MICM分型诊断在鉴别M_2和M_3型急性髓性白血病中的意义

Significance of MICM classification diagnosis in differentiating between M_2 and M_3 subtype of acute myeloid leukemia

目的:探讨形态学、免疫学、细胞遗传学和分子生物学(MICM)分型诊断在鉴别M2、M3 型急性髓性白血病(AML)中的意义。方法:对10 例按FAB方案难以区分M2、M3 型的AML及2 例在基层医院诊断为M3b,用全反式维甲酸(ATRA)治疗未获缓解的患者应用常规细胞遗传学(CC)进行核型分析;以筑巢式逆转录聚合酶链反应(nested RT PCR)技术检测PML/RARa及AML1/ETO融合基因转录本;以流式细胞术检测白血病细胞免疫表型。对2例在基层医院诊断为M3b 而用ATRA治疗效果不好的病例用间期双色FISH 技术检测AML1/ETO融和基因。结果:12例患者中,4例有t(8;21),AML1/ETO融合基因转录本阳性,确诊为M2;2 例有t(15;17),PML/RARa融合基因转录本阳性,确诊为M3;其他6例患者为正常核型,其中,3例AML1/ETO阳性,确诊为M2;1 例PML/RARa阳性,确诊为M3;2 例PML/RARa及AML1/ETO均为阴性,1 例免疫表型为CD13+、CD33+、CD34+、CD19-,最后诊断为M2,另1 例免疫表型为CD13+、CD33+、CD34-、CD19-,最后诊断为M3。2例行FISH检测的患者AML1/ETO融和基因均为阳性。结论:对形态学无法鉴别M2、M3 的AML进一步进行细胞遗传学、分子生物学及免疫学检测,可提高确诊率,并为治疗提供可靠的依据。

Objective:To explore the significance of Morphologic, Immunologic, Cytogenetic and Molecular biologic (MICM) classification diagnosis in differentiating between M_2 and M_3 subtype of acute myeloid leukemia (AML).Method:Conventional cytogenetics (CC), nested-reverse transcription-polymerase chain reaction (nested-RT-PCR) and flow cytometry were simultaneously carried out to detect chromosomal karyotype, PML-RARa and AML1/ETO fusion gene transcript, and immunophenotype in 10 cases of AML that couldn't be differentiated between M_2 and M_3 subtype by FAB classification and 2 cases of patients who were diagnosed as M_3b in basic hospital and didn't attain complete remission (CR) after all-trans-retinoic acid (ATRA) induction chemotherapy. For the 2 patients diagnosed as M_3b in basic hospital, AML1/ETO fusion genes were detected by interphase dual-color fluorescence in situ hybridization (FISH).Result:In 12 patients, 4 cases had t(8;21) and AML1/ETO fusion gene transcript positive, diagnosed as M_2; 2 cases had t(15;17) and PML-RARa fusion gene transcript positive, diagnosed as M_3; the other six cases had a normal karyotype, of which, 3 cases were AML1/ETO fusion gene transcript positive, diagnosed as M_2; 1 case was PML-RARa fusion gene transcript positive, diagnosed as M_3; 2 cases were PML-RARa and AML1/ETO fusion gene transcript negative, one patient's immunophenotype was CD13+, CD33+, CD34+, CD19-, diagnosed as M_2; another was CD13+, CD33+, CD34-, CD19-, diagnosed as M_3. 2 patients detected by FISH were AML1/ETO fusion gene positive.Conclusion:Cytogenetic, molecular biologic and Immunologic detection should be carried out in patient who couldn't be differentiated between M_2 and M_3 subtype by Morphology. This can increase the rate of definite diagnosis and provide the dependable basis for treatment.