Immunity-Suppressing Drugs Often Relieve Pain Autoimmunity is a condition in which the body's immune system turns against its own tissues. Pain Research Forum, a website for the pain research community, recently highlighted several studies suggesting that some chronic pain may be associated with autoimmunity. Multiple sclerosis and rheumatoid arthritis are two examples of diseases caused by autoimmune reactions. The clinical studies found that some patients with chronic pain had antibodies (specialized cells of the immune system which can recognize organisms that invade the body such as bacteria, viruses, and fungi) in their blood against selected proteins on the membranes of their nerve cells. The membrane proteins in question are members of a family called voltage-gated potassium channel complex (VGKC-complex) and play an important role in regulating a nerve cell’s excitability. Autoantibodies directed against selected VGKC members could make cells in pain pathways hyperexcitable, causing pain or making existing pain worse. What’s more, when pain patients with autoantibodies were treated with drugs to suppress immunity, their pain symptoms (which varied from widespread to specific body sites such as the head or face) were often relieved. Exactly what triggers the autoimmune reaction, how the autoantibodies work and whether immune system cells themselves (which also have VGKC proteins on their surface) play a role, are among the many questions stimulating researchers in the field.