Induction of adhesion molecule expression on blood vessels and keratinocytes in recurrent oral ulceration

Adhesion molecules are known to play a crucial role in the recruitment of inflammatory cells to sites of inflammation. In this study endothelial cell and keratinocyte adhesion molecule expression in recurrent oral ulcers (ROU) (n = 13) was compared with that found in normal oral mucosa (NOM) (n = 11) and experimentally induced ulcers (EIU) (n = 5) by using immunohistochemistry. Significantly greater expression of both vascular cell adhesion molecule- (VCAM-1) and E-selectin was demonstrated on vasculature in ROU compared with that found in both NOM and EIU. Induction of keratinocyte intercellular adhesion molecule-1 (ICAM-1) was also a prominent feature of ROU. The expression of VCAM-1 and E-selectin on blood vessels in ROU is likely to be important in the accumulation of lymphocytes that characterise early aphthous lesions. The induction of keratinocyte ICAM-1 may facilitate lymphocyte invasion of the epithelium in ROU, which may ultimately result in ulcer formation.