Intestinal transglutaminase 2 specific antibody deposits in non-responsive coeliac disease

Background and aims The diagnosis of coeliac disease is problematic in individuals not responding to a gluten-free diet. Small-bowel villous atrophy occurs in other enteropathies and non-responsive patients are often seronegative. We investigated whether small-bowel mucosal transglutaminase-2 specific autoantibody deposits distinguish non-responsive coeliac disease from other enteropathies. Methods Small-bowel mucosal autoantibody deposits were determined in 27 non-responsive, 28 responsive coeliac patients and 10 controls with other enteropathies. Of the non-responsive coeliac patients six were adhering poorly and 21 strictly to the diet; six of the 21 had enteropathy-associated lymphoma, five refractory coeliac disease and 10 otherwise persistent villous atrophy. The presence of mucosal autoantibody deposits was compared to serology, villous morphology, densities of intraepithelial lymphocytes (IELs) and markers of refractory coeliac disease. Results Twenty out of 21 well-adhering, all six poorly adhering non-responsive and all 28 untreated responsive coeliac patients had small-bowel mucosal autoantibody deposits present, while controls with other enteropathies were negative. Small-bowel mucosal autoantibody deposits were more accurate in detecting coeliac disease than serology or IEL densities. Refractory coeliac markers revealed only cases with the most severe condition. Conclusions Small-bowel mucosal autoantibody deposits differentiate coeliac disease from other enteropathies, enabling the design of appropriate therapeutic strategies.