Patients recovering from a severe spinal cord injury can develop an immune deficiency that makes life-threatening infections more likely, according to a new study by researchers at The Ohio State University Wexner Medical Center and collaborators in Germany, Switzerland, and Canada.
The findings could lead to improvements in spinal cord injury care through staging a patient’s susceptibility to infection. This would help identify patients whose immune systems are especially compromised and speed the development of new treatments to reduce the chance of early infection.
The study found that monocytes, which are white blood cells required to fight bacterial infections, were deactivated shortly after spinal cord injuries. It also found lower blood levels of antibodies and immunoglobulins, which are part of the body’s “learned” or adaptive immunity.
The findings could lead to improvements in spinal cord injury care through staging a patient’s susceptibility to infection.
In addition, the more severe injury, the more compromised the person’s immune system was likely to be. This is on top of other consequences of spinal cord injuries that also weaken the immune system, such as being bed ridden, receiving anesthesia, or undergoing surgery.
“Infections and subsequent sepsis are the main cause of death after spinal cord injury,” co-corresponding author Jan Schwab, a professor of neurology and neurosciences at the Ohio State College of Medicine, says in a press release. “Our study provides evidence for an immune deficiency that sets spinal-cord injured patients up to develop infections.”
Schwab is also medical director of the Belford Center for Spinal Cord Injury and a scholar of the Chronic Brain Injury Initiative at Ohio State.
The study is reported in the journal Brain.
Patients with high complete injury had the highest rate of pulmonary and urinary tract infections, including recurring infections.
Patients with infections had levels of a cell-surface molecule called mHLA-DR below the reference value for “immune suppression” within two weeks after injury.
Patients with infections in the first or second week after injury had especially low mHLA-DR values in the range of “borderline immunoparalysis” at 15 hours after injury.
A drop in immunoglobulin levels after spinal cord injury suggested depressed humoral immunity as well. This was most pronounced in high completely injured patients.
Both cellular and non-cellular immune defense mechanisms were compromised in spinal cord injury patients and associated with early onset of infections.
Enhanced Care for SCI Patients
Dr. Schwab says results will facilitate “a novel treatment strategy to protect the best possible outcome” for SCI patients.
“Staging a patent’s susceptibility to infection will allow the identification of which specific patients are at high risk, even before the patient will develop an infection,” he tells TwP. “This can enable the development of escalated care modalities for those at risk to prevent infections. [By preventing] infections, the attributed detrimental impact on propagating mortality and morbidity (impairing recovery) could be prevented as well.”
How the study was done
The study involved 111 patients enrolled in the international prospective multicenter cohort study known as SCIentinel study.
To detect the presence and severity of immune suppression in the blood of patients, the researchers measured the levels of mHLA-DR on monocytes.
A low number of mHLA-DR molecules is a recognized and quantifiable marker for monocyte deactivation and has been shown to predict susceptibility to sepsis in critically ill patients. TwP