Outcome of Hematopoietic Stem Cell Transplantation in Wiskott-Aldrich Syndrome / 임상소아혈액종양

ABSTRACT

BACKGROUND: Wiskott-Aldrich syndrome (WAS) is a very rare disease and patients who do not receive timely treatment suffer from bleeding, infection, and malignancy. Hematopoietic stem cell transplantation (HSCT) has been recognized as an effective treatment, but the standard transplantation protocol has not been established. We report the outcomes of WAS patients who underwent HSCT in our institution. METHODS: We retrospectively studied patients who underwent HSCT at Seoul National University Children's Hospital from 2005 to 2018. Busulfan-based myeloablative conditioning regimen was used, and an intensive daily therapeutic drug monitoring (TDM) for busulfan dosing was started for effective myeloablation and to reduce toxicity since 2008. We collected and analyzed data regarding symptoms, engraftment, transplantation-related toxicities, and survival. RESULTS: Six WAS patients who received HSCT were evaluated. The median age of the patients at diagnosis was 5 years (range, 1–11). There were 2 matched unrelated donor bone marrow transplantations, 3 matched unrelated peripheral blood stem cell transplantations (PBSCT), and 1 haploidentical PBSCT. No patient experienced engraftment failure. Three patients developed grades II to IV acute graft-versus-host disease (GVHD). Two patients had veno-occlusive disease (VOD). Two patients died (due to VOD and acute GVHD). The 5-year overall survival was 66.7% with 8 years of median follow-up. Particularly, a patient who underwent haploidentical PBSCT using targeted busulfan is alive with a follow-up duration of 3 years after HSCT. CONCLUSION: In conclusion, WAS patients may be cured with HSCT with targeted busulfan-based myeloablative conditioning. But, long-term and multi-center studies are needed.