Test Id : DGLDN

The following algorithms are available:

-Celiac Disease Comprehensive Cascade Test Algorithm

-Celiac Disease Diagnostic Testing Algorithm

-Celiac Disease Gluten-Free Cascade Test Algorithm

-Celiac Disease Routine Treatment Monitoring Algorithm

-Celiac Disease Serology Cascade Test Algorithm

Cascade testing is recommended for celiac disease. Cascade testing ensures that testing proceeds in an algorithmic fashion. The following cascades are available; select the appropriate one for your specific patient situation.

-CDCOM / Celiac Disease Comprehensive Cascade, Serum and Whole Blood: complete testing including HLA DQ

-CDSP / Celiac Disease Serology Cascade, Serum: complete serology testing excluding HLA DQ

-CDGF / Celiac Disease Gluten-Free Cascade, Serum and Whole Blood: for patients already adhering to a gluten-free diet

To order individual tests, see Celiac Disease Diagnostic Testing Algorithm.

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 0.5 mL

Collection Instructions: Centrifuge and aliquot serum into a plastic vial.

• Celiac Disease Diagnostic Testing Algorithm
• Celiac Disease Comprehensive Cascade Test Algorithm
• Celiac Disease Gluten-Free Cascade Test Algorithm
• Celiac Disease Routine Treatment Monitoring Algorithm
• Celiac Disease Serology Cascade Test Algorithm

If not ordering electronically, complete, print, and send a Gastroenterology and Hepatology Test Request (T728) with the specimen.

0.4 mL

Assessment of deaminated gliadin IgA and IgG antibodies for evaluating patients suspected of having celiac disease, including patients with compatible clinical symptoms, patients with atypical symptoms, and individuals at increased risk (family history, previous diagnosis with associated disorder, positivity for HLA DQ2 and/or DQ8)

Monitoring response to a gluten-free diet in patients with celiac disease.

The following algorithms are available:

-Celiac Disease Comprehensive Cascade Test Algorithm

-Celiac Disease Diagnostic Testing Algorithm

-Celiac Disease Gluten-Free Cascade Test Algorithm

-Celiac Disease Routine Treatment Monitoring Algorithm

-Celiac Disease Serology Cascade Test Algorithm

Celiac disease (gluten-sensitive enteropathy, celiac sprue) results from an immune-mediated inflammatory process that occurs in genetically susceptible individuals following ingestion of wheat, rye, or barley proteins.(1) The inflammation in celiac disease occurs primarily in the mucosa of the small intestine, which leads to villous atrophy. Common clinical manifestations related to gastrointestinal inflammation include abdominal pain, malabsorption, diarrhea, and/or constipation. 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. 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. The disease is also associated with other clinical disorders including thyroiditis, type I diabetes mellitus, Down syndrome, and IgA deficiency.

Individuals with family members who have celiac disease are at increased risk of developing the disease.(2) Genetic susceptibility is related to specific human leukocyte antigen (HLA) markers. More than 97% of individuals with celiac disease in the United States have DQ2 and/or DQ8 HLA markers, compared to approximately 40% of the general population. For this reason, HLA-DQ2 and HLA-DQ8 are considered genetic risk factors for celiac disease and are required, but not sufficient, for the disease process to occur.

A definitive diagnosis of celiac disease requires a jejunal biopsy demonstrating villous atrophy.(3) Given the invasive nature and cost of the biopsy, serologic tests may be used to identify individuals with a high probability of having celiac disease. Because no single laboratory test can be relied upon completely to establish a diagnosis of celiac disease, individuals with positive laboratory results may be referred for small intestinal biopsy, thereby decreasing the number of unnecessary invasive procedures (see Celiac Disease Diagnostic Testing Algorithm). In terms of serology, celiac disease is associated with a variety of autoantibodies, including endomysial antibody, tissue transglutaminase (tTG), and deamidated gliadin antibodies.(4) Although the IgA isotype of these antibodies usually predominates in celiac disease, individuals may also produce IgG isotypes, particularly if the individual is IgA deficient. The most sensitive and specific serologic tests is tTG IgA isotype, in individuals who produce sufficient total IgA. For individuals who are IgA deficient, testing for tTG and deamidated gliadin IgG antibodies is required.

