C5a complement and cytokine signaling mediate the pronociceptive effects of complex regional pain syndrome patient IgM in fracture mice.

It has been proposed that complex regional pain syndrome (CRPS) is a posttraumatic autoimmune disease. Previously, we observed that B cells contribute to CRPS-like changes in a mouse tibia fracture model, and that early (12 months duration) CRPS patient IgM antibodies have pronociceptive effects in the skin and spinal cord of muMT fracture mice lacking B cells. The current study evaluated the pronociceptive effects of intraplantar or intrathecal injections of early CRPS IgM (5 µg) in muMT fracture mice. Skin and lumbar spinal cord were collected for immunohistochemistry and polymerase chain reaction analyses. Wild-type mice exhibited postfracture increases in complement component C5a and it…