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Bburgdorc6abcsfacnc

Published: August 9, 2026Updated: August 16, 2026

This test detects C6 antibodies against Borrelia burgdorferi in cerebrospinal fluid (CSF) to help diagnose Lyme disease affecting the central nervous system.

Quick summary

{"Detects antibodies against Borrelia burgdorferi (Lyme disease bacteria) in cerebrospinal fluid","Used to diagnose neuroinvasive Lyme disease when the infection spreads to the nervous system","Sample is collected via lumbar puncture (spinal tap)","A positive result indicates the bacteria may have entered the central nervous system","Results should be interpreted alongside clinical symptoms and other test findings"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
43074-4
Short code
LymeCSF
Synonyms
B burgdor C6 Ab CSF-aCnc
Category
chemistry
Sample
csf
Container
Sterile CSF collection tube, polypropylene, screw-cap, tube #2 or #3 (preferred for microbiology/serology); avoid first tube to minimize blood contamination
Units
N/A
Ref low
0
Ref high
4.9
Fasting
false
Population
adult
Sex
all
Age range
≥ 0 years
Method
Enzyme-linked immunosorbent assay (ELISA) using C6 peptide antigen for detection of Borrelia burgdorferi antibodies
CPT
86618
SNOMED
395202002
Specimen volume
1.0-2.0 mL of CSF; minimum 0.5 mL acceptable
Stability
Room temperature: 8 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 30 days; avoid repeated freeze-thaw cycles
Hemolysis max
200
TAT
24–72 hours
Order
routine

What is this test?

The C6 antibody test for Lyme disease in cerebrospinal fluid (CSF) is a specialized laboratory test that detects antibodies specifically targeting the C6 peptide of Borrelia burgdorferi, the bacteria that causes Lyme disease. The C6 antibody is part of the immune response generated when the body fights a Borrelia infection. This test is different from standard Lyme disease blood tests because it analyzes CSF, the clear fluid surrounding the brain and spinal cord, rather than blood.

Why is it performed?

This test is primarily ordered when a patient has symptoms suggesting that Lyme disease has spread to the central nervous system (neuroinvasive Lyme disease). Symptoms may include severe headaches, neck stiffness, facial paralysis, limb weakness, numbness, fatigue, memory problems, or confusion. The test helps doctors determine whether the Lyme disease bacteria have crossed the blood-brain barrier and are affecting the nervous system.

How is the sample collected?

The sample is collected through a procedure called lumbar puncture, also known as a spinal tap. During this procedure, a healthcare provider inserts a thin needle between the vertebrae in the lower back to withdraw cerebrospinal fluid. The area is first numbed with local anesthetic to minimize discomfort. The collected fluid is then sent to a laboratory for analysis.

What do the results mean?

A positive result indicates that C6 antibodies against Borrelia burgdorferi have been detected in the CSF, suggesting that the Lyme disease bacteria have infected the central nervous system. A negative result means no antibodies were detected, but this does not completely rule out neuroinvasive Lyme disease, especially if symptoms are recent. The test is most reliable when performed at least 4-6 weeks after initial infection, as the immune system needs time to produce detectable antibodies. Results should always be interpreted by a healthcare provider in the context of clinical symptoms, exposure history, and other diagnostic findings.

Reference range

Negative: <5.0 Units; Equivocal: 5.0-9.9 Units; Positive: ≥10.0 Units (laboratory-specific interpretive criteria apply)N/A

Specimen: csf

No special patient preparation required. Lumbar puncture is performed under sterile conditions by qualified healthcare provider. Inform patient of procedure risks including headache, bleeding, and infection.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

Is this test painful?
The lumbar puncture procedure may cause some discomfort or pressure, but the area is numbed with local anesthetic beforehand. You may feel a brief sting during the injection and some pressure during the needle insertion. Most patients describe it as uncomfortable rather than severely painful. After the procedure, you may have a mild headache, which can be relieved by lying flat and drinking fluids.
How long does it take to get results?
Results are typically available within 1-2 weeks, depending on the laboratory. The test is usually performed at specialized reference laboratories that have the expertise to perform CSF antibody testing for Lyme disease.
Do I need to fast before this test?
No fasting is required for this test. However, you should inform your healthcare provider about any medications you are taking, as some drugs may affect the test results or need to be adjusted before the procedure.
Can this test give false results?
Like all tests, there is a small possibility of false results. False negatives can occur if the test is done too early in the infection, before the immune system has produced detectable antibodies. False positives are rare but can occur due to cross-reactivity with other similar infections. The test is most accurate when used in combination with clinical evaluation and other laboratory findings.
Why not just use a blood test instead?
Blood tests for Lyme disease detect antibodies in the bloodstream, but they cannot directly show whether the bacteria have invaded the central nervous system. CSF testing provides direct evidence of infection in the nervous system and is more specific for diagnosing neuroinvasive Lyme disease. In some cases, both blood and CSF testing may be ordered together for comprehensive evaluation.
  1. 1
    CDC - Lyme Disease DiagnosticsSource
  2. 2
    Mayo Clinic Laboratories - Lyme Disease CSF TestingSource
  3. 3
    IDSA Guidelines for Lyme DiseaseSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy