Fc gamma-receptors in skin and serum from patients with psoriasis, before and after therapy

Abstract

IgG-Fc receptors (FcR) are present on most immune competent cells. We have examined FcR in skin lesions from 8 patients with stationary plaque psoriasis and 12 patients with highly active psoriasis using MoAbs against FcR and binding of soluble immune complexes. FcR in serum were measured in ELISA. The patients were treated with cyclosporin (n = 5), acitretin (n = 7) and Goeckerman regimen (n = 8). As controls served 8 skin biopsies and 22 sera from healthy individuals. Highly active psoriatic lesions showed strongest activity for FcRI, II and III and immune complex binding. The FcR+ mononuclear cells were located perivascularly and along the dermo-epidermal junction. The FcR activity decreased in correlation to the improvement following therapy. Epidermal Langerhans cells (LC) were positive for FcRII and immune complex binding. FcR activity on LC decreased during therapy. Keratinocytes expressed FcRI and III, irrespective of disease activity and therapy. FcR levels were lower in sera from psoriatics than in controls, median 0.15 vs. 0.27 (p < 0.01), and not correlated to disease activity. In 4 patients the FcR levels increased during therapy. The reduced levels of FcR in psoriatic sera might be due to consumption in the skin or anti-FcR autoantibodies.