Effect of diet and age on jejunal and circulating lymphocyte subsets in children with coeliac disease: persistence of CD4-8-intraepithelial T cells through treatment.

Monoclonal antibodies were used to determine the relative numbers of T lymphocyte subsets in 61 jejunal biopsies and in peripheral blood of 35 children with coeliac disease, and of 13 healthy controls. The T cell numbers in the lamina propria were unaffected by a change from gluten-free to gluten containing diet in the patients. The number of intraepithelial lymphocytes (where the CD8 cells predominated) were significantly raised in patients taking gluten. Ten to 20% of the patients' intraepithelial CD3 (mature T) cells expressed neither CD8 nor CD4 surface antigens. This CD4 8 T cell population persisted through gluten elimination and challenge. The circulating lymphocyte subsets showed little variation with the diet although there was a marked increase in the proportion (14.9%) of CD4 8 T cells in patients during gluten elimination. In the histologically normal jejunal mucosa from control subjects, the age of the subject showed a positive correlation with villus intraepithelial CD3+ and CD8+ cells, and crypt intraepithelial CD4+ cells. No clear cut effect of age was observed on lamina propria lymphocyte counts of the controls, or on the lymphocyte counts in jejunal mucosa of the coeliac patients. The observed CD3+4-8- lymphocytes may represent activated cells unable to present their surface antigens, or they may be gamma delta-receptor bearing T cells, which could have a significant role in the pathogenesis of coeliac disease.