The treatment for celiac disease is maintenance of a gluten-free diet. In most patients who adhere to this diet, concentrations of associated autoantibodies decline, which is sometimes also accompanied by reconstitution of the small intestinal villi. In most patients, an improvement in clinical symptoms is observed. For evaluation purposes, all serologic tests ordered for the diagnosis of celiac disease should be performed while the patient is on a gluten-containing diet. Once a patient has initiated the gluten-free diet, serologic testing may be repeated to assess the response to treatment. In some patients, it may take up to 1 year for antibody titers to normalize. Persistently elevated results suggest poor adherence to the gluten-free diet or the possibility of refractory celiac disease.

See Celiac Disease Diagnostic Testing Algorithm for the recommended approach to a patient suspected of celiac disease.

An algorithm is available for monitoring the patient's response to treatment, see Celiac Disease Routine Treatment Monitoring Algorithm.

Negative: <20.0 U

Weak positive: 20.0-30.0 U

Positive: >30.0 U

Reference values apply to all ages.

Positive test results for deamidated gliadin IgA or IgG antibodies, are consistent with a diagnosis of celiac disease.

Negative results for deamidated gliadin IgA or IgG antibodies indicate a decreased likelihood of celiac disease.

A decrease in the concentrations of deamidated gliadin IgA or IgG antibodies may begin after initiation of a gluten-free diet and could indicate a response to therapy.

This test should not be solely relied upon to establish a diagnosis of celiac disease. It should be used to identify patients who have an increased probability of having celiac disease and in whom a small intestinal biopsy is recommended.

Affected individuals who have been on a gluten-free diet prior to testing may have a negative result.

For individuals who test negative, IgA deficiency should be considered. If total IgA is normal and deamidated gliadin IgA is negative, there is a low probability of the patient having celiac disease and a biopsy may not be necessary.

If serology is negative or there is substantial clinical doubt remaining, then further investigation should be performed with endoscopy and bowel biopsy. This is especially important in patients with frank malabsorptive symptoms since many syndromes can mimic celiac disease. For the patient with frank malabsorptive symptoms, a bowel biopsy should be performed regardless of serologic test results.

Testing for IgA and IgG antibodies to unmodified gliadin proteins is no longer recommended because of the low sensitivity and specificity of these tests for celiac disease.

This test should not be ordered as a replacement for TSTGP / Tissue Transglutaminase Antibodies, IgA and IgG Profile, Serum.

1. Rubin JE, Crowe SE: Celiac disease. Ann Intern Med. 2020 Jan;172(1):ITC1-ITC16. doi: 10.7326/AITC202001070

2. Lebwohl B, Rubio-Tapia A: Epidemiology, presentation, and diagnosis of celiac disease. Gastroenterology. 2021 Jan;160(1):63-75. doi: 10.1053/j.gastro.2020.06.098

3. Rubio-Tapia A, Hill ID, Kelly CP, Calderwood AH, Murray J, American College of Gastroenterology: ACG clinical guidelines: Diagnosis and management of celiac disease. Am J Gastroenterol. 2013 May;108(5):656-76; quiz 677. doi: 10.1038/ajg.2013.79

4. Penny HA, Raju SA, Sanders DS: Progress in the serology-based diagnosis and management of adult celiac disease. Exp Rev Gastroenterol Heptatol. 2020 Mar;14(3):147-154. doi: 10.1080/17474124.2020.1725472

IgA and IgG antibodies to deamidated gliadin peptides are detected by enzyme-linked immunosorbent assay by binding to purified peptides adsorbed to the wells of a microtiter plate. Peptides are bound to the wells under conditions that preserve the antigens in their native states. Prediluted controls and diluted patient sera are added to separate wells allowing antibodies to bind to the deamidated gliadin peptides. Unbound sample constituents are washed away, and horseradish peroxidase-labeled antihuman IgA or IgG antibody conjugate is added to each well. After a second incubation, unbound enzyme-labeled conjugate is washed away, and bound conjugate is detected by adding tetramethylbenzidine chromogenic substrate. After a final incubation, colored product is measured spectrophotometrically, and the absorbance compared to the low, positive calibrator. The intensity of color is directly proportional to the level of IgA or IgG antibodies to deamidated gliadin peptides expressed in arbitrary units.(Package inserts: QUANTA Lite Gliadin IgA II.  INOVA Diagnostics, Inc; Rev 2,10/2019; QUANTA Lite Gliadin IgG II. INOVA Diagnostics, Inc; Rev 4, 02/2020)

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This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

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