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Provider Points
 

TesTing for CeliaC disease
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I

ntestinal biopsy is the gold standard for diagnosing 

celiac disease, but serologic tests provide an effec 

tive first step in identifying biopsy candidates. In 

addition, genetic tests that confirm the presence or 

absence of specific genes associated with celiac dis 

ease may be useful in some circumstances. However, 

serologic and genetic tests are adjuncts to, not 

replacements for, biopsies. If serologic or genetic 

tests indicate the possibility of celiac disease, a biopsy 

should be done promptly and before initiating any 

change in the patient’s diet. 

serologiC TesTs 

Serologic tests look for three antibodies common in 

celiac disease: 

■■ anti-tissue transglutaminase (tTG) antibodies 

■■ endomysial antibodies (EMA) 

■ antigliadin antibodies (AGA) 

The most sensitive antibody tests are of the immunoglobulin A (IgA) class, but immunoglobulin G (IgG) tests 

may be used in patients with IgA deficiency. Because 

no one serologic test is ideal, panels are often used. 

However, the tests included in a celiac panel vary by lab 

and may include one or more that are unwarranted. The 

American Gastroenterological Association recommends 

beginning with tTG in the clinical setting.1 

For accurate diagnostic test results, patients must be on 

a gluten-containing diet. 

1

American Gastroenterological Association. AGA Institute medical 

position statement on the diagnosis and management of celiac disease. 

Gastroenterology. 2006;131:1977–1980. 

tTg anTibody 

The tTG test is an enzyme-linked immunosorbent assay 

(ELISA) test. The tTG test has a sensitivity of more than 

90 percent, yielding few false negative results. The test 

also has a specificity of more than 95 percent, meaning it yields few false postive results.1 Point-of-care tTG 

tests have been developed but are not yet approved for 

use by clinicians in the United States. 

eMa 

The test for EMA is slightly less sensitive than tTG 

but is highly specific for celiac disease, approaching 

100 percent accuracy.2 EMA is measured by indirect 

immunofluorescent assay, a more expensive and timeconsuming process than ELISA testing. In addition, the 

EMA test is subject to operator interpretation, making 

the results more subjective than those for tTG. 

Some studies show the titers, or relative concentrations, 

of tTG and EMA are correlated with the degree of intestinal damage, making these tests less sensitive among 

patients with milder celiac disease.3 

2

Green PHR, Cellier C. Medical progress: celiac disease. The New England 

Journal of Medicine. 2007;357:1731–1743. 

3

Tursi A, Brandimarte G, Giorgetti GM. Prevalence of antitissue 

transglutaminase antibodies in different degrees of intestinal damage in 

celiac disease. Journal of Clinical Gastroenterology. 2003;36(3):219–221. 

www.celiac.nih.gov www.celiac.nih.gov
Provider Points

aga

Tests for AGA are not sensitive or specific enough for 

routine use. However, they may be useful for screening 

children younger than 18 months old in whom tTG and 

EMA tests may yield false negative results.2

 

A new generation of tests that use deaminated gliadin 

peptides (DGP) have sensitivity and specificity that 

are substantially better than the older gliadin tests.4

 

DGP tests are more accurate than tTG and AGA and may 

be the most reliable tests to detect celiac disease in 

people with IgA deficiency. 

iga defiCienCy

Between 2 and 3 percent of celiac patients have selective IgA deficiency—a rate about 10 times higher than 

in the general population. If IgA tTG or IgA EMA are 

negative but celiac disease is still suspected, total IgA 

should be measured to identify selective IgA deficiency. 

In cases of IgA deficiency, IgG tTG or DGP-IgG should be 

measured. 

geneTiC sCreening TesTs

Nearly all people with celiac disease have gene pairs that 

encode for at least one of the human leukocyte antigen 

(HLA) gene variants, or alleles, designated HLA‐DQ2

or HLA‐DQ8. However, these alleles are common. 

They are found in about 40 percent of the general U.S. 

population, and most people with these alleles do not 

have celiac disease. Negative findings for HLA-DQ2

and HLA-DQ8 can essentially rule out current or future 

celiac disease in patients for whom other tests, including 

biopsy, do not provide a clear diagnostic result.

aCknowledgMenTs

Publications produced by the Clearinghouse are carefully reviewed by both NIDDK scientists and outside 

experts. This publication was reviewed by Alessio 

Fasano, M.D., University of Maryland School of 

Medicine, and Joseph A. Murray, M.D., Mayo Clinic, 

Rochester, MN.

4

Rashtak S, Ettore MW, Homburger HA, Murray JA. Combination 

testing for antibodies in the diagnosis of celiac disease: comparison of 

multiplex immunoassay and ELISA methods. Alimentary Pharmacology & 

Therapeutics. 2008;28(6):805–813.

The Celia Disease wareness Campaign

The National Institutes of Health Celiac Disease Awareness Campaign 

provides current, comprehensive, science-based information about the 

symptoms, diagnosis, and treatment of celiac disease, also known as 

celiac sprue, nontropical sprue, and gluten-sensitive enteropathy. The 

Awareness Campaign is an initiative of the National Digestive Diseases 

Information Clearinghouse, a service of the National Institute of 

Diabetes and Digestive and Kidney Diseases.

Download this publication and learn more about the Awareness 

Campaign at www.celiac.nih.gov.

Celiac Disease Awareness Campaign 

c/o National Digestive Diseases Information Clearinghouse

2 Information Way 

Bethesda, MD 20892–3570 

Phone: 1–800–891–5389 

TTY: 1–866–569–1162 

Fax: 703–738–4929 

Email: nddic@info.niddk.nih.gov 

Internet: www.digestive.niddk.nih.gov

The National Digestive Diseases Information Clearinghouse (NDDIC) is a 

service of the National Institute of Diabetes and Digestive and Kidney 

Diseases (NIDDK). The NIDDK is part of the National Institutes of Health 

of the U.S. Department of Health and Human Services. Established in 

1980, the Clearinghouse provides information about digestive diseases 

to people with digestive disorders and to their families, health care 

professionals, and the public. The NDDIC answers inquiries, develops 

and distributes publications, and works closely with professional and 

patient organizations and Government agencies to coordinate resources 

about digestive diseases.

This publication is not copyrighted. The Clearinghouse encourages 

users of this publication to duplicate and distribute as many copies as 

desired. 

This publication may contain information about medications. When 

prepared, this publication included the most current information 

available. For updates or for questions about any medications, contact 

the U.S. Food and Drug Administration toll-free at 1–888–INFO–FDA 

(1–888–463–6332) or visit www.fda.gov. Consult your health care 

provider for more information.

ublication o. 09–7351 

pril 2009

www.celiac.nih.gov www.celiac.nih.gov

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