Study Points to a New Way to Curb Joint Inflammation in Rheumatoid Arthritis

A chemical compound has shown promise against rheumatoid arthritis in preclinical trials, offering a potential new treatment option for patients who do not respond to existing therapies. The research from Aarhus University focused on a substance called 4-octyl itaconate, or 4-OI, and points to a mechanism of action distinct from most current treatments.

Rheumatoid arthritis occurs when the body's own cells attack the joints, causing inflammation, pain, and swelling. Most treatments available today target immune cells. A therapy based on 4-OI would take a different approach, acting instead on connective tissue cells in the synovial membrane that play a central role in chronic inflammation and joint damage.

"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," said Benedicte Bech Andersen, first author of the study published in EULAR Rheumatology Open.

In practical terms, 4-OI works by activating the body's own anti-inflammatory and antioxidant system. When that system is engaged, the synoviocytes—the connective tissue cells in the synovial membrane—are not activated in the same way, which reduces inflammation in the joint. 

In trials involving both cell samples and animal models, the treatment showed a meaningful effect. "In our trials, both swelling and inflammation were reduced. We therefore hope that, in time, the results may pave the way for a more personalized and targeted treatment of patients with severe or treatment-resistant rheumatoid arthritis," said senior author Morten Aagaard Nielsen.

Further research is needed before the approach could be tested in patients. "Our results are 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," Nielsen added.