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Galactomannan antigen (qualitative) in cerebrospinal fluid

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

This test detects a fungal antigen that may indicate infection with *Aspergillus* or other mold species in your spinal fluid.

Quick summary

["A positive result may signal fungal meningitis or brain infection requiring urgent medical attention."]

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

Key facts at a glance

LOINC
62467-6
Short code
Galactomannan Ag Spec IA-aCnc
Synonyms
Galactomannan Ag Spec IA-aCnc
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
ia
CPT
86038
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why is this test done?

Your doctor may order this test if you have symptoms like severe headaches, neck stiffness, fever, or neurological concerns—especially if you’ve had recent surgery, weakened immunity, or exposure to mold.

What does a positive result mean?

A positive result suggests possible fungal infection in the central nervous system, but further testing and medical evaluation are needed to confirm diagnosis and guide treatment.

What does a negative result mean?

A negative result means no detectable fungal antigen was found in your spinal fluid, but other causes of symptoms (like viral infections or inflammation) could still be present.

How is this test performed?

A small sample of your cerebrospinal fluid is collected via a spinal tap (lumbar puncture) and tested for the presence of galactomannan antigen using an immunoassay method.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical significance: This test is primarily used to diagnose invasive fungal infections in the central nervous system, particularly in high-risk patients. It helps differentiate fungal meningitis from bacterial or viral causes, guiding targeted antifungal therapy.

Short name

Galactomannan CSF

Frequently asked questions

What does it measure?
This test measures the concentration of galactomannan, a polysaccharide released by certain fungal species (e.g., *Aspergillus*).
How soon will I get results?
Results are typically available within 24 to 48 hours, depending on lab processing times.
Can I take anything before the test?
No special preparations are needed, but inform your doctor about any medications or recent illnesses, as they may affect results or test safety.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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