Rheumatoid arthritic pain could be caused by antibodies - News
Rheumatoid arthritic pain could be caused by antibodies
In a recently published study, researchers at CMM has shown that antibodies that exist in the joints before the onset of rheumatoid arthritis can cause pain even in the absence of arthritis. The researchers believe that the finding can represent a general mechanism in autoimmunity and that the results can facilitate the development of new ways of reducing non-inflammatory pain caused by rheumatoid arthritis and other autoimmune diseases.
Camilla Svensson, professor at the Department of Physiology and Pharmacology, and research group leader at CMM, has led the study toghether with Rikard Holmdahl, professor the Department of Medical Biochemistry and Biophysics at Karolinska Institutet.
“We all know that inflammation is painful,” says Camilla Svensson, “But pain can appear before any sign of inflammation in the joints and can remain a problem after it has healed. Our aim was to find possible mechanisms to explain that.”
After injecting cartilage-binding autoantibodies into mice, which served as a model for human rheumatoid arthritis, the researchers found that the mice became more sensitive to pain even before they could observe any signs of inflammation in the joints. Antibodies that had been designed not to activate immune cells and trigger inflammation also induced pain-like behavior in the mice, suggesting increased pain sensitivity in the joints.
The results may explain the early pain symptoms in rheumatoid arthritis patients, as well as non-inflammatory pain caused by other autoimmune diseases.
“Antibodies in these immune complexes can activate the pain neurons directly, and not, as previously thought, as a result of the destructive joint inflammation,” Camilla Svensson says.
“The antibodies can affect the pain neurons also in conditions without any distinct tissue damage or inflammation.”
Camilla Svensson. Photo: Magnus Bergström
Read more about the study at Karolinska Institutet website.
The study ”Cartilage binding antibodies induce pain through immune complex mediated activation of neurons” was published in Journal of Experimental Medicine, online 13 June 2019.