: Coccidioides immitis/posadasii Immunoglobulin M Antibody, Cerebrospinal Fluid, Qualitative
: This test looks for IgM antibodies against the fungi Coccidioides immitis and Coccidioides posadasii in cerebrospinal fluid (CSF). IgM antibodies are an early immune response and may help support the diagnosis of coccidioidal meningitis.
[": A positive CSF Coccidioides IgM result can support early fungal meningitis, but results must be interpreted with symptoms, exposure history, and other tests."]
Key facts at a glance
- LOINC
- 75710-4
- Short code
- C immitis+posadasii IgM CSF Ql ID
- Synonyms
- C immitis+posadasii IgM CSF Ql ID
- Category
- chemistry
- Sample
- csf
- Container
- Sterile tube
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- immune-diffusion
- 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 detects IgM-class antibodies that the body can produce against Coccidioides, a fungus found in certain dry, dusty regions. It is performed on cerebrospinal fluid, the fluid that surrounds the brain and spinal cord, and is reported as either detected or not detected (qualitative).
: Why CSF May Be Tested
: CSF testing may be ordered when a person has signs of meningitis, such as fever, severe headache, stiff neck, or confusion, especially with a history of travel to or residence in areas where Coccidioides is common. Testing CSF directly can help evaluate whether the infection has reached the central nervous system.
: Detected Versus Not Detected
: A “detected” result means IgM antibodies were found and may support the possibility of coccidioidal infection. A “not detected” result means they were not found, but it does not by itself rule out infection, because antibody production can vary and may be absent early or in some people.
: How the Result Fits the Whole Picture
: Results are interpreted along with symptoms, exposure history, imaging, CSF cell counts and chemistry, and sometimes additional antibody or fungal tests. A single result should not be used alone to start or stop treatment.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
: Coccidioidal meningitis is a serious form of disseminated coccidioidomycosis. IgM antibodies can appear relatively early in infection, so CSF IgM testing may aid diagnosis, but sensitivity and specificity are not perfect. False positives and false negatives can occur, and cross-reactivity with other fungi is possible. Diagnosis and treatment decisions should be made by a clinician using the full clinical picture.
Short name
: Coccidioides IgM (CSF)
Frequently asked questions
: Can a negative result rule out coccidioidal meningitis?
: Does a positive result mean I definitely have a fungal infection?
: Is this the same as testing blood for Coccidioides antibodies?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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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