62. Molecular profile of patients with Acute Myeloid Leukemia at diagnosis

Aly Abdelkareem

Paulo Campregher

Paulo Campregher, MD, PhD is a hematologist and molecular pathologist in charge of cancer genomics assays in solid tumors and hematology at Hospital Israelita Albert Einstein, São Paulo, Brazil. He is also a professor at Health Sciences Graduate School from Albert Einstein Research Institute, São Paulo, Brazil, with a research focus on genomics of myeloid malignancies.


Paulo Campregher, Susana Rosa, Caroline Silveira, Larissa Lima, João Bosco de Oliveira, Karla Pelegrino

Hospital Israelita Albert Einstein, Sao Paulo, SP, Brazil

The characterization of the molecular profile in acute myeloid leukemia (AML) is essential for diagnosis, prognosis, risk stratification and therapeutic management. The aims of this study were: 1) To evaluate the molecular profile of patients with acute myeloid leukemia in a clinical laboratory at diagnosis and 2) To evaluate the sensitivity of different strategies for detection of FLT3 ITD mutation. We included 118 patients with a diagnosis of acute AML from March 2018 to December 2021 from a single diagnostic center. After extraction of DNA from peripheral blood or bone marrow samples were subjected to library preparation according to the Illumina Trusight Myeloid Sequence Panel, sequenced in a NextSeq550 (Illumina) and processed in a bioinformatic pipeline that used the following variant callers: Mutec1, Mutect2, Freebayes and Pindel. In addition we used ITDSeq for FLT3 ITD detection. Of the samples analyzed, 86.4% (102/118) presented clinically relevant variants. The most frequently mutated genes were FLT3 (26.4%), DNMT3A (24.5%), ASXL1 (16.7%), SRSF2 (14.7%), TP53 (12.7%), NPM1 (12,7%), TET2 (10.8%), NRAS (10.8%) and IDH2 (10.8%). Of 24 samples harboring FLT3-ITD mutation detected by capillary electrophoresis, our bioinformatics pipeline detected 83%, and the algorithm ITDseek also detected 83% of the mutations. When both strategies were combined, the detection rate was 95%. In one case, the only positive method was capillary electrophoresis. The data obtained reinforce the need to include panels like this in the diagnostic routine and reveal the importance of complementary analysis of the FLT3-ITD mutation by capillary electrophoresis.