Combination Of Factors?
Researchers think Sjogren's syndrome is caused by a combination of genetic and environmental factors. Several different genes appear to be involved, but scientists are not certain exactly which ones are linked to the disease since different genes seem to play a role in different people. For example:
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.
Possible Triggers
Scientists think that the trigger may be a viral or bacterial infection. It might work like this:
Apoptosis
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.
Scientists think that resistance to apoptosis may be genetic. The possibility that the endocrine and nervous systems play a role is also under investigation.

