Test Code #
CPT Code(s) #
IgA Tissue Transglutaminase Antibody
Type of Study:
<20 Units Negative
20-30 Units Weak Positive
> 30 Units Moderate to Strong Positive
Assay performed once every week.. Report availability is within one week from the time of specimen receipt
Collect 5-10 ml of blood in a red top or serum separator tube. If possible, separate serum from clot and place into red capped tube provided with Beutner Laboratories collection kits. If separation facilities are not available, the blood can be sent in the tube used for collection.
Stable at ambient temperature during shipment. If sample is stored prior to shipment, it is stable refrigerated (2-8ºC) up to five days and frozen (-20ºC or lower) up to one year.
Presence of the tissue transglutaminase (tTG) IgA antibody is associated with gluten sensitive enteropathies such as celiac disease and dermatitis herpetiformis. tTG IgA antibody concentrations greater than 40 U/mL usually correlate with results of duodenal biopsies consistent with a diagnosis of celiac disease. For antibody concentrations greater or equal to 4 U/mL but less than or equal to 40 U/mL, additional testing for endomysial (EMA) IgA concentrations may improve the positive predictive value for disease.