Anti-tissue transglutaminase antibodies in the follow-up of adult coeliac disease

Background The detection of auto antibodies directed against tissue transglutaminase (anti-tTG antibodies) has a well-established role in the diagnosis of coeliac disease, but the value of these antibodies in long-term follow-up is controversial. Aims To determine if serial anti-tTG antibody measurements could confirm adherence to a gluten-free diet (GFD) and identify patients at risk of disease complications. Methods In a 54-month cohort follow-up study, 182 adult patients were assessed. Data recorded included self-assessment of GFD adherence; anti-tTG antibody concentration and serum ferritin, vitamin B12 and folate. Where available, bone mineral density (BMD) and duodenal histology data were retrieved. Results Persistently elevated anti-tTG antibody levels were significantly associated with abnormal duodenal histology (P < 0.001), low ferritin (P < 0.01) and poor adherence to the GFD (P < 0.001). The specificity was >85% while the sensitivity was 39-60%. Anti-tTG antibody concentrations fell rapidly following successful initiation of a GFD, and maintenance of normalization identified those who continued to be adherent to the diet. Conclusions This study supports a strategy of using anti-tTG antibody concentrations to monitor newly diagnosed and established patients with coeliac disease, and to target dietetic intervention to reduce the risk of complication.