Bone marrow transplantation for beta-thalassaemia major by an HLA-mismatched parent.
A six-year-old boy was diagnosed with beta-thalassaemia major during infancy. Since then, he required monthly blood transfusion and irregular iron chelation therapy. He had hepatosplenomegaly and elevated liver enzymes; the serum ferritin was up to 3800 ng/mL. An echocardiogram showed left-ventricular enlargement. His one-antigen-mismatched mother was chosen as a bone marrow donor. He was pretreated with intensive red blood cell transfusion and hydroxyurea for 6 weeks prior to conditioning. The conditioning included total body irradiation (300 cGy), busulfan (14 mg/kg), cyclophosphamide (160 mg/kg) and anti-thymocyte globulin (rabbit; 90 mg/kg). Marrow cell dose was 5.4 x 108/kg. Graft versus host disease (GVHD) prophylaxis included cyclosporine A (CSA) and methylprednisolone. Neutrophil engraftment occurred on day 23. Grade II acute GVHD occurred on day 45. The patient developed complications including septicaemia, haemorrhagic cystitis, intracranial haemorrhage and heart failure. He subsequently recovered from the complications without sequelae. The patient remained transfusion-independent at a follow-up examination after 18 months. This case suggested that a mismatched family member may be considered as a bone marrow donor for beta-thalassaemia major. In places where conventional treatment is not feasible, for example, in China, this approach may be an alternative option. A more intensive immunosuppressive regimen and a higher marrow cell dose may be important for successful engraftment. High-dose anti-thymocyte globulin may also prevent severe GVHD.