• Posted September 29, 2025

Hidden Signs Of Rheumatoid Arthritis Found In Blood Long Before Diagnosis

An invisible storm might rage for years inside the bodies of people at risk for rheumatoid arthritis, prior to any joint pain occurring, a new study says.

These folks experience dramatic immune system changes long before they feel symptoms, researchers reported in the journal Science Translational Medicine.

“Overall, we hope this study raises awareness that rheumatoid arthritis begins much earlier than previously thought and that it enables researchers to make data-driven decisions on strategies to disrupt disease development,” senior researcher Mark Gillespie, an assistant investigator at the Allen Institute in Seattle, said in a news release.

During the seven-year study, researchers tracked 45 healthy people carrying anticitrullinated protein antibodies, or ACPAs. These antibodies are a known marker for people who are at risk of developing rheumatoid arthritis (RA).

RA occurs when the body’s immune system attacks the joints in a person’s hands, wrists and knees. It causes chronic pain, swelling, deformed joints and problems maintaining balance.

During the study, 16 of the folks with ACPA wound up developing rheumatoid arthritis.

Results showed that these folks experienced widespread systemic inflammation throughout their bodies before their rheumatoid arthritis diagnosis, resembling that seen in people with active RA.

The researchers also found many significant abnormalities among their immune cells, including:

• Normally protective B cells that had started promoting inflammation.

• T “helper” cells that had become overactive, potentially directing autoimmune attacks against healthy tissue.

• “Naïve” T cells — ones that haven’t been trained to counter any specific threat — showing changes in the way their genes turn on and off.

These individuals also had high levels of inflammatory cells in the bloodstream that closely resemble those found in the inflamed joint tissue of RA patients.

All these might serve as new early-warning signs that could help docs identify which people at risk for RA are more likely to develop the disease, researchers said.

If caught early, RA might be stopped before it starts, saving folks years of pain and disability, researchers said.

“We expect that going forward the findings from this study will support additional studies to identify ways to better predict who will get RA, identify potential biologic targets for preventing RA as well as identify ways to improve treatments for those with existing RA,” researcher Dr. Kevin Deane said in a news release. He’s a professor of rheumatology at the University of Colorado Anschutz Medical Campus.

More information

The U.S. Centers for Disease Control and Prevention has more on rheumatoid arthritis.

SOURCE: Allen Institute, news release, Sept. 24, 2025