Multiple sclerosis, often called MS, is a long-lasting disease that affects the brain and spinal cord. It happens when the body’s immune system mistakenly attacks the nervous system.
This attack damages the protective coating around nerve cells, which slows or blocks messages between the brain and the rest of the body. Over time, this can cause problems with movement, balance, vision, thinking, and memory.
MS affects millions of people worldwide, and Canada has one of the highest rates of the disease. Each year, more than 4,000 Canadians are diagnosed, often at a young age, and many will live with the condition for decades.
One of the biggest challenges in MS care is understanding why the disease gets worse in some people but not others. A new study led by researchers at the University of Toronto has uncovered an important biological signal that may help explain this difference.
The researchers believe they have found a possible marker in the body that shows when MS is entering a more dangerous stage, known as progressive MS. This discovery could help doctors identify which patients are most likely to benefit from new treatments.
MS does not affect everyone in the same way. Many people are first diagnosed with relapsing-remitting MS, which means symptoms come and go. During this stage, patients may have flare-ups followed by periods of recovery. There are now several medicines that can reduce these flare-ups.
However, about 10 percent of patients are diagnosed from the start with progressive MS, a form in which symptoms slowly worsen without clear recovery periods. Others with relapsing-remitting MS eventually move into this progressive stage. Once MS becomes progressive, treatment options are very limited, and disability often increases steadily.
Scientists have long suspected that progressive MS is driven by a type of hidden inflammation deep inside the brain and spinal cord. This inflammation is trapped behind protective barriers and cannot be easily detected with standard scans or blood tests.
Because doctors cannot easily see this process, it has been extremely difficult to know which patients are truly progressing and which treatments might help them.
To better understand this hidden process, the research team created a new mouse model that closely copies the brain damage seen in people with progressive MS. In particular, it mimics injury to gray matter, which is responsible for thinking, memory, and decision-making.
The researchers focused on inflammation in a thin layer of tissue that surrounds the brain and spinal cord. When inflammation builds up in this area, it can quietly damage nearby brain tissue over time.
Using this model, the scientists noticed a dramatic imbalance between two immune signals. One signal, called CXCL13, was extremely high, while another signal, called BAFF, was much lower than normal.
When the researchers treated the mice with experimental drugs known as BTK inhibitors, this imbalance improved, and inflammation was reduced. These drugs are already being tested in human MS trials, but results so far have been inconsistent.
The researchers then asked an important question. Could the balance between CXCL13 and BAFF act as a sign that this hidden inflammation is happening?
To answer this, they examined brain tissue from people who had MS and also tested fluid taken from the spinal area of living MS patients. In both cases, people with more severe hidden inflammation had a much higher ratio of CXCL13 to BAFF.
This finding may explain why past drug trials have struggled. Without a way to identify patients with this specific type of inflammation, many trials likely included people who were unlikely to benefit. Any positive effects in the right patients may have been lost in the larger group.
By using this ratio as a guide, doctors may one day be able to select the right patients for the right treatments. This could change how MS trials are designed and how patients are treated. It could also help identify people early who are at risk of developing progressive MS, allowing doctors to intervene sooner.
When reviewing and analyzing the study, the findings appear strong because they were confirmed in both animals and humans. The research also addresses a long-standing gap in MS treatment by focusing on disease progression rather than early flare-ups.
However, more studies are still needed to confirm how well this marker works in everyday clinical care. Larger trials will be necessary to see whether using this marker truly improves patient outcomes. Even so, this discovery represents a major step toward more precise and personalized treatment for people living with MS.
If you care about health, please read studies that vitamin D can help reduce inflammation, and vitamin K could lower your heart disease risk by a third.
For more health information, please see recent studies about new way to halt excessive inflammation, and results showing foods that could cause inflammation.
The study is published in Nature Immunology.
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