Research Tracker›Biomarker Atlas›Marker Pages›5-Hydroxykynurenine

5-Hydroxykynurenine: biomarker evidence

5-Hydroxykynurenine appears in 1 entry of the OSMF biomarker atlas, covering Long COVID. Across those entries it is elevated in 1. It is currently reported in a single condition in this atlas; cross-condition comparison will be added as the dataset grows. Each row below links to a page with the comparison group, associated symptoms, test details and primary citation.

Long COVID

Where 5-Hydroxykynurenine is reported

Also listed as: Kynurenine pathway

ConditionDirectionCompared againstAssociated symptomsSource
Long COVID↑ elevatedhealthy controlsNeurotoxic metabolite pathwaySaito et al. 2024

Frequently asked questions

In which conditions is 5-Hydroxykynurenine altered?

In the OSMF atlas 5-Hydroxykynurenine is reported in Long COVID. It is elevated in 1 across 1 entries.

Is there a standard clinical test for 5-Hydroxykynurenine?

The atlas entries for 5-Hydroxykynurenine do not carry a LOINC code, which usually means the marker was measured with research assays or study-specific methods rather than a routine clinical panel.

Is one abnormal 5-Hydroxykynurenine result diagnostic?

No single biomarker result is diagnostic of any of these conditions. Findings reflect group averages from published cohorts with substantial overlap between patients and controls.

Cite this page

Open Source Medicine Foundation. (2026). 5-Hydroxykynurenine across conditions: biomarker evidence. OSMF Research Tracker. Retrieved October 7, 2026, from https://research.opensourcemed.info/biomarkers/markers/5-hydroxykynurenine.html
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Last reviewed: 2026-06-29 · Browse: Biomarker Index · All marker pages · Biomarker Atlas

Disclaimer: Educational synthesis of peer-reviewed research; not medical advice. Findings are group-level and vary with study design. Discuss any result with a qualified clinician.