αß+ /CD19+ -depleted haploidentical stem cell transplantation for children with acute leukemia: Is there a protective effect of increased γδ+ T-cell content in the graft?

BACKGROUND: Haploidentical hematopoietic stem cell transplantation (HSCT) with depletion of αß+ T cells and CD19+ B cells has emerged as a viable alternative to traditional donors for treating acute leukemia in children. As the use of this innovative approach continues to grow and more experience is gained, it is essential to identify and comprehend the key factors that contribute to successful transplantation and improved outcomes. METHODS: We conducted a retrospective analysis of single-center data from 27 children with acute lymphoblastic leukemia and 11 children with acute myeloid leukemia who underwent haploidentical HSCT with depletion of αß+ T cells and CD19+ B cells between the years 2013 and 2020. RESULTS: Engraftment was successful in 34 out of 38 patients (90%). The 5-year overall survival and event-free survival rates were 51% and 42%, respectively. There were no cases of grade III-IV acute graft-versus-host disease, and only two patients developed chronic graft-versus-host disease. Patients with a higher content of γδ+ T cells in the graft demonstrated a longer event-free survival. CONCLUSIONS: αß+ /CD19+ -depleted haploidentical hematopoietic stem cell transplantation can offer long-term remission for children with acute leukemia with minimal graft-versus-host disease.

Bortezomib-based Anthracycline-free Induction for Pediatric Relapsed ALL as a Bridge to Immunotherapy.

BACKGROUND: Immunotherapy may lead to durable remissions in patients with relapsed and refractory acute lymphoblastic leukemia (R/R ALL). Patients receiving immunotherapy with a lower disease burden tend to have improved long-term outcomes and less toxicity. Thus, an induction protocol to achieve lower disease burden is required. Bortezomib added to a 4-drug induction was shown to lead to high rates of remission in R/R ALL patients. Inclusion of anthracyclines in this protocol may preclude most patients, having maximized the cumulative dose of anthracyclines. Thus, our goal was to evaluate anthracycline-free bortezomib-based induction for patients with R/R ALL. PROCEDURE: We conducted a retrospective analysis of patients treated with bortezomib-based protocols for R/R ALL between 2011 and 2019 at our center. Data regarding toxicity and response rate was collected and analyzed. RESULTS: Eighteen children with R/R ALL were treated with bortezomib-based induction, 13 of them without anthracyclines. Eleven patients did not complete the induction course: 6 due to toxicity, and 5 due to physician decision to proceed to immunotherapy early. Two events of treatment-related mortality occurred. There was no significant difference in toxicity between patients who treated with anthracycline and those who were not. Ten patients achieved complete remission, with 4 patients having polymerase-chain-reaction minimal residual disease below 10-4. Fifteen patients proceeded directly to immunotherapy: 11 patients received CD19 chimeric-antigen receptor-T-cells, 2 blinatumomab and 2 hematopoietic stem cell transplant. CONCLUSION: Anthracyclines can be safely omitted from bortezomib-based therapies in patients with R/R ALL, when planning to proceed to immunotherapy.

High-dose adenosine for refractory supraventricular tachycardia: a case report and literature review.

Supraventricular tachycardia is the most common significant arrhythmia in children. If prolonged, it may cause heart failure and progress to cardiogenic shock warranting prompt treatment. The recommended interventions following vagal manoeuvres are intravenous adenosine and in the unstable patient electrical cardioversion. We present an infant with an unstable supraventricular tachycardia that was resistant to electrical cardioversion and recommended doses of adenosine. He reverted to sinus rhythm with a higher dose of adenosine, suggesting that such doses may be required in refractory supraventricular tachycardia.