Abstract
The ultrastructural binding sites of endomysium antibodies, specific serological markers of gluten sensitive enteropathy, were investigated in the rabbit oesophagus using the immunogold technique. Endomysium antibodies from sera of patients with dermatitis herpetiformis and with coeliac disease bound in an identical manner in a non-fibrillar material closely associated with fine collagenous-reticulin fibrils and also with similar fibrils connecting smooth muscle cells and elastic tissue in the endomysial connective tissue. These observations suggest that IgA antibodies in sera from patients with dermatitis herpetiformis and coeliac disease recognise a common antigen in an amorphous component associated with the reticular connective tissue of oesophageal lamina muscularis mucosae and thus confirm the probable identity of IgA class endomysium and jejunal antibodies.