# Plasma Neurofilament Light Chain as a Complementary Biomarker for Alzheimer's Disease and Mild Cognitive Impairment: A Systematic Review and Meta-Analysis

Review · Kim KY, Shin KY, Chang KA

- Archive id: doi:10.3390/ijms27198574
- Published: 2026-09-25
- Venue: International journal of molecular sciences
- DOI: https://doi.org/10.3390/ijms27198574
- PMID: 42883821
- PMCID: PMC13664730
- Citations: 0
- Source URL: https://doi.org/10.3390/ijms27198574
- PDF: https://europepmc.org/articles/PMC13664730/pdf
- Provenance: europepmc

## Abstract

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by cognitive decline and memory loss, ultimately leading to a loss of independence and reduced quality of life. As current treatments are most effective in the early stages, reliable blood-based biomarkers are required for early diagnosis, therapeutic monitoring, and disease staging. Plasma neurofilament light chain (NfL), a marker of neuroaxonal injury, is a candidate biomarker; its value relative to established amyloid- and tau-based biomarkers is unclear. A systematic review and meta-analysis comparing plasma NfL with Aβ42, Aβ40, the Aβ42/Aβ40 ratio, and p-tau217 across cognitively normal (control, Con), mild cognitive impairment (MCI), and AD groups was conducted. Fourteen studies that met specific criteria were included. Plasma NfL and p-tau217 increased across disease stages. Aβ42 and Aβ42/Aβ40 were lower in AD/MCI than in Con; Aβ40 was similar across groups. Heterogeneity (I 2 \< 99%) was observed across biomarkers. Plasma NfL reliably reflected neuroaxonal injury and disease severity from the earliest clinically detectable stage of AD. Plasma NfL may be most valuable when combined with p-tau217/Aβ-based assays to provide a more comprehensive, blood-based assessment of both AD-specific pathology and neurodegeneration. Further studies are needed to validate its prognostic utility and establish clinically applicable cut-off values.

_Abstract reproduced under CC-BY (article license as recorded by Europe PMC; abstract reproduced unmodified apart from markup removal)._

Topics: [Alzheimer's, Parkinson's & Neurodegeneration](https://space-kitty.com/topics/neurodegeneration)

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