Unusually high titres of anti-tissue transglutaminase antibodies in monozygotic twins.

Anti-tissue transglutaminase antibodies (anti-tTG) play a vital role in the screening process for coeliac disease (CD). Levels above 30 U/ml suggest a possible diagnosis of CD, prompting further investigation, usually by taking a duodenal biopsy. We report an unusual case of 39-year-old male twins, one presenting with iron deficiency anaemia and the other asymptomatic, with anti-tTG antibodies of >4,965.5 U/ml, an extraordinary level. A duodenal biopsy confirmed a diagnosis of CD and following the adoption of a gluten-free diet, anti-tTG levels were found to decrease back to normal levels. This case demonstrates how CD can cause significant biochemical and histological pathology, but present with mild or no symptoms.