CARCINOEMBRYONIC ANTIGEN AND RELATED ANTIGENS EXPRESSED ON KERATINOCYTES IN INFLAMMATORY DERMATOSES

Carcinoembryonic antigen (CEA) is recognized as being important not on ly as a tumour marker, but also as a cell adhesion molecule in the met astasis of malignant tumour cells, and in the development of inflammat ory disorders in some organs. However, the role played by this antigen in inflammatory dermatoses has not been studied previously. To invest igate the expression of CEA in inflamed skin, we performed immunohisto chemical studies to detect the antigen in both frozen and formalin-fix ed, paraffin-embedded biopsy specimens of inflammatory dermatoses, usi ng five different monoclonal antibodies and one polyclonal antibody ag ainst human CEA or CEA-related molecules. CEA and CEA-related antigens were expressed by epidermal keratinocytes and by some infiltrating in flammatory cells in inflamed skin. The expression was observed primari ly in the upper part of the malpighian layers of the epidermis. On the basis of the distribution of this expression, we suggest an additiona l role for CEA-related molecules, differing from their roles as tumour markers and adhesion molecules, namely that these molecules may be as sociated with the state of differentiation of epidermal keratinocytes. Unexpected expression of CEA-related antigens was seen on normal foll icular keratinocytes, Thus, it is conceivable that CEA-related antigen may also play a role in the biology of hair follicles.