Sorted By Test Name - Mayo Medical Laboratories

DGLDN
89031
2 0.70-3.49 Positive
3 3.50-17.4 Positive
4 17.5-49.9 Strongly positive
5 50.0-99.9 Strongly positive
6 > or =100 Strongly positive Reference values
apply to all ages.
Clinical References: Homburger HA: Allergic diseases. In Clinical Diagnosis and Management by
Laboratory Methods. 21st edition. Edited by RA McPherson, MR Pincus. New York, WB Saunders
Company, 2007, Chapter 53, Part VI, pp 961-971
Gliadin (Deamidated) Antibodies Evaluation, IgG and IgA,
Serum
Clinical Information: 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.(1) Common clinical manifestations related
to gastrointestinal inflammation include abdominal pain, malabsorption, diarrhea, and/or 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, Down syndrome, and IgA deficiency.(1,3) Celiac
disease tends to occur in families; individuals with family members who have 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 have DQ2 and/or DQ8 HLA markers
compared to approximately 40% of the general population.(3) A definitive diagnosis of celiac disease
requires a jejunal biopsy demonstrating villous atrophy.(1-3) 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,
those individuals with positive laboratory results should be referred for small intestinal biopsy, thereby
decreasing the number of unnecessary invasive procedures. Celiac disease is associated with a variety of
autoantibodies, including endomysial (EMA), 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.(2) The most
sensitive and specific serologic tests are tTG and deamidated gliadin antibodies. 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; however, recent studies have identified specific B-cell epitopes
on the gliadin molecule that, when deamidated by the enzyme tTG, have increased sensitivity and
specificity for celiac disease.(5,6) The tests for deamidated gliadin antibodies, IgA and IgG, replace the
older gliadin antibody tests, which have been discontinued at Mayo Clinic. The sensitivity and specificity
of DGLDN/89031 Gliadin (Deamidated) Antibodies Evaluation, IgG and IgA, Serum for untreated,
biopsy-proven celiac disease were comparable to test TSTGP/83671 Tissue Transglutaminase (tTG)
Antibodies, IgA and IgG Profile, Serum in a study conducted at Mayo Clinic.(5) The treatment for celiac
disease is maintenance of a gluten-free diet.(1-3) In most patients who adhere to this diet, levels of
associated autoantibodies decline and villous atrophy improves. This is typically accompanied by an
improvement in clinical symptoms. 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
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