EXPRESSION OF MYELOID PHENOTYPES DURING HUMAN B-CELL DIFFERENTIATION : ANALYSIS OF CHRONIC LYMPHOCYTIC LEUKEMIA

我们研究了26例日本慢性B细胞白血病患者白细胞分化抗原的表面表达和免疫球蛋白(Ig)重链可变区(VH)基因家族的利用，特别是CD5抗原的表达。26例白血病细胞表达CD5者21例(CD5^+)，5例不表达(CD5^-)。5例CD5~+患者白血病细胞均表达CD13抗原，CD5~+患者白血病细胞表达CD11b抗原的频率明显高于CD5~+患者(80%vs11%，P<0.01)。CD33在CD5~+和CD5~-白血病细胞上均不表达。CD5~+白血病细胞表达CD22的频率高于CD5~+白血病细胞(80%vs33%，p&lt；0.05)。CD5^+组和CD5^-组CD23的表达频率相近(67%比60%)。尽管CD45RA在大多数白血病B细胞上表达，但CD5~+患者的CD45RA表达水平显著高于CD5~+患者(p&lt；0.01)。在对慢性B细胞白血病VH基因表达的分析中，CD5~+患者优先利用VH4家族成员(48%，10/21)。CD5~-病例主要利用VH3家族(80%，4/5)，因此，从我们目前对有限患者群体的观察中，我们发现VH基因家族利用与慢性B细胞白血病CD5抗原表达有关。我们还证实了CD5~+和CD5~-慢性B细胞白血病中粒单核细胞标志物的差异表达。这些结果与以前的建议一致，即CD5阳性是不同临床实体的标志，在文献中通常被称为慢性淋巴细胞白血病。

We investigated the surface expression of leukocyte differentiation antigens and the immunoglobulin (Ig) heavy chain variable region (VH) gene family utilization in leukemic cells from 26 Japanese patients with chronic B cell leukemias with special reference to CD5 antigen expression. CD5 was expressed on leukemic cells in 21 of 26 cases (CD5^+), but not in five cases (CD5^-). Myelomonocytic marker, CD13 antigen was expressed on the leukemic cells in all five CD5^- cases, but in none of CD5^+ cases Leukemic cells in CD5^- cases also expressed CD11b antigen more frequently than those in CD5^+ cases (80% vs 11%, p<0.01). Another myeloid marker, CD33 was expressed neither on CD5^+ nor CD5^- leukemic cells. CD22, a restricted B cell marker, was expressed more frequently on CD5^- leukemic cells than CD5^+ leukemic cells (80% vs 33%, p<0.05). Another restricted B cell activation marker, CD23 was expressed at similar frequency in both the CD5^+ and CD5^- groups (67% vs 60%). Although CD45RA was expressed on the majority of leukemic B cells, the CD45RA expression level was significantly higher among CD5^- cases than CD5^+ cases (p<0.01).In the analysis of VH gene expressed in chronic B cell leukemias by PCR amplification, CD5^+ cases preferentially utilized VH4 family members (48%, 10/21). CD5^- cases, on the other hand, mainly utilized VH3 family (80%, 4/5).Thus, from our present observation of an albeit limited patient population, we have found an association between VH gene family utilization and CD5 antigen expression in chronic B cell leukemias. We have also demonstrated the differential expression of myelomonocytic markers in the CD5^+ and Cd5^- chronic B cell leukemias. These result are in agreement with previous suggestions that CD5 positivity is the hallmark for distinct clinical entity commonly referred in the literature as chronic lymphocytic leukemia.