A tracking detection on chimerism after allogeneic hematopoietic stem cell transplantation

    ZHANG Qingª²Xia1,2, YAN Jiangª²Wei1,2, JIAO Zhangª²Ping2, TANG Hui2, HUO Zhenª²Yi2, WANG Jing2, GAO Junª²Wei2, YANG Jian2, ZHU Xiaoª²Jun2, MA Wanª²Shan2, JIA Shuª²Qin2, LIU Yaª²Cheng2

    1Postª²graduate College, Chinese Academy of Sciences, Beijing 100049, China, 2Forensic Medical Examination and Identification Center, Beijing Public Security Bureau, Beijing 100085, China

    ¡¾Abstract¡¿AIM: To evaluate the chimerism after allogeneic hematopoietic stem cell transplantation by analysing multiª²loci of short tandem repeats (STR). METHODS: Thirtyª²one 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 Genotyper. 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¬ð blood changed from full donor chimeras to full receptor genotype. One patient changed from mixed chimeras to full donor chimeras, and he had no evidence of relapse. One patient had mixed chimerism at all times and died. Eighteen of the 31 patients had full donor chimeras at all times, and 16 of them survived leukemiaª²freely, 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. ......