A new study published in The Journal of Neuroscience reveals that immune function in mice with spinal cord injury (SCI) can be restored. A group of researchers from The Center for Brain and Spinal Cord Repair at The Ohio State University Wexner Medical Center found that weakened immune function can be caused by a condition known as autonomic dysreflexia. The condition “is a potentially dangerous complication of high-level spinal cord injury characterized by exaggerated activation of spinal autonomic (sympathetic) reflexes,” according to the researchers.
Individuals with SCI are more susceptible to infections, and the reason why, besides the link between weakened immune function and autonomic dysreflexia, is not known, according to MedicalXpress. Autonomic dysreflexia was shown to cause very high blood pressure that can lead to other complications. The researchers found that immune systems in people with SCI are suppressed because there may be damage in regions of the spinal cord that control immune function. Additionally, immune function can be suppressed by ordinary occurrences that trigger normal spinal autonomic reflexes such as using the restroom because the reflexes become hyperactive due to the SCI.
In the study, mice with SCI developed autonomic dysreflexia spontaneously. The condition was shown to become more frequent as time went on. Drugs that inhibit norepinephrine and glucocortoids, hormones produced with autonomic dysreflexia, were used to restore immune function in mice with SCI. In addition, researchers “also observed in a patient with a high-level spinal cord injury that briefly inducing autonomic dysreflexia impaired immune function, confirming that their findings in mice have relevance to humans.”
According to the researchers, “autonomic dysreflexia causes immune suppression in part by releasing into blood and immune organs high levels of immune modulatory hormones that non-selectively kill mature and immature white blood cells in the spleen.” The researchers say that the findings open the door for more studies about how to reverse immune suppression in patients with SCI.