Lettuce-Specific IgG Antibody, Qualitative — Radioallergosorbent Test (RAST)
A qualitative RAST assay for IgG antibodies directed against lettuce. The slug is marked deprecated, and this result does not by itself diagnose food allergy.
["Detects lettuce-specific IgG antibodies, which may indicate exposure but do not alone confirm a clinical allergy."]
Key facts at a glance
- LOINC
- 21366-0
- Short code
- Deprecated Lettuce IgG RAST Ql
- Synonyms
- Deprecated Lettuce 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 test looks for IgG antibodies that recognize proteins in lettuce. The slug is marked as deprecated, meaning this test may no longer be routinely offered or may have been replaced by another testing method.
Why might I need this test?
It may have been ordered to evaluate an immune response to lettuce or investigate a suspected food-related reaction. Food-specific IgG testing is not generally recommended by itself to diagnose allergy because IgG can occur without symptoms.
How is the test performed?
A blood-derived sample is analyzed using a radioallergosorbent testing method, or RAST. The laboratory checks whether the sample contains antibodies that bind to lettuce proteins and reports the result qualitatively.
How do I prepare for the test?
Fasting is usually not required, but follow the instructions provided by the ordering clinician or laboratory. Tell the healthcare team if you have recently eaten lettuce, started or stopped medicines, or had a recent 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.
A detectable result indicates that lettuce-specific IgG antibodies are present, which may reflect prior exposure or a non-allergic immune response. It does not by itself establish that lettuce causes symptoms. If a clinical allergy is suspected, the clinician may consider the history, physical findings, and other allergy tests such as skin-prick testing or food-specific IgE testing.
Short name
Lettuce IgG antibody test
Frequently asked questions
Does a positive result mean I am allergic to lettuce?
What symptoms may be related to a lettuce allergy?
Why is this test described 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