Altered expression of the alpha2 laminin chain in psoriatic skin: the effect of treatment with cyclosporin

The histopathological pattern of psoriasis is characterized by dermal inflammatory reaction and hyperproliferation of the epidermis. The mechanism of the epidermal hyperproliferation is not completely understood, but it is probably modulated by the basal lamina (BL), the alterations of which have not been described. We performed the present study to evaluate the expression of the α1, α2, β1 and γ1 laminin chains and collagen IV in the BL of active psoriasis vulgaris before and after cyclosporin treatment administered until the psoriasis was in remission. The results showed that the α2 chain is weak and irregular in the lesions; while the α1, β1 and γ1 chains and collagen IV are normal, with intense and continuous reaction. In the same subjects, this alteration was absent in skin that was clinically unaffected. After treatment with cyclosporin, the altered expression of the α2 chain returned to normal in the healing lesions.