Discover the Simoa® LDT NfL Test for Highly Sensitive Detection of Neurofilament Light Chain
Test: 104291
| Expected turnaround time | 10 days Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary. |
| Related documents | For more information, please view the literature below: The Benchmark for Neurofilament Testing NfL Test Report Sample Collection and Frozen Shipping Instructions Sample Collection and Refrigerated Shipping Instructions |
Specimen Requirements
| Specimen | Serum |
| Volume | 1 mL |
| Minimum volume | 0.5 mL |
| Collection container | Red-top tube, gel-barrier tube |
| Transport container | Transfer the separated serum to a plastic Cryo-tube |
| Storage instructions | Refrigerated |
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 7 days |
| Frozen | 7 days |
| Freeze/thaw cycles | Stable x 3 |
Test Details
| Use | This test is used for the measurement of the level of neurofilament light chain in human serum |
| Limitations | This test was developed and its performance characteristics determined by Quanterix. It has not been cleared or approved by the US Food and Drug Administration |
| Interpretation | There are significant variations in measured serum NfL levels among different methods and labs. Care must be taken when interpreting results obtained in different studies. Nf-L elevation in blood can be due to many different causes, including neurodegenerative diseases or a head impact. Nf-L results should only be used in conjunction with other clinical information when evaluating patients. Various demographic, lifestyle, and comorbidity factors can influence Nf-L levels in serum. The largest demographic variable is age, necessitating age-adjusted reference intervals. A reference range study was conducted across 113 presumed normal healthy individuals varying in age from 19 to 69 years old. Table 1 exhibits median values and expected ranges of serum Nf-L in different age groups based on 5th percentile through 95th percentiles as estimated from Anderson-Darling fitting. Nf-L test results are based on a normative study of over 10,000 samples and exhibits both the age and BMI dependence of serum Nf-L (1). |
| Test information | The Quanterix Nf-L Test is a digital immunoassay for the quantitative determination of neurofilament light chain (Nf-L) in human serum. Nf-L is a 68 kDa cytoskeletal intermediate filament protein that is expressed in neurons. It associates with the 125 kDa neurofilament medium and the 200 kDa neurofilament heavy chains to form neurofilaments (2). Neurofilaments are major components of the neuronal cytoskeleton and are believed to function primarily to provide structural support for the axon and to regulate axon diameter (3). Neurofilaments can be released in significant quantities into the cerebrospinal fluid (CSF) following axonal damage or neuronal degeneration. A fraction of these proteins diffuses into the blood, where concentrations are typically 50 to 100-fold lower than in CSF (4). Nf-L elevations have been demonstrated with traumatic brain injury, multiple sclerosis, frontotemporal dementia, Alzheimer’s disease, and other neurodegenerative diseases (5)-(8). |
| Method description | Neurofilament light (Nf-L) is measured on the Quanterix Simoa HD-X analyzer using the Simoa NF-Light advantage kit. The assay uses two Nf-L specific monoclonal antibodies. Sample, paramagnetic capture beads coated with anti-Nf-L antibody, and a biotinylated detector antibody are combined. Anti-Nf-L antibody coated paramagnetic capture beads and labeled biotinylated detector antibody will bind to Nf-L molecules present in the sample. Following a washing step, a conjugate of streptavidin-beta-galactosidase (SBG) is mixed with the capture beads. The captured Nf-L 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 sealed into the microwells while excess beads are washed away with a synthetic fluorinated polymer sealing oil. If Nf-L 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. (Package insert: Simoa NF-Light Advantage Kit. Quanterix Corporation; 2019) |
Table 1
| Age (y) | Median (pg/mL) | Range (pg/mL) |
|---|---|---|
| 19-39 | 4.86 | 2.47 – 7.25 |
| 40-49 | 7.01 | 4.44 – 9.58 |
| 50-59 | 11.02 | 4.79 – 17.25 |
| 60-69 | 13.12 | 3.97 – 22.27 |
Citations
- Benkert P, Meier S, Schaedelin S, et al. Serum neurofilament light chain for individual prognostication of disease activity in people with multiple sclerosis: a retrospective modelling and validation study. Lancet Neurol. 2022;21(3):246-257.
- Yuan A, Rao MV, Veeranna, Nixon RA. Neurofilaments at a glance. J Cell Sci. 2012;125(Pt 14):3257-3263. doi:10.1242/jcs.104729
- Lalonde R, Strazielle C, et al. Neurobehavioral characteristics of mice with modified intermediate filament genes. Rev Neurosci 2003; 14 (4): 369–85.
- Gaiottino J, Norgren N, Dobson R, et al. Increased neurofilament light chain blood levels in neurodegenerative neurological diseases. PLoS One. 2013;8(9):e75091. Published 2013 Sep 20.
- Shahim P, Gren M, Liman V, Andreasson U, Norgren N, Tegner Y, Mattsson N, Andreasen N, Öst M, Zetterberg H, Nellgård B, Blennow K. Serum neurofilament light protein predicts clinical outcome in traumatic brain injury. Sci Rep. 2016 Nov 7;6:36791.
- Disanto G, Barro C, Benkert P, et al. Serum Neurofilament light: A biomarker of neuronal damage in multiple sclerosis. Ann Neurol. 2017;81(6):857-870.
- Meeter LH, Dopper EG, et al. Neurofilament light chain: a biomarker for genetic frontotemporal dementia. Ann Clin Transl Neurol 2016;3(8):623#36.
- Giacomucci G, Mazzeo S, Bagnoli S, Ingannato A, Leccese D, Berti V, Padiglioni S, Galdo G, Ferrari C, Sorbi S, Bessi V, Nacmias B. Plasma neurofilament light chain as a biomarker of Alzheimer’s disease in subjective cognitive decline and mild cognitive impairment. J Neurol. 2022 Aug;269(8):4270-4280.