Autoimmune disorders impact one in ten people, new study finds

An international research team has highlighted the important socioeconomic, seasonal, and regional differences for several autoimmune disorders, with the findings published in The Lancet providing new clues on possible causes behind these diseases. 

A consortium of experts from the University of Leicester, University of Oxford, University of Glasgow, University College London, Imperial College London, Cardiff University and KU Leuven in Belgium, have come together to conduct this population-based study on autoimmune disorders.

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, such as type 1 diabetes,rheumatoid arthritis and multiple sclerosis. 

The study used a very large dataset of anonymised electronic health records from 22 million individuals living in the UK to investigate 19 of the most common autoimmune diseases – and to examine if cases of autoimmune diseases are rising over time, who is most affected by these conditions and how different autoimmune diseases may co-exist with each other. 

The researchers found that the 19 autoimmune diseases studied affect about 10 per cent of the population – 13 per cent of women and seven per cent of men. This is higher than previous estimates, which often relied on smaller sample sizes and included fewer autoimmune conditions and shows how important it is to study autoimmune diseases and to better understand their causes and treatments.

They also discovered evidence of socioeconomic, seasonal, and regional disparities among several autoimmune disorders. They suggest that such variations are unlikely to be attributable to genetic differences alone and may point to the involvement of potentially modifiable risk factors contributing to the development of some autoimmune diseases.

Finally, their research also confirmed that some autoimmune diseases tend to cluster together, however at a much larger scale and for a much larger set of autoimmune diseases than previous studies. 

These findings reveal novel patterns that will likely inform the design of further research on possible common causes behind different autoimmune disease presentations.

First author of the paper, Dr Nathalie Conrad, commented: “We observed that some autoimmune diseases tended to co-occur with one another more commonly than would be expected by chance or increased surveillance alone. 

“This could mean that some autoimmune diseases share common risk factors, such as genetic predispositions or environmental triggers.” 

Dr Conrad added: “This was particularly visible among rheumatic diseases and among endocrine diseases. But this phenomenon was not generalised across all autoimmune diseases - multiple sclerosis for example, stood out as having low rates of co-occurrence with other autoimmune diseases, suggesting a distinct pathophysiology.”

University of Leicester lead for the consortium, Professor Kamlesh Khunti CBE, Director of ARC East Midlands and Director of the Leicester Real World Evidence Unit, said: “As our study shows, autoimmune disorders are surprisingly common and can have a major impact on people’s health and quality of life. 

“This research shows that some conditions can co-occur and may have a major impact on people living with such multiple long term conditions .” 

To access the study, click here: https://www.sciencedirect.com/science/article/pii/S0140673623004579?dgcid=author.