Test Directory

This test is used for the measurement of the level of Neurofilament Light Chain in serum

Preferred Specimen Type: Serum

Preferred Collection Container: Red Top, Plain 

Alternate Collection Container: Gold Top, Serum Separator 

Desired Specimen Volume: 1 mL

1. Collect red top plain or serum separator tube via venipuncture.
2. Separate serum from cells
3. Transfer 1 mL of serum to a clear aliquot tube

This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H, or coenzyme R). It is recommended to ask all patients who may be indicated for this test about biotin supplementation. Patients should be cautioned to stop biotin consumption at least 72 hours prior to the collection of a sample.

Transport to the laboratory refrigerated. 

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.

Direct comparisons of absolute values can only be done on the same source fluid (plasma or serum).

A rise in NfL is not specific for a specific disease factor and may be caused by both neurodegenerative diseases or a head impact during sports. Results should only be used in conjunction with other clinical information when evaluating patients with neurodegeneration. Due to a lack of specificity to a particular neurodegenerative disease, its role as a diagnostic marker is limited.

There are numerous demographic, life style, and comorbidity factors that potentially influence NfL levels in serum. Variables such as exercise, blood volume, body mass index may impact measured serum NfL levels.

NfL levels measured in the morning are more than 10% higher than those measured in the evening.

Caution should be taken in interpreting NfL levels when disease treatment induced neurological complications that can potentially impact NfL levels.

Serum NfL levels can be decreased in patients with high immunoglobulin G (IgG) levels.

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).