Autoimmune diseases occur when the immune system mistakenly turns on the body, attacking healthy cells instead of unhealthy ones. Overwhelmingly, autoimmune diseases – think lupus, rheumatoid arthritis and multiple sclerosis (MS) – are far more common in women.
How common are autoimmune diseases?
A strong immune system is the body’s first line of defence against foreign invaders, like viruses and bacteria. If something derails it, though, it’s not just the body’s enemies that come under fire – the healthy cells and tissues do too. This is what happens in the 80 or so autoimmune diseases (ADs) that – when grouped together – are the third most common cause of serious illness in the US and UK. Although there are no concrete figures on the incidence of ADs locally, experts estimate that up to four-million South Africans could be affected, and almost three times as many women as men.
“Something – we don’t know exactly what – causes the immune system to go into overdrive, triggering the production of antibodies against the body’s own tissues,” explains rheumatologist, and former editor of the Journal of Autoimmune Diseases, Professor David D’Cruz.
Which parts of the body are at risk?
ADs can affect any organ: the pancreas (Type 1 – and some now think Type 2 – diabetes), the nervous system (multiple sclerosis), the joints (rheumatoid arthritis), the thyroid (Graves’ and Hashimoto’s diseases), and the bowel (ulcerative colitis and Crohn’s disease). They can also target the whole body (lupus).
Why are they more common in women?
“There’s no clear answer, but oestrogen and other female hormones may increase immune-system activity. Genetic differences between men and women may also play a part,” says rheumatology expert Professor Alan Silman. Plus,the immune system has to make many changes to cope with pregnancy and childbirth and this could send it into overdrive.
Is there a family connection?
ADs tend to cluster in families. “There’s also a lot of overlap,” says Professor D’Cruz. If you have rheumatoid arthritis, for example, you’ll have a higher risk of developing Type 1 diabetes. And, if you have multiple sclerosis (MS) or lupus, there’s also a greater chance you’ll develop thyroid problems at some stage.
Are there genetic markers?
They have been detected but, as yet, there’s no test to predict whether you’ll develop an AD. Scientists have, however, pinpointed several “pathways” shared by common ADs, and the hope is that these may provide new targets for treatment. For example, people with coeliac disease who stick closely to a strict gluten-free diet are less likely to develop other ADs.
Is there a link to allergies?
Yes. Allergies develop when the immune system has an exaggerated reaction to foreign bodies, rather than to “self”. This means that people with lupus are more likely to have allergies and are often allergic to sulphur-containing medications.
No one knows what triggers ADs, but research has highlighted potential environmental factors. Epstein-Barr Virus, for example, causes glandular fever and is linked with an increased risk of MS and lupus; smoking, on the other hand, is linked with a higher risk of rheumatoid arthritis, lupus, MS and Graves’ disease (overactive thyroid).
Is there a cure?
Autoimmune diseases can be hard to diagnose and treat. “The trouble is that symptoms are often woolly – things like fatigue, dizziness or aches and pains,” says Professor D’Cruz. If you think something may be going on in your body, keep a symptom diary, make a note of any ADs in your family, be prepared to persevere and, if necessary, seek a second opinion. Unfortunately, ADs can’t be cured, but they can be managed. Usually, symptoms fluctuate between periods of relative quiet (remission) and flare ups.