Chlamydia trachomatis IgM Antibody, Cerebrospinal Fluid, Immunoassay, Qualitative
This test looks for IgM antibodies against Chlamydia trachomatis in cerebrospinal fluid (CSF) using an immunoassay. It is a specialized test used to help evaluate possible Chlamydia-related infection affecting the central nervous system.
["It detects an early immune response (IgM) to Chlamydia in CSF, but results must be interpreted with clinical context."]
Key facts at a glance
- LOINC
- 16592-8
- Short code
- Chlamydia IgM CSF IF-aCnc
- Synonyms
- Chlamydia IgM CSF IF-aCnc
- Category
- chemistry
- Sample
- csf
- Container
- Sterile tube
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- if
- CPT
- 82784
- Specimen volume
- 1-2 mL
- Stability
- Immediate analysis required, Refrigerated: 1h
- Hemolysis max
- 200
- TAT
- 4–24 hours
- Order
- routine
What This Test Measures
The test measures IgM-class antibodies, which are typically produced early after exposure to Chlamydia trachomatis. Because the specimen is cerebrospinal fluid, the test is intended to assess whether the immune system is responding to Chlamydia in or near the central nervous system.
Why a CSF Sample Is Used
Cerebrospinal fluid surrounds the brain and spinal cord and is collected by lumbar puncture (spinal tap). Testing CSF rather than blood helps clinicians look for evidence of infection localized to the central nervous system, which blood tests alone cannot confirm.
How the Immunoassay Works
An immunoassay uses antibodies or antigens to detect specific immune proteins in the sample. A qualitative result is reported as positive or negative rather than as a precise number, indicating whether IgM antibodies against Chlamydia were detected.
What Results Can Mean
A positive result suggests IgM antibodies to Chlamydia were found in the CSF, which may support a recent or active immune response. A negative result does not by itself rule out infection. Because IgM testing can be affected by cross-reactions and timing of infection, results are interpreted alongside symptoms, imaging, and other tests.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Chlamydia trachomatis is a common sexually transmitted bacterium that can occasionally cause infection involving the central nervous system, though this is uncommon. CSF IgM testing is a specialized adjunct and is not a stand-alone diagnostic test. Clinicians combine it with clinical findings, other CSF studies, and molecular testing such as nucleic acid amplification to reach a diagnosis. Treatment decisions should always be made by a qualified healthcare provider.
Short name
Chlamydia IgM (CSF)
Frequently asked questions
Does a positive result mean I definitely have a Chlamydia infection of the nervous system?
Is this the same as a routine Chlamydia screening test?
Does a negative result rule out Chlamydia?
Sources
- 1
- 2Lab Tests OnlineSource
- 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