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Antibody to *Aspergillus* spp. (IgG)

Published: August 9, 2026Updated: August 15, 2026

This test measures the level of antibodies your immune system produces in response to exposure to *Aspergillus* fungi, commonly found in moldy environments.

Quick summary

["Helps assess risk of severe fungal infections in certain high-risk patients."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 15, 2026Editorial policy

Key facts at a glance

LOINC
18416-8
Short code
ASNIDG
Synonyms
A nidulans IgG Qn
Category
chemistry
Sample
serum
Container
Red-top serum separator tube (SST) or plain red-top tube
Units
N/A
Ref low
160
Ref high
1
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
Enzyme Immunoassay (EIA) / Immunofluorescence Assay (IFA)
CPT
86606
SNOMED
122291007
Specimen volume
1-2 mL serum
Stability
Room temperature: 8 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 30 days; avoid repeated freeze-thaw cycles
Hemolysis max
100
Lipemia max
100
Icterus max
50
TAT
24–72 hours
Order
routine

What This Test Measures

The test detects IgG antibodies against *Aspergillus* fungi, which your body creates if exposed to these mold spores. These antibodies are part of your immune response and can indicate past or ongoing exposure.

Why It’s Ordered

Doctors may order this test if you have a weakened immune system (e.g., from chemotherapy, HIV, or organ transplants) or certain lung conditions (e.g., cystic fibrosis, chronic obstructive pulmonary disease). It helps monitor for *Aspergillus* infections that could be life-threatening.

How the Test Works

A blood sample is taken and analyzed using an immunoassay method to detect IgG antibodies against *Aspergillus* antigens. The result tells whether your immune system has mounted a response to these fungi.

What the Results Mean

A positive result suggests your body has produced antibodies to *Aspergillus*, possibly from exposure. However, elevated levels alone don’t confirm an active infection—additional testing (like a fungal culture) may be needed.

Reference range

Negative: <1:160; Equivocal: 1:160-1:320; Positive: >1:320 (titer-dependent; reference ranges vary by laboratory and assay methodology)N/A

Specimen: serum

No special preparation required. Fasting is not necessary.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

IgG Anti-Aspergillus Antibody

Frequently asked questions

Why might my doctor ask for this test?
Your doctor may order this test if you have a compromised immune system or symptoms like persistent cough, fever, or lung issues that could signal a fungal infection. It helps identify whether *Aspergillus* exposure is a concern before further testing.
What does a positive result mean?
A positive result means your immune system has detected *Aspergillus* antibodies, which could indicate past exposure or a latent infection. However, it doesn’t confirm an active illness—your doctor will consider other factors, like symptoms and imaging, to guide next steps.
How often should I get this test?
This test is typically ordered as needed, depending on your health status and risk factors. Your doctor will determine how often to repeat it based on your treatment plan and symptoms.
  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 15, 2026. · Read our editorial policy