[Dynamic detection of FLT3 gene in patients with AML and its significance]

Minimal residual disease (MRD) is an important cause of relapse and disease-free survival time decrease in patients with acute myeloid leukemia (AML). This study was aimed to explore the role of FLT3 gene in AML pathogenesis and its significanse for detection of MRD. Using genomic PCR, 125 AML patients were detected for FLT3 gene expression before and after chemical therapy and allogeneic hematopoietic stem cell transplantation (allo-HSCT), meantime the AML patients with FLT3 positive expression were observed by follow-up. The results showed that the sensitivity of PCR was 10(-4) in FLT3 gene detection; the rates of FLT3 positive expression were 69.6% and 44.90% in the newly diagnosed AML patients and complete remission (CR) patients respectively. The rate of FLT3 expression coverted to negative was 48.98% in treated AML patients, while no change of FLT 3 expression was found in 6.12% treated patients. The FLT3 expression converted to positive in relapsed patients, and FLT3 expression remains positive in non-remitted patients. The CR rate in FLT3 positive expression patients before treatment was significantly lower than that in FLT3 negative expression patients, the difference of which was statistically significant (p < 0.05). The AML relapse rate in FLT3 positive patients was significantly higher than that in FLT3 negative expression patients (p < 0.05). It is concluded that FLT3 gene expression is related to leukemia pathogenesis; the dynamic levels of FLT3 expression before and after treatment can be used for estimating prognosis of AML patients and detecting MRD.