Researchers link spinal-cord injury to decreased immune response
Researchers at The Ohio State University Wexner Medical Center believe they have found evidence that supports a direct link between spinal-cord injuries (SCI) and the reduced ability to fight off infections like pneumonia.
Principal investigator Jan M. Schwab, a spinal cord researcher at Ohio State’s Neurological Institute, says pneumonia is the leading cause of death after acute SCI and is associated with poor neurological outcomes.
Findings of the study are published in the March issue of the journal Brain.
The study, which included mouse and human models, examined whether SCI also causes the immune system to become “paralyzed,” leaving these patients more susceptible to pneumonia and other infections.
First, researchers analyzed whether mice with SCI were impaired in their ability to combat a controlled infection compared to control mice with minor injury of the vertebral bones and unaffected spinal cord.
In the control group, 86% were able to clear inoculated bacteria completely from their lung within 24 hours. In contrast, after SCI, this ability was reduced to 35% and the majority 65% of SCI animals of different injury levels displayed elevated bacterial loads in infected lungs after 24 hours.
In order to investigate whether findings are mirrored in SCI patients, the researchers analyzed 1,221 data sets from patients enrolled in the National Spinal Cord Injury Database from 1993 to 2006.
Their analysis verified that patients with a higher-level thoracic injury were more likely to develop infections compared to lower thoracic injuries.
One of the aims of this study was to investigate whether SCI-induced immune deficiency syndrome elevates susceptibility to infection more than a non-SCI in a clinically relevant model.
The researchers hope a better understanding of how pneumonia affects these patients will lead to more effective treatment strategies to reduce mortality and improve neurological outcomes, Schwab says.
The project received funding from the German Research Council, the German Academic Exchange Service, Wings for Life Spinal Cord Research Foundation and the W.E Hunt and C.M. Miller Endowment.