What is Sjogren’s syndrome?|
Sjogren’s (pronounced show-grins)syndrome is a chronic inflammatory, autoimmune disorder that affects approximately 3-4% of adults in the general population. It is characterised by dry eyes and dry mouth as a result of the autoimmune destruction of the tear and salivary glands in our body.
It is named after the Swedish eye doctor, Dr. Henrik Sjogren and can affect people of any age and race. However, about 90% of patients with Sjogren’s Syndrome are women between the ages of 35-45 years.
There are two forms of the disorder. The more common primary Sjogren's syndrome occurs by itself without any association with other diseases, whereas the secondary form usually occurs in patients with other disorders such as rheumatoid arthritis, systemic lupus erythematosus (lupus), polymyositis, sclerodema, vasculitis, or thyroiditis.
What causes the disease?
It is known that Sjogren's syndrome is an autoimmune disease. Autoantibodies are special molecules in our body’s defence mechanism but they react to human antigens (autoantigens). These antibodies are found in 50-80% of patients with Sjogren's syndrome. When these antibodies react with the antigens, they cause an inflammatory response in the body. This stimulates the white blood cells causing proliferation, which results in a mass population of identical cells. The white blood cells accumulate and invade the glandular tissue causing fibrosis (cells becoming fibrous tissue) and atrophy (death of cells). This impairs the normal function of the gland and therefore, reduces the secretion of saliva and tears.
However the actual cause of this disease is unknown. This is because the nature of the autoantigen recognised by these white blood cells is still unknown. How the autoimmune reaction is initiated is also uncertain. Genetic inheritance and viral infections may contribute. There is some evidence that people who are infected with these two human retroviruses - HIV (human immunodeficiency virus) and HTLV (Human T-cell lymphotropic virus) - show similar symptoms to Sjogren's syndrome. However, whether they play a role in causing Sjogren's syndrome is not entirely clear.
Patients of Sjogren's syndrome will show various symptoms:
- Dry mouth - Since there is a decrease in the secretions from salivary glands, patients will have less saliva and this results in swallowing and chewing problems. Also, there’s difficulty in speaking and a reduced ability to taste. The tongue may also crack due to the dryness.
- Dry eyes - Again, reduced secretions from tear glands will cause the patient’s eyes to feel dry or ‘sandy’. Eyes may also look red and suffer from a burning sensation, itchiness and pain upon blinking. Vision is most likely to be blurred and the tear glands will be painful and swollen.
- Salivary gland enlargement - We have three glands that produce saliva in our body. They are the sublingual gland (under the tongue), the submandibular gland (back of the mouth) and the parotid gland (in front of the ear). These glands may be swollen and tender for patients with Sjogren's syndrome. Parotid enlargement is found in 50% of patients with this disease.
- Dental cavities: This is a very common problem. It is due to the dry mouth, which correlates with reduced saliva secretion. Saliva fights bacteria and helps prevent cavities thus it is easier for patients to develop these cavities if they don’t have enough saliva in their mouth.
Although tear and salivary glands are the major targets of the disease, other exocrine glands such as respiratory, guts and vagina may also be involved. Therefore, you’ll also get symptoms such as;
- Dry nose, throat and lungs: Patient’s throat may feel dry and tickly. Dry cough, hoarseness, decrease sense of