Anti-tissue transglutaminase antibodies (IgA and IgG) in both Crohn's disease and autoimmune diabetes

Abstract

Objective: a strong association has been observed between celiac disease, generally its silent clinical form, and autoimmune disorders. A potential correlation with inflammatory bowel disease has also been suggested. Anti-tissue transglutaminase antibodies have been detected in Crohn's disease. We investigated the prevalence of celiac disease in patients with autoimmune diabetes and in Crohn's disease patients and also evaluated the correlation between anti-transglutaminase antibody positivity and the clinical status of these diseases. Methods: anti-tissue transglutaminase and anti-endomysium antibodies were assessed by enzyme-linked immunosorbent assay and indirect immunofluorescence, respectively. Upper digestive endoscopy and duodenal biopsy were indicated for cases with positive serology. Results: anti-transglutaminase antibodies were detected in five diabetic patients (prevalence of 11.1%), only one serum sample was positive for IgG isotypes. Nine of thirty-three patients with Crohn's disease had low positive levels for IgA anti-transglutaminase. Anti-endomysium antibodies were detected only in celiac patients. Celiac disease was confirmed in all diabetic patients submitted to duodenal biopsies who presented both anti-transglutaminase and anti-endomisyum antibodies positivity. In Crohn's disease, its clinical status and the diagnosis of celiac disease were not associated with positive anti-transglutaminase result. Conclusions: the prevalence of celiac disease was high in diabetic patients. Anti-tissue transglutaminase antibodies were sensitive and specific markers of celiac disease in this diabetic group, while these antibodies were of limited value for celiac disease screening in patients with Crohn's disease