Isobe K, Tamaru J, Uno T, Yasuda S, Aruga T, Itoyama S, Harigaya K, Mikata A, Ito H
Department of Radiology and First Department of Pathology, Chiba University School of Medicine, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan.
Leuk Lymphoma. 2001 Jul;42(3):499-506. doi: 10.3109/10428190109064607.
We analyzed the immunoglobulin heavy chain variable region (VH) gene in 4 Japanese cases of B cell chronic lymphocytic leukemia (B-CLL) with enlarged lymph nodes to clarify the presence of somatic mutations and intraclonal diversity. We also attempted to determine the role of the follicular dendritic cell (FDC) network in some proliferation centers, where tumor cells are mitotically active. Immunohistochemical studies revealed that all 4 cases showed the typical immunophenotype: CD5+, CD23+, IgM+ and IgD+. DNA was extracted from paraffin sections (lymph node) and rearranged VH gene was amplified by PCR. All but one exhibited a moderate number of somatic mutations, with percentages ranging from 4.1 to 9.5, and one of which indicated the effect of antigen selection on its VH gene. Multiple clone analysis of whole tissues showed intraclonal diversity in one case, whose VH gene carried a somatic mutation but the effect of antigen selection was not apparent. We further examined microdissected tissues to elucidate the relationship between FDC network and VH gene status in 2 cases. In one case, intraclonal diversity was not apparent irrespective of FDC network, however, both tumor cells around the FDC network and those apart from the FDC showed signs of intraclonal diversity in another case, suggesting that intraclonal diversity was not related to the FDC network in B-CLL. Here we demonstrate that some cases of B-CLL involved in lymph node carried mutated VH genes and showed intraclonal diversity like the tumor cells in the peripheral blood. However, the significance of the FDC network in the proliferation center still remains to be resolved.
我们分析了4例伴有淋巴结肿大的日本B细胞慢性淋巴细胞白血病（B-CLL）患者的免疫球蛋白重链可变区（VH）基因，以阐明体细胞突变和克隆内多样性的存在情况。我们还试图确定滤泡树突状细胞（FDC）网络在一些增殖中心的作用，在这些增殖中心肿瘤细胞有丝分裂活跃。免疫组织化学研究显示，所有4例均表现出典型的免疫表型：CD5+、CD23+、IgM+和IgD+。从石蜡切片（淋巴结）中提取DNA，通过聚合酶链反应（PCR）扩增重排的VH基因。除1例之外，其余均表现出中等数量的体细胞突变，百分比范围为4.1%至9.5%，其中1例显示抗原选择对其VH基因有影响。对整个组织进行的多克隆分析显示，1例存在克隆内多样性，其VH基因携带体细胞突变，但抗原选择的影响不明显。我们进一步检查了显微切割组织，以阐明2例中FDC网络与VH基因状态之间的关系。在1例中，无论FDC网络如何，克隆内多样性均不明显，然而，在另1例中，FDC网络周围的肿瘤细胞和远离FDC的肿瘤细胞均显示出克隆内多样性的迹象，这表明B-CLL中的克隆内多样性与FDC网络无关。在此我们证明，一些累及淋巴结的B-CLL病例携带突变的VH基因，并表现出与外周血肿瘤细胞类似的克隆内多样性。然而，FDC网络在增殖中心的意义仍有待解决。
