Test Catalog

Test Id : NFLC

Neurofilament Light Chain, Plasma

Useful For
Suggests clinical disorders or settings where the test may be helpful

Assessing neuronal damage related to various neurodegenerative diseases

Method Name
A short description of the method used to perform the test

Digital Immunoassay

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Neurofilament Light Chain, P

Specimen Type
Describes the specimen type validated for testing

Plasma EDTA

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Collection Container/Tube: Lavender top (EDTA)

Submission Container/Tube: Plastic screw-top vial

Specimen Volume: 1.5 mL

Collection Information: Centrifuge and aliquot plasma into a plastic vial. Do not submit specimen in original tube.


If not ordering electronically, complete, print, and send a Neurology Specialty Testing Client Test Request (T732) with the specimen.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

0.75 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject
Gross lipemia OK
Gross icterus OK

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Plasma EDTA Frozen (preferred) 90 days
Refrigerated 7 days

Useful For
Suggests clinical disorders or settings where the test may be helpful

Assessing neuronal damage related to various neurodegenerative diseases

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

<20 years: Not established

20 to 29 years: < or =8.4 pg/mL

30 to 39 years: < or =11.4 pg/mL

40 to 49 years: < or =15.4 pg/mL

50 to 59 years: < or =20.8 pg/mL

60 to 69 years: < or =28.0 pg/mL

70 to 79 years: < or =37.9 pg/mL

> or =80 years: < or =51.2 pg/mL

Provides information to assist in interpretation of the test results

Blood neurofilament light chain (NfL) is a marker of neuro-axonal injury showing promising associations with outcomes in several neurological conditions. In neurodegenerative diseases, NfL could serve as a prognostic marker of decline and an efficacy biomarker of experimental therapies. In a meta-analysis of Alzheimer disease (AD), frontotemporal dementia, and amyotrophic lateral sclerosis (ALS), plasma NfL levels were elevated in patients compared to controls with utility in differentiating neurodegenerative conditions from non-neurodegenerative mimics. However, due to a lack of specificity to a particular neurodegenerative disease, its role as a diagnostic marker is limited.


In multiple sclerosis (MS), NfL is elevated in the blood of newly diagnosed patients and concentrations correlate with disease severity and prognosis. Early measures of blood NfL in newly diagnosed MS patients can predict brain atrophy and lesion load on magnetic resonance imaging. The use of blood NfL in serial disease monitoring and treatment response has been evaluated in various prospective clinical trials. Reductions in NfL concentrations after different treatments tend to follow the hierarchy of treatment efficacy, with greatest reductions observed with the most intensive treatments. A study that included over 1000 MS patients receiving various treatments, reported the largest reductions in plasma NfL concentrations following alemtuzumab treatment (54% reduction), and the smallest reduction with teriflunomide treatment (7%).


In AD, blood NfL concentrations have been shown to correlate with cortical thinning and cognitive decline in both sporadic and familial AD. However, at this point the clinical utility of blood NfL in AD is not fully understood.


In ALS, NfL concentrations have been suggested to be able to discriminate ALS from ALS-mimics. NfL levels at symptom onset may be prognostic of disease progression rate and may be used to stratify patients into groups with a similar prognosis in clinical trials. Blood NfL concentrations remain relatively stable throughout the disease.


Parkinson disease (PD) patients with elevated NfL concentrations have been reported to have worse cognitive decline, brain cortical atrophy, and motor scores. Blood NfL concentrations in atypical forms of Parkinson disease are higher than in PD and may be used to help differentiate PD from atypical parkinsonian disorders.


In frontotemporal dementia (FTD), blood NfL was able to discriminate patients with the behavioral form of FTD from patients with primary psychiatric disorders. It has been suggested that blood NfL could be used to support the diagnosis of the behavioral form of FTD, monitor disease progression, and prognosis of FTD.


A study that evaluated blood NfL concentrations in 13 neurodegenerative disorders, Down syndrome, depression, and cognitive normal controls showed that plasma NfL concentrations were elevated in all cortical neurodegenerative disorders, ALS, and atypical parkinsonian disorders. Plasma NfL was clinically useful in differentiating atypical parkinsonian disorders from PD, in identifying dementia in Down syndrome, distinguishing neurodegenerative disorders from depression in older adults, and potentially identifying frontotemporal dementia in patients with cognitive impairment. Individuals with ALS, FTD, and Down syndrome with AD presented with the highest concentrations of plasma NfL.

Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Increases in neurofilament light chain (NfL) are not disease specific. Results should only be used in conjunction with other clinical information when evaluating patients with neurodegeneration.


Higher concentrations of NfL may be found in persons with history of stroke, atrial fibrillation, myocardial infarction, chronic kidney disease, pregnancy, and diabetes.


Lower concentrations of NfL may be found in individuals who are obese (BMI > or =30).


All immunometric assays can, on rare occasions, be subject to a hooking effect at extremely high analyte concentrations (false-low results), heterophilic antibody interference (false-high results), or autoantibody interference (unpredictable effects). If the laboratory result does not fit the clinical picture, these possibilities should be considered.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Barro C, Chitnis T, Weiner HL: Blood neurofilament light: a critical review of its application to neurologic disease. Ann Clin Transl Neurol. 2020 Dec;7(12):2508-2523

2. Ashton NJ, Janelidze S, Al Khleifat A, et al: A multicentre validation study of the diagnostic value of plasma neurofilament light. Nat Commun. 2021 Jun 7;12(1):3400

3. Khalil M, Teunissen CE, Otto M, et al: Neurofilaments as biomarkers in neurological disorders. Nat Rev Neurol. 2018 Oct;14(10):577-589

4. Lambertsen KL, Soares CB, Gaist D, Nielsen HH: Neurofilaments: The C-reactive protein of neurology. Brain Sci. 2020 Jan 18;10(1):56

5. Disanto G, Barro C, Benkert P, et al: Serum neurofilament light: A biomarker of neuronal damage in multiple sclerosis. Ann Neurol. 2017 Jun;81(6):857–870

6. Verde F, Steinacker P, Weishaupt JH, et al: Neurofilament light chain in serum for the diagnosis of amyotrophic lateral sclerosis. J Neurol Neurosurg Psychiatry. 2019 Feb;90(2):157-164

7. Mielke MM, Syrjanen JA, Blennow K, et al: Plasma and CSF neurofilament light: Relation to longitudinal neuroimaging and cognitive measures. Neurology. 2019 Jul 16;93(3):e252-e260

8. Khalil M, Pirpamer L, Hofer E, et al: Serum neurofilament light levels in normal aging and their association with morphologic brain changes. Nat Commun. 2020 Feb 10;11(1):812

9. Bornhorst JA, Figdore D, Campbell MR, et al: Plasma neurofilament light chain (NfL) reference interval determination in an age-stratified cognitively unimpaired cohort. Clin Chim Acta. 2022 Aug 27;535:153-156. doi: 10.1016/j.cca.2022.08.017

Method Description
Describes how the test is performed and provides a method-specific reference

Neurofilament light (NfL) is measured on the Quanterix Simoa HD-X analyzer using the Simoa NF-Light advantage kit. The assay uses two NfL specific monoclonal antibodies. Sample, paramagnetic capture beads coated with anti-NfL antibody, and a biotinylated detector antibody are combined. Anti-NfL antibody coated paramagnetic capture beads and labeled biotinylated detector antibody will bind to NfL molecules present in the sample. Following a washing step, a conjugate of streptavidin-beta-galactosidase (SBG) is mixed with the capture beads. The captured NfL becomes enzymatically labeled when the SBG binds to the biotinylated detector antibodies. A second wash is performed, and the capture beads are resuspended in a resorufin beta-D-galactopyranoside (RGP) substrate solution.


This suspension is transferred to the Simoa Disc. Individual paramagnetic capture beads settle into 216,000 femtoliter-sized microwells designed to hold no more than one bead per well. The beads are sealed into the microwells while excess beads are washed away with a synthetic fluorinated polymer sealing oil. If NfL is present in the sample and subsequently captured and labeled, the beta-galactosidase hydrolyzes the RGP substrate and produces a fluorescent signal. This signal is detected and counted by the Simoa optical system. The concentration of NfL is interpolated from a standard curve.(Unpublished Mayo method)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday, Thursday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

1 to 7 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

3 months

Performing Laboratory Location
Indicates the location of the laboratory that performs the test


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Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.


LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
NFLC Neurofilament Light Chain, P 101281-4
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
616854 Neurofilament Light Chain, P 101281-4

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports

Test Update Resources

Change Type Effective Date
New Test 2022-04-19