A new study could allow physicians to diagnose a patient’s multiple sclerosis disease state using a simple blood test.
Michael E. Buckland, MD, PhD
Scientists say they are another step closer to developing a blood test that could quickly diagnose multiple sclerosis (MS) and its subtypes.
The news is based on the identification of exosomal microRNA molecules that appear to be biomarkers for MS. It is believed to be the first time scientists have shown that circulating exosomes can be used not only to diagnose MS, but also to determine whether a patient’s disease if relapsing-remitting or progressive.
Researchers from the University of Sydney studied the exosomes in the blood of healthy patients and volunteers with MS. They hypothesized that exosomes released by the brain might have valuable information about the presence of neurological disease, such as MS. Just as they suspected, the samples yielded a microRNA profile that accurately predicted whether a patient had MS, and if so, what type.
They found 9 microRNA molecules that differentiate between relapsing-remitting MS (RRMS) and progressive MS. They then looked at an independent group of patients with progressive MS, and validated the presence of 8 of 9 microRNA molecules.
Study co-author Michael E. Buckland, MD, PhD, associate professor of pathology at the University of Sydney, told MD Magazine a blood test could prove to be a major asset to physicians and patients when treating MS.
It might not eliminate the need for other types of diagnostic tools and monitoring, but it could allow for a more tailored approach, he said.
“In particular, monitoring of disease activity relies heavily on MRI scans, usually performed 6 monthly or yearly if the patient is feeling well,” Buckland said. “A blood test may allow for much closer monitoring, such as monthly, without causing too much inconvenience and not costing too much. This may eventually lead to MRI scans being needed less often.”
Buckland, who leads the Department of Neuropathology at Royal Prince Alfred Hospital and the university’s Brain and Mind Centre, said it’s also possible that the blood test might be able to detect “smoldering” MS, a condition in which a patient’s brain continues to atrophy even though MRI scans suggest the disease is inactive.
Another potential benefit of a blood test could be the ability to more quickly pinpoint when a patient’s disease is switching from relapsing-remitting to progressive MS. Currently, it’s difficult to spot the transition, and the diagnosis often occurs only after the transition has taken place. Buckland said an early detection test could be a beneficial corollary to new disease-modifying therapies (DMTs).
“With the new generation of drugs that seem to be effective for progressive forms of MS, it may be advantageous to accurately identify the transition early and so appropriate treatment can be started earlier,” Buckland said. “At the moment this is speculative, but we do know that initiating DMTs early in RRMS has long term benefits, and it may be a similar story for progressive MS.”
The next step in his research is to study the biomarkers in longitudinal clinical trial samples.
“These samples will have extensive clinical and radiological (volumetric 3T MRI) follow-up so we will be able to see how the biomarkers behave over time and closely correlate with disease activity as well as brain atrophy rates,” Buckland said.
The study, "Exosomal microRNA signatures in multiple sclerosis reflect disease status," was published online in Scientific Reports last month.