Edinburgh scientists have uncovered the group of genes responsible for increasing people’s risk of rheumatoid arthritis, which they say may lead to new treatments reach patients in the next three years.

The University of Edinburgh study looked at genetic data from 450,000 people in the UK Biobank to understand the effect of common mutations in particular genes on the risk of arthritis.

Despite up to 217,000 people in Scotland suffering from rheumatoid arthritis or osteoarthritis – causing pain, swelling and stiffness in their joints – no cure exists, and most treatments have focused on alleviating pain.

While less common than osteoarthritis, rheumatoid arthritis has a stronger genetic link and stems from the body’s immune system attacking the lining of joints.

Looking for the genes that could underpin this autoimmune condition, the researchers found 16 genes linked to rheumatoid arthritis, six of which are known to cause immune system problems when faulty.

The Edinburgh team believe that treatments targeting these six genes may be hold the key to treating or even curing rheumatoid arthritis. Medicines which target a protein the genes produce called ‘programmed death protein 1’ (PD-1), have already shown promising results.

The University of Edinburgh’s Professor of Genetic Epidemiology and Statistical Genetics, Paul McKeigue said the new study marks a step-change in how researchers and clinicians understand arthritis:

“This work reshapes our understanding of the causes of rheumatoid arthritis.

“We expect drugs that target the causes of the disease to be more effective than the drugs used now, which only target inflammation.

“We’re encouraged by the promising results of trials of drugs that target PD-1 in rheumatoid arthritis.

“Our research can help identify which other autoimmune diseases these drugs are likely to be effective in.”

Caroline Alyott, Head of Research Delivery at Versus Arthritis, said that while drugs targetting inflammation have revolutionised treatment of rheumatoid arthritis, they do not work for every patient. 

She told healthandcare.scot that there is currently no reliable way to predict which drugs will be effective for each person and this new research marks a step forward for patients in Scotland and beyond:

“This is thoroughly exciting research which has used cutting-edge techniques.

“Identifying new genes responsible for rheumatoid arthritis has the potential to enable earlier diagnosis and target treatments more effectively to individual patients.

“We know that early and effective treatment for rheumatoid arthritis can greatly improve long-term outcomes.

“Funding research to better understand the causes of different forms of arthritis has the potential to speed up the development of new drugs to benefit the 10 million people living with arthritis in the UK today and the 27,000 adults newly diagnosed with rheumatoid arthritis each year.” 

Last month, AnaptysBio revealed that its PD-1 targeting drug was effective at treating patients with moderate-to-severe rheumatoid arthritis, and has been shown to be safe and well tolerated over six months.

Professor McKeigue told healthandcare.scot the phase 2 trial findings are not only encouraging as they validate the Edinburgh team’s research, but they also showcase the potential of target treatment:

“This is exciting as we’d found that this is a core gene underpinning rheumatoid arthritis, and the clinical trial shows that by PD-1 targeted treatments can modify the immune-checking system.

“It’s encouraging as well for the first time we’re seeing treatments that address the causes rather than just the inflammatory impact of rheumatoid arthritis.”

He added that the next stage will be a phase 3 clinical trial monitoring how patients respond to the treatment over a longer time, meaning it could take three years for the treatment to reach patients through NHS Scotland.

Professor McKeigue said this genetic target could also translate into treatment for other autoimmune conditions, and work is underway to investigate broader applications.

The Edinburgh team will now study whether the activity of these core genes can further guide treatment for people living with rheumatoid arthritis, and is reaching out to companies researching targeted treatments.

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