Allogeneic bone marrow transplantation for thalassemia in Taiwan: factors associated with graft failure.

Fourteen thalassemia patients (aged 1.6-13.5 years; median age of 6 years) underwent allogeneic bone marrow transplantation (BMT) between March 1984 and May 1987. The preconditioning regimens consisted of oral busulfan, intravenous cyclophosphamide, with or without irradiation. Two of the patients, who received maternal transplants, failed to engraft but experienced autologous recovery. Of the 12 patients who received sibling marrow, two experienced autologous recovery and one developed marrow chimerism. Five patients died of complications of bone marrow transplantation: two died of intracranial hemorrhage, two died of sepsis, and one succumbed to acute graft-versus-host disease associated with cytomegalovirus infection. Six patients engrafted and have been followed for 1-4 years (median of 2.6 years) without intoward events. The overall survival rate was 64% (nine out of 14) with follow-up of 1-4 years. These results demonstrate that bone marrow transplantation can cure thalassemia but infection, graft-versus-host disease, and hemorrhage were major causes of morbidity and mortality in this group of patients. Other factors of importance include the unfavorable influence of engraftment of prior multiple transfusions and sex-mismatched transplantation. In patients who fail to engraft, autologous recovery usually occurs within 2 months of transplantation.