Levels of NFL Protein Could Help Track Huntington’s Progression, Study Suggests

Levels of a protein called neurofilament light (NFL) could be a valuable biomarker for tracking Huntington’s disease progression, according to a study.

The research, “Tau Or Neurofilament Light—Which Is The More Suitable Biomarker For Huntington’s Disease?,” was published in the journal PLoS One.

Huntington’s is caused by an abnormal accumulation of certain proteins — including neurofilament light or tau — that interfere with nerve activity. That means increased levels of NFL or tau could be used as markers of a person’s disease stage.

To test this hypothesis, researchers analyzed levels of both proteins in samples of cerebrospinal fluid (CSF) from 12 Huntington’s patients. The disease was manifest in some patients — that is, they were showing symptoms — and premanifest in others.

Researchers related the protein measurements to the disease stage by using the Unified Huntington’s Disease Rating Scale (UHDRS).

Levels of NFL were significantly higher in the patients with symptoms than in the other group. Tau levels showed a similar, but weaker, tendency, but it disappeared when researchers adjusted the results for age.

In addition, NFL and tau levels were significantly correlated with each other and with the disease stage.

In fact, NFL levels were strongly correlated with all UHDRS items, including total functional capacity and total motor score. The correction between tau levels and the scores were only slightly weaker.

Importantly, NFL levels were significantly correlated with the probability of the disease following the progression pattern that is often seen in Huntington’s over five years, contrary to tau levels.

Together, the results suggest that NFL may be a reliable biomarker of Huntington’s disease progression and the way it manifests itself over time.

“This study strengthens the case for NFL as a useful biomarker of disease stage,” researchers wrote. “NFL was strongly correlated to all evaluated items in the UHDRS assessment. Tau also has a potential for use as a biomarker but correlations to clinical tests are weaker in this study. We suggest that NFL and possibly tau be used in clinical drug trials as biomarkers of disease progression that are potentially influenced by future disease-modifying therapies.”

The study had limitations, such as the small number of patients enrolled, researchers cautioned. They called for studies involving larger groups to validate the results.