Autoimmune disorders found to affect around one in ten people

A new population-based study of 22 million people shows that autoimmune disorders now affect about one in ten individuals. The work, published in The Lancet , also highlights important socioeconomic, seasonal, and regional differences for several autoimmune disorders and provides new clues on possible causes behind these diseases. Autoimmune diseases occur when the normal role of the immune system in defence against infections is disturbed, resulting in it mistakenly attacking normal healthy cells in the body. Examples of such diseases include rheumatoid arthritis, type 1 diabetes and multiple sclerosis and there are more than 80 types of autoimmune diseases known. Some autoimmune disorders, such as type 1 diabetes, are reported to have increased over the past several decades, raising the question as to whether the overall incidence of autoimmune disorders is on the rise, driven perhaps by common environmental factors or behavioural changes. Exact causes of autoimmune diseases, particularly with respect to relative contributions of genetic predisposition or environmental factors, also remain largely a mystery and are subject to much research. Because individual autoimmune diseases are rare, and because there are so many different types of autoimmune diseases, it has been very difficult to undertake sufficiently large studies and establish reliable estimates to answer these questions.