A MORE IMMUNOSUPPRESSIVE PRETRANSPLANT CONDITIONING MAY BE REQUIRED FOR CHINESE PATIENTS WITH THALASSEMIA

Bone marrow transplantation was performed on 14 Chinese patients with transfusion dependent thalassaemia major (n = 13) and haemoglobin H di sease (n = 1). The donors were HLA identical siblings. The source of h aematopoietic stem cells were from bone marrow (n = 13) and umbilical cord blood (n = 1). The pre-transplant conditioning regimens were (1) busulphan 14 mg/kg and cyclophosphamide 200 mg/kg in two patients; (2) busulphan 16 mg/kg, cyclophosphamide 200 mg/kg and antithymocyte glob ulin 110 mg/kg in five patients; (3) busulphan 16 mg/kg, cyclophospham ide 150 mg/kg and antithymocyte globulin 110 mg/kg in seven patients. Graft-versus-host disease prophylaxis was cyclosporin A and methotrexa te. All patients engrafted and achieved stable haematopoiesis except t he one who underwent the umbilical cord blood transplant, who had auto logous marrow recovery. One patient who had stable engraftment rejecte d the marrow graft and developed aplastic anaemia 4 months after BMT. This patient had a second BR IT but rejection recurred again. She even tually died of septicaemia. The other 12 patients were transfusion ind ependent and disease free. The majority have gone back to school or wo rk. Disease-free and actuarial survival probability were 85 and 93%, r espectively with a median follow-up time of 30 months (13 to 42 months ). Our data suggest that BMT from HLA identical siblings for transfusi on dependent thalassaemia gives a high chance of cure with acceptable mortality and morbidity, and that a more immunosuppressive pre-transpl ant conditioning schedule may be required to prevent rejection.