Transcription profiling by array of human mononuclear cells from patients with multilineage dysplasia and wild-type or mutant copies of FLT3 and NPM1

Multilineage dysplasia (MLD) has no impact on biological, clinico-pathological and prognostic features of AML with mutated nucleophosmin (NPM1) NPM1-mutated AML is a provisional entity in the WHO-2008 classification of myeloid neoplasms. The significance of concomitant multilineage dysplasia (MLD) in NPM1-mutated AML is unclear. Thus, in the WHO-2008 classification, NPM1-mutated AML with MLD is classified as AML with myelodysplasia(MD)-related changes. We evaluated the MLD impact in 378 NPM1-mutated AML patients. MLD was found in about 25% cases. Except for a lower WBC and FLT3-ITD incidence in MLD+ group, no significant differences were observed in age, sex, cytogenetics and FLT3-TKD between NPM1-mutated AML with and without MLD. Notably, NPM1-mutated AML with/without MLD showed overlapping immunophenotype (CD34-negativity) and GEP (CD34 downregulation and HOX genes upregulation). Moreover, OS and EFS did not differ among NPM1-mutated AML patients, independently of whether they carried or not MLD, the NPM1-mutated/FLT3-ITD negative cases showing the better prognosis. Lack of MLD impact on survival was confirmed by multivariate analysis that highlighted FLT3-ITD as the most significant prognostic parameter in NPM1-mutated AML. Our findings indicate that NPM1 mutations rather than MLD dictate the distinctive features of NPM1-mutated AML. Thus, irrespective of MLD, NPM1-mutated AML should be considered as one disease entity clearly distinct from AML with MD-related changes. These findings have important diagnostic and prognostic implications in AML. All bone marrow samples were obtained from untreated patients at the time of diagnosis. Cells used for microarray analysis were collected from the purified fraction of mononuclear cells after Ficoll density centrifugation. 48 samples