Changing jejunal gamma delta T cell receptor (TCR)-bearing intraepitheliallymphocyte density in coeliac disease

The function of jejunal intraepithelial gamma delta(+) T cells is obscure, but they are commonly implicated as playing a role in inflammatory and auto immune conditions. In coeliac disease (CoD), there are controversial report s as to gluten dependency of these cells. We have now studied the small bow el mucosal intraepithelial T cell densities, and the ratios of gamma delta( +) to CD3(+) T cells and gamma delta(+) to alpha beta(+) T cells during ear ly disease development and on a gluten-free diet. Nine children initially e xcluded for CoD were followed up and rebiopsy after 0.8-4.5 years showed mu cosal deterioration. Further, 21 biopsy specimens from newly diagnosed CoD patients were studied, together with 20 specimens taken from children on a gluten-free diet. During CoD development the density of gamma delta(+) and alpha beta(+) T cells as well as the ratios of gamma delta(+) to CD3(+) T c ells and gamma delta(+) to alpha beta(+) T cells increased. In the latent s tage of CoD when the small bowel mucosal architecture was still normal, two children had clearly normal densities of gamma delta(+) (<2.5 cells/100 ep ithelial cells) and alpha beta(+) (<25.0 cells/100 epithelial cells) T cell s, and low ratios as well. In patients with newly diagnosed CoD the densiti es decreased significantly on a long-term gluten-free diet. We conclude tha t the density of intraepithelial gamma delta(+) T cells as well as alpha be ta(+) T cells in CoD is gluten-dependent. CoD can develop in a child ingest ing normal amounts of gluten and having normal jejunal mucosal morphology o n biopsy and a normal density of gamma delta(+) T cells.