Peanut-Specific IgG Antibody (RAST), Qualitative — Deprecated
A qualitative test that looks for IgG antibodies to peanut, which may indicate prior exposure or sensitization.
["A positive result shows peanut-specific IgG, but it does not by itself confirm a peanut allergy."]
Key facts at a glance
- LOINC
- 21447-8
- Short code
- Deprecated Peanut IgG RAST Ql
- Synonyms
- Deprecated Peanut 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 qualitative laboratory test looks for IgG antibodies directed against peanut. These antibodies can develop after exposure to peanut and are sometimes used to assess sensitization.
Why might I need this test?
The test may be used to evaluate immune sensitization to peanut or help interpret a suspected food reaction. It is often considered alongside food-specific IgE testing, medical history, and symptoms.
How is the test performed?
A patient sample is tested for peanut-specific IgG using a qualitative laboratory method, commonly referred to as RAST testing. The result is reported as detected or not detected rather than as a specific concentration.
How do I prepare for the test?
No special preparation is usually required for this test. Follow any instructions provided by the ordering clinician, especially if this test is being performed during evaluation of an allergic reaction.
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.
Detected peanut-specific IgG may indicate previous exposure or immune sensitization to peanut. It does not by itself establish a clinical peanut allergy, because IgG can also be present in people without symptoms. Results should be interpreted with food-specific IgE testing, reaction history, and clinical evaluation.
Short name
Peanut IgG antibody test
Frequently asked questions
Does a positive peanut IgG result mean I have a peanut allergy?
Is this the same as a peanut IgE test?
Why was 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.
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Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy