Immunohistochemical study of cyclosporin-induced gingival overgrowth in renal transplant recipients

Background: Cyclosporin A (CsA) is an immunosuppressant widely used to treat transplant patients and various systemic diseases with immunological components. Gingival overgrowth (GO) is a common side effect of CsA administration; however, the pathogenesis of drug-induced GO is poorly understood. The aim of this study was to evaluate the expression of Ki-67, activation molecules (CD71, CD98), leukocytes activation antigens (CD45, CD45RA, CD50, CD11a, CD162, CD227, CD231), neurothelin (CD147), and novel endothelial cell antigens (B-F45, SCF87, B-D46, B-C44, VJ1/6) in gingival tissue in renal transplant recipients treated with CsA. Methods: Tissues from 15 renal transplant patients with significant GO and 10 systemically healthy control subjects with gingivitis were studied. Frozen-section biopsies were stained with monoclonal antibodies specific for the above-mentioned antigens using an indirect immunoperoxidase technique. Results: Comparison of the CsA-treated and control groups revealed no significant differences with respect to expression of Ki-67; CD50; activation molecules; neurothelin; or novel endothelial cell antigens B-D46, B-C44, and VJ1/6. However, expression patterns of CD45, CD45RA, CD11a, CD162, CD227, CD231, B-F45, and SCF87 were significantly different in CsA and control groups. Conclusion: Leukocyte activation antigens play an important role in CsA-induced gingival overgrowth.