• Posted June 24, 2025

Blood Test Might Predict MS Relapse

A blood test might predict when multiple sclerosis patients are about to suffer a relapse in their symptoms, a new study says.

Blood levels of a protein called neurofilament light chain rise significantly in MS patients up to a year before they have a relapse, researchers reported Monday at a meeting of the European Academy of Neurology in Helsinki.

This sort of early detection can help doctors prepare for a relapse, ensuring timely treatment and potentially slowing the progression of MS, researchers said.

“Our findings significantly support the idea that serum neurofilament light chain (sNfL) has real potential for integration into routine monitoring of MS,” lead researcher Maria Martinez-Serrat, a doctoral student at the Medical University of Graz in Austria, said in a news release.

“Interpreted correctly, it could help clinicians anticipate disease activity, evaluate treatment response, and personalize care for patients at greater risk and ultimately enable earlier, more targeted interventions,” she said.

MS occurs when the immune system starts attacking the protective sheath that covers nerve cells, which is called myelin. This causes a wide-ranging and irreversible damage, impairing people’s ability to move, damaging their vision and causing problems with mood and memory.

People with early MS often will enter long periods of remission, with weeks or months of recovery between symptom flare-ups.

To see if these relapses could be predicted, researchers turned to neurofilament light chain — a protein that is released when nerve cells are damaged.

“Our aim was to explore how sNfL levels evolve over time and how they might serve as an early clinical warning sign of relapses in real-world settings,” Martinez-Serrat said.

For the study, researchers analyzed data from 162 MS patients tracked for around 10 years.

Results showed that sNfL levels could indeed predict an MS flare up, but only among those patients not currently suffering symptoms.

“When someone is already in relapse, sNfL levels are high due to ongoing nerve injury, which limits its predictive power,” Martinez-Serrat said. “But during remission, unexpected spikes in sNfL can flag hidden, emerging pathology — making it an effective early warning signal.”

However, the test could only predict MS flare-ups out to one year.

The test reflects current or recent nerve damage, “which makes it excellent for short-term risk assessment," Martinez-Serrat said. "But long-term prediction is confounded by treatment changes, lifestyle factors, or new inflammatory events.”

The protein’s levels also remained elevated for up to nine months after a person’s relapse, reflecting how long it can take for the body to recover, researchers said.

While sNfL shows promise as a test for MS patients, Martinez-Serrat cautioned against using it in isolation.

“MS is a multifaceted disease, and sNfL is one piece of the puzzle,” she said. “Future research may focus on combining it with other biomarkers … to build a more complete picture of disease trajectory.”

Findings presented at medical meetings should be considered preliminary until published in a peer-reviewed journal.

More information

The Cleveland Clinic has more on neurofilament light chain.

SOURCE: European Academy of Neurology, news release, June 23, 2025