Research suggests that high levels of a nerve protein in the blood can predict worsening disability in people with multiple sclerosis.

“In a disease like multiple sclerosis that is so unpredictable and varies so much from one person to the next, having a noninvasive blood test like this could be very valuable, especially since treatments are most effective in the earliest stages of the disease,” said lead researcher Ali Manouchehrinia, PhD, from the Karolinska Institutet in Stockholm, Sweden.

Neurofilament light chain is a protein that is released into the blood when nerve cells die. The study measured levels of this protein in 4385 people with early-stage multiple sclerosis (MS) and 1026 age and gender-matched controls without MS. Their health status was then measured for the next five years.

At the beginning of the study, average levels of the protein were 11.4 and 7.5 pg/ml in the group with MS and the controls, respectively. The results of the research, which were published in the journal Neurology, showed that MS patients with high levels of this nerve protein—defined as being more than 80% higher than that of people in the control group (3524 MS patients)—had a 40-70% increased risk of worsening disability due to their condition after one year.

The Expanded Disability Status Scale (EDSS) is a point scale used to measure how disabled someone with MS is and is also a way of measuring how this status changes over time. People with a score of 1.0-4.5 are able to walk without aid, whereas a score of 5.0 or above signifies an impaired ability to walk.

Manouchehrinia and colleagues found that having a high level of neurofilament light chain protein increased the risk of reaching an overall EDSS score of 3.0 or 4.0 at the end of the study by more than 50%. However, levels of this protein did not seem to be significantly associated with reaching higher levels of disability that impacted walking.

“These results suggest that elevated levels of these proteins measured early on in the course of the disease may help us to predict how the disease will develop and monitor how treatment is working,” commented Manouchehrinia.

The researchers caution that while their results are promising, more research is needed to refine use of this potential biomarker as there was a lot of variation in individual levels of neurofilament light chain protein both in the control and MS group. While they did control for a number of factors including age, body mass index and EDSS score at the beginning of the study, they think that other medical conditions and environmental factors could also play a role in influencing levels of this protein.