Summary
| Direction in Lyme Disease | ↑ Elevated — higher than in the comparison group |
|---|---|
| Category | Serologic |
| Also described as | Outer surface protein A |
| Compared against | Uninfected |
| Associated symptoms | Tick-borne transmission phase |
| Test type | Blood test (serum / plasma / whole blood) |
| Source | Lantos et al. 2021 — doi:10.1016/j.idc.2021.05.001 |
| Condition atlas | Lyme Disease Biomarker Atlas |
Related Serologic markers in Lyme Disease
- Anti-OspC antibodies ↑
- Anti-p41 (flagellin) antibodies ↑
- Anti-VlsE antibodies ↑
- C6 peptide ELISA (VisE) ↑
- IgM immunoblot (≥2 of 3 bands) ↑
- IgG immunoblot (≥5 of 10 bands) ↑
- B. burgdorferi EIA (screening) ↑
- Synovial fluid anti-Bb antibodies ↑
Full list: Lyme Disease Biomarker Atlas.
Frequently asked questions
Is Anti-OspA antibodies high or low in Lyme Disease?
Elevated. Studies summarised in the OSMF atlas report higher Anti-OspA antibodies in Lyme Disease than in Uninfected. Source: Lantos et al. 2021.
What symptoms is Anti-OspA antibodies associated with in Lyme Disease?
The cited literature associates this marker with Tick-borne transmission phase. These are population-level associations and do not mean the marker causes the symptoms.
Which test measures Anti-OspA antibodies?
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 Anti-OspA antibodies result diagnostic of Lyme Disease?
No. No single biomarker is diagnostic of Lyme Disease. Anti-OspA antibodies 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.
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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.