Unrelated partially matched peripheral blood stem cell transplantation with highly purified CD34+ cells in a child with Wiskott-Aldrich syndrome.

Stem cell transplantation is the only curative approach to the treatment of Wiskott-Aldrich syndrome. However, using grafts from partially matched unrelated donors is associated with increased risk of graft rejection and graft-versus-host disease. In an attempt to prevent these problems, a 6-year-old boy with Wiskott-Aldrich syndrome lacking a suitable family donor, was transplanted with large numbers of unrelated highly purified CD34+ peripheral blood stem cells mismatched at one C locus. Conditioning consisted of busulfan 16 mg/kg body weight, cyclophosphamide 200 mg/kg body weight and antithymocyte globulin 20 mg/kg body weight x 3 days. The boy had a rapid hematopoietic engraftment and showed immunologic reconstitution by day +92. Although he did not receive prophylactic immunosuppression he did not develop any graft-versus-host disease and is well and alive up to now, 25 months after transplantation.