Silver Birch (rBet v 2) Allergen-Specific IgE, Qualitative (Deprecated)
A blood test that detects IgE antibodies to Bet v 2, a major silver birch pollen allergen. A positive result suggests sensitization but does not by itself confirm clinical allergy.
["This test shows whether your immune system has produced IgE antibodies to the silver birch allergen Bet v 2."]
Key facts at a glance
- LOINC
- 51574-2
- Short code
- Deprecated Silver Birch (rBet v) 2 IgE RAST Ql
- Synonyms
- Deprecated Silver Birch (rBet v) 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 test looks for allergen-specific IgE antibodies directed against Bet v 2, a protein found in silver birch pollen. It is performed using a blood sample. This test is marked as deprecated, so a newer allergy test may be preferred.
Why might I need this test?
It may be considered when symptoms such as sneezing, watery eyes, nasal congestion, or wheezing occur after exposure to birch or related trees. Your clinician may use it to help assess whether an allergy is likely.
How is the test performed?
A blood sample is collected and tested in a laboratory for IgE antibodies specific to Bet v 2. The result is reported as positive or negative.
How do I prepare for the test?
No special preparation is usually required for a routine blood test. Antihistamines or other allergy medicines can sometimes affect allergy testing, so tell your clinician about all medicines and supplements you use before testing.
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 Bet v 2, consistent with sensitization to silver birch. It does not necessarily mean that you will have symptoms, and the result should be interpreted with your exposure history and symptoms. Because this test is deprecated, your clinician may recommend a current alternative.
Short name
Silver birch Bet v 2 IgE
Frequently asked questions
Does a positive result mean I am allergic to silver birch?
Can I have birch allergy symptoms with a negative result?
Why is this test marked as deprecated?
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