多色流式细胞术在222例儿童急性白血病免疫分型中的应用

目的　探讨多色流式细胞术在儿童急性白血病 (AL)免疫分型中的应用价值 ,了解儿童AL抗原表达规律和免疫亚型的分布情况。方法　采用CD45/侧散射 (SSC)双参数散点图设门方法进行三色或四色流式细胞术细胞表面及浆内分化抗原的分析。结果　 2 2 2例儿童白血病免疫分型可分为 4类 :未分化型占 0 9% ,急性髓细胞性白血病 (AML)占 35 1% ,急性淋巴细胞白血病 (ALL)占5 5 9% ,混合型急性白血病占 8 1%。 12 4例儿童ALL中 ,B淋巴细胞白血病 (B ALL)占 75 8% ,T淋巴细胞白血病 (T ALL)占 2 4 2 %。AML伴淋巴系抗原表达为 2 4 4 % ,主要表达CD7(12 8% ) ,其次为CD19(6 4 % )和CD2 (5 1% )。B ALL及T ALL伴髓系抗原表达分别为 36 2 %及 30 0 % ,主要表达CD13(18 5 % ) ,其次为CD15(11 3% )、CD11b(6 5 % )和CD3 3 (4 3% )。CD117和CD56主要在AML中表达 ,分别为 73 3%和 38 6 % ,而在ALL中表达率极低 ,仅为 2 0 % (P <0 0 1)。胞浆内抗原CD2 2 、CD3 及髓过氧化物酶 (MPO)分别特异地表达在B ALL、T ALL及AML ,并比胞膜抗原检测更为敏感。结论　应用多色流式细胞术几乎能对所有儿童急性白血病进行准确分型 ,对儿童白血病患者的治疗方案选择及预后判断等均有重要价值。

Immunophenotyping of 222 children with acute leukemia by multi-color flow cytometry

Objective Acute leukemia (AL) is one of the most common malignant diseases in children. AL immunophenotypes are known to be benefit to the predictable prognoses and specific therapy. Recently, the accuracy of AL immunophenotyping was dramatically improved with the application of the flow cytometry, the new monoclonal antibodies, the improvement of the gating strategies and the multi-parameter analytic techniques. The aim of this study was to evaluate the value of multi-color flow cytometry in the immunophenotyping of acute leukemia in children. Methods Three- or four-color flow cytometry and CD 45/Side Scatter (SSC) gating were used to analyze the surface and cytoplasmic (Cy) antigen expressions in 222 successive cases of childhood acute leukemia. Results Cells from 222 cases of children with acute leukemia were analyzed. Based on the diagnostic criterion proposed by European Group for the Immunological Characterization of Leukemia (EGIL), four categories could be identified: the undifferentiated type accounted for 0.9%, acute myeloid leukemia (AML) 35.1%, acute lymphoblastic leukemia (ALL) 55.9%, and mixed lineage AL 8.1%. Of 124 patients with ALL, 94 patients (75.8%) were classified as B lineage and 30 patients (24.2%) T lineage ALL. Antigen aberrant expressions were found in AML (24.4%), B lineage ALL (36.2%) and T lineage ALL (30.0%). CD 7 was the most commonly expressed lymphoid antigen in AML (12.8%), followed by CD 19 (6.4%) and CD 2 (5.1%). CD 13 was the most commonly expressed myeloid antigen in ALL (18.5%), followed by CD 15 (11.3%), CD 11b (6.5%) and CD 33 (4.3%). CD 117 and CD 56 presented in 73.3% and 38.0% cases of AML, respectively, but were generally absent on blast cells of ALL. CyCD 22, CyCD 3 and CyMPO were specifically expressed in B lineage, T lineage and myeloid lineage leukemia, respectively, and the first two could be more sensitively detected than they were on cell membrane surface. Conclusions Multi-color flow cytometry is a reliable technique in the diagnosis, differential diagnosis and classification of acute leukemia in children.