Research shows that fibrin, a protein normally involved in blood clotting, also plays an important role in the inflammatory response and development of rheumatoid arthritis.

Fibrin deposits are a prominent feature of arthritic joints, and the protein appears to be a link between systems that control inflammation and bleeding within joints, according to a study funded by the Arthritis Foundation and published in the Journal of Clinical Investigation. Lead author Jay Degen, PhD, and his colleagues explain that in arthritic joints, the meshlike matrices formed by fibrin to create blood clots may control local activity of inflammatory cells as well as support inappropriate tissue reorganization.

The study suggests that inflammatory disease is driven by the inflammatory cells within fibrin matrices through a specific protein in the plasma membrane called aMB2. If that is so, developing medications that can stop the interaction between fibrin and aMB2 might help treat RA as well as many other inflammatory diseases, such as multiple sclerosis, says Degen, a researcher in developmental biology at Cincinnati Children’s Hospital.