Analytical and pre-analytical aspects of neurofilament light chain determination in biological fluids
Abstract
The aim of this review is to inform clinical and laboratory workers about the most important pre-analytical and analytical aspects of neurofilament light chain (NfL) determination in bio-logical fluids. NfLs represent a promising nonspecific bio-marker of neuronal and axonal damage that occurs in a variety of neurological diseases.
Before introducing NfL determination into routine clinical practice, it is necessary to characterize the pre-analytical and analytical aspects of the assays, which can significantly affect the accuracy of the analysis results. When evaluating NfL concentrations, the patient's age should be taken into account and body mass index may also have an effect.
The advantages of NfLs are their long-term storage stability at different temperatures as well as resistance to repeated freezing and thawing cycles. NfL concentrations in clinical trials are determined primarily by immunoassay methods that vary in sensitivity.
There are several immunoassay technologies for the determination of NfL suitable for reliable determination in cerebrospinal fluid (CSF) and serum/plasma. The choice of the optimal analytical approach depends, among other things, on the concentration of NfL in bio-logical fluids.
ELISA methods can be used to determine NfL in CSF, which show sufficient sensitivity for higher concentrations of NfL occurring in this bio-logical fluid. Newly introduced technologies characterized by significantly higher sensitivity in comparison with the ELISA methods enabled reliable examination of NfL also in serum/plasma.
The principles of methods based on Simoa(R) technology, SimplePlexTM, and immunomagnetic reduction are mentioned in more detail.