Prospective Evaluation of Neurofilament Light Chains as a Biomarker in Hereditary Amyloidosis (ATTRv), Including Correlation With Various Measurements of Disease Severity and Progression.

ATTR amyloidosis is a rare and progressively disabling disease caused by the deposition of misfolded TTR protein in multiple tissues including the nerves, heart, and gastrointestinal tract. Polyneuropathy (PN) and cardiomyopathy (CM) are the two most frequent phenotypes and many patients presented a mixed picture of PN and CM. There are different methods to search for the existence and extent of PN and disability caused by ATTR amyloidosis (e.g. mNIS+7, Norfol, QoL-DN), these methods may not be sensitive enough to search for the onset of disease in patients carrying the pathogenic TTR variants or progression of PN in patients undergoing treatment. Also, some of the available methods can be difficult and time-consuming to perform. For this reason, there is a need for sensitive biomarkers that can aid in the investigation and follow-up of PN in patients with hATTR amyloidosis. NfL, a well-known biomarker of nerve damage due to both central and peripheral nervous system disorders, was recently evaluated as a potential biomarker of nerve damage in patients with hATTR amyloidosis. The results of this study can help understand the potential value of NfL in patients with PN of hATTR amyloidosis establishing i changes levels of this biomarker in response to different pathology-specific treatment options correlation between NfL levels and different ratings clinics. The primary objective of the study is to establish the potential of NfL as a biomarker of severity of polyneuropathy, progression and response to treatment in patients with symptomatic hATTR amyloidosis.