Investigation of Individuals with Positive Endomysial Antibodies and Normal Duodenal Biopsy for Evidence of Coeliac Disease

Introduction: Coeliac disease (CD) is an immune mediated disease, induced by gluten. Anti-endomysial (EMA) antibodies are widely used in screening for CD. The classical gut lesion in CD is characterized by a flattened small intestinal mucosa with an inflammatory cells infiltratation, increased epithelial cell proliferation and crypt hyperplasia.

Aim: To examine biopsy tissue from EMA positive individuals, in whom the duodenal mucosa was reported to be normal, for evidence of CD.

Methods: Paraffin-embedded formalin fixed duodenal sections from 19 EMA positive individuals with normal duodenal mucosa were investigated. In addition, sections from 16 untreated CD (UTCD) and 13 treated CD (TCD) patients and 20 normal control subjects were examined. Immunoperoxidase staining was performed using anti-CD2, CD3, CD4, CD7, CD8, CD69 and Ki-67 antibodies. Intraepithelial lymphocytes (IELs) were counted per 500 enterocytes. Positively stained lamina propria cells were counted at high power magnification using an eyepiece graticule and results were expressed as a percentage of total cells examined.

Results: In the epithelial layer, the percentages of CD3⁺, CD7⁺, CD8⁺ and Ki-67⁺ cells were all significantly increased in the EMA positive individuals when compared with the control subjects. These cell populations were also significantly increased in the untreated and treated CD patient groups. In the lamina propria, similar percentages of cells bearing these markers were obtained in all groups examined.

Conclusion: Increased numbers of CD3⁺, CD7⁺, CD8⁺ and Ki-67⁺ cells in EMA positive individuals with apparently normal duodenal mucosa may represent early changes preceding the development of an overt gut lesion in CD.