Pasquali J L, Waltzinger C, Kuntz J L, Knapp A M, Levallois H
Laboratoire d'immunopathologie, Faculté de Médecine, Strasbourg, France.
Blood. 1991 Apr 15;77(8):1761-5.
The mixed cryoglobulinemia is considered to be a nonmalignant human B-cell proliferation that frequently produces a monoclonal IgM with anti-IgG activity (rheumatoid factor). Using murine monoclonal anti-idiotypic antibodies specific for private or minor idiotopes on monoclonal IgM from three patients suffering from nonmalignant mixed cryoglobulinemia, we investigated the presence of the CD5 antigen on the monoclonal IgM producing cells in these patients. It is shown by two-color cytofluorometric analysis that the majority of the peripheral blood monoclonal IgM rheumatoid factor secreting cells is CD5 negative in these three patients. One of the monoclonal rheumatoid factor K variable regions was sequenced at the protein level and belongs to the human VK III group, as a high proportion of monoclonal rheumatoid factors and some B-cell chronic lymphocytic leukemia (CLL) membrane bound Igs. Thus, despite the preferential use of similar VK genes and the absence of somatic mutation affecting these variable regions in both malignant B-cell CLL and nonmalignant mixed cryoglobulinemia, these proliferating B cells differ in the CD5 membrane expression.
混合性冷球蛋白血症被认为是一种非恶性的人类B细胞增殖疾病，常产生具有抗IgG活性的单克隆IgM（类风湿因子）。我们使用针对三名非恶性混合性冷球蛋白血症患者单克隆IgM上的独特型或微小独特型的鼠单克隆抗独特型抗体，研究了这些患者中产生单克隆IgM的细胞上CD5抗原的存在情况。双色细胞荧光分析显示，这三名患者外周血中分泌单克隆IgM类风湿因子的细胞大多数为CD5阴性。对其中一种单克隆类风湿因子的K可变区进行了蛋白质水平测序，它属于人类VK III组，这与高比例的单克隆类风湿因子以及一些B细胞慢性淋巴细胞白血病（CLL）的膜结合Ig相似。因此，尽管在恶性B细胞CLL和非恶性混合性冷球蛋白血症中都优先使用相似的VK基因且这些可变区不存在体细胞突变，但这些增殖的B细胞在CD5膜表达上存在差异。
