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CSF lymphocytic pleocytosis in Lyme Disease

CSF lymphocytic pleocytosis, also described as WBC >5/μL, is a csf marker reported as elevated in Lyme Disease (Lyme borreliosis, Borrelia burgdorferi infection) when patients are compared with Normal CSF. Symptom domains tied to this marker in the source include CNS inflammation. The finding is drawn from Lantos et al. 2021; it describes group-level differences, not a threshold that classifies an individual.

↑ ElevatedCSF

Summary

Direction in Lyme Disease↑ Elevated — higher than in the comparison group
CategoryCSF
Also described asWBC >5/μL
Compared againstNormal CSF
Associated symptomsCNS inflammation
Test typeTissue / pathology test
SourceLantos et al. 2021 — doi:10.1016/j.idc.2021.05.001
Condition atlasLyme Disease Biomarker Atlas

Related CSF markers in Lyme Disease

Full list: Lyme Disease Biomarker Atlas.

Frequently asked questions

Is CSF lymphocytic pleocytosis high or low in Lyme Disease?

Elevated. Studies summarised in the OSMF atlas report higher CSF lymphocytic pleocytosis in Lyme Disease than in Normal CSF. Source: Lantos et al. 2021.

What symptoms is CSF lymphocytic pleocytosis associated with in Lyme Disease?

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

Which test measures CSF lymphocytic pleocytosis?

It is measured as a tissue / pathology test. Many of the cited studies used research-grade assays, so clinical availability may vary.

Is one abnormal CSF lymphocytic pleocytosis result diagnostic of Lyme Disease?

No. No single biomarker is diagnostic of Lyme Disease. CSF lymphocytic pleocytosis 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). CSF lymphocytic pleocytosis in Lyme Disease: direction, evidence and what it means. OSMF Research Tracker. Retrieved October 7, 2026, from https://research.opensourcemed.info/biomarkers/lyme/csf-lymphocytic-pleocytosis.html
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Last reviewed: 2026-06-29 · Page generated from lyme.json · Browse: Lyme Disease 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.