Coeliac serology (tTG antibody)

IgA anti-tissue transglutaminase (tTG) antibodies are the first line test for coeliac disease (NICE guideline 2015 1, ESPGHAN guideline 2020 2) and have a reported specificity and sensitivity of >95% in untreated coeliac disease, provided patients are consuming sufficient gluten at time of testing.

• Chronic/intermittent diarrhoea/constipation/abdominal pain
• Recurrent nausea and/or vomiting
• Weight loss/failure to thrive in paediatrics
• Chronic fatigue
• Unexplained iron/vitamin B12/folate deficiency
• Severe/persistent mouth ulcers
• Dermatitis herpetiformis-type rash
• Abnormal liver biochemistry
• First-degree relatives with coeliac disease
• Autoimmune conditions including, type 1 diabetes, thyroid disease, liver disease.

• Insufficient gluten consumption – gluten must be eaten in more than 1 meal per day for at least 6 weeks prior to testing (1)
• IgA deficiency – IgA tTG analysis may be less sensitive when total IgA is <0.2 g/L 2. IgG coeliac serology (tTG) should be performed
• Panhypogammaglobulinaemia – all coeliac serology may be insensitive.

• Routine monitoring is not required more frequently than annually (1).
• If tTG titres are persistently high after 12 months and exposure to gluten has been excluded, consider gastroenterology referral (1).

Please note local management protocols may vary and local guidelines should be followed.

References:

National Institute for Health and Care Excellence. Coeliac disease: recognition, assessment and management [Internet]. [London]: NICE; 2015 [cited 2022 Oct 04]. (NICE guideline [NG20]). Available from: https://www.nice.org.uk/guidance/ng20

New Guidelines for the Diagnosis of Paediatric Coeliac Disease [Internet]. European Society for Pediatric Gastroenterology, Hepatology, and Nutrition; 2020 [cited 2022 Oct 04]. Available from: https://www.espghan.org/dam/jcr:a82023ac-c7e6-45f9-8864-fe5ee5c37058/2020_New_Guidelines_for_the_Diagnosis_of_Paediatric_Coeliac_Disease._ESPGHAN_Advice_Guide.pdf