Introduction to Sjogren's Syndrome

What is Sjogren's Syndrome?

Most healthy people seldom give much thought to "automatic" physiological functions such as saliva production by our salivary glands or tear production by our lacrimal (tear) glands. We take for granted the fact that our salivary glands constantly produce the salivary fluids that keep our mouths moist and clean and that our lacrimal glands continuously produce a slow, steady flow of tears that lubricate our eyes to keep them comfortable and healthy. It is only when the normal physiological production of saliva and tears is disrupted, do we come to realize just how important a role these secretions play in our overall health and well-being.

Sjogren's syndrome is a chronic, slowly progressive, inflammatory autoimmune disorder characterized by the infiltration of specialized cells of the immune system called lymphocytes, monocytes, and plasma cells into the parotid (salivary) glands and lacrimal (tear) glands. These glands are part of a group of exocrine glands whose secretions pass into a system of ducts that lead ultimately to the exterior of the body. This chronic lymphocytic infiltration interferes with the normal function of these glands and eventually results in a significant reduction or cessation in the production and secretion of saliva and tears. The condition is named after Henry Sjogren, a Swedish ophthalmologist, who first described the primary clinical features of this disorder in 1933.

In approximately 40% of patients, Sjogren's syndrome progresses beyond the exocrine glands and they develop systemic (extraglandular) features.

Two distinct forms of Sjogren's syndrome have been recognized:

• Primary Sjogren's syndrome - defined as dry eye and dry mouth that occurs by itself and is not associated with another autoimmune disorder. Primary Sjogren's syndrome occurs in approximately 50% of cases according to the Sjogren's Foundation of America.
• Secondary Sjogren's syndrome - characterized by dry eye and dry mouth that occurs in the presence of a major underlying autoimmune connective tissue disease such as rheumatoid arthritis, systemic lupus erythematosus, or scleroderma.