Proliferative responses of fibroblasts from psoriatic and normal skin to clobetasol propionate.

The proliferation of fibroblasts cultured from psoriatic and normal skin was compared following addition of clobetasol propionate to the culture medium. Proliferation was stimulated at 0.1 microgram/ml and progressively inhibited at 1-10 micrograms/ml. A differential sensitivity to the drug was demonstrated: the fibroblasts from involved psoriatic skin were more stimulated than normal fibroblasts at 0.1 microgram/ml and then more inhibited at 10 micrograms/ml. The fibroblasts from uninvolved psoriatic skin displayed intermediate responses. There was some cytotoxicity in cultures of the psoriatic cells at 10 micrograms/ml. The results demonstrate a further abnormality of fibroblasts from psoriatic skin.