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Test Code LAB0208014 Celiac Disease Serology Cascade, Serum

Additional Codes

Mayo Test ID
CDSP

Reporting Name

Celiac Disease Serology Cascade

Useful For

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 HLA-DQ2 and/or DQ8)

Profile Information

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

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

Testing Algorithm

If the IgA result is within the age-specified normal range, then tissue transglutaminase (tTG) IgA antibody testing will be performed at an additional charge.

 

If the tTG IgA antibody result is equivocal, then endomysial IgA and deamidated gliadin IgA antibody testing will be performed at an additional charge.

 

If the IgA result is greater or equal to 1.0 mg/dL but lower than the age-specified normal range, then tTG IgA, tTG IgG, deamidated gliadin IgA, and deamidated gliadin IgG antibody testing will be performed at an additional charge.

 

If the IgA result is below the limit of detection (<1.0 mg/dL), then tTG IgG and deamidated gliadin IgG antibody testing will be performed at an additional charge.

 

The following algorithms are available:

-Celiac Disease Serology Cascade Test Algorithm

-Celiac Disease Diagnostic Testing Algorithm

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Serum


Ordering Guidance


This cascade should not be used in patients who have previously been or are currently being treated with a gluten-free diet. For these individuals, order CDGF / Celiac Disease Gluten-Free Cascade, Serum and Whole Blood.

 

This cascade should not be used in individual who are negative for HLA-DQ2 or DQ8, as a diagnosis of celiac disease is unlikely. For individuals who are positive for either HLA-DQ2 and/or DQ8, this test may be ordered to assess for the presence of autoantibodies associated with celiac disease.

 

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



Specimen Required


Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 5 mL

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


Specimen Minimum Volume

2 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Refrigerated (preferred) 14 days
  Frozen  21 days

Reference Values

Immunoglobulin A (IgA)

0-<5 months: 7-37 mg/dL

5-<9 months: 16-50 mg/dL

9-<15 months: 27-66 mg/dL

15-<24 months: 36-79 mg/dL

2-3 years: 27-246 mg/dL

4-6 years: 29-256 mg/dL

7-9 years: 34-274 mg/dL

10-14 years: 42-295 mg/dL

13-15 years: 52-319 mg/dL

16-17 years: 60-337 mg/dL

≥18 years: 61-356 mg/dL

Test Classification

See Individual Test IDs

CPT Code Information

82784

86258 (if appropriate)

86364 (if appropriate)

86231 (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
CDSP Celiac Disease Serology Cascade 94494-2

 

Result ID Test Result Name Result LOINC Value
IGA Immunoglobulin A (IgA), S 2458-8
28991 Celiac Disease Interpretation 69048-7

Interpretation

Immunoglobulin A:

Total IgA levels below the age-specific reference range suggest either a selective IgA deficiency or a more generalized immunodeficiency. For individuals with a low or high IgA level, additional clinical and laboratory evaluation is recommended. Some individuals may have a partial IgA deficiency in which the IgA levels are detectable but fall below the age-adjusted reference range. For these individuals, both IgA and IgG isotypes for tissue transglutaminase (tTG) and deamidated gliadin antibodies are recommended for the evaluation of celiac disease; tTG IgA, tTG IgG, deamidated gliadin IgA, and deamidated gliadin IgG antibody assays are performed in this cascade. For individuals who have selective IgA deficiency or undetectable levels of IgA, only tTG IgG and deamidated gliadin IgG antibody assays are performed.

 

tTG IgA/IgG Antibodies:

Individuals positive for tTG antibodies of the IgA isotype likely have celiac disease and a small intestinal biopsy is recommended. For individuals with selective IgA deficiency, testing for tTG antibodies of the IgG isotype is performed. In these individuals, a positive tTG IgG antibody result suggests a diagnosis of celiac disease. However, just as with the tTG IgA 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 have been following a gluten-free diet.

 

Deamidated Gliadin IgA/IgG Antibodies:

Positivity for deamidated gliadin antibodies of the IgA isotype is suggestive of celiac disease; small 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 deamidated gliadin IgG antibody result suggests a diagnosis of celiac disease. However, just as with the deamidated gliadin IgA 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 have been following a gluten-free diet.

 

Endomysial IgA Antibodies:

Positivity for endomysial antibodies (EMA) of the IgA isotype is suggestive of celiac disease, and small intestinal biopsy is recommended. For individuals with selective IgA deficiency, evaluation of EMA is not indicated. Negative EMA serology does not exclude a diagnosis of celiac disease as antibody levels decrease over time in patients who have been following a gluten-free diet.

Report Available

7 to 9 days

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject
Gross icterus OK

Method Name

Nephelometry

Forms

If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-General Request (T239)

-Gastroenterology and Hepatology Test Request (T728)

Specimen Retention Time

See individual test IDs

Day(s) Performed

Profile tests: Monday through Friday; Reflex tests: Monday through Saturday