What is gluten allergy test

Evaluating patients suspected of having celiac disease, including patients with compatible symptoms, patients with atypical symptoms, and individuals at increased risk (family history, previous diagnosis with associated disease, positivity for DQ2 and/or DQ8)


Reflex Tests

Test ID Reporting Name Available Separately Always Performed
EMA Endomysial Abs, S (IgA) Yes No
DAGL Gliadin(Deamidated) Ab, IgA, S Yes No
TTGG Tissue Transglutaminase Ab, IgG, S Yes No
DGGL Gliadin(Deamidated) Ab, IgG, S Yes No
TTGA Tissue Transglutaminase Ab, IgA, S Yes No


Profile Information

Test ID Reporting Name Available Separately Always Performed
IGA Immunoglobulin A (IgA), S Yes Yes
CDSP1 Celiac Disease Interpretation No Yes


Reporting Name

Celiac Disease Serology Cascade


Analytic Time

7 days


Interpretation

Immunoglobulin A (IgA):

Total IgA levels under the age-specific reference range propose either a selective IgA deficiency or a more generalized immunodeficiency.

What is gluten allergy test

For individuals with a low IgA level, additional clinical and laboratory evaluation is recommended. Some individuals may own a partial IgA deficiency in which the IgA levels are detectable but drop under the age-adjusted reference range.

What is gluten allergy test

For these individuals, both IgA and IgG isotypes for tTG and deamidated gliadin antibodies are recommended for the evaluation of celiac disease; IgA-tTG, IgG-tTG, IgA-deamidated gliadin, and IgG-deamidated gliadin antibody assays are performed in this cascade. For individuals who own selective IgA deficiency or undetectable levels of IgA, only IgG-tTG and IgG-deamidated gliadin antibody assays are performed.

Tissue Transglutaminase (tTG) Ab, IgA/IgG:

Individuals positive for tTG antibodies of the IgA isotype likely own celiac disease and a little intestinal biopsy is recommended.

What is gluten allergy test

For individuals with selective IgA deficiency, testing for tTG antibodies of the IgG isotype is performed. In these individuals, a positive IgG-tTG antibody result suggests a diagnosis of celiac disease.

What is gluten allergy test

However, just as with the IgA-tTG antibody, a biopsy should be performed to confirm the diagnosis. Negative tTG IgA and/or IgG antibody serology does not exclude a diagnosis of celiac disease, as antibody levels decrease over time in patients who own been following a gluten-free diet.

Gliadin (Deamidated) Ab, IgA/IgG:

Positivity for deamidated gliadin antibodies of the IgA isotype is suggestive of celiac disease; little intestinal biopsy is recommended. For individuals with selective IgA deficiency, testing for deamidated gliadin antibodies of the IgG isotype is performed. In these individuals, a positive IgG-deamidated gliadin antibody result suggests a diagnosis of celiac disease.

However, just as with the IgA-deamidated gliadin antibody, a biopsy should be performed to confirm the diagnosis. Negative deamidated gliadin IgA and/or IgG antibody serology does not exclude a diagnosis of celiac disease, as antibody levels decrease over time in patients who own been following a gluten-free diet.

Endomysial (EMA) Ab, IgA:

Positivity for EMA antibodies of the IgA isotype is suggestive of celiac disease, and little intestinal biopsy is recommended.

What is gluten allergy test

For individuals with selective IgA deficiency, evaluation of EMA antibodies is not indicated. Negative EMA antibody serology does not exclude a diagnosis of celiac disease as antibody levels decrease over time in patients who own been following a gluten-free diet.


Clinical Information

Celiac disease (gluten-sensitive enteropathy, celiac sprue) results from an immune-mediated inflammatory process following ingestion of wheat, rye, or barley proteins that occurs in genetically susceptible individuals.(1) The inflammation in celiac disease occurs primarily in the mucosa of the little intestine, which leads to villous atrophy.(1) Common clinical manifestations related to gastrointestinal inflammation include abdominal pain, malabsorption, diarrhea, and constipation.(2) Clinical symptoms of celiac disease are not restricted to the gastrointestinal tract.

Other common manifestations of celiac disease include failure to grow (delayed puberty and short stature), iron deficiency, recurrent fetal loss, osteoporosis, chronic fatigue, recurrent aphthous stomatitis (canker sores), dental enamel hypoplasia, and dermatitis herpetiformis.(3) Patients with celiac disease may also present with neuropsychiatric manifestations including ataxia and peripheral neuropathy, and are at increased risk for development of non-Hodgkin lymphoma.(1,2) The disease is also associated with other clinical disorders including thyroiditis, type I diabetes mellitus, Below syndrome, and IgA deficiency.(1,3)

Celiac disease tends to happen in families; individuals with family members who own celiac disease are at increased risk of developing the disease.

Genetic susceptibility is related to specific HLA markers. More than 97% of individuals with celiac disease in the United States own DQ2 and/or DQ8 HLA markers, compared with approximately 40% of the general population.(3)

A definitive diagnosis of celiac disease requires a jejunal biopsy demonstrating villous atrophy.() Given the invasive nature and cost of the biopsy, serologic and genetic laboratory tests may be used to identify individuals with a high probability of having celiac disease.

Subsequently, those individuals with positive laboratory results should be referred for little intestinal biopsy, thereby decreasing the number of unnecessary invasive procedures.

What is gluten allergy test

In terms of serology, celiac disease is associated with a variety of autoantibodies, including endomysial, tissue transglutaminase (tTG), and deamidated gliadin antibodies.(4) Although the IgA isotype of these antibodies generally predominates in celiac disease, individuals may also produce IgG isotypes, particularly if the individual is IgA deficient.(2) The most sensitive and specific serologic tests are tTG and deamidated gliadin antibodies.

The treatment for celiac disease is maintenance of a gluten-free diet.() In most patients who adhere to this diet, levels of associated autoantibodies decline and villous atrophy improves (see Celiac Disease Routine Treatment Monitoring Algorithm in Special Instructions).

This is typically accompanied by an improvement in clinical symptoms.


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What is gluten allergy test