Successful Allogeneic Peripheral Blood Stem Cell Transplantation in 4 Wiskott-Aldrich Syndrome Patients

Background: Allogeneic hematopoietic stem cell transplantation is a potential curative treatment in Wiskott-Aldrich syndrome (WAS). Here, we analyzed the outcomes in 4 WAS patients who underwent this procedure with peripheral blood stem cell (PBSC) in our center. Patients and Methods: Four patients with severe WAS phenotype have received allogeneic hematopoietic stem cell transplantation between January 2014 and December 2019 from matched sibling donors with PBSC. Two different preparative conditioning regimens were provided: the first associated busulfan-cyclophosphamide (2 patients) and the second with busulfan-fludarabine administered to the others. Cyclosporine gave as preferred graft-versus-host disease prophylaxis with a short course of methotrexate. Results: All patients achieved engraftment after PBSC with a median CD34(+) cell count: 13.6x10(6)/kg (8 to 24.9x10(6)/kg). Chronic graft-versus-host disease developed in 2 patients treated by cyclosporine-steroids with complete resolution. Chimerism for all the patients was fully donor (>95% donor). After a median follow-up of 41 months (8 to 74 mo), all patients (100%) are alive, healthy, with complete clinical, immunologic, and hematologic recovery, without signs of WAS. Conclusion: This limited study with high-dose PBSC transplantation approach for WAS, demonstrated a safe and effective treatment option, with rapid engraftment, without complications, excellent long-term outcomes, independent of conditioning regimen.