Superoxide dismutase in psoriasis, squamous cell carcinoma and basal cell epithelioma: an immunohistochemical study

Monoclonal antibodies against human Cu, Zn‐superoxide dismutase (SOD) and Mn‐SOD were used to stain frozen sections of normal and abnormal human skin. In normal human epidermis, the Cu, Zn‐SOD antibody almost exclusively stained the basal cells. Mn‐SOD antibody weakly stained the whole of the epidermis but more predominantly the basal cell layer. In psoriasis, Cu, Zn‐SOD antibody mainly stained the basal cells of the lowest parts of the elongated rete ridges. Basal cells corresponding to the tip of the dermal papillae were weakly stained. Mn‐SOD staining was considerably decreased in the psoriatic epidermis. In squamous cell carcinoma, staining with both Cu, Zn‐SOD and Mn‐SOD antibodies was decreased, and single cells positive for Cu, Zn‐SOD were scattered throughout the tumour nests. In basal cell epithelioma, Cu, Zn‐SOD staining was intense and diffusely distributed throughout the tumour nests, while Mn‐SOD staining was absent.