Assessing neuronal damage related to various neurodegenerative diseases

• 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,76 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.

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

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

Patients should be cautioned to stop biotin consumption at least 72 hours prior to the collection of a sample.

Gold serum separator (SST) tube

Immediately following collection, mix sample thoroughly by gentle inversion, 5 times

1. Allow sample to clot for a minimum of 30 minutes
2. Spin within two (2) hours of sample collection

Gold serum separator (SST) tube

Red serum vial/tube, 5 mL

1. Allow sample to clot for a minimum of 30 minutes
2. Spin within two (2) hours of sample collection
3. Transfer serum to a (insert appropriate aliquot tube, using name from transport container tab), labelled as serum

Transfer vial/tube with cap - 12mL (LabCorp)

Ambient (preferred) – 14 days

Refigerated - 14 days

Frozen - 14 days

Freeze/thaw cycles x 3

Roche Diagnostics Electrochemiluminescence Immunoassay (ECLIA)