ABSTRACT
UNLABELLED: In 83 patients with cytogenetically normal acute myeloid leukemia (CN-AML), those with NPM1 and wild-type FLT3 (FLT3-wt) mutation and their poor prognostic combination had distinctive flow cytometric findings: CN-AML with a mutation of NPM1 (NPMI-Mt) were CD34(-), CD14(-), and CD2pos and CD4; those with FLT3-internal tandem duplications (ITD) were CD56pos, those with NPM1-Mt and FLT3-wt were CD34(-) and CD56(-); and those with poor prognostic combination NPM1-wt and FLT3-ITD were CD34pos and TdTpos. METHODS: We retrospectively correlated NPM1 and FLT3 mutation status with flow cytometric profile of leukemic blasts in 83 adult patients with cytogenetically normal acute myeloid leukemia (CN-AML). RESULTS: Mutation of the NPM1 gene (NPM1.mt) was found in 39 (47%) of 83 patients, and internal tandem duplication (ITD) of the FLT3 gene (FLT3-ITD) was seen in 38 (46%) of 83 patients. Patients with CN-AML and with NPM1.mt were less likely to express CD34 (33% vs. 93%; 2P = .0001), CD2 (0% vs. 14%; 2P = .0187), and CD14 (6% vs. 22%, 2P = .0476), and were more likely to express CD4 (65.5% vs. 37%; 2P = .0367) and CD19 (49% vs. 27%; 2P = .0506). The patients with CN-AML and with FLT3-ITD were more likely to express CD56 (47% vs. 23%; 2P = .0393). Moreover, patients with favorable prognostic combination of NPM1.mt and wild-type (wt) FLT3 (n = 18) were less likely to express CD34 (33% vs. 74% all others; 2P = .0021) and CD56 (6% vs. 37% all others; 2P = .0072). The group with an unfavorable prognostic combination of NPM1-wt and FLT3-ITD (n = 17) were more likely to express CD34 (88% vs. 45% all others; 2P = .0011) and TdT (40% vs. 2% all others; 2P = .0054). CONCLUSIONS: In patients with CN-AML, characteristic flow cytometric profile is associated with NPM1 and FLT3 mutation status.
