Evaluation of serum neurofilament light chain, GFAP, and peripherin as biomarkers in hereditary transthyretin amyloidosis.

Early diagnosis and accurate monitoring of disease progression are crucial for timely therapeutic intervention in hereditary transthyretin amyloidosis (ATTRv). Neurofilament light chain (NfL) has emerged as a sensitive biomarker of neuroaxonal injury across neurodegenerative disorders. This study aimed to investigate serum levels of NfL, glial fibrillary acidic protein (GFAP), and peripherin (PRPH) in patients with ATTRV30M amyloidosis and pre-symptomatic gene carriers, compared with controls. Serum samples from 34 ATTRV30M patients, 17 pre-symptomatic ATTRV30M carriers, and 35 controls were analysed using conventional commercially available ELISA platforms to quantify NfL, GFAP, and PRPH concentrations. Serum NfL (sNfL) levels were significantly elevated in ATTRV30M patients compared with controls (threefold, p = 0.0005) and were 1.6-fold higher than in pre-symptomatic ATTRV30M carriers. No significant differences were observed between pre-symptomatic carriers and controls. sNfL concentrations were higher in patients with polyneuropathy disability (PND) score > I compared with PND I (p = 0.0007). Serum GFAP and PRPH levels did not differ significantly among the study groups. Serum NfL represents a promising non-invasive biomarker for assessment of early symptomatic disease and monitoring of disease progression in ATTRV30M amyloidosis. In contrast, sGFAP and sPRPH appear to have limited diagnostic utility in this context.