Research Tracker›Biomarker Atlas›ME/CFS›NK cell cytotoxicity

NK cell cytotoxicity in ME/CFS

NK cell cytotoxicity, also described as Natural killer cell function, is a immune marker reported as reduced in ME/CFS (ME/CFS, CFS) when patients are compared with healthy controls. Clinically, it has been associated with impaired antiviral immunity. The evidence summarised here comes from Maksoud et al. 2023 and reflects averages across cohorts rather than any single patient's result.

↓ ReducedImmune

Summary

Direction in ME/CFS↓ Reduced — lower than in the comparison group
CategoryImmune
Also described asNatural killer cell function
Compared againstHC (healthy controls)
Associated symptomsImpaired antiviral immunity
Test typeBlood test (serum / plasma / whole blood)
SourceMaksoud et al. 2023 — doi:10.1186/s12916-023-02893-9
Condition atlasME/CFS Biomarker Atlas

Related Immune markers in ME/CFS

Full list: ME/CFS Biomarker Atlas.

Frequently asked questions

Is NK cell cytotoxicity high or low in ME/CFS?

Reduced. Studies summarised in the OSMF atlas report lower NK cell cytotoxicity in ME/CFS than in healthy controls. Source: Maksoud et al. 2023.

What symptoms is NK cell cytotoxicity associated with in ME/CFS?

The cited literature associates this marker with Impaired antiviral immunity. These are population-level associations and do not mean the marker causes the symptoms.

Which test measures NK cell cytotoxicity?

It is measured as a blood test (serum / plasma / whole blood). Many of the cited studies used research-grade assays, so clinical availability may vary.

Is one abnormal NK cell cytotoxicity result diagnostic of ME/CFS?

No. No single biomarker is diagnostic of ME/CFS. NK cell cytotoxicity 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.

Cite this page

Open Source Medicine Foundation. (2026). NK cell cytotoxicity in ME/CFS: direction, evidence and what it means. OSMF Research Tracker. Retrieved October 7, 2026, from https://research.opensourcemed.info/biomarkers/me-cfs/nk-cell-cytotoxicity.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.