Inflammation outside the brain linked to faster MS progression
This inflammation can be caused by infections like common cold, flu, UTIs
Inflammation outside of the brain and spinal cord, which can be caused by infections like the common cold, flu, or urinary tract infections (UTIs), is associated with more damage to the nervous system in people with progressive forms of multiple sclerosis (MS).
That’s according to the study “Systemic inflammation associates with and precedes cord atrophy in progressive multiple sclerosis,” which was published in Brain Communications. The work was funded in part by MS Society UK.
“The results of this study suggest it is important for people with MS to minimise inflammation where they can,” Ian Galea, MD, PhD, co-author of the study and a professor at the University of Southampton, said in a press release. “This includes receiving all recommended vaccinations and seeking prompt attention for bladder infections. Following a healthy lifestyle could also be beneficial, as factors like smoking, alcohol and obesity are linked to inflammation. As health care professionals we can help too, by talking about these things with our patients so they have the facts they need.”
Inflammation in MS causes damage to nerve fibers in brain, spinal cord
In MS, inflammation causes damage to nerve fibers in the brain and spinal cord (collectively called the central nervous system or CNS). Over time, people with MS experience atrophy (shrinkage) in parts of the CNS due to the progressive damage and loss of nerve cells.
Studies done in animal models have indicated that inflammation outside the CNS, which can be triggered by common infections, can lead to faster atrophy within the CNS. In the new study, scientists set out to see if this phenomenon also happens in people with the disease.
“Our results build on decades of research showing inflammation causes nerve cell loss in the laboratory,” Galea said.
The study enrolled 50 people with progressive types of MS, including 28 with primary progressive MS and 22 with secondary progressive disease. The patients had been living with MS for about 12 years, and three quarters needed assistance to walk.
Participants were followed for 2.6 years on average, during which they provided weekly urine samples that were tested to measure markers of inflammation outside the CNS. The patients also underwent routine MRI scans to assess brain and spinal cord atrophy.
With all these data in hand, the researchers conducted statistical tests looking for associations between atrophy and inflammation. Results revealed patients with more inflammation had statistically more atrophy in the spinal cord.
‘Robust association’ between systemic inflammation, spinal cord atrophy
“In this longitudinal study following individuals with established progressive MS over a 2.5-year study period, we observed a robust association between markers of increased systemic inflammation and cord atrophy,” the scientists wrote.
In some patients, such as Richard Humpston, 43, from Portsmouth, U.K., the data showed signs of inflammation even when patients themselves didn’t realize they had an infection (though the researchers stressed they didn’t have detailed data on causes of inflammation for individual patients).
“There was some evidence that I had urine infections during the study,” Humpston said. “The results of this trial have highlighted how vital it is for me to stay hydrated to avoid this type of infection in future. And it also makes me realise how important it is to know the signs and symptoms of having a UTI, and to get help as soon as possible for any infection.”
Although inflammation was linked to cord atrophy, the study’s findings didn’t show a significant association between inflammation and atrophy in the brain. The researchers noted it’s not clear whether this lack of association is because the spinal cord is particularly sensitive to inflammation outside of the body, or because of technical limitations that make it harder to accurately track brain atrophy, highlighting a need for more study.
“In the future, lab research could help us understand what’s going on at a molecular level when this inflammation happens — which could perhaps help us develop new drug treatments,” Galea noted.
Given the evidence that bodywide inflammation may worsen the progression of MS, the findings suggest “efforts to minimize systemic inflammation in people with MS may be warranted, using a combination of vaccination, optimized symptom management and early treatment of infections,” the researchers concluded.
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