染色体t(8;21)急性髓系白血病cCD79a/cCD22的异常表达

目的报道新发现的4例cCD79a／cCD22异常表达的t（8；21）急性髓系白血病（AML）。方法分析4例患者的细胞形态学、免疫学、细胞遗传学、分子生物学（MICM）分型及临床特征。结果伴cCD79a／cCD22表达的t（8；21）（q22；q22）的AML特点：①无显著的性别差异；②发病年龄较轻；③可有髓外浸润；④外周血白细胞计数不增高；⑤骨髓细胞形态学显示为粒细胞白血病，且原始细胞显著增多；⑥免疫表型均为B淋巴系和髓系共表达，CD34表达阳性，且为高表达；⑦染色体改变除t（8；21）（q22；q22）外，亦常见性染色体缺失及复杂染色体改变；⑧AML1／ETO融合基因检测均阳性；⑨对兼顾髓系和淋巴系的联合治疗方案反应较好。结论t（8；21）AML患者易伴有B细胞表型共表达。

Abnormal expression of cCD79a/cCD22 in acute myeloid leukemia with t (8;21)

OBJECTIVE: To report abnormal expression of cCD79a/cCD22 in four cases of acute myeloid leukemia (AML) with t (8;21). METHODS: The characteristics of morphology, immunophenotype, chromosome karyotype (MIC) and clinical manifestations of 4 AML patients with t (8;21) expressing cCD79a/cCD22 were analyzed. RESULTS: The features of the 4 patients were: (1) no difference in gender; (2) young age; (3) exmedullary infiltration may be present; (4) normal number of white blood cells in peripheral blood; (5) morphology showed acute myeloid leukemia with high percentage of blast cells; (6) B-lymphoid and myeloid immunophenotype, and high expression of CD34; (7) frequent depletion of Y chromosome and complex changes of chromosomes; (8) positive for AML1/ETO fusion gene; (9) response well to chemotherpy regimen which simultaneously treated myeloid and lymphocytic leukemia. CONCLUSION: Abnormal expression of cCD79a/cCD22 in AML with t (8;21) (q22;q22) suggested that this kind of leukemia might be related with abnormal expression gene of B cell.