应用双色荧光原位杂交检测急性髓系白血病中inv(16)重排的研究

A dual-color fluorescence in situ hybridization study on the detection of inv(16) in acute myeloid leukemia

目的 探讨双色荧光原位杂交 (dual- color fluorescence in situ hybridization,D- FISH)对检测急性髓系白血病 (acute myeloid leukemia,AML )中 inv(16 ) (p13q2 2 )异常的价值。方法 采用平滑肌肌球蛋白的重链基因断裂点分开的两侧序列作为探针 ,分别以红、绿荧光素直接标记后对 11例形态学诊断为急性粒单核细胞白血病伴异常嗜酸细胞 (acute myelomonocytic leukemia with abnormal marroweosinophils,M4 Eo)或形态学上无 M4 Eo特征但经逆转录 -聚合酶链反应 (reverse transcriptase- polymerasechain reaction,RT- PCR)或单色 FISH证实有核心结合因子 -平滑肌肌球蛋白的重链基因融合基因的AML患者进行 D- FISH检测 ,并将其结果与细胞形态学、染色体核型分析、单色 FISH和 RT- PCR相联系或比较。结果 G带核型分析发现 4例 inv(16 ) (3例 M4 Eo和 1例 M2 a) ,其中 1例同时伴有 2 2三体(+2 2 ) ;其余未发现 inv(16 )的 7例中 ,5例为正常核型 (3例 M4 Eo,2例 M4 ) ,1例 (M2 a)有 5 p+和 +2 2异常 ,1例 (M4 Eo)有 t(9;2 2 )易位。 11例 D- FISH均为阳性 ,其平均阳性细胞检出率为 93.4 5 % (86 .6 %～98.7% )。其中 4例患者除 inv(16 )外还在部分细胞中发现 16 p13的微小缺失。D- FISH检测结果与 RT-

Objective: To explore the value of dual-color fluorescence in situ hybridization (D-FISH) in the detection of inv(16) in acute myeloid leukemia (AML). Methods: Eleven AML patients were investigated by D-FISH with two-color break apart probe for MYH11 labeled directly by fluorescein isocyanate (FITC) and a Texas Red. The results were associated or compared with those of cell morphology, cytogenetics, single color fluorescence in situ hybridization (FISH) and reverse transcription-polymerase chain reaction (RT-PCR). Results: Four cases (M4Eo three cases, M2a one case) had inv (16), of which one had trisomy 22 in addition to inv(16), while the other seven cases had no inv(16), of which, five cases (M4Eo three cases, M4 two cases) had a normal karyotype, one (M2a) had 5p+ and trisomy 22, one (M4Eo) had a translocation t (9; 22) on G-banded karyotypic analysis. All 11 cases of AML were positive for the rearrangement of inv(16) detected by D-FISH. The average positive cell rate for these 11 AML patients was 93.45% (range 86.6%-98.7%). Of them, four had a minimal deletion of 16p13 in addition to inv(16). The results of D-FISH coincided with those of RT-PCR or single color FISH. Conclusion: D-FISH is a powerful tool for the detection of inv(16) due to its sensitivity and specificity. For raising the detecting rate of inv(16), it is necessary to screen inv(16) rearrangement by D-FISH in all M4- and M2-AML cases or the cases with trisomy 22, no matter whether they are accompanied by bone marrow eosinophilia.