Intraepithelial gamma/delta-positive T lymphocytes and intestinal villous atrophy.

We have evaluated the expression of different molecular forms of T cell antigen receptor (TcR) in duodenal biopsies of pediatric patients with different forms of villous atrophy: celiac disease, autoimmune enteropathy, intractable diarrhea of unknown origin, and severe cow milk intolerance. A panel of monoclonal antibodies recognizing alpha/beta and gamma/delta TcR (and gamma/delta TcR subsets) was used for immunostaining. The results showed an increase of T cells with gamma/delta-type TcR in celiac patients and also in patients with other forms of villous atrophy with respect to normal controls. Amongst the gamma/delta TcR-positive cells, the subset expressing the molecular product of V delta 1 region was the most represented. The gamma/delta TcR-positive T cells were mainly located within the epithelium: few of them were observed in the lamina propria. On the basis of these results, we hypothesize that the increased homing of gamma/delta TcR-positive T lymphocytes in gut epithelium observed in celiac disease is, at least in part, related to villous atrophy per se.