STRUCTURAL ALTERATIONS OF BASAL KERATINOCYTES AND CAPILLARY LOOP IN PSORIASIS DURING TREATMENT WITH TOPICAL CALCIPOTRIOL

Recent research has demonstrated the activity of calcipotriol, effecti ve as a potent inhibitor of cellular proliferation and known to increa se differentiation in a number of cell lines in the topical treatment of psoriasis. Vit D3 receptors are expressed in keratinocytes and vasc ular endothelial cells. We studied the alterations in basal kertinocyt es (stem cells or anchoring cells) and endothelial cell modification i n 6 patients with psoriasis treated with calcipotriol ointment twice a day for 4 weeks. The samples were embedded in Epon resin for thin sec tion and ultrathin section examination by electron microscopy. A norma l pattern of distribution of the two different types of basal keratino cytes was observed before treatment. After treatment, only anchoring c ells were detected. The alterations of endothelial cells in capillary loop disappeared after treatment, presenting normal aspects. Our morph ological findings suggest that calcipotriol is therapeutically effecti ve, due principally to an inhibition of cellular proliferation.