Mayo Test Catalog, (Sorted By Test Name) - Mayo Medical ...

FGLIP
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 tissue transglutaminase, 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 test
DGLDN/89031 Gliadin (Deamidated) Antibodies Evaluation, IgG and IgA, Serum for untreated,
biopsy-proven celiac disease were comparable to TSTGP/83671 Tissue Transglutaminase (tTG)
Antibodies, IgA and IgG Profile, Serum in a recent 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 suggest poor adherence to the gluten-free diet or the possibility of refractory celiac
disease.(1) See Celiac Disease Diagnostic Testing Algorithm in Special Instructions 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 in Special Instructions. For your convenience, we recommend utilizing cascade testing 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. Algorithms for the
cascade tests are available in Special Instructions. -CDCOM/89201 Celiac Disease Comprehensive
Cascade: complete testing including HLA DQ -CDSP/89199 Celiac Disease Serology Cascade:
complete testing excluding HLA DQ -CDGF/89200 Celiac Disease Comprehensive Cascade for
Patients on a Gluten-Free Diet: for patients already adhering to a gluten-free diet To order individual
tests, see Celiac Disease Diagnostic Testing Algorithm in Special Instructions.
Useful For: Evaluating patients suspected of having celiac disease; this includes patients with
symptoms compatible with celiac disease, patients with atypical symptoms, and individuals at increased
risk of celiac disease Evaluating the response to treatment with a gluten-free diet
Interpretation: Positive test results for deamidated gliadin antibodies, IgA or IgG, are consistent with
the diagnosis of celiac disease. Negative results indicate a decreased likelihood of celiac disease.
Decreased levels of deamidated gliadin antibodies, IgA or IgG, following treatment with a gluten-free diet
are consistent with adherence to the diet. Persistence of high levels of antibodies following dietary
treatment suggest poor adherence to the diet or the presence of refractory disease.
Reference Values:
Negative: 30.0 U
Clinical References: 1. Green PH, Cellier C: Celiac disease. New Eng J Med 2007;357:1731-1743
2. Green PH, Jabri B: Celiac disease. Annu Rev Med 2006;57:207-221 3. Harrison MS, Wehbi M,
Obideen K: Celiac disease: More common than you think. Cleve Clinic J Med 2007;74:209-215 4. Dale
JC, Homburger HA, Masoner DE, Murray JA: Update on celiac disease: New standards and new tests.
Mayo Communique 2008;33(6):1-9 5. Rashtak S, Ettore MW, Homburger HA, Murray JA: Comparative
usefulness of deamidated gliadin antibodies in the diagnosis of celiac disease. Clin Gastroenterol Hepatol
2008 Apr;6(4):426-432 6. Sugai E, Vazquez H, Nachman F, et al: Accuracy of testing for antibodies to
synthetic gliadin-related peptides in celiac disease. Clin Gastroenterol Hepatol 2006;4:1112-1117
Glipizide (Glucotrol)
91097
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