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Afumgtusigg4qn

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

This blood test measures IgG4 antibodies against Aspergillus fumigatus fungus to help diagnose fungal infections and allergic conditions.

Quick summary

{"Measures IgG4 antibodies to Aspergillus fumigatus mold","Helps diagnose allergic bronchopulmonary aspergillosis (ABPA)","Used to monitor treatment response in fungal diseases","Simple blood test with no special preparation needed","Results help doctors determine if you have an active or past fungal infection"}

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

Key facts at a glance

LOINC
26405-1
Short code
A fumgtus IgG4 Qn
Synonyms
A fumgtus IgG4 Qn
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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 is this test?

The Aspergillus fumigatus IgG4 antibody test is a blood test that detects and measures IgG4 antibodies specifically produced by your immune system in response to Aspergillus fumigatus, a common type of mold found in soil, decaying vegetation, and indoor environments. IgG4 is a subtype of immunoglobulin G (IgG) antibodies, and its detection can indicate whether your body has been exposed to this particular fungus.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

Why do I need this test?
Your doctor may order this test if you have chronic respiratory symptoms such as wheezing, coughing, or shortness of breath that haven't responded to typical asthma treatments, especially if you have underlying conditions like asthma, cystic fibrosis, or a weakened immune system.
How is the test performed?
A healthcare professional will draw a blood sample from a vein in your arm. The sample is then sent to a laboratory where it is analyzed for the presence and level of IgG4 antibodies specific to Aspergillus fumigatus.
Do I need to fast before this test?
No special preparation, such as fasting, is typically required for this test. You can eat and drink normally before having your blood drawn.
What do the results mean?
Results vary by laboratory and are interpreted in context with your symptoms and other test results. Elevated IgG4 antibody levels may indicate ABPA or another form of aspergillosis. Your doctor will explain your specific results and what they mean for your health.
Are there any risks?
The risks are minimal and include slight pain, bruising, or bleeding at the needle site. These typically resolve quickly.
  1. 1
    Mayo Clinic - Allergic bronchopulmonary aspergillosisSource
  2. 2
    MedlinePlus - AspergillosisSource
  3. 3
    American College of Chest PhysiciansSource

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