Bone marrow, peripheral blood and cord blood stem cell transplantation in children: ten years' experience at Siriraj Hospital.

Stem cell transplantations were performed in 69 children at Siriraj Hospital over a ten year period. The source of stem cells was bone marrow (60), peripheral blood (3), or cord blood (6). The diseases treated included 35 thalassemias, 11 Burkitt's lymphoma, five non-Hodgkin's lymphoma, five aplastic anemia, eight acute leukemia, and one each of neuroblastoma, severe combined immunodeficiency, Wiskott-Aldrich syndrome, myelodysplastic syndrome, and pyruvate kinase deficiency. The success rate of stem cell transplantation in Thai children varied according to the underlying diseases of the patients, ranging from 50% in acute leukemia to 100% in aplastic anemia. The outcome of stem cell transplantation in 35 thalassemic children revealed 23 (79.4%) were cured, whereas three (10.3%) remain alive with disease and the other three (10.3%) died. The incidence of graft-versus-host disease was low hen compared with that of Western countries. It is concluded that bone marrow, peripheral blood and cord blood stem cell transplantation will be the treatment of choice and will be widely used in the future to cure many hematologic and malignant disorders in children.

Study of hematopoietic progenitor cells in thalassemia after bone marrow transplantation.

The hematopoietic committed progenitor cells (BFU-E and CFU-GM) in blood and bone marrow were studied in thalassemic patients before and after bone marrow transplantation. Eighteen transplants were performed in 17 patients with thalassemia. Five were homozygous beta-thalassemia and 12 were beta-thalassemia/hemoglobin E disease. The age ranged from 1.2-14 years (median = 3.4 years). The conditioning regimen comprised busulfan 3.5-4 mg/kg/day for 4 days and cyclophosphamide 50 mg/kg/day for 4 days. Cyclosporin in combination with methotrexate were administered post transplant for GVHD prophylaxis. Before transplantation, BFU-E and CFU-GM in the blood of the patients were significantly higher compared with normal (p < 0.05) but were normal in the bone marrow. Only the CFU-GM in the bone marrow of the successful cases after transplantation recovered to the normal level at the first month through the 12th month whereas the BFU-E were low. Both CFU-GM and BFU-E in the blood were lower than normal after follow up to the 12th month. Inspite of the low number of progenitor cells, there was hematological recovery in the blood of the patients. It may be due to the capacity of the hematopoiesis react to stress which could be amplified the differentiation compartment or the shortened-transit time through the stem cell compartment.

Collection of cord blood stem cells for transplantation in thalassemic patients.

Thalassemia is widely distributed throughout the world and is one of the major public health problems. The use of bone marrow transplantation, the only curative therapy for thalassemia, is limited because less than 30% of the patients have unaffected and HLA-identical siblings as donors. Cord blood stem cells, an alternative source of stem cells for transplantation, have been successfully transplanted into patients with several diseases after myeloablative therapy. Twenty cord blood samples from unaffected neonates whose siblings had severe thalassemia were collected. The median volume was 80 ml. The median number of cells and colony forming units-granulocyte-macrophage in cord blood was 9.2 x 10(8) and 3.4 x 10(5), respectively. Four of 20 cord blood samples had HLA-matched to the affected siblings. One patient underwent cord blood transplantation with success; one patient is waiting for transplantation.