It is unclear what causes Guillain-Barré syndrome. However, most people develop the condition following a recent illness. This is usually a viral infection, such as a throat infection or flu, or sometimes a bacterial infection.
It is thought that the infection may trigger the immune system (the body’s natural defence against infection and illness) to attack the body.
The immune system
The immune system uses white blood cells to produce antibodies. Antibodies are infection-fighting proteins that travel around the body in the blood vessels and lymphatic vessels (part of the lymphatic system).
The role of antibodies is to attack the bacteria or virus that is causing the infection. However, in this case, the antibodies react to the cells of the protective covering (myelin sheath) of the peripheral nerves (see box, right).
This reaction damages the nerves and prevents them from sending signals to your muscles. This causes the tingling, weakness and eventual short-term paralysis that you might experience.
Possible triggers
Although some cases occur without a known cause, some cases of Guillain-Barré syndrome are related to:
- a virus, such as the cytomegalovirus (a member of the herpes group) or the HIV infection
- a bacterial infection, such as infection from Campylobacter bacteria
- Hodgkin's lymphoma – tumour of the lymph glands (the small, bean-sized organs that carry white blood cells)
Vaccination has also been linked to Guillain-Barré syndrome. However, studies suggest a very low risk of developing the syndrome after receiving a vaccine.
For example, since the swine flu pandemic in 2009, around 6 million doses of the vaccine Pandemrix have been given in the UK. The Medicines and Healthcare products Regulatory Agency (MHRA), which monitors the safety of vaccines, received 15 suspected reports of Guillain-Barré syndrome during the pandemic. The diagnosis was not confirmed in any of these cases.
You cannot catch Guillain-Barré syndrome from other people or inherit it from your parents.
