AbstractObjective: To investigate the sample selection, result correction and clinical application value of multi nucleotide polymorphism chimerism detection method based on Next-generation sequencing.
Methods: The chimerism samples from November 2018 to June 2020 were collected, and Pearson correlation coefficient (r) was used to analyze the consistency of bone marrow and peripheral blood results detected by MNPseq; according to the different information integrity before transplantation, the calibration model was constructed to analyze the correction value of the micro chimerism results in each model; the clinical results were retrospectively analyzed to verify the reliability and practicability of chimerism results correction and the clinical value of MNPseq method.
Results: The results of bone marrow and peripheral blood chimerism detected by MNPseq method were consistent with each other and showed significant correlation (r=0.985, P<0.01). The three groups of calibration models were constructed according to different pre-transplant information. For the no donor and pre-transplant patients information group, the correction value was 1%; while for the group with pre-transplant patients and without donor information, 0.61% of the chimerism rate and 13 heterotopic points were used as the correction value; 0.26% of the chimerism rate and 21.57% of the heterotopic points were used as the correction value for the group with pre-transplantation patients and donor information. After correction, the number of the patients with incomplete chimerism decreased from 276 (74.19%) to 141 (37.91%) (P<0.01). Among 18 (18/141, 12.77%) patients with incomplete chimerism, the results of MNPseq in the patients were 25-39 days earlier than those in STR and flow MRD, and the result showed statistical significance.
Conclusion: MNPseq method can be used to monitor chimerism with peripheral blood instead of bone marrow samples, and the results can be corrected to detect the changes of graft status in vivo in a more timely manner.
题目: 多核苷酸多态性分析在异基因造血干细胞移植后嵌合体检测的策略优化及临床分析.
目的: 探讨基于高通量测序的多核苷酸多态性嵌合体检测法的标本选取、结果校正，以及其临床应用价值.
方法: 收集2018年11月-2020年6月本院嵌合体标本，采用皮尔森相关系数（r）对MNPseq法检测的骨髓和外周血结果进行一致性分析；根据移植前信息完整性的不同构建校正模型，分析各模型的微小嵌合结果校正值；对临床结果进行回顾分析，验证嵌合体结果校正的可靠性和实用性，并进一步探讨MNPseq法的临床价值.
结果: MNPseq法检测骨髓和外周血嵌合体结果差异无统计学意义（Z=-1.075，P=0.282），且相关性显著（r=0.985，P＜0.01）。通过移植前信息不同构建3组校正模型，无供者和移植前患者信息组校正值为1%；有移植前患者、无供者信息组嵌合率校正值为0.61%和13个差异位点；有移植前患者和供者信息组嵌合率校正值为0.26%和差异位点比例校正值21.57%。对372位患者嵌合体结果进行校正，校正后不完全嵌合患者由276人（74.19%）下降至141人（37.91%），且有统计学意义（P＜0.01）。结合临床对18例（18/141，12.77%）复发患者的MNPseq、STR和流式MRD结果进行比较，结果显示，MNPseq法早25-39 d检测出移植物状态的改变，且差异有统计学意义（P＜0.01）.
结论: MNPseq法可用外周血代替骨髓样本进行嵌合体监测，结果经校正后能够更早的发现体内移植物状态的变化.
Keywords: STR; allogeneic hematopoietic stem cell transplantation; chimerism; multiple nucleotide polymorphism.