and bone marrow morphology.

SUMMARY

Auto-UCB transplantation without chemotherapy conditioning can be considered a therapeutic option for children with stored cord blood cells.