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Tissue Transglutaminase IgA Antibody, Qualitative, Serum

Published: August 9, 2026Updated: August 16, 2026

A blood test for IgA antibodies to tissue transglutaminase, used to help evaluate for celiac disease.

Quick summary

["A positive result supports possible celiac disease, while interpretation depends on the person's total IgA level."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
105178-8
Short code
ITA tiss Ql ImStn
Synonyms
ITA tiss Ql ImStn
Category
liver
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
immune-stain
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 checks a blood sample for IgA antibodies against tissue transglutaminase, an enzyme associated with celiac disease. It is commonly used as an initial screening test when celiac disease is suspected.

Why might I need this test?

The test may be ordered for symptoms such as chronic diarrhea, bloating, abdominal pain, weight loss, anemia, or problems absorbing nutrients. It may also be used to evaluate suspected gluten-related illness or monitor people already diagnosed with celiac disease.

How is the test performed?

A blood sample is collected and tested in a laboratory for anti-tTG IgA antibodies. Many laboratories also measure total IgA because low IgA levels can make the antibody test falsely negative.

How do I prepare for the test?

No special preparation is usually required, and you generally should not stop eating gluten before testing. If you avoid gluten, tell your clinician because this may affect the results and whether additional testing is needed.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

A positive anti-tTG IgA result supports the possibility of celiac disease but must be interpreted with symptoms, other laboratory findings, and sometimes intestinal biopsy. A negative result lowers the likelihood of celiac disease, particularly when total IgA is normal, but does not completely exclude it. People with selective IgA deficiency may need alternative antibody tests or other evaluation.

Short name

Anti-tTG IgA

Frequently asked questions

What does a positive tissue transglutaminase IgA result mean?
It indicates that IgA antibodies to tissue transglutaminase are present, which can occur with celiac disease. Your clinician will consider your symptoms, diet, other test results, and sometimes a biopsy before confirming the diagnosis.
Can I have celiac disease if this test is negative?
Yes. A negative result is less likely to indicate celiac disease when total IgA is normal, but false-negative results can occur, especially with low IgA levels or certain uncommon conditions.
Should I stop eating gluten before this test?
Usually not. Eating a normal gluten-containing diet gives the most reliable results, and stopping gluten without medical guidance may delay diagnosis. Tell your clinician if you already avoid gluten.
  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 16, 2026. · Read our editorial policy