Research Tracker›Biomarker Atlas›ME/CFS›Neurofilament light chain (NfL)

Neurofilament light chain (NfL) in ME/CFS

In ME/CFS (ME/CFS, CFS), the direction of change for Neurofilament light chain (NfL), also described as Axonal damage marker, is inconsistent across studies that used healthy controls as the reference group. Clinically, it has been associated with cognitive dysfunction subset. The evidence summarised here comes from Maksoud et al. 2023 and reflects averages across cohorts rather than any single patient's result.

↕ InconsistentNeurologicalLOINC 94635-5

Summary

Direction in ME/CFS↕ Inconsistent — reported as both higher and lower across studies, with no consistent direction
CategoryNeurological
Also described asAxonal damage marker
Compared againstHC (healthy controls)
Associated symptomsCognitive dysfunction subset
Test typeBlood test (serum / plasma / whole blood)
LOINC code94635-5
SourceMaksoud et al. 2023 — doi:10.1186/s12916-023-02893-9
Condition atlasME/CFS Biomarker Atlas

Other conditions where Neurofilament light chain (NfL) is reported

See the cross-condition hub: Neurofilament light chain (NfL) across conditions.

Trials, interventions and tests

Commercial test availability

Neurofilament light chain (NfL) — specialty laboratory test. Growing specialty/neurology send-out; check local lab menus.

Links are for reference only; availability, specimen requirements and coverage vary by location.

Related Neurological markers in ME/CFS

Full list: ME/CFS Biomarker Atlas.

Frequently asked questions

Is Neurofilament light chain (NfL) high or low in ME/CFS?

Mixed. Some studies report higher and others lower Neurofilament light chain (NfL) in ME/CFS compared with healthy controls, so no single direction is established. Source: Maksoud et al. 2023.

What symptoms is Neurofilament light chain (NfL) associated with in ME/CFS?

The cited literature associates this marker with Cognitive dysfunction subset. These are population-level associations and do not mean the marker causes the symptoms.

Which test measures Neurofilament light chain (NfL)?

It is measured as a blood test (serum / plasma / whole blood). The standard laboratory code is LOINC 94635-5. Commercial laboratories such as Quest Diagnostics, LabCorp list an orderable assay.

Is one abnormal Neurofilament light chain (NfL) result diagnostic of ME/CFS?

No. No single biomarker is diagnostic of ME/CFS. Neurofilament light chain (NfL) findings come from group comparisons, overlap considerably between patients and controls, and vary with study design, timing and comparison group. A result should be interpreted by a clinician alongside symptoms, history and other tests.

Is Neurofilament light chain (NfL) specific to ME/CFS?

No. The same marker is also reported in Alzheimer's Disease and Other Dementias, Long COVID, Multiple Sclerosis, PACVS in this atlas, so it reflects shared biology (for example inflammation or vascular stress) rather than a condition-specific signature.

Cite this page

Open Source Medicine Foundation. (2026). Neurofilament light chain (NfL) in ME/CFS: direction, evidence and what it means. OSMF Research Tracker. Retrieved October 7, 2026, from https://research.opensourcemed.info/biomarkers/me-cfs/neurofilament-light-chain-nfl.html
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Last reviewed: 2026-06-29 · Page generated from me-cfs.json · Browse: ME/CFS atlas · Biomarker Index · All marker pages

Disclaimer: This page is an educational synthesis of published, peer-reviewed research and is not medical advice. Biomarker findings vary across studies with case definitions, comparison groups, timing and assay methods. Direction of change reflects the predominant finding in the cited source and does not establish a diagnostic threshold. Discuss any test result with a qualified clinician.