Ia-like antigens in the small intestinal mucosa of normal and celiac children.

The small-intestinal mucosa of normal children and of celiac patients was studied using the Class II DP (SB) Ia-like monoclonal antibody ILR-1 and an immunoperoxidase technique. Positive staining of the Golgi region of the epithelial cells of villi and crypts, and of the brush border of villous epithelium, was seen in the histologically normal mucosa. In active celiac disease with "flat" mucosa, the surface epithelium showed poor staining, but the crypt epithelium stained strongly in the Golgi region. We suggest that the Ia-like antigens are a product of the epithelial cells themselves, arising most likely in the Golgi apparatus, and that this staining pattern is altered in active celiac disease.