Silver Birch rBet v 4-Specific IgE, Serum — RAST, Qualitative (Deprecated)
A blood test that detects IgE antibodies directed against the rBet v 4 component of silver birch pollen. It helps evaluate possible allergic sensitization.
["A positive result suggests an immune sensitization to silver birch, but it must be interpreted alongside symptoms and exposure history."]
Key facts at a glance
- LOINC
- 51575-9
- Short code
- Deprecated Silver Birch (rBet v) 4 IgE RAST Ql
- Synonyms
- Deprecated Silver Birch (rBet v) 4 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 blood test looks for allergen-specific IgE antibodies against rBet v 4, a protein found in silver birch pollen. The legacy RAST method measures antibodies associated with allergic sensitization.
Why might I need this test?
Your clinician may order this test if you have symptoms such as sneezing, watery eyes, nasal congestion, wheezing, or hives after exposure to birch or related pollen. It may also be useful when considering allergy testing for pollen-related food reactions.
How is the test performed?
A blood sample is collected and analyzed for IgE directed against the silver birch rBet v 4 allergen component. The result is reported as detectable or not detectable.
How do I prepare for the test?
Fasting is usually not required. Continue taking medications unless your clinician instructs you otherwise, and tell the clinician about your allergy symptoms, pollen exposure, and any relevant food reactions.
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 detectable result indicates that the immune system has produced IgE antibodies against silver birch rBet v 4. This supports possible allergic sensitization but does not by itself prove that silver birch causes your symptoms, and it does not identify the severity of a reaction. Results should be interpreted with your exposure history, symptoms, and other allergy tests by your clinician.
Short name
Silver Birch-Specific IgE
Frequently asked questions
Does a positive result mean I am allergic to silver birch?
Can I be allergic to other pollens or foods?
Why is this test listed 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