Blood proteins can predict multiple sclerosis years before diagnosis

A scientific breakthrough has identified a specific group of blood proteins that change in individuals who later develop multiple sclerosis (MS). These alterations can appear in some cases more than a decade before a formal diagnosis is made.

This discovery suggests that a simple blood test could eventually identify high-risk individuals, allowing medical professionals to act before permanent neurological damage occurs.

The Critical Window for Prevention

In neurological diseases like MS, prevention is considered the most effective cure. While brain damage that has already occurred is difficult or impossible to repair, early detection can often prevent the most debilitating effects of the disease.

Currently, many patients are diagnosed only after the disease has progressed significantly, meaning the window for early intervention has already closed.

How the Predictive Markers Were Found

A research team led by Dr. Adil Harroud, a neurologist and researcher at The Neuro (Montreal Neurological Institute-Hospital) of McGill University, analyzed proteins to find early warning signs of MS.

Using a statistical technique called Mendelian Randomization, the team screened more than 2,500 blood proteins. They discovered that 39 of these proteins were linked to MS risk, with most residing in the signaling pathways used by immune cells to communicate.

To verify these findings, the researchers analyzed samples from 124 individuals in the UK Biobank who eventually developed MS. These samples were taken an average of six years before diagnosis, and in some instances, more than ten years prior.

Identifying Risk and Prognosis

The study found that eight proteins were already altered in people who would later be diagnosed with MS. One specific protein, DKKL1, was linked to both a lower risk of developing the disease and a milder course of illness for those who did develop it.

This makes DKKL1 a candidate marker for both risk assessment and prognosis. The researchers compare this logic to cholesterol screening for heart disease, where blood levels flag risks years before a heart attack occurs.

“In MS, we now know that intervening early can delay or even prevent symptoms altogether. What we lack is a way to identify the right people in time. These blood markers point toward a way to do that, and to act before damage is done.”
— Dr. Adil Harroud, neurologist and researcher, The Neuro (Montreal Neurological Institute-Hospital) of McGill University

Next Steps in MS Screening

The research team intends to validate these findings using larger cohorts of patients. A possible next step is testing whether these protein markers, when combined with other diagnostic tools, could be developed into formal screening tests.

The study was published in the journal Annals of Neurology on May 22, 2026, and was supported by the Canada Brain Research Fund, the Brain Canada Foundation, the Bougie Family Young Investigator Award, and Fonds de Recherche du Québec Santé. View the full study here.

Frequently Asked Questions

How early can these blood proteins signal a risk of MS?
The study found that certain proteins were altered an average of six years before diagnosis, and in some cases, more than a decade earlier.

What is the significance of the protein DKKL1?
DKKL1 was linked to both a lower risk of developing multiple sclerosis and a milder disease course, making it a potential marker for both risk and prognosis.

What method did researchers use to screen the proteins?
The team used a statistical technique known as Mendelian Randomization to screen more than 2,500 blood proteins.

Do you believe predictive blood screening should become a standard part of preventative healthcare?