[Application of multiple nucleotide polymorphism analysis in chimerism detection after allogeneic hematopoietic stem cell transplantation].

Objective: To establish a new method for chimerism analysis after allogeneic hematopoietic stem cell transplantation by using multiple nucleotide polymorphism sequencing (MNPseq) , and to explore its feasibility and superiority. Methods: One hundred MNP fragments were screened and chimeric analysis was performed by high-throughput sequencing technology. The accuracy and sensitivity of the method were verified by simulating chimeric samples and post-transplant samples and comparing them with short tandem repeat (STR) analysis, fusion gene quantitative detection and flow cytometry for minimal residual disease. Results: The accuracy and sensitivity of MNPseq were better than those of STR, in which the sensitivity could reach 0.01%, about 100 times more sensitive than STR. MNPseq could further distinguish 42 STR fully chimeric samples, and after corrected by cutoff value, it was correlated with the quantitative detection of fusion gene. MNPseq could correct false positive of STR caused by the shadow peak, and could be used to detect chimeric samples lacking pre-transplant information from donors and recipients. Conclusion: MNPseq analysis based on high-throughput sequencing is a more accurate and sensitive chimerism detection method, and it solves the problem that chimerism cannot be detected due to the lack of pre-transplant information, which has extremely high clinical application value.