Immunohistochemical localization of cytokines in nevi.

Eight common nevi and 11 dysplastic nevi were evaluated for the presence of basic fibroblast growth factor, platelet-derived growth factor, transforming growth factor-alpha, interleukin-1-alpha, and interleukin-1-beta by immunohistochemical labelling with highly specific monoclonal antibodies. Basic fibroblast growth factor was abundant in the nevus cells and keratinocytes of nevi. Dysplastic nevus cells on average stained less intensely for basic fibroblast growth factor than did common nevus cells. In both types of nevi, basic fibroblast growth factor was identified in the basement membranes at the dermoepidermal junction and surrounding nevus cell nests and individual nevus cells. Labelling of nevus cells for transforming growth factor-alpha was variable, while there was moderate labelling for platelet-derived growth factor and light labelling for interleukin-1-alpha. Only two nevi, both dysplastic, stained (very faintly) for interleukin-1-beta. It is possible that these cytokines, especially basic fibroblast growth factor, act in autocrine fashion to maintain nevocellular growth and may also contribute to the epidermal hyperplasia and fibrosis frequently observed in nevi.