Haploidentical Stem Cell Transplantation With TCR αβ/CD19 Depletion in Children With Nonmalignant Hematologic Disorders: Outcomes From a Referral Center in Peru.

Background: Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) with TCR αβ/CD19 cell depletion is a promising therapeutic alternative for children with nonmalignant hematologic disorders, especially in low-income countries where finding a compatible donor is challenging. The use of this transplantation approach for nonmalignant hematologic disorders has not been previously described in the Peruvian pediatric population.

Methods: We present the outcomes of children under 19 with nonmalignant hematologic disorders who underwent haplo-HSCT with TCR αβ/CD19 cell depletion between 2018-2022 at a referral center in Lima, Peru. Survival probabilities and cumulative incidence functions were calculated using the Kaplan-Meier method.

Results: A total of 17 children aged between 1 to 18.6 years (median = 9.7 years) were included. The follow-up period ranged from 10 days to 66.20 months, with a median of 4.34 months. The probability of overall survival, event-free survival, and failure-free survival was 33.70%, 31.40%, and 68.8%, respectively. The incidence rate of graft failure was 49.80%, while the mortality rate not associated with graft failure was 18.8%. The incidence rate of acute graft-versus-host disease (GvHD) was 25.60%, and the incidence rate of viral infections was 59.40%.

Conclusions: The high incidence rates of graft failure and viral infections suggest that these factors may negatively impact the survival of children with nonmalignant hematologic disorders who undergo haplo-HSCT with TCR αβ+/CD19+ cell depletion. Therefore, optimizing the current conditioning regimens and ensuring timely access to first, second, and third-line antivirals is crucial to improve the survival of these patients.