[Correlation of NPM1, FLT3-ITD mutations with leukocyte count and myeloblasts percentage in AML patients with normal karyotype].

This study was aimed to investigate the correlation of NPM1 and FLT3-ITD mutations with leukocyte count in peripheral blood and bone marrow blasts in patients with acute myeloid leukemia (AML). Fifty-one acute myeloid leukemia patients with normal karyotype from January 2009 to December 2011 were enrolled in this study. The clinical data of 51 cases were analyzed retrospectively. Out of 52 cases 22 were male, and 29 were female. The median age was 47 years old (ranged from 14 to 83 years old). The de novo patients were examined by bone marrow cytomorphology and blood routine analysis. Polymerase chain reaction was used to analyze the NPM1 and FLT3-ITD mutations. The results showed that the patients with NPM1 mutations had higher leukocyte count compared with those without mutations (30.7×10(9)/L vs 8.6×10(9)/L, P = 0.002). FLT3-ITD mutation was related to higher leukocyte count (42.38×10(9)/L vs 11.45×10(9)/L without mutation, P = 0.033) and blasts (74.0% vs 60.25% without mutation, P = 0.036). The leukocyte count and percentage of bone marrow blasts were lowest in the patients with neither mutations, and gradually increasing in the NPM1(-) mutation, FLT3-ITD(-) mutation, and NPM1(+) mutation, FLT3-ITDI(+) mutation, and NPM1(+)/FLT3-ITD(+) mutation groups (P < 0.05). The patients tended to have NPM1 (P = 0.002) and FLT3-ITD (P = 0.033) mutations when their leukocyte counts were more than 12.55×10(9)/L and 37.85×10(9)/L, respectively. Those with bone marrow blast more than 72.25% showed higher rate of FLT3-ITD mutation (P = 0.008). Patients with NPM1 mutations had higher complete remission rate than those without NPM1 mutation (78.13% vs 40.0%, χ(2) = 4.651, P = 0.031) after remission induction therapy. It is concluded that both NPM1 and FLT3-ITD mutations are linked to higher leukocyte count and blast percentage, suggesting that both mutations may be associated with increased proliferation of leukemia cells, and may have a synergistic function in stimulating proliferation.