Researchers have identified a biomarker that reveals who will develop multiple sclerosis (MS) years in advance. In work reported in Nature Medicine, scientists showed that one in ten people who eventually are diagnosed with MS generate a specific set of autoantibodies many years before any symptoms of MS arise. These autoantibodies, which are antibodies that attack the self, seem to be able to attach to human cells as well as the cells of pathogens. This could explain why MS patients experience autoimmune attacks on the central nervous system, which can lead to a debilitating loss of movement.
MS can cause an array of symptoms including fatigue, dizziness, and spasms, and is sometimes difficult to distinguish from other disorders. MRI scans are often used to diagnose MS. T
here are some treatments for MS that can slow the progression of the disease and that can reduce the loss of mobility. But a clear, advanced warning of the disorder could reduce symptoms and help patients even more.
"Over the last few decades, there's been a move in the field to treat MS earlier and more aggressively with newer, more potent therapies," said corresponding study author Michael Wilson, MD, a neurologist at the University of California, San Francisco. "A diagnostic result like this makes such early intervention more likely, giving patients hope for a better life."
Aberrant immune responses to common infections are thought to be one cause of MS. In this study, the researchers looked for autoantibodies in blood samples from 250 MS patients that were taken after they were diagnosed, as well as samples that had been taken many years earlier. This study was made possible by veterans who submitted blood samples when they joined the military. Samples from another 250 unaffected veterans were also used as a control group.
This work showed that 10 percent of individuals who would go on to be diagnosed with MS had significant levels of autoantibodies years before their disease was identified by clinicians. The autoantibodies in the MS patients had a chemical signature that is also seen in some viruses, such as Epstein-Barr Virus (EBV). Many people with MS have evidence of previous EBV infections.
There were also signs of problems with autoimmunity in the brain many years before an MS diagnosis in this group of patients with autoantibodies. These people also carried high levels of a molecule called neurofilament light (Nfl), which is a sign of neurodegeneration.
The investigators suggested that the immune system may be confusing human proteins for a virus, and launching an aberrant attack, causing MS.
While only ten percent of MS patients had this autoantibody signature, anyone who carried these autoantibodies was also eventually diagnosed with MS.
"Diagnosis is not always straightforward for MS, because we haven't had disease specific biomarkers," Wilson said. "We're excited to have anything that can give more diagnostic certainty earlier on, to have a concrete discussion about whether to start treatment for each patient."
"Imagine if we could diagnose MS before some patients reach the clinic," said study co-author Stephen Hauser, MD, director of the UCSF Weill Institute for Neurosciences. "It enhances our chances of moving from suppression to cure."
Sources: University of California, San Francisco; Nature Medicine