Authors: Eline A.J. Willemse, Charlotte E. Teunissen, Philip Scheltens, Everard Vijverberg
Published: 2020-12-07
DOI: 10.1002/alz.045155
Source: Full article
AbstractBackgroundNeurofilament Light (NfL) is an accurate blood biomarker for axonal damage across the spectrum of neurology. Although serum NfL (sNfL) levels are increased in dementia, the diagnostic value of sNfL and appropriate use criteria need to be defined before implementation. The aim of this study is to evaluate the clinical use of sNfL in a tertiary memory clinic cohort.MethodThis single‐center implementation study included 111 patients that visited the Alzheimer Center Amsterdam between May–Oct 2019. In addition to routine neurological examination and cerebrospinal fluid (CSF) biomarker analysis, sNfL levels were analysed on Simoa (NfL‐Light kit, Quanterix) and reported together with normal values in relation to age. Six neurologists filled out a questionnaire regarding the added value of sNfL after discussing the results with the patient (n=5–43 questionnaires per neurologist). The clinical usefulness of sNfL was evaluated with regard to age (62±9 years) and diagnosis (subjective cognitive decline:n=31; Alzheimer’s disease:n=28; psychiatry:n=9; other diagnoses:n=43), whether diagnosis was uncertain (n=19), and whether CSF biomarker results were available (n=76). These results were translated into recommendations for use of sNfL in clinical practice.ResultSNfL was evaluated as useful diagnostic tool in 54% of the cases. SNfL was more often useful in patients below the age of 61 (60%,n=42); patients with a diagnosis of subjective cognitive decline (61%) or psychiatry (78%), in cases for which there was uncertainty regarding the diagnosis (68%) and less in Alzheimer’s disease (39%). Whether sNfL was regarded as useful, strongly depended on which neurologist filled out the questionnaire (ranging from 0–73% of useful cases per neurologist). Availability of CSF biomarker results at time of result discussion had no influence.ConclusionIn more than half of the evaluated cases, sNfL was perceived as useful diagnostic tool for memory clinic practice. SNfL analysis is mostly recommended as biomarker tool to exclude neurodegeneration in patients below 61 years old or in patients with suspected subjective cognitive decline, psychiatric disorders, or uncertainty regarding the diagnosis. The appreciation of sNfL as useful diagnostic tool was different across neurologists, probably due to differences in level of experience with biomarker sNfL.