Expression of the CD54 (ICAM-1) and CD11a (LFA-1) adhesion molecules in oral mucosal inflammation.

Previous studies of chronic dermatoses have suggested that expression of the CD54 cell surface antigen (intercellular adhesion molecule-1, ICAM-1) by keratinocytes is a feature of chronic inflammation. However, whether such expression is a prerequisite for intraepithelial migration of lymphocytes is unclear. The present study evaluated the expression of CD54 and its ligand, CD11a (lymphocyte function-associated antigen, LFA-1) in oral lesions of lichen planus, recurrent aphthous stomatitis, secondary Sjögren's syndrome and traumatic ulceration using an immunoperoxide technique. In 33 of 56 lesions examined, substantial numbers of CD11a + cells were present within oral mucosal epithelium despite an absence of detectable keratinocyte CD54 antigen expression. Consequently, CD54/CD11a adhesion interactions may not be critical in the initiation of oral mucosal inflammation.