[Apheresis in dermatologic diseases].

This report discusses the different types of apheresis used to treat skin diseases and focuses specifically on photopheresis or ECP (extracorporeal photochemotherapy). ECP is a systemic immunomodulatory therapy used successfully to treat many different, mainly autoimmune diseases such as cutaneous T-cell lymphomas, graft-versus-host disease, systemic sclerosis, atopic dermatitis, and pemphigus vulgaris. It has also proved effective against graft rejection after transplant. The exact mechanism by which the ECP performs its therapeutic activity is not yet entirely clear. However, at least 2 mechanisms have been identified that may explain the therapeutic effect. Firstly, ECP is able to induce downregulation of the self-allogeneic immune response that occurs in graft-versus-host disease, systemic sclerosis and atopic dermatitis, and secondly, it can stimulate an immune response against the neoplastic clones in patients with cutaneous T-cell lymphomas. At the Dermatology Clinic of the University of Siena, more than 100 patients with different immune-mediated diseases were treated with ECP. The results obtained are very interesting and our 20 years of experience confirm that the treatment is well tolerated. ECP can therefore be considered of great utility in the modulation of the immune system.