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Neurofilament Light Chain, Plasma
Test CodeNLC
Alias/See Also
Epic: LAB16342
Mayo: NFLC
Mayo: NFLC
CPT Codes
0361U
Preferred Specimen
Specimen Type: Plasma EDTA
Collection Container: Lavender top (EDTA)
Specimen Volume: 1.5 mL
Minimum Volume
0.75 mL
Instructions
- Centrifuge and aliquot plasma into a plastic vial.
- Do not submit specimen in original tube.
Transport Container
Plastic vial
Specimen Stability
Room temperature: Unacceptable
Refrigerated: 7 days
Frozen: 90 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis
Methodology
Digital Immunoassay
Setup Schedule
Monday, Thursday
Report Available
1 to 7 days
Limitations
CAUTIONS
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.
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.
Reference Range
REFERENCE VALUES
<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
INTERPRETATION
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.
<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
INTERPRETATION
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.
Clinical Significance
USEFUL FOR
Assessing neuronal damage related to various neurodegenerative diseases
CLINICAL INFORMATION
Neurofilaments (NF) are exclusively located in the neuronal cytoskeleton and are released to the interstitial fluid upon axonal injury or neurodegeneration. NF concentrations in cerebrospinal fluid (CSF) and blood have been shown to correlate with the extent of axonal damage or neurodegeneration in various diseases. Of the family of NF proteins, neurofilament light chain (NfL) has gained the most interest as a candidate marker of neurodegeneration. During axonal damage, NfL is released into the CSF, and eventually into the blood where concentrations are 40-fold lower than in the CSF. NfL concentrations increase with age with a reported increase in healthy control of 2.2% per year. While the specific cause of this increase has not been elucidated, it is believed to be related to aging itself as well as to the development of subclinical ischemic events. NfL concentrations in blood reflect the extent of axonal damage, making them a generic marker of disease activity. Increases in NfL concentrations have been reported in individuals with traumatic brain injury, amyotrophic lateral sclerosis, multiple sclerosis, frontotemporal dementia, Alzheimer disease, and other neurodegenerative diseases.
Assessing neuronal damage related to various neurodegenerative diseases
CLINICAL INFORMATION
Neurofilaments (NF) are exclusively located in the neuronal cytoskeleton and are released to the interstitial fluid upon axonal injury or neurodegeneration. NF concentrations in cerebrospinal fluid (CSF) and blood have been shown to correlate with the extent of axonal damage or neurodegeneration in various diseases. Of the family of NF proteins, neurofilament light chain (NfL) has gained the most interest as a candidate marker of neurodegeneration. During axonal damage, NfL is released into the CSF, and eventually into the blood where concentrations are 40-fold lower than in the CSF. NfL concentrations increase with age with a reported increase in healthy control of 2.2% per year. While the specific cause of this increase has not been elucidated, it is believed to be related to aging itself as well as to the development of subclinical ischemic events. NfL concentrations in blood reflect the extent of axonal damage, making them a generic marker of disease activity. Increases in NfL concentrations have been reported in individuals with traumatic brain injury, amyotrophic lateral sclerosis, multiple sclerosis, frontotemporal dementia, Alzheimer disease, and other neurodegenerative diseases.
Performing Laboratory
Mayo Clinic Laboratories - Rochester
3050 Superior Drive NW
Rochester, MN 55901
Last Updated: April 12, 2023
Last Review: N. Wolford, April 12, 2023