双色荧光原位杂交技术检测B系急性淋巴细胞白血病IgH基因重排

Detection of IgH Gene Rearrangement in B-cell Acute Lymphoblastic Leukemia by Dual-color Fluorescence in Situ Hybridization

目的研究急性B淋巴细胞白血病(B-ALL)中免疫球蛋白重链基因(IgH)重排的发生率,并分析其临床特点及其他细胞遗传学特征。方法选取158例初诊B-ALL患者的骨髓标本,应用短期培养法制备染色体悬液,采用R显带技术进行核型分析。选用位于14q32 IgH基因两端的序列特异性探针,应用荧光原位杂交技术(FISH)对158例患者的染色体悬液进行IgH基因重排检测。结果 158例中,检出IgH基因重排阳性11例(6.9%),其阳性细胞比例为10.5%～88.2%。结合染色体核型分析发现,11例中同时伴随染色体核型异常的有9例,其中8例为复杂异常。9例染色体异常病例中明确累及14q32的有5例。不同染色体核型异常患者IgH基因重排阳性率差异有统计学意义(P<0.05),其中染色体复杂异常患者IgH基因重排阳性率(14.5%)高于正常核型(3.8%)及非复杂异常(1.9%)。而不同性别、年龄及不同白细胞、血红蛋白、血小板水平患者IgH基因重排阳性率差异均无统计学意义(均P>0.05)。结论 IgH基因重排在B-ALL中有较高的发生率。FISH技术以其较高的敏感性和特异性对提高IgH基因重排的检出率起着重要的作用。

Objective To explore the incidence of IgH gene rearrangement in B-cell acute lymphoblastic leukemia（B-ALL） and to analyze its clinical and other cytogenetic features.Methods One hundred and fifty-eight newly diagnosed B-ALL patients were enroled in this study.Conventional R-banding assay was used for karyotypic analysis.Fuorescence in situ hybridization（FISH ） was performed to analyze the IgH gene rearrangement.Results IgH gene rearrangements were found in 6.9%patients,and the percentage of IgH gene rearrangement positive cells ranging from 10.5%to 88.2%.Among 11 B-ALL cases with IgH rearrangements showed by FISH analysis,2 cases presented normal karyotype.In 9 cases with chromosomal abnormalities,complex karyotype was detected in 8 cases and rearrangements involving 14q32 were found in 5 cases.The incidence of IgH gene rearrangement in those cases with complex chormosome abnormalities was higher than that in the normal karyotype and non-complex chromosome abnormalities（14.5%vs3.8%vs 1.9%,P〈0.05）.Conclusion The IgH gene rearrangement is a recurrent cytogenetic abnormality in B-ALL.FISH analysis plays an important role in identifying the rearrangements involving the IgH gene.