Nurofilament Light Chain, Plasma

Message

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.

Test Code

140555 (LAB CORP)

CPT Codes
83520

Preferred Specimen

1 mL EDTA plasma

Patient Preparation
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.

Minimum Volume

0.7 mL(NOTE: This volume does NOT allow for repeat testing.)

Instructions

Separate plasma and transfer specimen to a plastic transport tube.

Transport Temperature

Room temperature

Specimen Stability

Room Temperature: 14 days
Refrigerated: 14 days
Froze: 14 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Samples not labeled with full first and last name
Samples not labeled with patient;s date of birth.

Report Available

1-3 days

Limitations

This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.

There are significant variations in measured plasma 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).1

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 plasma. Variables such as exercise,2 blood volume, body mass index may impact measured plasma NfL levels.

NfL levels measured in the morning are more than 10% higher than those measured in the evening.3,4

Caution should be taken in interpreting NfL levels when disease treatment induced neurological complications that can potentially impact NfL levels.5,6

Plasma 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).

Performing Laboratory
LabCorp

Last Updated: December 27, 2023

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.