Aspergillus IgG Antibody, Qualitative (RAST)
This qualitative test checks for IgG antibodies to Aspergillus. It can indicate previous exposure but does not by itself diagnose infection or allergy.
["A positive result shows Aspergillus-specific IgG antibodies, which may reflect previous exposure but require clinical interpretation."]
Key facts at a glance
- LOINC
- 21082-3
- Short code
- Deprecated Asparagus IgG RAST Ql
- Synonyms
- Deprecated Asparagus IgG RAST Ql
- Category
- liver
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 10
- Ref high
- 40
- Critical range
- — – 500 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 84484
- SNOMED
- 302774002
- 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?
This test looks for IgG antibodies directed against Aspergillus, a group of fungi commonly found in the environment. A positive result shows that the immune system has produced antibodies against Aspergillus.
Why might I need this test?
It may be ordered when a clinician is evaluating a possible chronic fungal lung condition or other forms of prior Aspergillus exposure. Results are interpreted with symptoms, medical history, imaging, and other laboratory findings.
How is the test performed?
A laboratory analyzes a patient sample for Aspergillus-specific IgG using an antibody-detection method. The result is reported qualitatively, and the exact specimen and laboratory method should be confirmed with the ordering clinician.
How do I prepare for the test?
No special preparation is commonly required for this type of antibody test, although the laboratory's instructions may vary. Tell your clinician about immune disorders, recent infections, or immunosuppressive treatment because these can affect antibody results.
Reference range
Adult: 10-40 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A positive result indicates that Aspergillus-specific IgG antibodies are present, which may occur after environmental exposure, colonization, or a past fungal infection. It is not by itself proof of active infection or allergic sensitization and must be interpreted with other clinical findings. Although the legacy name includes RAST, this test is labeled for IgG and should not be confused with an Aspergillus-specific IgE allergy test.
Short name
Aspergillus IgG antibody
Frequently asked questions
Does a positive result mean I have an Aspergillus allergy?
Does a positive result mean I have an active fungal infection?
What should I do with my result?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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 17, 2026. · Read our editorial policy