[Allogeneic umbilical cord blood stem cell transplantation in Duchenne muscular dystrophy]

Abstract

Objective: To study the feasibility of treatment of Duchenne muscular dystrophy (DMD) with umbilical cord stem cell transplantation.

Methods: HLA matching was conducted for a 11-year-old DMD boy with family history was underwent umbilical cord blood stem cell transplantation and a sample of umbilical cord stem cells with 5 matched HLA sites was found in the cord blood bank with 27.32 x 10(8) nucleated cells, about 2.6 times that of the treatment dosage for him. After pretreatment with busulfan 14 mg/kg.d, cyclophosphamide 50 mg/kg.d, and rabbit anti-human thymocyte globulin 10 mg/kg.d, the allogeneic cord blood stem cells were transplanted intravenously. Cyclosporin A, methylprednisolone and MMF were used after the transplantation so as to prevent graft versus host reaction. Prostaglandin E1 was used to prevent Budd-Chiari syndrome, and ganciclovir was used to prevent cytomegalovirus infection. At the same time, Gran, granulocytic cell stimulating factor, and gammaglobulin were also used. Biochemistry test, including serum creatine kinase (CK), was conducted. Evidence of reconstruction of blood making, including conversion of blood type, was observed. PCR-STR analysis was used to observe the status of implantation of the donor umbilical cord blood stem cells.

Results: (1) 12 days after transplantation, the white blood cells (WBC) of peripheral blood were 0.5 x 10(9)/L, 14 days after, the numbers of WBC and neutrophils were 1.0 x 10(9)/L and 0.6 x 10(9)/L respectively. In 37 days, granulocytic cell stimulating factor was no more used, the peripheral blood WBC fluctuated around 3.34 approximately 12.2 x 10(9)/L. In the 27th day, the number of blood platelets was more than 20 x 10(9)/L and hemoglobin rose to 88 g/L. On the 24th day red blood cells transfusion was stopped. (2) In the 42nd day, the blood type of the patient transformed from type A before transplantation to type AB (the blood type of transplanted stem cells is type B). (3) PCR-STR test of the peripheral blood made 17, 26, and 42 days after transplantation showed that the gene type of the patient was mixed mosaic: The ratio of donor gradually increased from 40% approximately 45% to 55% approximately 65%. (4) In the 38th day I degrees GVHD appeared. (5) serum CK level declined from 6000 U/L to 600 approximately 2200 U/L. (6) In the 42nd day, physical examination revealed obviously improvement in walking, turning the body over, and standing up.

Conclusion: This is first case of prospective clinical transplantation on DMD by allogeneic cord blood stem cell. Umbilical cord stem cell transplantation helps re-build blood-making function, and improve locomotive function with a mild GVHD reaction. The genotype of rebuilt blood is mosaic but the ratio of gene mosaic gradually turn from recipient gene type > donor gene type to recipient gene type < donor gene type. The serum CK level decreases significantly after transplantation, which may slow down the necrosis of muscle cell. DMD patient will be benefited by stem cell transplantation.