Clinical stage and plasma neurofilament concentration in adults with Friedreich ataxia

Magnus Johnsson; Henrik Zetterberg; Kaj Blennow; Christopher Lindberg

doi:10.1016/j.heliyon.2023.e23347

Clinical stage and plasma neurofilament concentration in adults with Friedreich ataxia

Heliyon. 2023 Dec 7;10(1):e23347. doi: 10.1016/j.heliyon.2023.e23347. eCollection 2024 Jan 15.

Authors

Magnus Johnsson¹, Henrik Zetterberg^{2

3

4

5

6

7}, Kaj Blennow^{2

3}, Christopher Lindberg¹

Affiliations

¹ Department of Neurology, Sahlgrenska University Hospital, Gothenburg, Sweden.
² Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden.
³ Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden.
⁴ Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UK.
⁵ UK Dementia Research Institute at UCL, London, UK.
⁶ Hong Kong Center for Neurodegenerative Diseases, Hong Kong, China.
⁷ Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA.

Abstract

Objectives: Friedreich Ataxia (FRDA) is the most common recessive ataxia disorder. Yet, little is known of the prevalence in Sweden. In the future, there may be effective disease-modifying therapies, and use of clinical rating scales as well as possible biomarkers in serum or cerebrospinal fluid may be of importance. We evaluated the axonal protein neurofilament light in plasma (p-NfL) as a possible biomarker for disease severity in FRDA.

Materials & methods: We searched for all possible genetically confirmed FRDA cases in the Västra Götaland Region (VGR) of Sweden, and investigated each patient clinically and obtained blood sample for analysis of p-NfL.

Results: We found eight patients corresponding to 1/170.000 adults in the VGR, and 5 of these participated in the study. Three out of the five FRDA patients displayed a small or moderate increase in the p-NfL value, compared to the age-adjusted cut-offs for p-NfL established in the Clinical Neurochemistry Laboratory at our hospital. The two others were the oldest and most severely affected, displayed normal values according the cut-off values. The cohort is too small to make any statistically significant correlation between the five p-NfL values with regard to disease severity.

Conclusions: FRDA is less prevalent in our region of Sweden than could be assumed. In concordance with previous studies from other authors, we find that p-NfL may be increased in patients with FRDA, but less so in older more clinically affected patients. Thus, we conclude that on an individual basis, p-NFL is of uncertain clinical value as a suitable biomarker.

Keywords: Biomarker; Friedreich ataxia; Neurofilament light.