Understanding Your Laboratory Test: What It Is, How the Sample Is Collected, and What Your Results Mean
This test detects antibodies against Borrelia burgdorferi (the bacteria that causes Lyme disease) in the fluid from a joint.
{"This test checks if your immune system is reacting to Lyme disease bacteria in a joint","It requires a sample of fluid taken from the affected joint (synovial fluid)","A positive result suggests a Lyme disease infection involving the joint","Results should be interpreted alongside your symptoms and other test findings","The test is often used when Lyme disease arthritis is suspected"}
Key facts at a glance
- LOINC
- 44454-7
- Short code
- LYME-SYN
- Synonyms
- B burgdor Ab Snv-aCnc
- Category
- chemistry
- Sample
- fluid
- Container
- Sterile, leak-proof, screw-cap container; plain red-top tube or synovial fluid collection tube without anticoagulants for serological testing.
- Units
- N/A
- Ref low
- 2
- Ref high
- 4
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- Enzyme Immunoassay (EIA) or Immunofluorescence Assay (IFA); confirmatory testing via Western Blot
- CPT
- 86618
- SNOMED
- 41734-7
- Specimen volume
- 1-2 mL of synovial fluid
- Stability
- Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 30 days; Room temperature (15-25°C): 24 hours. Avoid repeated freeze-thaw cycles.
- Hemolysis max
- 300
- TAT
- 24–96 hours
- Order
- routine
What is this test, and why might my healthcare provider have ordered it for me?
The Borrelia burgdorferi antibody test in synovial fluid is a specialized laboratory test that looks for antibodies (prote made by your immune system) against the bacteria Borrelia burgdorferi. This bacterium causes Lyme disease, which is typically transmitted through tick bites. When the infection spreads to the joints, it can cause Lyme arthritis. This test helps doctors determine if joint inflammation is due to Lyme disease.
How is the sample for this test collected, and what can I expect during the collection process?
A healthcare provider will perform a procedure called joint aspiration (arthrocentesis) to collect synovial fluid from your affected joint. The area will be cleaned and numbed, then a needle will be inserted into the joint to withdraw fluid. This fluid is then sent to a laboratory for testing. You may feel some pressure or discomfort during the procedure, but it is generally well-tolerated.
What do the results of this test mean, and how will my doctor use them to guide my care?
Results are reported as positive or negative for Borrelia burgdorferi antibodies. A positive result indicates that antibodies were detected in the joint fluid, suggesting that the bacteria is present in the joint and causing an immune response. This supports a diagnosis of Lyme arthritis. A negative result means no antibodies were detected, but this does not completely rule out Lyme disease, especially if the infection is very early or late in the course.
Reference range
Negative: Antibodies not detected. Equivocal: Repeat testing recommended in 2-4 weeks. Positive: Antibodies detected, suggestive of Borrelia burgdorferi exposure.N/A
No special patient preparation is required. Arthrocentesis should be performed under standard aseptic technique by a qualified healthcare provider. Inform the ordering physician of any current antibiotic therapy.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
This test is primarily used to diagnose Lyme disease when it affects the joints (Lyme arthritis). It is particularly useful when patients have joint swelling and pain, especially if they have a history of tick exposure or the characteristic bull's-eye rash. Early detection and treatment of Lyme arthritis is important to prevent long-term joint damage. The test helps differentiate Lyme arthritis from other types of arthritis, such as rheumatoid arthritis or osteoarthritis.
Frequently asked questions
Why is this test done on joint fluid instead of blood?
Is the joint aspiration procedure painful?
How long does it take to get results?
What happens if the test is positive?
Sources
- 1Lyme Disease - CDCSource
- 2
- 3
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.
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