Studies on the nature and significance of connective tissue antibodies in adult coeliac disease and Crohn's disease.

Sera from 92 patients with adult coeliac disease, 20 patients with Crohn's disease, and 89 control patients were tested for the presence and immunoglobulin class of anticonnective tissue antibodies. In adult coeliac disease patients taking a normal diet there was a high frequency of sera positive for connective tissue antibodies and the majority were IgA in class. Following gluten withdrawal, IgA class connective tissue antibody activity was strikingly reduced. No such antibody activity was detected in concentrated jejunal fluid collected from 15 patients with adult coeliac disease, seven of whose sera were positive for connective tissue antibody. Connective tissue antibody activity was not absorbed by fractions of gluten. Similarly, preparations of human reticulin and glomerular basement membrane together with elastin and collagen failed to absorb connective tissue antibody.