Endometriosis and immune diseases linked, study shows

The study has analyses more than 8,000 cases of endometriosis, a condition that causes severe pain and affects about 1.5 million women in the UK

Women with endometriosis are at a significantly higher risk for developing a range of autoimmune diseases, new research has shown.

The new study, involving researchers from the University of Oxford, has identified a significant genetic link between conditions such as rheumatoid arthritis, coeliac disease and multiple sclerosis to endometriosis.

Women with endometriosis were found to have a 30-80% increased risk of developing autoimmune diseases.

The research team said the new information could be used "to look for new treatment avenues that may work across these conditions".

Endometriosis, a condition where cells similar to those in the lining of the womb grow in other parts of the body, affects about 1.5 million women in the UK.

Symptoms include severe period pain and it causes extreme tiredness.

The study used data from the UK Biobank to analyse more than 8,000 endometriosis cases and 64,000 clinical disease cases.

The researchers examined the association between endometriosis and 31 different immune conditions.

Prof Krina Zondervan, joint senior author and head of the Nuffield Department of Women's and Reproductive Health at the University of Oxford, said such large studies provided "valuable new insights into disease biology".

"In this case, we have provided solid evidence of a link between endometriosis and subsequent risk of diseases such as osteoarthritis and rheumatoid arthritis, and we have shown this has a biological basis," she said.

"This new information can now be leveraged to look for new treatment avenues that may work across these conditions."

The team said that understanding "opens up exciting possibilities" for new therapeutic approaches, such as drug repurposing or the development of combined treatments.

The findings also suggest that women with endometriosis should be more closely monitored for the development of immunological conditions.

The research was mainly funded by Wellbeing of Women UK.

Chief executive Janet Lindsay said it was "an important step" in building a more accurate understanding of endometriosis.

"For too long there has been too little investment in research into women's health issues like endometriosis," she said.

"It is crucial that we increase research investment in the next generation of women's health researchers to expand our knowledge and improve patient outcomes."

The full paper can be read in the Human Reproduction journal.