SIMILAR ECTOPIC EXPRESSION OF ICAM-1 AND HLA CLASS-II MOLECULES IN HYPERTROPHIC SCARS FOLLOWING THERMAL-INJURY

In previous studies we have shown that HLA Class II antigens are expre ssed by keratinocytes and fibroblasts in hypertrophic scars. Because o f the potential role of immunological events in the pathogenesis of hy pertrophic scars, in the present study we have tested hypertrophic sca rs for the expression of intercellular adhesion molecule-1 (ICAM-1), a molecule which plays an important role in immunological phenomena. Im munoperoxidase staining with anti-ICAM-1 MoAb of 10 hypertrophic scar samples detected this molecule on epidermal keratinocytes and on about 30 per cent of fibroblasts at the site of lymphoid infiltration. The expression of ICAM-1 in hypertrophic scars was similar to that of HLA Class II antigens. Since the concomitant expression of ICAM-1 and HLA Class II by keratinocytes is known to enhance their antigen-presenting properties, the present results support the possibility that immunolo gical events play a role in the disruption of the normal processes of wound healing and tissue remodelling which result in hypertrophic scar s.