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Fungal Antigen Detection (Serum/Plasma) – Quantitative

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

This test measures the presence of fungal antigens in your blood, helping identify infections caused by certain fungi like *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
98400-5
Short code
Fungus Islt Seq
Synonyms
Fungus Islt Seq
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
sequencing
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

What This Test Measures

The test looks for specific proteins (antigens) produced by fungi in your bloodstream. These antigens are not present in healthy individuals but appear when fungi invade your body. The test uses a sensitive immunoassay method to detect even small amounts.

How the Test Works

Your blood sample is analyzed to identify fungal antigens. If fungi are present, the test can detect their unique molecular markers, aiding diagnosis of systemic fungal infections.

When You Might Need This Test

Your doctor may order this test if you have symptoms like fever, fatigue, weight loss, or lung/skin issues, especially if you live in a fungal-endemic region or have weakened immunity.

Common Uses

This test is particularly useful for diagnosing cryptococcal meningitis (a fungal brain infection) or other systemic fungal diseases in immunocompromised patients (e.g., HIV, chemotherapy).

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Fungal Antigen Level

Frequently asked questions

Why might my doctor recommend this test?
Your doctor may recommend this test if you have symptoms of fungal infection, live in an area with high fungal exposure, or have a weakened immune system (e.g., HIV, organ transplant, chemotherapy).
What does a positive result mean?
A positive result indicates the presence of fungal antigens in your blood, suggesting an active fungal infection. Your doctor will work with you to determine the best course of treatment based on the test results and your symptoms.
How long does it take to get results?
Results are typically available within 24 to 48 hours, depending on lab processing times. Your doctor will discuss the findings with you during your follow-up appointment.
  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