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A B C D E F G H I J K L M N O P Q

Test Identifier Information

 
Registration CodeTTG
Method

ELISA

External Price$40.26(Exclusive of GST)
  

Specimen Collection

 
Pre-Testing Requirements

Must not be on gluten free diet

Specimen Collection Protocols

Serum is the preferred sample type.

Li Hep. plasma may be used if serum not available. 

Coeliac screen should be requested as TTG.

Patient Specimen5 mL clotted blood (Red)
Paediatric Specimen0.5 mL clotted blood (Red)
Sample Delivery to LabRoom temperature
  

Instructions for Referral to CHLabs

 
Aliquot Instructions200 uL serum (minimum) 1 mL serum (preferred)
Aliquot Transport to CHLRoom temperature
  

CHLabs Laboratory

 
DepartmentBiochemistry - Immunology
Contact Details Email Email
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Contact Phone Number(03) 364 0414 | x80414
Test AvailabilityBatched at least weekly
Turnaround Time2 weeks
Reference Interval

Negative = < 3 units

Equivocal = 3-5 units

Positive = > 5 units

Interpretation

IgA TTG Abs are highly disease specific markers for untreated Coeliac Disease. Diagnosis of Coeliac Disease should be confirmed by small bowel biopsy. We recommend that patients with positive titres be referred for specialist clinical assessment before any treatment is undertaken. Patients with IgA deficiency will give negative results, therefore, testing for IgG TTG or IgG deamidated gliadin antibodies is recommended.

In screening for Coeliac Disease greater reliance should be placed on the Endomysial Antibody (EMA) result than either TTG or anti-deamidated gliadin antibody results. Evaluated in this laboratory, EMA has the highest sensitivity of any single test ie the least false negatives.

TTG may be useful in monitoring dietary compliance. It tends to become negative earlier than EMA in response to dietary gluten restriction. For this reason TTG and EMA results may not correlate in patients on a gluten free diet.

 

Additional Information

If IgA deficiency is suspected, the sample should be tested for total IgA. Please request this as well as ttg.

Patients with IgA deficiency will give falsely negative results.

Patients who are shown to be IgA deficient will be tested for anti-TTG IgG antibodies.

Delphic Number Test Number7640

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