Quantification of neurofilament light and glial fibrillary acidic protein in finger-prick blood

Magdalena A Kolanko; Hanna Huber; Michael C B David; Laia Montoliu-Gaya; Joel Simrén; Kaj Blennow; Henrik Zetterberg; Ramin Nilforooshan; Paresh Malhotra; David J Sharp; Nicholas J Ashton; Neil S N Graham

doi:10.1093/braincomms/fcae151

Quantification of neurofilament light and glial fibrillary acidic protein in finger-prick blood

Brain Commun. 2024 Apr 29;6(3):fcae151. doi: 10.1093/braincomms/fcae151. eCollection 2024.

Authors

Magdalena A Kolanko^{1

2}, Hanna Huber³, Michael C B David^{1

2}, Laia Montoliu-Gaya³, Joel Simrén^{3

4}, Kaj Blennow^{3

4}, Henrik Zetterberg^{3

4

5

6

7

8}, Ramin Nilforooshan^{1

9

10}, Paresh Malhotra^{1

2}, David J Sharp^{1

2

11}, Nicholas J Ashton^{3

12

13

14}, Neil S N Graham^{1

2

11}

Affiliations

¹ UK Dementia Research Institute Centre for Care Research and Technology, Imperial College London, 9SMUB, White City Campus, W12 0BZ London, UK.
² Department of Brain Sciences, Imperial College London, W12 0BZ London, UK.
³ Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, 43141 Mölndal, Sweden.
⁴ Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal 43180, Sweden.
⁵ Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, WC1N 3BG London, UK.
⁶ UK Dementia Research Institute at UCL, WC1N 3BG London,UK.
⁷ Hong Kong Center for Neurodegenerative Diseases, Clear Water Bay, Hong Kong, China.
⁸ Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, 53792 WI, USA.
⁹ Surrey and Borders Partnership NHS Foundation Trust, Leatherhead, KT22 7AD Surrey, UK.
¹⁰ University of Surrey, GU2 7XH Guildford, UK.
¹¹ Centre for Injury Studies, Imperial College London, W12 0BZ London, UK.
¹² Institute of Psychiatry, Psychology and Neuroscience Maurice Wohl Institute Clinical Neuroscience Institute, King's College London, SE5 9RT London,UK.
¹³ NIHR Biomedical Research Centre for Mental Health and Biomedical Research Unit for Dementia at South London and Maudsley NHS Foundation, SE5 8AF London, UK.
¹⁴ Centre for Age-Related Medicine, Stavanger University Hospital, 4011 Stavanger, Norway.

Abstract

An accurate diagnosis of neurodegenerative disease and traumatic brain injury is important for prognostication and treatment. Neurofilament light and glial fibrillary acidic protein (GFAP) are leading biomarkers for neurodegeneration and glial activation that are detectable in blood. Yet, current recommendations require rapid centrifugation and ultra-low temperature storage post-venepuncture. Here, we investigated if these markers can be accurately measured in finger-prick blood using dried plasma spot cards. Fifty patients (46 with dementia; 4 with traumatic brain injury) and 19 healthy volunteers underwent finger-prick and venous sampling using dried plasma spot cards and aligned plasma sampling. Neurofilament light and GFAP were quantified using a Single molecule array assay and correlations between plasma and dried plasma spot cards assessed. Biomarker concentrations in plasma and finger-prick dried plasma spot samples were significantly positively correlated (neurofilament light ρ = 0.57; GFAP ρ = 0.58, P < 0.001). Finger-prick neurofilament light and GFAP were significantly elevated after acute traumatic brain injury with non-significant group-level increases in dementia (91% having Alzheimer's disease dementia). In conclusion, we present preliminary evidence that quantifying GFAP and neurofilament light using finger-prick blood collection is viable, with samples stored at room temperature using dried plasma spot cards. This has potential to expand and promote equitable testing access, including in settings where trained personnel are unavailable to perform venepuncture.

Keywords: biomarkers; dementia; diagnosis; head injury; testing.