Rheumatoid arthritis (RA) is a chronic autoimmune disease that affects the joints. Specifically, the immune system is attacking the body’s own tissues thinking they are pathogenic or deleterious. It is characterized by swelling of the synovium, which lines the joints and can cause pain and stiffness. Not only does it generate inflammation at the joints but can damage other parts of the body including the skin, eyes, lungs, blood vessels, and heart (among others). RA can not only target the synovium, but also the bones underneath. Consequently, this can cause deformity which refers to the joints getting out of shape.
Rheumatoid arthritis can have detrimental effects on the body overall. Patients with RA should monitor themselves to assess any changes in their body if their RA progresses. Physicians might also monitor to confirm their patients are not experiencing other symptoms. For example, nodules and rashes can appear on the skin, scarring on the whites of the eyes causing blurred vision, difficulty breathing through lung fibrosis, and damaged blood vessels can all result from RA progression. As a consequence of other conditions that arise from chronic inflammation, RA can be fatal in rare cases. Treatment for RA includes a combination of disease-modifying antirheumatic drugs (DMARDs) and/or anti-inflammatory drugs, physical therapy (PT), and sometimes surgery. Unfortunately, while treatment can manage symptoms, slow progression, and improve quality of life, there is no cure for RA. Scientists are currently working to learn more about this autoimmune disease to improve treatment.
A recent article in Science immunology, by Dr. Hiroyuki Yoshitomi and others, reported that specific immune cells responsible for inflammation reside in specialized immune hubs that allow for continued inflammation of the joints. This discovery can lead to improved therapies by targeting immune cells to reduce inflammation. Yoshitomi is an Associate Professor at Kyoto University in Japan. He is part of the Ueno Group and specializes in human immunology. Specifically, he investigates chronic inflammatory diseases and how the immune system becomes dysregulated in these processes. Yoshitomi’s research works to understand the complexities of the immune system to improve therapies for patients.
Yoshitomi and his group investigated a hub of immune cells proximal to inflamed joints called “tertiary lymphnodes” (TLN). These hubs contain special immune or T cells, which drive inflammation. Researchers used next generation sequencing to identify helper T cells in the joints. These cells were found to accumulate in TLNs and activate other immune cells that promote inflammation. This is a major finding, because previously it was unclear how the mechanism behind chronic inflammation occurred. While it was known that immune cells cause inflammation, scientists did not understand that these specific T cells had such a strong effect. Not only were helper T cells found inside the joint and nearby TLN, but also around the synovium promoting further immune activation.
Yoshitomi and others have discovered the presence of specialized helper T cells with defined roles within inflamed tissue. They reported the mechanism that drives chronic inflammation in RA. This discovery better informs scientists of the underlying progression of RA-driven inflammation. It also provides the opportunity to improve current RA therapies and quality of life in patients.
Article, Science immunology, Hiroyuki Yoshitomi, Kyoto University