Embarrassing Illnesses

The immune system

The immune system is designed to recognise any foreign body that represents a threat to the body, such as a virus or bacterial infection, and then attack it with special cells known as lymphocytes.

In cases of Sjogren's syndrome, the immune system mistakes healthy tissue for a foreign body and attacks it with lymphocytes. The parts of the body usually affected are the tear, saliva and vaginal glands, which are collectively known as the exocrine glands.

The lymphocyte damages the exocrine glands, meaning that they can no longer function normally. There is also some evidence that the immune system damages the nerves that control these glands, further reducing their effectiveness.

The immune system can go on to damage other part of the body such as muscles, joints, blood vessels, nerves and, less commonly, organs.

Possible triggers for Sjogren's syndrome

The exact cause of Sjogren's syndrome is unknown but most researchers believe that it is triggered by a combination of genetic and environmental factors.

The general thinking is that certain people are born with specific genes which makes their immune system more likely to malfunction. Then many years later, environmental factors, most likely a virus such as the Epstein-Barr virus or hepatitis C, triggers that malfunction.

Hormones, specifically oestrogen, seem to play an important role as well. Sjogren's syndrome occurs mostly in women, and usually occurs around the time of the menopause when levels of oestrogen begin to fall. This may suggest that this reduction in oestrogen somehow disrupts the normal functioning of the immune system. Exactly how this may occur is still unclear.

The importance of exocrine glands

The reason that Sjogren's syndrome can cause such a wide range of troublesome symptoms is that your saliva and tear glands play a vital role in protecting your mouth and eyes.

The importance of tears

We tend to only notice our tears when something happens that makes us cry. But the truth is that our eyes are always covered by a thin layer of tears - known as a tear film.

Tears are not simply made up of water. In fact they are a complex mix of water, proteins, fats, mucus and infection-fighting cells. Tears serve several important functions:

• they lubricate the eye, keeping it clean and free of dust,
• they protect the eye against infection, and
• they aid sight by helping to stabilise your vision.
  

The importance of saliva

Saliva also serves several important functions:

• it keeps the mouth and throat naturally lubricated,
• it aids digestion by moistening food and also contains enzymes that can break down certain starches, and
• it acts as a natural disinfectant, saliva contains antibodies, enzymes and proteins that provide protection against some common bacterial and fungal infections.