抗人CD20单克隆抗体治疗B细胞淋巴瘤研究进展

近年来，对B细胞淋巴瘤的抗原靶向性治疗已取得了巨大进展。出现了一种新的非常有发展前景的治疗方法。即以B细胞分化抗原CD20为靶抗原的单克隆抗体（McAb)疗法。CD20是非糖基化的跨膜磷酸蛋白，分子质量为35kD。表达在大多数成熟B细胞表达，分化为浆细胞后，CD20表达消失。CD20可能参与B细胞成熟与分化的调节，作为钙离子通道发挥某些生物学作用。更为重要的是，95%以上的B细胞淋巴瘤表达CD20，且无显内化及脱落，这些特点使其成为单克隆抗体疗法的理想靶抗原，临床试验结果表明，抗CD20单克隆抗体既可单独应用，亦可作为放射性同位素或细胞毒制剂的载体，其疗效显，且使用安全，副反应小，许多研究报道已阐明了抗CD20单克隆抗体治疗B细胞淋巴瘤的几种可能的效应机制。目前，人们正致力于探索一些新的治疗策略以期提高这种疗法的特异性，减少其非特异性的毒副作用。

Recent Advance in Anti-CD20 Monoclonal Antibody Therapy in B-Cell Lymphoma

Substantial advances in antigen-targeted lymphoma therapy have been achieved in recent years.Monoclonal antibodies targeting B-cell differential antigen CD20 have emerged as promising new treatments. CD20 is a 35 kD non-glycosylated transmembrane phosphoprotein. It is expressed on most mature B-lymphocytes and disappears from the surface of B lineage cells during terminal differentiation into plasma cells. The antigen appears to be involved in the regulation of B-cell development and differentiation and may mediate some of its effects by functioning as a calcium channel. Most importantly, CD20 is expressed on more than 95% of B-cell lymphomas and is not significantly internalized or shed. These features make it an ideal target for monoclonal antibody therapy for B-cell lymphomas. The results of clinical trials have showed that anti-CD20 monoclonal antibodies, which can be utilized in either unmodified form or as carrier for radioisotopes or cytotoxic agents, have significant effects and can be administrated safely with minimum side effects. Many studies have proposed several potential mechanisms to mediate the eradication of tumor cells targeted by anti-CD20 monoclonal antibodies.Ongoing prospective studies will establish some new therapeutic strategies with high anti-lymphoma specificity and low unspecific toxicity.