Immunohistochemical localization of basic fibroblast growth factor in skin diseases.

The basic fibroblast growth factor (bFGF) is an angiogenic factor and also a mitogen for epidermal keratinocytes. In order to investigate the role of bFGF in human skin we examined the distribution of bFGF immunoreactivity in normal and diseased human skin. Antigen expression was demonstrated by direct immunofluorescence staining of cryostat sections with a polyclonal anti-bFGF antibody. In normal human skin, bFGF-like immunoreactivities were observed in the basal cells, while in the case of psoriasis, positive immunoreactivities were observed in the basal cells and several supra-basal layers at rete ridges. Seborrheic keratosis and basal cell epithelioma showed diffuse immunoreactivities in the basaloid cells of the tumor. Concurrently, benign nevus cell nevus, capillary hemangioma, squamous cell carcinoma and malignant melanoma displayed negative immunoreactivities. These results suggest that bFGF is important for basal or basaloid cell proliferation.