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Gluten-Specific IgG Antibodies, Qualitative — Radioallergosorbent Test (RAST), Deprecated

Published: August 9, 2026Updated: August 17, 2026

A historical qualitative blood test for antibodies to gluten. It may appear in older records and is not usually used by itself to diagnose celiac disease or a true gluten allergy.

Quick summary

["This older test detects gluten-directed IgG antibodies, but its result cannot confirm or exclude celiac disease by itself."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
21311-6
Short code
Deprecated Gluten IgG RAST Ql
Synonyms
Deprecated Gluten 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 blood test looked for IgG antibodies directed against gluten, a group of proteins found in wheat, barley, and rye. The historical RAST method was reported as a qualitative result, meaning it indicated whether detectable antibodies were present.

Why might I need this test?

It may be included in an older medical record or discussed during evaluation of a suspected gluten-related condition. Today, it is generally replaced by more specific tests because gluten-specific IgG can occur in people who do not have celiac disease.

How is the test performed?

A blood sample is collected, and the serum is tested in the laboratory for antibodies that react with gluten. Older RAST testing used a radioallergosorbent method, while current laboratory methods may use different immunoassays.

How do I prepare for the test?

Fasting is usually not required for this type of antibody test. Follow any instructions from your clinician, and do not eliminate gluten from your diet without medical guidance if celiac disease is being evaluated.

Reference range

Adult: 10-40 U/LN/A

Specimen: serum

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

Gluten IgG antibody test (qualitative)

Frequently asked questions

Does a positive gluten IgG result mean I have celiac disease?
No. Gluten-specific IgG can be present in people without celiac disease, so this result must be interpreted with symptoms, medical history, and more specific celiac testing.
Is this the same as a gluten allergy test?
Not necessarily. A true immediate-onset gluten allergy is usually associated with IgE, not IgG, and is evaluated differently. Your clinician can explain which allergy testing is appropriate.
Why was this test deprecated?
The test is not specific enough to reliably distinguish celiac disease from other conditions or from gluten avoidance. It has therefore largely been replaced by more appropriate testing strategies.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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