急性白血病细胞CD19和CD20表达比较

本研究目的是观察CD19和CD20在急性白血病（AL）细胞中的表达与分布,为急性B系白血病靶向分子的选择提供合理依据.采用27个荧光直标单克隆抗体及CD45/SSC双参数设门多色流式细胞术对321例AL细胞进行免疫诊断和分型,并对CD19和CD20在各种类型AL细胞中的表达情况进行分析.结果表明,在116例B系ALL病例中,CD19持续稳定表达,其阳性率（115/116,99.1%）明显高于CD20（33/116,28.4%,P=0.001）;在17例含B系成分的混合型白血病（acute mixed lineage leukemia,AMLL）细胞中,前者的阳性率也明显高于CD20（P＜0.01）,而在29例T细胞系ALL和7例T/My HAL细胞中,两者均无表达;在152例急性髓系白血病（AML）细胞中,CD19和CD20阳性率均很低,分别为7.2%和2.0%;CD19和CD20在B-ALL及B/My AMLL组中的荧光强度差别有显著性（t=20.68,P＜0.001）;CD19和CD20的特异性分别为92.3%（132/143）和92.7%（38/41）,敏感性分别为99.2%（132/133）和28.6%（38/133）,前者敏感性明显高于后者（X^2=144.018,P=0.001）.结论：CD19在B细胞系细胞的各分化阶段上持续稳定表达,反应谱比CD20宽,特异性及敏感性均高,尤其是其敏感性显著高于后者.这提示CD19抗原分子可能成为治疗B系ALL的最佳靶点.

Comparison between CD19 and CD20 Expression Patterns on Acute Leukemic Cells

In order to provide the evidences for CD19 as a better antibody targeting molecule for B lineage acute leukemias than CD20 through the multi-parameter flow-cytometry analysis of leukemia cells, the samples from 321 patients with acute leukemia (AL) were immunophenotyped by multi-color flow cytometry and CD45/SSC gating strategy followed by the analysis of CD19 and CD20 expression. The results showed that the positive rate of CD19 (115/116, 99.1%) in 116 cases with B lineage acute lymphoblastic leukemia (B lineage ALL) was significantly higher than that of CD20 (33/116, 28.4%) (P < 0.01); in 17 patients with B lineage/Myeloid (B/My) acute mixed lineage leukemia (AMLL), the former positive rate (17/17, 100%) was also higher than the latter (5/17, 29.4%) (P < 0.01). Both of the two antigens were negative in 29 patients with acute T lymphoblastic leukemia and 7 patients with T/My AMLL. The positive rates of CD19 and CD20 in 152 patients with acute myeloid leukemia (AML) were 7.2% and 2.0%, respectively. The difference of the fluorescence intensity between the two antigens on the cells from each patient with B lineage ALL or B/My AMLL was statistically significant (t = 20.68, P < 0.001). The specificity of CD19 and CD20 in B lymphocytic lineage was 92.3% (132/143) and 92.7% (38/41), respectively, while the sensitivity was 99.2% (132/133) and 28.6% (38/133), respectively, the former sensitivity was significantly higher than the latter (chi(2) = 144.018, P = 0.001). It is concluded that CD19 continuously and steadily express on almost all subtypes of B lineage leukemic cells with homogeneous pattern while only a small number of leukemias express CD20. Both the specificity and sensitivity of CD19 were very high with a much broader reaction pattern than that of CD20 on this group of diseases. These indicate that CD19 may be a better antibody targeting molecule than CD20 for patients with B-lineage acute leukemia.