伴有t(2;21;8)(p12;q22;q22)急性髓系白血病M2的MICM特征与诊断的探讨

MICM Characteristics and Typing Diagnosis in Acute Myelogenous Leukemia Patients (AML-M2) with Complex Karyotype t(2;21;8)(p12;q22;q22)

本研究应用形态学、免疫学、细胞遗传学和分子生物学(M ICM)分型技术联合检测伴有复杂变异核型t(2;21;8)(p12;q22;q22)的急性髓系白血病(AML-M2),并探讨其特征及诊断意义。取患者骨髓涂片行瑞氏-姬姆萨染色和细胞化学染色进行骨髓细胞形态学FAB分型;流式细胞术(FCM)检测白血病细胞免疫表型;新鲜骨髓细胞短期培养法常规制备染色体标本,RHG显带技术进行核型分析,采用双色双融合AML/ETO探针及全染色体涂染(CP)探针检测有丝分裂中期荧光原位杂交(FISH)信号,并与常规R显带细胞遗传学检测结果进行比较分析,巢式RT-PCR检测AML1-ETO融合转录本。结果表明:病例1原始粒细胞伴嗜酸粒细胞及单核细胞比例增高;病例2符合以异常中幼粒细胞增高为主的AML-M2b;染色体核型分析结合FISH检测证实两例患者均存在t(2;21;8)(p12;q22;q22)复杂核型;AML1/ETO融合基因转录本阳性,免疫表型显示CD34和HLA-DR共表达,伴CD19和CD56表达。结论:应用WHO提出的细胞形态学、免疫学、细胞遗传学和分子生物学技术(M ICM)联合检测的实验室诊断方法对准确诊断复杂变异核型t(2;21;8)(p12;q22;q22)AML的分型具有重要意义。

This study was purposed to investigate the acute myeloid leukemia with complex karyotype t （2;21;8） （ p12; q22 ; q22） （ AML-M2 ） by using morphologic, immunologic, cytogenetic and molecular biologic clasification technique （MICM） and to analyze the MICM characteristics of AML-M2 and their diagnostic significance. The FAB typing of bone marrow cells （BMCs） was performed by Wright-Giemsa staining and histochemical staining of BM smears; the immunophenotype of leukemic cells was detected by flow cytometry ; the karyotypes of chromosome samples prepared by short-term （48 hours） conventional culture of fresh BMCs were analyzed by RHG banding technique; the FISH signaling in mitotic metaphase was determined by dual color and dual fusion AML/ETO probe and chromosome painting probe, and was compared with results of conventional cytogenetic assay; the AML/ETO fusion transcripts were detected by nested RT-PCR. The results indicated that the bone marrow smears of case 1 showed extremely hyperplasia with myelo- blasts in which a ratio of eosinophilic granulocytes and monocytes increased. Case 2 accorded with AML-M2b in which abnormal increase of myelocytes mainly appeared. The complex karyotype t（2;21;8 ）（p12;q22;q22） was detected by cytogenetic analysis combined with FISH in both two cases and AML1/ETO fusion transcripts were found by RT-PCR as well. The immunophenotype assay showed high co-expression of CD34 and HLA-DR accompanied with CD19 and CD56 expressions. It is concluded that application of MICM has an important significance for correct diagnostic typing of AML-M2 with complex karyotype variant of t（8; 21）（p12;q22;q22）.