Silver Birch-Specific IgG4 Antibody — Radioallergosorbent Test (RAST), Qualitative (Deprecated)
A qualitative blood test for IgG4 antibodies directed against silver birch allergen. This legacy RAST test is deprecated and is not a standard test for diagnosing allergy.
["This deprecated test looks for silver birch–specific IgG4 antibodies, but a result should not by itself establish an allergy diagnosis."]
Key facts at a glance
- LOINC
- 26410-1
- Short code
- Deprecated Silver Birch IgG4 RAST Ql
- Synonyms
- Deprecated Silver Birch IgG4 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 IgG4 antibodies that react with silver birch allergen using a radioallergosorbent test, or RAST. It is a qualitative test, meaning it reports whether the antibodies were detected rather than providing a measured concentration.
Why might I need this test?
This test may have been ordered as part of an evaluation of a suspected allergy to silver birch pollen or related exposure. It is now considered deprecated, so newer allergy testing and clinical assessment are generally preferred.
How is the test performed?
A laboratory sample is exposed to silver birch allergen in a RAST procedure that detects allergen-specific IgG4. The result is reported as detected or not detected, or with a qualitative interpretation such as negative, equivocal, or positive.
How do I prepare for the test?
No special preparation is usually required for this type of blood test. If the test is still being offered, follow the laboratory's collection instructions and tell the clinician about any allergy testing or immunotherapy you have received.
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.
◆Associated findings1
Short name
Silver Birch IgG4 RAST
Frequently asked questions
Does a positive result mean I am allergic to silver birch?
Why is this test listed as deprecated?
Should I stop allergy immunotherapy because of this 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