外周血微小残留白血病细胞的定量检测及临床应用

Quantitative detection of minimal residual leukemia cells in peripheral blood and clinical application

目的:探讨定量检测急性白血病患者外周血微小残留白血病细胞的临床价值。方法:采用极限稀释定量PCR法对25例初诊急性白血病患者及1个疗程化疗后外周血标本进行Fms样酪氨酸激酶3(FLT3)基因表达进行检测,并定量计算体内残留的白血病细胞数,10例门诊健康体检者为对照组。结果:①25例初诊急性白血病患者外周血标本FLT3基因表达阳性率为80.0%(20/25),其中急性髓细胞白血病(AML)88.2%(15/17),急性淋巴细胞白血病(ALL)62.5%(5/8)。②20例FLT3基因表达阳性的白血病初诊患者外周血DNA含量为(2.36±1.25)×108μg.L-1,外周血含有的白血病细胞数为(18.66±8.79)×106.μL-1。经过1个疗程化疗后,1例未缓解者,外周血DNA含量为1.69×107μg.L-1,残留的白血病细胞数为1.01×106.μL-1;3例部分缓解者,外周血DNA含量为(0.57±0.24)×106μg.L-1,残留的白血病细胞数为(1.82±0.19)×103.μL-1;16例完全缓解者,其中FLT3基因表达阴性9例,FLT3检测阳性7例,其外周血DNA含量为(0.16±0.06)×106μg.L-1,残留的白血病细胞数为(1.86±1.31)×102.μL-1。健康对照组FLT3基因表达均为阴性。结论:定期、定量检测急性白血病患者治疗后体内残留的白血病细胞数,有助于临床观察白血病治疗效果及时调整治疗方案。

Objective To explore the clinical application significance of quantitative detection of minimal residual leukemia cells in peripheral blood in acute leukemia patients. Methods Using PCR amplification of quantitative method of limited dilution, the FLT3 gene was detected in blast cells of peripheral blood from 25 newly diagnosed cases of acute leukemia, and the number of minimal residual leukemia cells in newly diagnosed cases and the cases after one course of chemotherapy was calculated respectively. 10 healthy subjects were used as control group. Results （1）The positive rate of FLT3 gene in 25 newly diagnosed cases of acute leukemia sample was 80% （20/ 25）, the positive rate in acute myeloblastic leukemia （AML） patients was 88.2% （15/17） and in acute lymphocytic leukemia （ALL） was 62.5% （5/ 8）.（2）The mean DNA content in peripheral blood in 20 cases with FLT3 positive expression in newly diagnosed group was （2. 36±1.25） × 10^8 /μg · L^-1 , being equal to （18.66± 8.79） × 10^6 leukemia cells in every microliter peripheral blood. After one course of chemotherapy , there was 1 case without remission, the DNA content in peripheral blood was 1.69× 10^7μg · L^-1 , being equal to 1.01 × 10^6 leukemia cells in every microliter peripheral blood; there were 3 cases with partial remission, the mean DNA content in peripheral blood was （0.57±0. 24） × 10^6 μg · L^-1, being equal to （1.82±0.19） ×10^3 leukemia cells in every microliter peripheral blood. There were 9 cases with complete remission with FLT3 negtive expression, and 7 cases with complete remission with FLT3 positive expression, the mean DNA content in peripheral blood was （0. 16±0.06）× 10^6 μg· L^-1 , being equal to （1.86±1.31） × 10^2 leukemia cells in every microliter peripheral blood. Conclusion The quantitative and periodic detection of minimal residual leukemia cells would help to evaluate leukemia chemotherapy efficiency and to adjust treatment scheme in time.