Haploidentical Stem Cell Transplantation With TCR-αβ + /CD19 + Depletion in High-risk Pediatric Leukemias: Experience From a Referral Center in Peru.

Haploidentical hematopoietic stem cell transplantation (haplo-HSCT) using TCR αβ+/CD19+ depletion provides an alternative treatment for patients with high-risk (HR) leukemias without a matched donor, especially in developing nations with limited donor registries. We present the outcomes of 36 patients <16 years with HR leukemia who underwent haplo-HSCT with TCR αβ + /CD19 + depletion between 2018 and 2022 at a referral center in Peru. Survival probabilities and cumulative incidence functions were calculated using the Kaplan-Meier method. Patients were followed for a median of 17.38 months (range: 2.34 to 60.36 mo). The 5-year overall survival (OS), 5-year event-free survival (EFS), and non-relapse mortality rates were 72.1%, 72.2%, and 16.7%, respectively. The incidence of relapse for the entire group was 11.1%. Acute graft versus host disease (GvHD) was observed in 36.1% of the patients, with only 2.8% experiencing grade III-IV acute GvHD. No patients developed chronic GvHD. Among all patients, CMV reactivations were observed in 27.78%, HHV-6 reactivations in 33.33%, and ADV or BK virus reactivations in 16.67%. Our study suggests that haplo-HSCT with TCR αβ+/CD19+ depletion is a safe and effective treatment for HR pediatric leukemias. Adopting this approach in major transplant centers throughout the country could improve outcomes for this group of patients.