A new autoantibody in celiac disease.

A 74-year-old female patient with therapy-resistant sprue (celiac disease) and a new IgA autoantibody is presented. This autoantibody was demonstrated by immunofluorescence and differs from the conventional antibody against type 3 connective tissue (so-called endomysium antibody). It reacts predominantly with the muscularis and less strongly with the muscularis mucosae of the monkey esophagus. The reaction is not retiform but punctiform; the typical reaction sites of the antibody against type 3 connective tissue are negative. Especially on esophageal sections the antibody can be mistaken for the characteristic antibody directed against tissue transglutaminase, in particular at low magnification. The antigen of the new antibody is as yet unknown.