Immunology and Sjögren’s Disease

Sjögren’s Disease occurs when the immune system mistakenly attacks the glands in your body that produce and control moisture. This causes long-term dryness through the body, especially the eyes and mouth. Immune cells called B cells play an important role in Sjögren’s disease. B cells are part of the adaptive immune response and are trained to produce antibodies for one specific germ. B cells can live a long time and use these antibodies to quickly respond in the future when the body encounters the same germ again. In Sjögren’s disease, B cells mistakenly make antibodies that attack the moisture glands in the body. These antibodies that attack self are called autoantibodies.

Scientists aren’t exactly sure what causes the immune system to attack this part of the body; however, they think genetics and environmental triggers, such as viral infections, play a role. Around half of the time, Sjögren’s disease occurs in patients with another autoimmune disease. While any autoimmune disease can trigger Sjögren’s disease, rheumatoid arthritis and lupus are commonly associated with Sjögren’s disease.

What’s Next for Sjögren’s Disease

There is no cure for Sjögren’s disease and current treatments address the symptoms of dryness rather than cause of the disease. Immunology research may be able to help.

A monoclonal antibody called inanlumab depletes B cells and blocks their activity and survival. Monoclonal antibodies are lab-made antibodies that are made specifically to fight a specific germ or a harmful cell. In this case, inanlumab is designed to fight the harmful B cells that produce autoantibodies. A recent phase III clinical trial showed that this drug significantly decreased disease activity and reduced disease burden for patients with Sjögren’s disease. The drug was shown to be safe and effective throughout clinical trials. If approved, inanlumab would be the first treatment for Sjögren’s disease. Important research understanding how the immune system works, and how it can be used to fix mistakes, like with monoclonal antibodies, is what has allowed researchers to be very close to offering a treatment for Sjögren’s disease.

Researchers are also expanding their knowledge of the different autoantibodies identified in patients with Sjögren’s disease. Characterizing newly identified autoantibodies could help predict which parts of the body will be affected, lead to improved diagnostics, and expand the possibility for personalized medicine.