PMC9266701_01
Increase in hemoglobin and hematocrit after AML chemotherapy, while the patient was in CR. Progressive increase of hemoglobin and hematocrit until August 2021, when the patient started to be treated with phlebotomies and hydroxiurea. AML: acute myeloid leukemia. CR: complete remission. HCT: hematocrit (%). HB: hemoglobin (g/dl).
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After two years, while still in CR, the patient's blood counts showed a progressive increase in hemoglobin and hematocrit (Figure 1).
Fish plot showing variation of mutations over time. Variant Allele Frequency by NGS (Percentage of sequence reads observed matching a specific DNA variant divided by the overall coverage at that locus); FA: Fractional abundance by ddPCR (Absolute quantification of mutant clone divided by the absolute quantification of mutant in addition to wild type clones); AML: Acute Myeloid Leukemia; PV: Polycythemia Vera.
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Figure 2 shows the expansion of the JAK2 V617F mutated clone.
Droplet digital PCR assay for JAK2 V617F mutation detection in BM-MNCs during the disease course. Profile of JAK2 V617F of the sequential samples at diagnosis and follow-up, analyzed by ddPCR. Representative 1-D plots of the ddPCR amplification of a JAK2 V617F mutant (left panel) and a JAK2 wild-type allele (right panel). The pink line indicates the threshold. NTC: no template control.
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To further exclude the presence of a JAK2-mutated clone at the time of AML diagnosis, we performed a digital droplet PCR (ddPCR) assay, which has a sensitivity of 0.05%, which resulted positive for JAK2 V617F (Figure 3), suggesting that this mutation was present at a subclonal levels at the time of AML diagnosis and undetectable when measured using other conventional diagnostic tools.