Researchers from the Barts and the London School of Medicine have found tiny structures in joints, which form as a response to the inflammation, that operate similarly to antibody-producing lymph nodes. These structures may produce certain antibodies that can contribute to the destruction of joints seen in rheumatoid arthritis (RA) patients.
Researcher Costantino Pitzalis and his colleagues began by studying joint biopsies from people who had rheumatoid arthritis. This led to the discovery of the structures, called ectopic lymphoid structures, in the joints. It was theorized that these ectopic lymphoid structures could produce antibodies that attacked the synovial lining in the joint.
The next step was to transplant joint tissue that included the lymphoid structures into mice that did not have their own immune system. They found that these lymphoid structures produced antibodies even though the mice did not have body lymph nodes.
The results of this study, published in PLoS Medicine, do not definitively demonstrate that these lymphatic structures are directly responsible for produce joint-damaging antibodies. However, it was noted in an accompanying Perspective article, that the results of this study could provide additional new treatment options for RA.