Immunogenetic Laboratory, EFS PACC, Marseille, France.
CNRS, EFS, ADES, Aix Marseille Université, Marseille, France.
Front Immunol. 2023 Jan 19;14:1023116. doi: 10.3389/fimmu.2023.1023116. eCollection 2023.
Quantification of chimerism showing the proportion of the donor in a recipient is essential for the follow-up of hematopoietic stem cell transplantation but can also be useful to document an immune tolerance situation after solid organ transplantation. Historically, chimerism has been quantified from genomic DNA, but with technological advances, chimerism from donor-derived cell-free DNA seems particularly relevant in solid organ transplantation.
The reference method was until recently the short tandem repeat technique, but new innovative techniques as digital PCR (dPCR) and NGS, have revolutionized the quantification of chimerism, such as the so-called microchimerism analysis. After a short review of chimerism methods, a comparison of chimerism quantification data for two new digital PCR systems (QIAcuity™ dPCR (Qiagen) and QuantStudio Absolute Q (ThermoFisher) and two NGS-based chimerism quantification methods (AlloSeq HCT™ (CareDx) and NGStrack™ (GenDX)) was performed.
These new methods were correlated and concordant to routinely methods (r²=0.9978 and r²=0.9974 for dPCR methods, r²=0.9978 and r²=0.9988 for NGS methods), and had similar high performance (sensitivity, reproductibility, linearity).
Finally, the choice of the innovative method of chimerism within the laboratory does not depend on the analytical performances because they are similar but mainly on the amount of activity and the access to instruments and computer services.
定量嵌合体显示供体在受体内的比例对于造血干细胞移植的随访至关重要，但也可用于证明实体器官移植后的免疫耐受情况。从历史上看，嵌合体是从基因组 DNA 中定量的，但随着技术的进步，来自供体游离 DNA 的嵌合体在实体器官移植中似乎特别相关。
参考方法直到最近一直是短串联重复技术，但新的创新技术，如数字 PCR（dPCR）和 NGS，已经彻底改变了嵌合体的定量，例如所谓的微嵌合体分析。在简要回顾嵌合体方法后，对两种新的数字 PCR 系统（Qiagen 的 QIAcuity™ dPCR 和 ThermoFisher 的 QuantStudio Absolute Q）和两种基于 NGS 的嵌合体定量方法（CareDx 的 AlloSeq HCT™ 和 GenDX 的 NGStrack™）的嵌合体定量数据进行了比较。
这些新方法与常规方法相关且一致（dPCR 方法的 r²=0.9978 和 r²=0.9974，NGS 方法的 r²=0.9978 和 r²=0.9988），并且具有相似的高性能（灵敏度、重现性、线性）。
最后，实验室中嵌合体创新方法的选择并不取决于分析性能，因为它们相似，但主要取决于活动量以及对仪器和计算机服务的访问。
