Immunohistochemical analysis of epidermal growth factor receptor in cyclosporin A-induced gingival overgrowth.

Cyclosporin A (CsA)induced gingival overgrowth represents a tissue of fibrosis and epidermal growth factor (EGF) has been shown to induce extracellular matrix synthesis by fibroblasts. The purpose of this study was to evaluate the expression of EGF-receptor (EGF-r) in frozen sections of CsA-induced overgrown gingival tissue using immunohistochemical and semiquantitative techniques. Gingival biopsies were obtained from 12 renal transplant patients receiving CsA as well as 9 systemically and periodontally healthy individuals. Immunohistochemical staining procedures were carried out in frozen sections of gingival tissue and the expression of EGF-r was compared between the two study groups. The expression of EGF-r was more pronounced in the oral gingival epithelium of CsA-induced overgrown gingiva as compared to those of the clinically healthy gingival specimens. The reactivity in the inflammatory infiltrate and connective tissue cells of both of the study groups was similar. In conclusion, the results of the present study may suggest that CsA affects EGF-r metabolism in gingival keratinocytes resulting in an increased number of cell surface receptors, which may eventually play a role in the pathogenesis of gingival tissue alterations.