High-throughput sequencing of Ig/TCR genes for MRD monitoring in B-ALL patients receiving immunotherapy

Introduction While immunotherapy is highly effective in leukemia, one of the main obstacles to MRD monitoring in ALL patients are CD19- relapses that impede FCM. Detection of clonal rearrangements of Ig/TCR genes is used as a routine method for MRD monitoring along with FCM, and unlike latter is applicable in all immunotherapy patients. Materials and methods: We tested 210 bone marrow samples from 35 patients diagnosed with refractory or relapsed B-ALL aged 1-21 years, receiving immunotherapy. Initial detection of clonal rearrangements was carried out by 8 multiplex PCRs of Ig and TCR loci followed by NGS. MRD detection included NGS of previously detected rearrangements in post-treatment samples and quantitative analysis. Results: In our cohort CD19- relapses were observed twice as often as CD19+ relapses. Both CD19- and CD19+ relapses were detected timely or at least 1 month earlier by NGS than by any other method, including FCM. Conclusions: High-throughput sequencing in patients undergoing immunotherapy is necessary for an adequate assessment of MRD level. The study is supported by RFBR grants 20-015-00462, 18-315-20038 and 18-29-09132 and Charity foundation Podari Zhizn

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Artikel online veröffentlicht:
13. Mai 2020