In vitro migration of human mononuclear cells towards a psoriatic scale extract

Extracts of psoriatic scales from patients with chronic plaque psoriasis and of normal human post-mortem skin were tested for their effects on the migration of healthy human mononuclear cells in a modified Boyden chamber. A preparation of cells containing 12-32% monocytes was obtained from whole blood by a density gradient technique. The cells were allowed to migrate through a polycarbonate filter towards various dilutions of the two types of extract, a known chemoattractant or towards buffer alone. There was enhancement of migration towards psoriasis scale extract, with significant differences only at the stronger concentrations tested. The results suggest that scales taken from stable plaque psoriasis contain an extractable water-soluble factor which stimulates the movement of peripheral blood mononuclear cells.