Second allogeneic transplants in children: twelve years of experience

Abstract

Introduction. A second hematopoietic stem cell transplant (HSCT) is required when the first transplant fails, usually due to relapse or graft failure, and is associated with increased morbidity and mortality. Survival rates range from 74-82% in non-neoplastic diseases and 39-58% in neoplastic conditions. Evidence on second HSCT in children is limited, particularly in low- and middle-income countries.
Objective.To describe the clinical characteristics, complications, and outcomes of children who underwent a second HSCT at a high-complexity center between 2012 and 2024.
Materials and methods. Case series study with descriptive and survival analysis using the Kaplan-Meier method in STATA 14®.
Results. A total of 346 allogeneic HSCTs were performed, of which 20 patients underwent a second HSCT. Of these, 17 of 20 patients received a haploidentical donor in their second transplant, and the primary indication was a neoplastic disease in 13 cases. The second HSCT was performed due to graft failure 11/20 or relapse 9/20. The mean age was 10.7 ± 5 years, with a male predominance 14/20. Haploidentical transplants accounted for 16/20 cases, and 11/20 used the same donor. The most common complications were acute graft-versus-host disease 7 cases, 2 of grade III, cytomegalovirus infection 10 cases, and graft failure after the second transplant 4 cases: 3 primary, 1 secondary. Transplant-related mortality was 31%. The 2-year overall survival was 54%, with a median follow-up of 11 months.
Conclusions. Second HSCT is a viable therapeutic option when no other alternatives are available, particularly in resource-limited settings.