Expression of cell adhesion molecules in jejunum biopsies of children with coeliac disease.

The composition of inflammatory cells as well as the expression of cell adhesion molecules (LFA-1/CD11a, ICAM-1/CD54, CD36) in jejunal biopsies from children with active, untreated coeliac disease (CD) has been analyzed and compared with control biopsies. In CD the number of intraepithelial and lamina propria T cells was greater than in controls. ICAM-1 was found on most cells in the lamina propria; many of them expressed LFA-1 as well. In contrast, no ICAM-1+ and a few LFA-1+ cells were noticed in the epithelium. The brush border from control biopsies reacted with HLADR and anti-CD36. In CD, de novo expression of HLADR was found in the cytoplasm of villous and cryptal enterocytes in contrast, CD36 disappeared from the brush border and no expression of ICAM-1 on the inflamed epithelium was noticed. The results indicate that adhesion molecules other than LFA-1, ICAM-1 and CD36 may be involved in the cellular interactions occurring in the intraepithelial compartment in CD; the lack of ICAM-1 and the reduced expression of LFA-1 on intraepithelial lymphocytes might reflect a defective activation of these cells. Several macrophages were found in the lamina propria in cases of CD; some of them were located beneath the surface epithelium, showed a spindle/dendritic morphology, and expressed the HLADR+, CD36+, CD11a- phenotype. These cells might be stimulated by luminal antigens and might play an important role in subsequent activation of T cells in the lamina propria.