异基因造血干细胞移植后嵌合状态的追踪监测

A tracking detection on chimerism after allogeneic hematopoietic stem cell transplantation

目的:应用荧光标记短串联重复序列(STR)复合扩增技术,探讨多个STR基因座在异基因造血干细胞移植后嵌合体状态评估中的作用.方法:对31例移植后患者进行追踪检验,分别PCR复合扩增各病例组常染色体9个STR基因座和Amelogenin基因座,扩增产物经DNA自动分析仪分离后,GeneScan扫描,Genotyper分型.结果:7例患者血由第1次检验结果与供者STR分型一致变为混合型,4例死亡,3例复发;4例患者血由第1次检验结果与供者一致变为受者自身型,均死亡;1例患者血由混合型变为与供者STR分型一致,无复发;1例患者血两次检验均为混合型,已死亡;其余18例患者血均与供者血STR分型一致,其中16例目前预后较好,2例已死亡.结论:复合扩增STR基因座具有较高的个体识别力,检测灵敏、准确、快速,在对异基因造血干细胞移植患者的植入情况进行动态检测的研究中有用,对移植物植入或被排斥、疾病复发均有预警作用,同时必须结合临床症状,及时地进行STR检测,以便于早期实施临床干预治疗.

AIM： To evaluate the chimerism after allogeneic hematopoietic stem cell transplantation by analysing multi-loci of short tandem repeats （STR）. METHODS： Thirty-one patients who had received allogeneic hematopoietic stem cell transplantation were evaluated. Their 9 STR loci and Amelogenin gene were amplified by fluorescent multiplex PCR. PCR products were separated by using DNA Sequencer and analyzed by using GeneScan and Genotypor. RESULTS： Seven patients showed full donor chimeras at the first test, and converted into mixed chimeras at the last test; 4 of them died, and the others relapsed. Four patients＇ blood changed from full donor chimeras to full receptor genotypo. One patient changed from mixed chimeras to full donor chimeras, and he had no evidence of relapse. One patient had mixed chimefism at all times and died. Eighteen of the 31 patients had full donor chimeras at all times, and 16 of them survived leukemia-freely, but 2 died. CONCLUSION： The system of fluorescent multiplex amplification of STRs had a high power of discrimination, and this detection method is sensitive, exact and rapid. It is a valuable tool for studying the engraftment, graft rejection, and relapse after allogeneic hematopoietic stem cell transplantation. At the same time, it is necessary to combine it with the clinical syndrome, and to detect STR of the patient＇ s blood earlier, for providing a basis for early intervention of clinical treatment.