Breakthrough Insights on Rheumatoid Arthritis Flares & Pain

Rheumatoid arthritis (RA) affects more than 1.5 million Americans and often limits patients’ ability to travel for care or research. To overcome this challenge, researchers at Rockefeller University, led by Dr. Dana Orange, developed an at-home finger-prick RNA sequencing test that enables patients to contribute samples without leaving home. This innovation has generated striking discoveries.

PRIME Cells Predict RA Flares

The team identified hundreds of gene expression changes that appear one to two weeks before a flare, including rare “pre-inflammatory mesenchymal” (PRIME) cells that migrate into joints and drive inflammation. These cells have also been detected in patients with psoriatic arthritis, inflammatory bowel disease (Crohn’s disease and ulcerative colitis), lupus, and multiple sclerosis, suggesting a broader autoimmune relevance.

Oral Bacteria from Gum Disease Fuel RA

The researchers also uncovered a surprising connection between RA and gum disease. When patients brushed their teeth before giving blood samples, oral bacteria sometimes entered the bloodstream. These bacteria carry proteins that closely resemble proteins in joint tissue, essentially tricking the immune system into repeated attacks. This constant bacterial “fuel” may explain why RA patients with gum disease often respond less effectively to standard treatments, even while on powerful medications.

Nerve-driven Pain Explains RA Drug Resistance in Some

Another breakthrough revealed why approximately one in five RA patients don’t experience relief from anti-inflammatory drugs. Unlike most patients, their pain isn’t driven by inflammation at all. Instead, joint cells stimulate the growth of new pain-sensing nerves. Because their pain stems from nerve overgrowth rather than inflammation, anti-inflammatory medications are ineffective, meaning these patients may require entirely different treatment approaches. This work opens the door to more precise therapies, from nerve-targeting strategies to interventions that anticipate flares before symptoms begin.

Citations

Smith, M. H., et al. (2025). Characterizing molecular targets in difficult-to-treat rheumatoid arthritis. Seminars in arthritis and rheumatism, 70S, 152588. https://doi.org/10.1016/j.semarthrit.2024.152588

Stephenson, W., et al. (2018). Single-cell RNA-seq of rheumatoid arthritis synovial tissue using low-cost microfluidic instrumentation. Nature communications, 9(1), 791. https://doi.org/10.1038/s41467-017-02659-x

Orange, D. E., et al. (2018). Identification of Three Rheumatoid Arthritis Disease Subtypes by Machine Learning Integration of Synovial Histologic Features and RNA Sequencing Data. Arthritis & rheumatology (Hoboken, N.J.), 70(5), 690–701. https://doi.org/10.1002/art.40428

Rockefeller University. (2025, August 27). These genetic insights into rheumatoid arthritis could help design better treatments. The Rockefeller University. https://www.rockefeller.edu/news/38188-these-genetic-insights-into-rheumatoid-arthritis-could-help-design-better-treatments/