Researchers began looking into the association after figures showed that pneumonia was increasingly the cause of death for people with after acute spinal cord injury. Data analysis showed patients with these injuries are 37 times more likely to die of pneumonia compared with the typical population.
It is thought the spinal cord injury causes the immune system to become “paralyzed,” so that is it less effective at fighting off infections such as pneumonia. The technical term applied is “induced immune deficiency syndrome.”
This effect has been examined in studies using mice. The research looked at whether mice given spinal cord injuries were impaired in their ability to combat a controlled infection. The same pathogenic organism was also given to control mice. The control mice were given a minor injury of the vertebral bones (but an unaffected spinal cord). Other supporting data has come from immunological changes detected in the blood of patients after spinal cord injury.
With the mouse study it was found 86 percent of the control mice could fight the infection within 24 hours, whereas only 35 percent of the test mice (with the spinal cord injury) could mount a sufficient response. Twenty-four hours later 65 percent of the mice with spinal cord injuries had high levels of the pathogen in their lungs.
In terms of the review of patient records, the research group looked at 1,221 data sets from patients enrolled in the U.S. National Spinal Cord Injury Database from 1993 to 2006. These findings affirmed that those who had suffered serious spinal cord injuries were more likely to develop pneumonia. The cause was a reduced ability to mount an immune defense.
Further analysis showed the ability to mount a strong immune defense was affected by where the spinal cord injury occurred along the spine, with the biggest risk areas being high thoracic regions.
The researcher shop the information will help better manage those who suffer spinal cord injuries, with better measures in place to prevent the risk of contracting bacterial pneumonia.
The research was conducted at the Ohio State University Wexner Medical Center, and led by Dr. Jan M. Schwab. The findings are published in the journal Brain. The research paper is “Spinal cord injury-induced immune deficiency syndrome enhances infection susceptibility dependent on lesion level.”
