PCR-SSCP分析急性淋巴细胞白血病患者FLT3基因及FLT3/ITD基因突变及意义(英文)

Detection of FLT3 gene and FLT3/ITD mutation by polymerase chain reaction-single-strand conformation polymorphismin in patients with acute lymphoblastic leukemia

目的研究急性淋巴细胞白血病(ALL)患者DNA水平FLT3基因及其内部串联重复(ITD)突变情况。方法采用多聚酶链反应(PCR)联合单链构象多态性(SSCP)方法检测63例不同免疫分型ALL患者DNA水平FLT3基因及FLT3/ITD基因突变。结果63例ALL患者经PCR扩增发现41例(65.1%)FLT3基因检测阳性,其中前前B细胞ALL、前B细胞ALL、成熟B细胞ALL及T细胞系ALL患者FLT3基因检测阳性率分别为93.3%(14/15),77.8%(14/18),41.7%(5/12)和28.6%(4/14);前前B细胞ALL和前B细胞患者ALLFLT3基因检测阳性率84.8%,显著高于成熟B细胞ALL(41.7%,P<0.005);B细胞系ALL患者FLT3基因检测阳性率为73.3%,显著高于T细胞系ALL患者(28.6%,P<0.001)。63例ALL患者中仅有2例(3.2%)出现FLT3/ITD基因突变,均为伴有两种髓系抗原表达、免疫学检查诊断为急性混合细胞白血病患者,均伴有外周血高白细胞数、骨髓中高白血病细胞比例,预后较差。结论B细胞系ALL和T细胞系ALL患者DNA水平均可检测出FLT3基因,但B细胞系ALL患者FLT3基因检测阳性率显著高于T细胞系ALL;B细胞系ALL中细胞分化越成熟则FLT3基因检测率阳性越低。ALL患者一般不出现FLT3/ITD基因突变,FLT3/ITD基因突变检测可能有助于急性白血病基因分型及预后判断。

Objective To analyze Fms-like tyrosine kinase 3 （FLT3） gene and FLT3 internal tandem duplication （ITD）mutation in acute lymphoblastic leukemia （ALL） patients of different immunological subtypes. Methods Polymerase chain reaction-single-strand conformation polymorphism （PCR-SSCP） was used to detect FLT3 gene and FLT3/ITD mutation in 63 ALL cases. Results Among the 63 ALL cases, FLT3 gene was detected in 41 （61.5%） cases. The positivity rate of FLT3 gene in pre-pre B-lineage ALL, pre-B-ALL, B-lineage ALL and T-lineage ALL cases were 93.3% （14/15）, 77.8% （14/18）, 41.7% （5/12） and 28.6% （4/14）, respectively. The positivity rate of FLT3 gene was significantly higher in pre-pre B-ALL/pre B-ALL subtypes （84.8%） than in B-ALL subtypes （41.7%, P＜0.005）, and the rate was significantly higher in B- ALL subtypes （73.3%）than in T-ALL subtypes （28.6%, P＜0.001）. Two cases （3.2%） were found to have FLT3/ITD mutation, which were also positive for myeloid antigen expression and diagnosed as acute mixed-lineage leukemia, showing leukocytosis and high percentage of bone marrow blast cells with poor prognosis. Conclusions FLT3 gene can be detected in both B- and T-lineage ALL patients, but more frequently in the former. In B-lineage ALL patients, FLT3 gene is more frequent in cases with undifferentiated than those with differentiated blast cells. FLT3/ITD is rarely detected in ALL patients and FLT3/ITD mutation detection might be helpful to identify the genotypes and evaluate the prognosis of acute leukemia.