Outcomes following hematopoietic cell transplantation for Wiskott-Aldrich syndrome

HLA-identical sibling donor transplantation remains the treatment of choice for Wiskott-Aldrich Syndrome (WAS). Since 1990, utilization of alternative donor sources has increased significantly. We report the hematopoietic cell transplantation (HCT) outcomes of 47 patients with WAS treated at a single center since 1990. Improved outcomes were observed after 2000 despite the increased number of alternative donors. Five-year OS improved from 62.5% (95% CI: 34.9% to 81.1%) to 90.8% (95% CI: 67.7% to 97.6%) for patients transplanted during 1990-2000 and 2001-2009, respectively. In multivariate analysis, transplant era significantly impacted OS (P=0.04), whereas age was only marginally significant (P=0.06, Cox proportional hazard analysis). No TRM occurred within the first 100 days among patients transplanted during 2001-2009 compared with 3/16 during 1990-2000, (P=0.03, Fisher's exact test). The extent of HLA mismatch did not significantly affect the incidence of acute GVHD, chronic GVHD or survival. Post-HCT autoimmune cytopenias were frequently diagnosed after 2001: 17/31 (55%) patients. Their occurrence was not associated with transplant donor type (P=0.53), acute GVHD (P=0.74), chronic GVHD (P=0.12), or post-transplant mixed chimerism (P=0.50).