Absence of IL-1 inhibitor in psoriatic scale extracts.

In the previous report we found that IL-1-like activity in horny tissue extracts from patients with psoriasis vulgaris and related sterile pustular dermatoses was remarkably low as compared to that in orthokeratotic horny tissue extracts prepared from non-inflammatory skin. In this report we studied the inhibitory activity of lesional horny tissue extracts from three psoriatics on recombinant IL-1-induced thymocyte proliferation in order to search for a possible coexistence of substances which may inhibit thymocyte proliferation. However, we failed to demonstrate any remarkable IL-1 inhibitory activity in each fraction after gel filtration high-performance liquid chromatography of the psoriatic scale extracts or in that of extracts from the plantar callus. We conclude that IL-1 stores are decreased in the pathologic horny layers of psoriatic lesions.