Cause of Sjogren's Syndrome
The exact cause of Sjogren's syndrome, and why the immune system mistakenly attacks the body's glands that provide moisture, is unknown. Research scientists believe that genetics and/or the environment may play a role. However, the possibility that the endocrine and nervous systems could play a role in the cause of Sjogren's syndrome is also under investigation.
No one knows the exact cause of Sjogren's syndrome and why the immune system, which is designed to protect the body from foreign invaders such as viruses and bacteria, mistakenly attacks the glands that provide moisture.
Sjogren's syndrome research scientists believe that genetics and/or the environment may play a role in the development of the disease.
Several different genes appear to be involved, but scientists are not certain as to exactly which ones are linked to Sjogren's syndrome, since different genes seem to play a role in different people. For example, there is one gene that predisposes Caucasians to Sjogren's syndrome. Other genes are linked to Sjogren's in people of Japanese, Chinese, and African American descent. Simply having one of these genes will not cause a person to develop the disease, however. Some sort of trigger must activate the immune system.
Scientists also think that a possible trigger of Sjogren's syndrome may be a viral or bacterial infection. It might work like this: A person who has a Sjogren's-associated gene gets a viral infection. The virus then stimulates the immune system to act, but the gene alters the attack, sending fighter cells (lymphocytes) to the eyes and mouth glands. Once there, the lymphocytes attack healthy cells, causing the inflammation that damages the glands and keeps them from working properly. These fighter cells are supposed to die after their attack in a natural process called apoptosis, but in people with Sjogren's syndrome, they continue to attack, causing further damage.
The possibility that the endocrine and nervous systems play a role is also under investigation.