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Fungal Antigen (Quantitative) in Serum/Plasma

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

This test measures the presence of fungal antigens in your blood, which can help detect infections caused by certain fungi such as *Cryptococcus* or *Histoplasma*.

Quick summary

["Detects fungal infections early with a simple blood draw."]

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

Key facts at a glance

LOINC
10666-6
Short code
Fungus Tiss FM Stn
Synonyms
Fungus Tiss FM Stn
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
fontana-masson-stain
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 This Test Matters

Fungal infections can be serious, especially in people with weakened immune systems, chronic illnesses, or those undergoing certain treatments. Early detection through this test helps doctors identify infections quickly and guide treatment decisions.

What to Expect Before the Test

You may have no preparation needed, but your doctor might ask you to stop certain medications that could affect results. A blood sample will be taken from a vein in your arm.

What the Results Mean

Results are typically reported as a concentration level of the fungal antigen. Elevated levels may indicate an active fungal infection, while normal levels suggest no detectable infection.

Possible Causes of Positive Results

Positive results can occur with infections caused by fungi like *Cryptococcus neoformans* (common in immunocompromised individuals) or *Histoplasma capsulatum* (found in soil). Other conditions, such as certain medications or lab errors, can also cause false positives.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Fungal Blood Test

Frequently asked questions

How soon will I get my results?
Results are usually available within 24 to 48 hours, depending on lab processing times. Your doctor will discuss the findings with you during your follow-up visit.
Can I have this test if I’m not sick?
This test is primarily used to diagnose fungal infections in people who have symptoms or risk factors, such as recent travel to areas with fungal exposure or a weakened immune system. It may not be routinely recommended for healthy individuals without symptoms.
What if my results are positive?
If your test shows elevated fungal antigen levels, your doctor will likely order additional tests or imaging to confirm the diagnosis and determine the best treatment plan, which may include antifungal medications.
  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