[Study of filaggrin in psoriasis].

Filaggrin is a histidine-rich basic protein that aggregates keratin filaments in fully differentiated cells of the epidermis. Filaggrin is synthesized in the granular cell layer as a high-Mr phosphorylated precursor, profilaggrin, that is processed to form the lower-Mr product present in cornified cells. The catabolism of filaggrin in stratum corneum produces urocanic acid and carboxylic-pyrrolidone acid that, respectively, absorb UV radiations and support cutaneous hydratation. In this study we evaluated by direct-immunofluorescence and by immunoperoxidase staining using rabbit antihuman filaggrin antiserum localization of filaggrin in psoriatic skin and in normal human skin before and after treatment with anthralin 0.1%, betamethasone 0.05% and hydrocolloid dressing. Antiserum against human filaggrin reacted with tissue sections of normal human skin, staining cells in the granular layer and in the stratum corneum, while no staining of human psoriatic skin sections was observed. After treatments, filaggrin resulted present in those psoriatic skin sections that showed complete clinical remission, while it was not observed in psoriatic patches which did not clear. These studies suggest that human skin filaggrin can be considered a marker of clinical remission of psoriasis.