HLA-DR-negative AML (M1 and M2): FLT3 mutations (ITD and D835) and cell-surface antigen expression

FLT3 mutations and cell-surface antigen were investigated in 29 DR-negative (DR−) M1/M2 AML samples in comparison with 30 DR-positive (DR+) M1/M2 AML samples. FLT3-ITD was detected in 59.3% and D835 was detected in 7.4% of the samples. The incidence of FLT3-ITD was higher in the DR− group (59.3%) than in the DR+ group (17.9%; P = 0.002). The DR− status was associated with the CD34− (82.8%), CD7− (92.9%) and CD45RO+ status (76%). Our results indicated that FLT3 mutation is the most common gene alteration found in the DR− M1/M2 AML. These results are important for further characterizing this phenotypic AML entity.