There is good news for patients with rheumatoid arthritis. Research from Aarhus University and Aarhus University Hospital may have opened the door to an entirely new way of reducing inflammation in the joints.
When joints begin to ache and arthritis sets in, it’s the body's own cells that go on the attack, causing inflammation, pain and swelling. Many patients with rheumatoid arthritis do not respond to the treatments currently available, but there may now be light at the end of the tunnel: researchers from the Department of Biomedicine at Aarhus University have found an entirely new way of inhibiting inflammation in the joints.
Specifically, the substance in question is 4-octyl itaconate (4-OI). A chemical compound that, in trials involving both cells and animals, showed efficacy against rheumatoid arthritis, says researcher and physician Benedicte Bech Andersen:
"Our research suggests that the substance 4-OI acts to inhibit the activation of the connective tissue cells in the synovial membrane, which play a central role in chronic inflammation and joint damage in patients with rheumatoid arthritis," she explains.
In practical terms, 4-OI activates the body's own anti-inflammatory and antioxidant system. When this system mounts a defence, the connective tissue cells in the synovial membrane — known as synoviocytes — are not activated in the same way. This in turn reduces inflammation in the joint.
Today, most treatments target the immune cells. A treatment involving 4-OI would therefore represent an entirely new option for patients with rheumatoid arthritis, and the prospects are encouraging: in the study, the researchers worked with both cell samples and animal models, in which the treatment showed a good effect, says postdoctoral researcher Morten Aagaard Nielsen:
"In our trials, both swelling and inflammation were reduced. We therefore hope that, in time, the results may pave the way for a more personalised and targeted treatment of patients with severe or treatment-resistant rheumatoid arthritis," he explains.
However, it will be some time before the treatment could potentially become available to patients with rheumatoid arthritis, as further research is needed, explains Morten Aagaard Nielsen:
"Our results are what are known as preclinical, and the treatment must be investigated further before it can be tested in patients. We now need to examine, amongst other things, its safety and efficacy, establish the dosage and form of treatment, and test whether the substance can be combined with existing treatments for rheumatoid arthritis. But it’s a promising step forward," he says.
Postdoctoral Researcher Morten Aagaard Nielsen
Aarhus University, Department of Biomedicine
Mail: morten.a.nielsen@biomed.au.dk
PhD Studerent Benedicte Bech Andersen
Aarhus University, Department of Biomedicine
Mail: bba@biomed.au.dk
Professor Bent Deleuran
Aarhus University, Department of Bomedicine
mail: bd@biomed.au
Revised 19.05.2026
EULAR Rheumatology Open
Randomized controlled/clinical trial
Human tissue samples
4-Octyl itaconate inhibits synovial fibroblast activation by targeting Nrf2 to exert anti-inflammatory effects in rheumatoid arthritis
15-May-2026
No conflicts of interest reported.