[Haploidentical hematopoietic stem cell transplantation for beta-thalassemia major in children]

Hematopoietic stem cell transplantation is currently a unique curative therapy for beta-thalassemia major. However, only 30% of patients have HLA-identical siblings to serve as donors. This study investigated the feasibility of hematopoietic stem cell transplantation from HLA mismatched related donors for beta-thalassemia major in children.

Between November 2001 and November 2007, 10 patients with beta-thalassemia major at median ages of 4.4 years (range:1.6-9.4 years) received 11 transplantations from their haploidentical donors, either HLA mismatched sibling umbilical cord bloods (n=6) or parents marrows (n=4) or sibling marrow (n=1). The conditioning regiment included fludarabine (100 mg/m2), busulfan (16 mg/kg), cyclophosphamide (200 mg/kg) and antithymocyte globulin.

Of the 10 patients, 6 (60%) had sustained engraftment and red blood cell transfusion independence; 2 patients showed transient engraftment but rejected the graft quickly; 1 patients had no evidence of engraftment and developed aplastic anemia; 1 patient who received two transplantations had no evidence of engraftment and developed persistent aplastic anemia. All eight engrafted patients showed grade I to III acute graft-versus-host disease (GVHD), and only one developed limited skin chronic GVHD. The probability of overall and disease-free survival was 90% and 60%, respectively, with a median follow-up duration of 57.1 months (range: 2.5 to 85.1 months).

Haploidentical stem cell transplantation is an alternative option for children with beta-thalassemia major, particularly when a matched sibling donor is not available.