Pilarski Linda M, Baigorri Eva, Mant Michael J, Pilarski Patrick M, Adamson Penelope, Zola Heddy, Belch Andrew R
Department of Oncology, University of Alberta and Cross Cancer Institute, 11560 University Avenue, Edmonton AB T6G1Z2, Canada.
Clin Med Oncol. 2008;2:275-87. doi: 10.4137/cmo.s615. Epub 2008 Mar 27.
Potential progenitor B cell compartments in multiple myeloma (MM) are clinically important. MM B cells and some circulating MM plasma cells express CD20, predicting their clearance by treatment with anti-CD20. Here we describe two types of clonotypic CD20+ B cell in peripheral blood of myeloma patients, identified by their expression of CD19 and CD20 epitopes, their expression of CD45RA and their light scatter properties. Thus, the circulating component of the MM clone includes at least two distinct CD19+ CD20+ B cell compartments, as well as CD138+ CD20+ plasma cells. To determine whether either or both B cell subsets and the CD20+ plasma cell subset were depleted by anti-CD20 therapy, they were evaluated before, during and after treatment of patients with rituximab (anti-CD20), followed by quantifying B cell subsets over a 5 month period during and after treatment. Overall, all three types of circulating B lineage cells persist despite treatment with rituximab. The inability of rituximab to prolong survival in MM may result from this failure to deplete CD20+ B and plasma cells in MM.
多发性骨髓瘤（MM）中潜在的祖B细胞区室具有重要临床意义。MM B细胞和一些循环中的MM浆细胞表达CD20，这预示着它们可通过抗CD20治疗被清除。在此，我们描述了骨髓瘤患者外周血中两种克隆型CD20+B细胞，通过它们对CD19和CD20表位的表达、CD45RA的表达及其光散射特性来识别。因此，MM克隆的循环成分包括至少两个不同的CD19+CD20+B细胞区室以及CD138+CD20+浆细胞。为了确定抗CD20治疗是否会使B细胞亚群之一或两者以及CD20+浆细胞亚群减少，在使用利妥昔单抗（抗CD20）治疗患者之前、期间和之后对它们进行了评估，随后在治疗期间和之后的5个月内对B细胞亚群进行定量。总体而言，尽管使用了利妥昔单抗治疗，但所有三种类型的循环B淋巴细胞系细胞均持续存在。利妥昔单抗无法延长MM患者生存期可能是由于未能清除MM中CD20+B细胞和浆细胞所致。
