Tissue Transglutaminase Antibody (TTG) (IgG and IgA)

Immunology

---

Description

Tissue transglutaminase ( TTG ) is an enzyme that has been identified as the autoantigen in coeliac disease. TTG antibodies are thought to play a pathological role in the development of coeliac disease. IgA antibodies to TTG are useful in the diagnosis and follow-up of coeliac disease. IgA TTG antibodies are a sensitive marker alone for coeliac disease although it may not predict recovery of villous atrophy in coeliac patients on a gluten free diet. The presence of IgA antibodies to TTG closely correlates with the detection of endomysial antibodies detected by indirect immunofluorescence but have the advantage that they are reported quantitatively. There has been a long standing controversy over the optimal testing strategy for patients with suspected coeliac disease however the Nice guidelines in 2009 recommend IgA TTG antibodies as the first line test followed by IgA endomysial antibodies if the IgA TTG antibodies are equivocal [1]. IgG TTG antibodies are a useful test for IgA deficient patients with suspected coeliac disease. IgA antibodies to TTG can be falsely positive especially in liver disease which is well documented in the literature [2].

---

Indications

Coeliac Disease, Dermatitis Herpetiformis.

---

Sample Type

2mL Serum ( Gel 5mL Yellow tube or 6mL Red tube ). Requests from outside Sheffield: Transport at ambient temperature via Royal Mail or Courier.

---

Reference Range

IgA TTG 0 - 7 U/mL.
IgG TTG 0 - 7 U/mL.

Reference ranges manufacturer derived and verified in house.

---

Turnaround Time

Within 5 days

---

Testing Frequency

Weekly

---

References

NICE Guidelines ( NG20 ) Coeliac disease: recognition, assessment and management. September 2015[Ref 1].Hopper AD, et al. What is the role of serologic testing in coeliac disease? A prospective, biopsy-confirmed study with economic analysis. Clinical gastroenterology and hepatology. 2008. 6:314-320.Hopper AD, et al. Pre-endoscopy serological testing for coeliac disease:evaluation of a clinical decision tool. BMJ. 2007. 334:729.Rostom A, et al. The diagnostic accuracy of serologic tests for coeliac disease: a systematic review. Gastroenterology. 2005. 128( 4 ):S38-46.Dahlbom D, Olsson M, Forooz NK. Immunoglobulin G ( IgG ) anti-tissue transglutaminase antibodies used as markers for IgA deficient coeliac disease patients. Clinical and Diagnostic Laboratory Immunology. 2005. 254-258.Villalta D, et al. False positive reactions for IgA and IgG anti-tissue transglutaminase antibodies in liver cirrhosis are common and method-dependent. Clinical Chimica Acta. 2005. 356( 1-2 ):102-109. [Ref 2]

---

See Also

Endomysial antibodies; Gliadin antibodies ( IgA and IgG )

Please note: the above information is subject to change and we endeavour to keep this website up to date wherever necessary.