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.