Detection of AML-specific mutations in pediatric patient plasma using extracellular vesicle-derived RNA.

Despite high remission rates, almost 25% of patients with AML will suffer relapse 3-5 years after diagnosis. Therefore, in addition to existing diagnostic and MRD detection tools, there is still a need for the development of novel approaches that can provide information on the state of the disease. Extracellular vesicles (EVs), containing genetic material reflecting the status of the parental cell, have gained interest in recent years as potential diagnostic biomarkers in cancer. Therefore, isolation and characterization of blood and bone marrow plasma-derived EVs from pediatric AML patients could be an additional approach in AML diagnostics and disease monitoring. In this study, we attempt to establish a plasma EV-RNA-based method to detect leukemia-specific FLT3-ITD and NPM1 mutations using established leukemia cell lines and primary pediatric AML plasma samples. We were successfully able to detect FLT3-ITD and NPM1 mutations in the EV-RNA using GeneScan-based fragment-length analysis and real-time PCR assays, respectively, in samples before therapy. This was corresponding to the gDNA mutational analysis from leukemic blasts, and supports the potential of using EV-RNA as a diagnostic biomarker in pediatric AML.