What is Sjögren's Syndrome?
Sjögren’s (sho΄grins) syndrome, named after the Swedish ophthalmologist, Henrik Sjögren, is an autoimmune disorder. An autoimmune disorder is one in which the immune system attacks a person’s own body. This attack gives rise to inflammation that may cause destruction of the tissues of the body or impair their function. In Sjögren’s syndrome salivary and tear glands are the major targets of the attack, which results in a decrease in production of saliva and tears. The lack of saliva may cause symptoms of dry mouth (known as xerostomia), difficulties with speech and swallowing food, extensive tooth decay, tooth loss, oral sores and fungal infections in the mouth. Inadequate production of tears can produce symptoms of irritation and a feeling of having grit or sand in the eyes. Many Sjögren’s syndrome sufferers experience debilitating fatigue. Blood tests show the presence of autoantibodies. Antibodies are substances produced by the immune system of the body to defend against foreign material, including viruses and bacteria. However, in Sjögren’s syndrome, these antibodies are directed against components of the body, such as cells or large molecules.
Who gets the disorder?
Sjögren’s syndrome is thought to affect one to four million people in the United States and occurs in all races and ethnicities. It is the most common autoimmune diesase after rheumatoid arthritis and can occur alone or in association with arthritis or lupus. The disorder can occur at any age, but the average age of onset is >50 years of age. Women with the disorder outnumber men by 9:1.
Where is the Clinic?
The Sjögren’s Syndrome Clinic is part of the Molecular Physiology and Therapeutics Branch in NIDCR. We are located on the first floor of the Clinical Center (Building 10) at the National Institutes of Health in Bethesda, Maryland.
The mission of the Sjögren’s Syndrome Clinic is to develop new therapies based on better understanding of the pathogenesis of this disease. To achieve this goal we conduct clinical studies, which address unmet clinical needs, bridge traditional medical specialties and include a close collaboration with both clinical and basic scientists.
Past, Present and Future
History of the Sjögren’s Syndrome Clinic
Drs. Bruce Baum and Phil Fox established the first dry mouth clinic in the United States in 1982. They made a conscious decision to operate a bench-to-bedside program bringing scientific discoveries to the clinical setting. The effort has progressed from fundamental bench studies of salivary physiology to immunological investigations and, most recently, towards gene therapy. In each of these areas the studies include research that has progressed from cellular studies to animal model studies and finally toward clinical studies. We have collected systematic clinical and laboratory data on the Sjögren’s syndrome (and salivary dysfunction) population for decades. Over 1,200 participants with salivary dysfunction have been evaluated since the inception of our clinic.
The ultimate goal of our research is to find treatments for Sjögren’s syndrome (SS) that are safe, effective and target specific steps in the pathogenesis of SS. To achieve this goal, we focus our research in two broad categories. Pathogenesis studies include observational and retrospective studies that aim to expand our knowledge about the causes and progression of Sjögren’s syndrome, improve our diagnostic and prognostic tools, and identify targets for new therapies. For example, we conduct studies to evaluate the role of the autonomic nervous system in Sjögren’s syndrome and to identify new biomarkers of SS. The other major area involves the testing of novel treatments in patients with Sjögren’s syndrome. We have an active protocol evaluating the effect of dexamethasone applied directly to the salivary gland. Other treatment protocols are under development.
Gene therapy has the potential for inserting molecules such as cytokines that could modulate inflammation in salivary glands to slow or prevent their destruction in Sjögren’s syndrome. Also, the capacity to produce molecules that enhance saliva production by residual salivary gland cells might be introduced by gene transfer. Eventually, development of artificial salivary glands may have application in patients who have lost all functional salivary glands because of radiation treatment or Sjögren’s syndrome.