Immunoglobulin A Anti‐tissue Transglutaminase Antibody Deposits in the Small Intestinal Mucosa of Children With No Villous Atrophy

Abstract

Anti-tissue transglutaminase (anti-TG2) immunoglobulin A (IgA) autoantibodies are detectable in the serum of most patients with untreated celiac disease (CD). Their deposits in the intestine of patients with CD with severe enteropathy are considered specific for this condition. The histological spectrum of CD includes cases with normal villous architecture. The aim of this study was to look for anti-TG2 IgA deposits in the intestine of children with normal villous architecture and to relate them with other markers of gluten sensitivity. A total of 57 children with normal duodenal villous architecture and markers of gluten sensitivity were considered. Of those, 39 showed positive serum anti-endomysium antibodies and/or high levels of anti-TG2 antibodies (group 1), and 18 were seronegative with only a greater density of gammadelta intraepithelial lymphocytes (group 2). Thirty-four children with no markers of gluten sensitivity and a normal mucosa represented the control group (group 3). The duodenal sections of all patients were investigated for deposited anti-TG2 IgA by double immunofluorescence. Human lymphocyte antigen molecular typing was performed. In group 1 and in group 2, 33 of 39 children (85%) and 12 of 18 children (66%) showed subepithelial anti-TG2 IgA intestinal deposits, respectively. Only in 3 of 34 (8.8%) children with no markers of gluten sensitivity were anti-TG2 IgA deposits noted. A subgroup of children with no serum CD-associated autoantibodies, but greater density of gammadelta intraepithelial lymphocytes, shows a clear anti-TG2 IgA deposition in the duodenal mucosa. These children must be investigated further for possible gluten sensitivity.