title: [FLT3 internal tandem duplication in patients with acute promyelocytic leukemia].
abstract: OBJECTIVE
  To analyze the mutation of FLT3 internal tandem duplication (FLT3-ITD) in bone marrow cells from patients with newly-diagnosed acute promyelocytic leukemia (APL).
  
  
  METHODS
  The mutation of FLT3-ITD in bone marrow mononuclear cells (MNCs) from 103 APL patients were screened by polymerase chain reaction (PCR) and the clinical features of ITD positive patients were analyzed.
  
  
  RESULTS
  FLT3-ITD mutations were identified in 19.4% (20/103) patients. It was associated with short/variant form of PML-RAR alpha isoforms (P < 0.0001). Among the 20 patients with FLT3-ITD mutation, 16 presented with short, 2 with variant and 2 with long form of PML-RAR alpha isoforms. Patients with FLT3-ITD mutation also presented significantly higher initial peripheral white blood cell count (WBC) (P < 0.01), especially in those with short/variant PML-RAR alpha isoforms (P = 0.015). For patients with long form PML-RAR alpha, there was no significant difference in initial WBC. Out of FLT3-ITD positive patients, 18/20 (90%) obtained complete remission and 16 evaluable patients (2 lost follow-up) remained in first remission in a median follow-up of 26 (11-47) months.
  
  
  CONCLUSIONS
  FLT3-ITDs are frequently identified in patients with newly diagnosed APL. FLT3-ITD mutation is associated with short/variant form of PML-RAR alpha fusion gene and higher initial WBC. No significant impact on treatment outcome was observed with a limited follow-up.
authors.affiliation: Department of Hematology, Shanghai Institute of Hematology, RuiJin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China.
authors.forename: Yong-mei
authors.initials: YM
authors.lastname: Zhu
authors.forename: Yuan-fang
authors.initials: YF
authors.lastname: Liu
authors.forename: Su-jiang
authors.initials: SJ
authors.lastname: Zhang
authors.forename: Zhi-xiang
authors.initials: ZX
authors.lastname: Shen
authors.forename: Jiong
authors.initials: J
authors.lastname: Hu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D015473:Leukemia, Promyelocytic, Acute / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D020080:Tandem Repeat Sequences; D051941:fms-Like Tyrosine Kinase 3 / Q000235:genetics*
chemical_list: C497970:FLT3 protein, human; D051941:fms-Like Tyrosine Kinase 3