Juhlin L, Juhlin C, Scheynius A, Klareskog L.
DOI: 10.2340/000155556993100

Monoclonal antibodies were produced by immunizing mice with dispersed epidermal cells from a psoriatic plaque. We obtained 128 growing hybridoma clones. The immunohistochemical reactivity of the antibodies produced by these hybridomas was primarily screened on sections of skin biopsies from psoriatic plaques. Supernatants with positive staining were then tested on other dermatoses and human organs. Six supernatants stained infiltrating dermal cells and the whole epidermis in psoriatic lesions, but showed no reaction with sections from normal skin, ichthyosis, or acutely inflamed skin. With these antibodies, positive staining was also seen in some areas of the normal-appearing skin of patients with increasingly active psoriasis as well as after treatment in recently clinically healed lesions. A different and more heterogenous staining of epidermis with no or fewer infiltrating cells was seen in longstanding inflammatory disorders such as chronic eczema, neurodermatitis, lichen planus, discoid lupus erythematosus and mycosis fungoides. Scattered staining with these antibodies was in addition seen on infiltrating macrophage-like cells present also in other organs than skin and in some of the organs also other types of cells were stained, such as neck mucosal cells of the stomach, parts of duodenal mucosal cells, certain secretory cells in parotid gland, lung bronchiole and Hassall´s bodies on the thymus. The cross-reactivity of antibodies to psoriatic lesions with other organs is of interest, since psoriasis might involve various tissues. Our findings support the idea that there exist unique cell surface antigens in psoriatic skin which might help elicit an immune reaction and/or be targets for such local immune reactions.