[Treatment of thalassemia major with unrelated donor bone marrow transplantation].

Objective: Allogeneic marrow transplantation is a curative therapy for thalassemia, but no more than 30% of patients have HLA-indentical sibling marrow donor. The selection of alternative donors of unrelative marrow and the study on the probability of treating thalassemia major with unrelated donor bone marrow transplantation are of importance.

Methods: Nine children with thalassemia were included in the study, and their gene mutational type were homozygote of thalassemia and double heterozygote, respectively. All of them were finally diagnosed of thalassemia major, and treated with unrelated donor bone marrow transplantation. To high-resolution HLA typing, two patients were matched, five had one unmatched isoform and two had two unmatched isoforms. The erythrocyte blood type was not matched in six patients. The preparative regimen included busulfan (oral use, 16 mg/kg, divided for 4 days), cyclophosphamide (intravenous use, 200 mg/kg, divided for 4 days), antithymocyte immunoglobulin (intravenous use, 30 mg/kg, divided for 3 days), and fludarabine (intravenous use, 125 mg/m(2), divided for 3 days). Ciclosporin A and methotrexate were used for graft-versus-host disease (GVHD) prophylaxis.

Results: All patients had allergen reactions. One had hypotension. Five patients experienced I degrees approximately III degrees acute GVHD in the skin, while one had II degrees acute GVHD in liver. One patient had III degrees GVHD of intestines and gradually developed chronic GVHD in the skin, lungs and brain. One patient died of pulmonary hemorrhage. The duration when peripheral blood neutrophil count exceeded 0.5 x 10(9)/L was 12 - 26 days. The recovery time of WBC was as long as 23 - 110 days. Thrombocytes exceeded 50 x 10(9) within 61 approximately 142 days. The time when hemoglobin reached 100 g/L varied from 23 to 116 days. The last blood transfusion was on 13 - 62 days. Eight patients were fully grafted, while one was not grafted. During the 6 - 24 months of follow-up, seven patients' genotype of thalassemia major became normal. The erythrocyte blood type of five patients also changed into the same as that of donor. The hemoglobin was kept over 110 g/L without blood transfusion.

Conclusion: The transplantation of unrelated donor bone marrow for thalassemia major was successful. Unrelated donor bone marrow transplantation could cure thalassemia major, which expanded the marrow donor source for the transplantation of thalassemia major.