DETECTION OF CELLULAR ADHESION MOLECULES IN INFLAMED HUMAN CORNEAS

Purpose: The expression of cellular adhesion molecules in 31 penetrati ng keratoplasty specimens from a broad range of corneal inflammatory d iseases was studied using monoclonal antibodies and an immunoperoxidas e technique. Methods: Corneas were divided into noninflamed, mild to m oderately inflamed, and severely inflamed groups based on histologic f indings. The panel of adhesion molecules studied included HLA-ABC, HLA -DR, CD3, LFA-1, MAC-1, ICAM-1, PECAM-1, VCAM-1, and E-selectin-1. Res ults: The adhesion molecules ICAM-1, HLA-DR, PECAM-1, CD3, VCAM-1, LFA -1, and MAC-1 were selectively expressed in areas of corneal inflammat ion. In general, HLA-DR and intercellular adhesion molecule ICAM-1 wer e co-expressed in similar regions. PECAM-1 was restricted to zones of marked inflammation and vascularization. E-selectin-1 was detected onl y in the stroma of a graft melt in a patient with active ocular cicatr icial pemphigoid, and may reflect a primary regulatory dysfunction in this disorder. The ICAM-1 ligand was, in general, more diffusely distr ibuted than its receptor LFA-1, a beta-2 integrin found on leukocyte c ell membranes. The localization of the integrin MAC-1, present on macr ophages, neutrophils, and some lymphocytes, did not always parallel th e staining pattern of ICAM-1, suggesting promiscuity in its binding to other ligands besides ICAM-1. Conclusions: Adhesion molecules are det ected readily at sites of corneal inflammation and may play a critical role in facilitating the recruitment of immune regulatory cells to th ese areas. Future efforts to block or modulate the expression of inter cellular adhesion molecules may provide new therapeutic options in the treatment of corneal inflammatory diseases.