**Author Listing - Lead/ Submitting Author (we will be communicating with this individual): Name, Institution, City and State where the work was done. Co-authors will be added in a separate section.**
Masateru Tajiri, Department of Medicine (Neurology and Rheumatology), Shinshu University School of Medicine, Matsumoto City, Nagano prefecture, Japan

**Main Body of the Abstract**
Background: Neurofilament light chain (NfL) is a potential biomarker of neuronal injury in hereditary ATTR (ATTRv) amyloidosis. However, the correlation between NfL and nerve conduction study (NCS), the current standard biomarker of ATTR amyloid neuropathy, has not been investigated.
Objective: Analyze the correlation between NfL and neurophysiological parameters assessed by NCS.
Methods: A total of 208 serum NfL measurements were performed in 48 ATTRv patients, 5 asymptomatic carriers, and 12 healthy subjects. These included 91 simultaneous NCS and serum NfL measurements that were conducted in 48 ATTRv patients.
Results: NfL levels of symptomatic patients (79.3 ± 59.8 pg/mL) were significantly higher than those of asymptomatic carriers (9.7 ± 5.5 pg/mL, p<0.001) and healthy controls (10.0 ± 5.3 pg/mL, p<0.001). Linear regression analysis revealed strong negative correlations between NfL levels and compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) amplitudes, that are indicators of axonal damage. CMAP/SNAP amplitudes were undetectable in 9 patients (no-amplitude group) because their peripheral neuropathy was already highly advanced. NfL levels in the no-amplitude group (135.7 ± 37.2 pg/mL) were significantly higher than those in patients with detectable CMAP/SNAP (61.7 ± 55.0 pg/mL, p<0.001).
Conclusions: NfL is found to be well-correlated with NCS in ATTRv patients. Also, compared with NCS, it has the potential to be a more useful biomarker for patients with advanced neuropathy.



**Author Listing - Lead/ Submitting Author (we will be communicating with this individual): Name, Institution, City and State where the work was done. Co-authors will be added in a separate section.**
Masateru Tajiri, Department of Medicine (Neurology and Rheumatology), Shinshu University School of Medicine, Matsumoto City, Nagano prefecture, Japan

**Main Body of the Abstract**
**Background**: Neurofilament light chain (NfL) is a potential biomarker of neuronal injury in hereditary ATTR (ATTRv) amyloidosis. However, the correlation between NfL and nerve conduction study (NCS), the current standard biomarker of ATTR amyloid neuropathy, has not been investigated.
**Objective**: Analyze the correlation between NfL and neurophysiological parameters assessed by NCS.
**Methods**: A total of 208 serum NfL measurements were performed in 48 ATTRv patients, 5 asymptomatic carriers, and 12 healthy subjects. These included 91 simultaneous NCS and serum NfL measurements that were conducted in 48 ATTRv patients.
**Results:** NfL levels of symptomatic patients (79.3 ± 59.8 pg/mL) were significantly higher than those of asymptomatic carriers (9.7 ± 5.5 pg/mL, p<0.001) and healthy controls (10.0 ± 5.3 pg/mL, p<0.001). Linear regression analysis revealed strong negative correlations between NfL levels and compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) amplitudes, that are indicators of axonal damage. CMAP/SNAP amplitudes were undetectable in 9 patients (no-amplitude group) because their peripheral neuropathy was already highly advanced. NfL levels in the no-amplitude group (135.7 ± 37.2 pg/mL) were significantly higher than those in patients with detectable CMAP/SNAP (61.7 ± 55.0 pg/mL, p<0.001).
**Conclusions**: NfL is found to be well-correlated with NCS in ATTRv patients. Also, compared with NCS, it has the potential to be a more useful biomarker for patients with advanced neuropathy.



Neurofilament light chain as a biomarker for hereditary ATTR amyloidosis - Correlation between neurofilament light chain and nerve conduction study - PB27 (#138)

We invite you to attend the XIX International Symposium on Amyloidosis to be held in Rochester, MN.

This symposium is organized as a hybrid meeting (with the focus on in-person) held from Sunday, May 26 through Thursday, May 30, 2024.

Together with the ISA Board and members of Mayo Clinic, a very attractive scientific hybrid program is being planned. The program will cover a variety of types of systemic amyloidosis: ATTR (hereditary and wild-type), AL (light-chain), AA and less frequent forms. There will be key lectures, specific symposia including those company sponsored, oral presentations and poster sessions of accepted abstracts.

COURSE DESCRIPTION
This program will provide a comprehensive review of state-of-the-art education in systemic amyloidosis: basic science, pathophysiology, diagnosis, current and emerging treatments. Scientific presentations will include competitive oral and poster abstracts. The rapid evolution of scientific discovery and expanding treatment options has created tremendous interest in the field and this meeting will fill and important gap in educating scientists and clinicians.