Plasma neurofilament light chain level is not a biomarker of Charcot–Marie–Tooth disease progression: Results of 3‐year follow‐up study

Background and purpose Charcot–Marie–Tooth disease (CMT) is a hereditary, slowly progressive neuropathy. Currently, there are no effective pharmacological treatments or sensitive disease activity biomarkers available. The aim of this study was to demonstrate the change in plasma neurofilament light chain (NfL) over time in a CMT cohort and analyse the association between CMT severity and NfL level. Methods Initially, 101 CMT patients and 64 controls were enrolled in the study. Repeated evaluation was performed in 73 patients and 28 controls at a 3‐year interval. Disease severity assessment included clinical evaluation with CMT Neuropathy Score version 2 (CMTNSv2). Plasma NfL concentration was measured using the Simoa (single molecule array) NfL assay. Results Plasma NfL concentration was increased in the CMT group compared with controls (p