LACK OF EXPRESSION OF INTERCELLULAR-ADHESION MOLECULE ICAM-1 IN LEPROMATOUS LEPROSY PATIENTS

It is conceivable that an abnormal expression of cell-adhesion molecul es can contribute to the poor inflammatory response seen in some infla mmatory skin diseases. Adhesins are cell-surface molecules that are ex pressed by many cell types. The main function of adhesins appears to b e the promotion of cellular interactions, such as those occurring betw een immune cells. The epidermis of patients with inflammatory skin dis eases exhibits an increased expression of ICAM-1, and it has been post ulated that such increased expression can be important in the genesis of cutaneous inflammation. The expression of cell-adhesion molecules ( LFA-1, LFA-2, LFA-3 and ICAM-1) in skin lesions of leprosy patients wa s studied, as well as the in vitro expression of these molecules induc ed with gamma interferon (IFN-gamma). A lack of expression of ICAM-1 i n the epidermis of lepromatous patients was noted; in addition, no exp ression of ICAM-1 was seen in the nearly normal skin from these patien ts incubated with IFN-gamma. A similar expression of the four molecule s studied was noted in the dermis of both the lepromatous and tubercul oid types of leprosy. The epidermis of the lepromatous leprosy patient s appears to have a defective expression of ICAM-1.