EPIDERMAL CYTOKERATIN AND IMMUNOCYTE RESPONSES DURING TREATMENT OF PSORIASIS WITH CALCIPOTRIOL AND BETAMETHASONE VALERATE

Changes in epidermal immunocytes and cytokeratins were investigated during treatment of psoriasis with calcipotriol and betamethasone valerate. Skin biopsies were obtained from 10 subjects on each treatment from lesional and non-lesional skin at baseline, and from treated lesions after 4 weeks. In each subject, changes in expression of cytokeratins K5, K10 and K16, and changes in epidermal immunocyte counts were assessed. Responses were compared with a separate histological parameter of improvement, epidermal thickness. Both treatments produced a marked normalization of cytokeratins. The reduction of K16 expression was similar on each treatment and correlated significantly with reduction in epidermal thickness. Expression of both K5 and K10 improved less than thickness with betamethasone valerate but more than thickness with calcipotriol, although these differences did not reach statistical significance. With calcipotriol there was an increase in K5 and K10 responses with increasing response of epidermal thickness, which was not seen with betamethasone valerate. T6+ cells, HLA-DR+ dendritic cells and T lymphocytes were all reduced by betamethasone valerate. There was a remarkable similarity in the level of normalization between cell types and also between cellular response and reduction in thickness. Calcipotriol produced a similar consistent reduction in cell numbers and in thickness, with the exception of T6+ cells which increased in some subjects during treatment. Only in subjects in whom thickness had virtually returned to normal was there a marked decrease in T6+ cells.