Aspergillus fumigatus rAsp f2 IgE — Qualitative Immunoassay
Detects IgE antibodies to the rAsp f2 allergen of Aspergillus fumigatus, helping assess allergic sensitization to this fungus.
["A positive result indicates IgE sensitization to Aspergillus fumigatus rAsp f2 but does not by itself diagnose an active allergy or infection."]
Key facts at a glance
- LOINC
- 51569-2
- Short code
- Deprecated A fumigatus (rAsp f) 2 IgE RAST Ql
- Synonyms
- Deprecated A fumigatus (rAsp f) 2 IgE 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 qualitative test looks for IgE antibodies directed against rAsp f2, a specific allergen component from Aspergillus fumigatus. These antibodies are part of the immune response to allergic sensitization.
Why might I need this test?
Your clinician may order this test when respiratory or other allergic symptoms could be related to exposure to Aspergillus fumigatus. It may also be used when evaluating suspected allergic bronchopulmonary aspergillosis or sensitization to a particular fungal allergen.
How is the test performed?
A blood sample is tested in the laboratory for antibodies to the recombinant rAsp f2 allergen. The result is reported as positive or negative, although some laboratories may also provide a reaction category or measurement.
How do I prepare for the test?
No special preparation is usually needed. Tell your clinician about your symptoms, allergic reactions, medicines, and any recent changes in exposure, because these details affect how the result is interpreted.
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 the immune system has produced IgE antibodies to the Aspergillus fumigatus rAsp f2 allergen. This supports allergic sensitization but may also occur in people without current symptoms. Clinical findings and other allergy or lung tests are needed to determine whether an active allergic condition is present.
Short name
Asp f2-specific IgE test
Frequently asked questions
Does a positive result mean I have an Aspergillus infection?
What symptoms may be associated with sensitization?
How should I discuss the result with my clinician?
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