OBJECTIVETo investigate the clinical characteristics of newly diagnosed acute myeloid leukemia (AML) with NPM1 mutation.

METHODSNPM1 mutation (including A, B, D mutation type) was detected in 206 patients with newly diagnosed AML by real-time quantitative RT-PCR.

RESULTSThe incidence of NPM1 mutation was 15.5% in total AML patients and 32.5% in normal karyotypes AML patients. The characteristics of 174 NPM1 wild type patients v.s. that of 32 NPM1 mutation patients was as follow, median age (46 vs 35 years old, P < 0.01), WBC counts (27 × 10(9)/L vs 8 × 10(9)/L, P < 0.01), BPC (82 × 10(9)/L vs 36 × 10(9)/L, P < 0.01), proportion of AML-M(5) (31.2% vs 5.8%, P = 0.01), incidence of normal karyotypes (92.6% vs 40.8%, P < 0.01), incidence of FLT3-ITD-positive (25.0% vs 7.5%, P < 0.01), CD34-positvie (23.3% vs 69.5%, P < 0.01), cases with fusion gene (0 vs 47.1%, P < 0.01). No statistic difference was found in sex, percentage of blasts in bone marrow, complete remission rate, overall survival between the two groups. Relapse-free survival in AML patients with NPM1-mutation and FLT3-ITD-negative tended to be higher than in those with NPM1-mutation and FLT3-ITD-positive.

CONCLUSIONIt is necessary to detect NPM1 mutation and FLT3-ITD in newly diagnosed AML patients, especially in patients with high WBC and BPC, CD34-negative, normal karyotype, which might help to molecular classification and treatment.