PUVA irradiation restores altered binding patterns of lectins in psoriatic epidermis

We examined a series of biopsy specimens obtained from lesional skin in five psoriatic patients receiving topical PUVA treatment to see the effect of PUVA on epidermal cell membrane glycoconjugates by fluorescent staining techniques using lectins as surface markers. In psoriatic epidermis, Ulex europaeus agglutinin and Concanavalin A depicted only cytoplasmic patterns and did not show the plasma membrane fluorescence that was normally seen in nonpsoriatic skin. Following PUVA treatment, these altered staining patterns gradually normalized, with the appearance of the plasma membrane fluorescence. Restoration of the membrane staining tended to precede improvement in clinical and histologic features of psoriasis, suggesting that normalization of the altered profiles of membrane glycoconjugates is one of the beneficial effects of PUVA irradiation on psoriatic epidermis.