Coffee-Specific IgG Antibody Test, Qualitative — Radioallergosorbent Test (RAST) [Deprecated]
A qualitative blood test for antibodies directed against coffee. This historical test does not reliably diagnose coffee allergy.
["A positive result usually reflects exposure to coffee, not necessarily a clinically significant allergy."]
Key facts at a glance
- LOINC
- 21214-2
- Short code
- Deprecated Coffee IgG RAST Ql
- Synonyms
- Deprecated Coffee 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 test looks for coffee-specific IgG antibodies using a radioallergosorbent method, with a qualitative positive or negative result. IgG antibodies commonly develop after exposure to a food. This test has been deprecated and is not routinely used to diagnose food allergy.
Why might I need this test?
It may appear in older medical records or have been offered to assess a suspected coffee-related reaction. Because food-specific IgG testing is not a validated allergy test, a clinician should interpret any result alongside symptoms, exposure history, and other appropriate evaluation.
How is the test performed?
A laboratory sample is analyzed for antibodies that bind to coffee proteins. The radioallergosorbent method reports whether coffee-specific IgG was detected rather than providing a detailed antibody measurement.
How do I prepare for the test?
No special preparation is usually required for this test. Follow the instructions provided by the laboratory or ordering clinician, and do not stop prescribed medicines unless specifically directed to do so.
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 generally indicates that the immune system has produced IgG antibodies after exposure to coffee; it does not by itself establish a clinically important allergy. A negative result does not rule out coffee allergy or a non-IgE-mediated reaction. Because this assay is deprecated, results should not be used alone to guide allergy diagnosis or treatment.
Short name
Coffee-specific IgG antibody test
Frequently asked questions
Does a positive coffee IgG result mean I am allergic to coffee?
Can this test rule out a coffee allergy?
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