053
Test #
IgA & IgG Tissue Transglutaminase Antibody
CPT Code(s) #
86364 x2
If Profile, Includes Tests:
N/A
Disease Name:
GSE, Celiac Disease, Dermatitis Herpetiformis
Type of Study:
Serum Studies
Methodology:
ELISA
Substrate:
ELISA plate
Reference Range:
tTG IgA (U/mL)
• Negative <4
• Weak Positive 4-10
• Positive >10
tTG IgG (U/mL)
• Negative <6
• Weak Positive 6-9
• Positive >9
Units:
U/mL
Schedule:
Assay performed once every week.
Specimen Requirements:
Collect 2-5 ml of blood in a red top Vacutainer or serum separator (SST) tube, allow blood to clot, and centrifuge. Label tube appropriately.
Sample Stability:
Room temperature = stable during shipment
2ºC to 8ºC = 5 days
-25ºC to -15ºC = 1 year
Clinical Relevance:
IgA anti-endomysium antibodies (EmA), IgA and IgG anti-deamidated gliadin peptides (DGP), and IgA anti-tissue transglutaminase (tTG) antibodies are considered specific and sensitive serologic markers for gluten sensitive enteropathies such as celiac disease and dermatitis herpetiformis (DH). Although the IgA isotype of these antibodies usually predominates in celiac disease and dermatitis herpetiformis, individuals may also produce IgG isotypes, particularly if the individual is IgA deficient. The sensitivity and specificity of commercially available IgA tTG ELISA tests for the diagnosis of DH have been reported to range from 42% to 99% and 92% to 100%, respectively.
