脐血干细胞移植治疗假肥大型肌营养不良症

目的比较假肥大型肌营养不良症(Duchennemusculardystrophy,DMD)患者经脐血干细胞移植治疗前后其肌肉再生、抗肌萎缩蛋白表达和运动功能的改变;以及评价治疗的安全性。方法对1例经基因分析和肌肉活检及抗肌萎缩蛋白检测确诊的、已丧失行走能力的DMD患儿,经HLA配型,在脐血库中寻找到一个全相合的脐血供体。采用白消安+环磷酰胺+兔抗胸腺淋巴细胞球蛋白预处理后进行异基因脐血干细胞移植;术后采用环孢素A和骁悉方案预防移植物抗宿主反应(graftversushostreaction,GVHD)。同时定期检测原发病的生化指标如血清肌酸激酶(creatinekinase,CK)、造血重建的植入证据(血型转变、肌肉和血液系统的聚合酶链反应短串联重复序列分析)、缺陷基因是否纠正、新生肌肉是否出现、肌肉中抗肌萎缩蛋白是否表达和运动功能是否改善。结果(1)中性粒细胞在脐血干细胞移植后第15天(+15天)达到0.5×109/L,白细胞在+25天达正常水平;血小板于+22天达到20×109/L;血红蛋白维持于85～100g/L。术后140天骨髓穿刺提示三系生长旺盛;(2)移植后140天血型转为供体AB型。至今没有出现移植物抗宿主反应。(3)术后18天、30天、43天、55天、74天、233天患者外周血DNA和术后140天、183天、235天骨髓细胞DNA经PCRSTR检测为供者独立植入;(4)患儿术后60天取外周血做基因分析,显示19号缺失的外显子得到完全纠正,患儿转变为正常基因型;(5)患儿在移植后75天的肌肉活检可见新生肌管形成,抗肌萎缩蛋白免疫组化呈弱阳性,少数为强阳性反应,DNA分析:供者基因DNA占1%～13%;移植后126天抗肌萎缩蛋白免疫组化检测显示阳性的肌纤维明显增多,供者基因DNA上升至2.5%～25%;(6)患儿血清CK从移植治疗前的5735U/L降至274U/L;(7)术后100天体检发现患儿肌力略有改善,肢端温暖。结论异基因脐血干细胞移植治疗DMD,可在移植后短期内重建造血功能、血清CK显著下降、肌肉抗肌萎缩蛋白表达,患儿运动有所改善,提示造血干细胞移植将有益于DMD的治疗。

Therapy of Duchenne muscular dystrophy with umbilical cord blood stem cell transplantation

OBJECTIVE: To analyze a Duchenne muscular dystrophy(DMD) patient's muscular regeneration, dystrophin expression and locomotive variation before and after he underwent umbilical cord blood stem cell transplantation in order to assess the therapeutic effect. METHODS: A 12-year-old DMD boy who could not walk for 3 years was confirmed by gene analysis and dystrophin protein immune test on his muscle. He had no other chronic disease. By HLA matching, a piece of umbilical cord blood stem cell with 6 HLA sites matching to the boy was found in Guangdong Umbilical Cord Blood Bank. The number of the nucleated cells of the umbilical cord blood stem cell was 24.08x 10(8). After pretreatment for the DMD boy with busulfan, cyclophosphamide and rabbit anti-human thymocyte globulin, the allergenic cord blood stem cells were transplanted into him by intravenous injection. Cyclosporin A, methylprednisolone, MMF, prostaglandin E1 and ganciclovir were given after the transplantation. At the same time, Gran, the granulocytic cell stimulating factor, and gamma globulin were administered. The biochemistry profile including serum creatine kinase (CK), the reconstruction of blood making, the deletion exon of DMD gene, the regenerating muscles, the dystrophin protein expression, and the locomotive function of the DMD boy were tested regularly. RESULTS: (1) The white blood cells (WBC) of peripheral blood decreased gradually to zero after pretreatment. In a period of 15 days after transplantation, the neutrophil increased to 0.5x 10(9)/L; at 25 days, WBC increased to normal level. Blood platelet was more than 20x 10(9)/L at 22 days. The hemoglobin rose to 85-100 g/L. At 140 days, sternal puncture revealed the rapid growth of neutrophil, blood platelet and hemoglobin. (2)At 140 days, the blood type of the DMD boy transformed from type O to type AB (the donor's blood type being AB). There was no grafe versus host reaction. (3) At 18, 30, 43, 55, 74 and 233 days after transplantation, the PCR-short tandem repeat test of the boy's peripheral blood DNA showed that his genotype was completely the same as the donor's. The results of PCR-short tandem repeat tests of the bone marrow cells DNA by sternal puncture at 140, 183 and 235 days were the same as those of the blood DNA. (4) At 60 days, DMD gene analysis by PCR showed that the defected DMD gene (exon 19 deletion) had been corrected by the umbilical cord stem cells transplantation. (5) At 75 days, the biopsy of calf muscle showed there were myoblast cells and muscular tubes growing. The dystrophin expressions were weak, but a few of them were strong. DNA analysis showed that the donor's gene DNA accounted for 1%-13%. At 126 days, obviously increased dystrophin positive muscular fibers of the boy were found. The donor's fibers rose to 2.5%-25%. (6) The serum CK of the boy declined from 5735 U/L to 274 U/L. (7) At 100 days, physical examination revealed improvement in his arms and legs. CONCLUSION: The therapy of Duchenne muscular dystrophy with allogeneic umbilical cord blood hematopoietic stem cell transplantation may reset up the blood-making function, decrease the serum CK level, restore the dystrophin in muscles, and improve the locomotive function of the DMD boy. These data suggest that the allogeneic umbilical cord blood hematopoietic stem cell transplantation may benefit the DMD boys.