CD40L－CD40信号转导系统是一种调控多种病理生理过程的重要生物信号表达系统，近年来大量的研究发现该系统对于类风湿性关节炎（RA）发病机制的调节具有十分重要的意义。主要表现在：（1）CD40促进了RA的免疫应答反应过程；（2）CD40参与了RA滑膜组织的炎症因子网络；（3）CD40可以促进滑膜血管翳的形成；（4）CD40参与了RA关节炎后期关节软骨与骨的破环过程。 CD40L-CD40 signal transduction system is an important biosignal expression system that regulates a variety of pathophysiological processes. In recent years, a large number of studies have found that this system plays an important role in the regulation of the pathogenesis of rheumatoid arthritis (RA). Mainly in the following aspects: (1) CD40 promotes the immune response process of RA; (2) CD40 participates in the inflammatory factor network of RA synovial tissue; (3) CD40 can promote the formation of synovial pannus; (4) The latter part of the RA articular cartilage and bone destruction process.