Cheddar Cheese–Specific IgG Antibody, Qualitative (RAST) — Deprecated
A legacy qualitative test for IgG antibodies against cheddar cheese. It is not a standard method for diagnosing food allergy.
["This retired test cannot reliably confirm or rule out food allergy; suspected reactions should be evaluated using current allergy testing."]
Key facts at a glance
- LOINC
- 21178-9
- Short code
- Deprecated Cheddar IgG RAST Ql
- Synonyms
- Deprecated Cheddar 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 deprecated test looked for IgG antibodies directed against cheddar cheese using a RAST-type laboratory method. Food-specific IgG results are not generally used to diagnose food allergy.
Why might I need this test?
It may appear in older medical records or be considered when a person has a suspected reaction to cheddar cheese. Current evaluation usually focuses on the reaction history, skin-prick testing, and sometimes IgE-specific blood testing.
How is the test performed?
A patient sample, typically blood, is tested in the laboratory for antibodies that bind to cheddar cheese antigen. The result is reported qualitatively as detectable or not detectable, although this test is no longer routinely available.
How do I prepare for the test?
No special preparation is usually required for this type of antibody test. If food allergy is suspected, keep a detailed record of the food eaten, symptoms, timing, and any other possible causes, and follow your clinician's instructions.
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.
Detectable IgG may indicate prior exposure or an immune response to cheddar cheese, but it does not establish that the food causes allergy symptoms. A negative result also does not rule out food allergy, so results from this deprecated test should not be interpreted alone. Suspected food allergy is generally assessed through clinical history and validated skin-prick or IgE testing.
Short name
Cheddar cheese IgG antibody test
Frequently asked questions
Does a positive result mean I am allergic to cheddar cheese?
Is this the same as a lactose intolerance test?
What should I do if an older report includes 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