Prolonged systemic administration of cyclosporin A affects gingival epithelium

Gingival biopsies were obtained from 12 patients suffering from Behcet's disease who were treated with Cyclosporin A (CsA) for up to 20 months. Preparations were made for examination with both light and scanning electron microscopy (SEM). Along with known changes in the gingival epithelial structure observed following CsA treatment, we also found unusual clusters of needle-like crystallites embedded in the epithelium, mostly at the base of the acanthotic projections. Toluidin blue staining revealed increased numbers of both intact and degranulated mast cells in the attached epithelium. It is concluded that CsA affects the gingival epithelium and that the clinically observed enlargement of gingival tissue following prolonged treatment with CsA is due primarily to CsA-epithelial interaction.