荧光原位杂交检测慢性粒细胞白血病

The application of fluorescence in situ hybridization in detecting chronic myeloid leukemia

目的 探讨对慢性粒细胞自血病进行荧光原位杂交（fluorescence in situ hybridization，FISH）检测的意义。方法 对158例慢性粒细胞白血病标本采用24h短期培养法制备染色体，然后应用双色双融合BCR／ABL探针进行FISH检测，部分标本同时采用R显带技术进行染色体核型分析。结果 158例中共检出Ph阳性标本98例，其中69例（70．4％）为典型双色双融合BCR／ABL探针信号模式（1RIG2F），其余29例（29．6％）为3类12种非典型模式。各种非典型信号模式中出现频率较高的依次为：1R1G1F7例（7．1%）、2R1G1F5例（5．1％）、1R1G2F＆1R1G3F4例（4．1％）、2R2G1F3例（3．1％）。对18例有核型资料的非典型信号的病例分析显示：其中3例特殊信号系由变异Ph易位引起；2例中出现的3个融合信号来源于附加的Ph染色体；4例核型与FISH结果不吻合，提示染色体分析存在错漏之处；3例染色体为典型Ph易位，而FISH结果为单个融合信号，系由der（9）号的部分缺失所致；3例核型中未发现Ph染色体，但FISH显示40％～64％的细胞中存在一个融合信号，从而明确慢性粒细胞白血病诊断；3例是移植或经格列卫治疗后的患者，染色体均为正常核型，而FISH检测到极小比例的阳性细胞。结论 FISH在慢性粒细胞白血病诊断、判断变异易位、隐匿Ph易位、衍生9号缺失、干扰素及格列卫的疗效观察以及移植后监测等诸多方面均具有重要价值。

Objective To evaluate the clinical significance of the application of fluorescence in situ hybridization （FISH） in detecting chronic myeloid leukemia （CML）. Methods Chromosome preparation was made by using 24-hour culture. FISH technique using dual color dual fusion （DC-DF） BCR/ABL probe was performed in all 158 cases and R-banding was also employed for karyotyping in some patients. Results Among the 158 cases, 98 cases were Ph positive, of which 69 cases （70.4%） were typical FISH pattern （1R1G2F）, the other 29 cases （29. 6%） showed 12 different types of atypical FISH pattern. The most frequent atypical patterns found were 1R1G1F in 7 cases （7.1%）, 2R1G1F in 5 cases （5. 1%）, 1R1G2F and 1R1G3F in 4 cases （4.1%）, 2R2G1F in 3 cases （3. 1%）. Karyotype analysis on 18 CML cases with atypical FISH patterns demonstrated that the atypical FISH patterns were due to variant translocation in 3 cases; the additional third signal was because of a supernumerary Ph chromosome. The karyotyping results did not conform to FISH results in four cases suggesting the conceivable mistakes in karyotyping. The 1R1G1F signal pattern seen in 3 cases with classical t（9; 22） resulted from the deletion of derivative chromosome 9. The 1R1G2F signal pattern detected in 40% to 64% of interphase cells of 3 cases without Ph chromosome by conventional cytogenetic analysis suggested a submicroscopic translocation. Three cases treated with Glivec or bone marrow transplantation showed normal karyotypes with a small amount of BCR/ ABL positive cells by FISH detection. Conclusion FISH technique is of great value for the diagnosis of CML and confirmation of variant translocation, occult Ph translocation, derivative chromosome 9 deletion, therapeutic effect of interferon and Glivec as well as detection of minimal residual disease after bone marrow transplantation.