Volume 71 • Number 1 Levels of Leukotriene B 4 and Platelet Activating Factor in Gingival Crevicular Fluid in Renal Transplant Patients Receiving Cyclosporine A Gülnur Emingil,* I¸ sil Çoker, † Gül Atilla,* and Afig Hüseyinov ‡ 50 Background: Cyclosporine A (CsA) is a potent immunosuppressant effectively used to prevent organ transplant rejection and also to treat several systemic diseases. CsA-induced gingival overgrowth (CsA GO) is the most widely seen side effect of this drug; its pathogenesis is not completely understood. The aim of the present study was to identify the role of leukotriene B 4 (LTB 4 ) and platelet activating factor (PAF) in the pathogenesis of CsA GO. Methods: LTB 4 and PAF levels were detected in gingival crevicular fluid (GCF) samples from renal trans- plant patients receiving CsA therapy and exhibiting CsA GO, from patients with gingivitis and from peri- odontally healthy subjects. Plaque index, papilla bleeding index, and hyperplastic index were recorded at each study site. GCF samples and clinical data were obtained from: 2 sites exhibiting CsA GO (CsA GO+) and 2 sites not exhibiting CsA GO (CsA GO-) in each CsA-treated patient; 2 diseased sites in each patient with gingivitis; and 2 healthy sites in each subject with clinically healthy periodontium. LTB 4 was extracted from the samples by solid-phase method using C 18 cartridge and purified by high-performance liquid chro- matographic (HPLC) method and analyzed by radioimmunoassay (RIA). PAF was extracted from GCF sam- ples passing through amberlit resin columns, purified by HPLC, and analyzed by RIA. Results: Total amounts of LTB 4 and PAF in GCF were higher in CsA GO+ sites compared to the healthy sites from healthy controls. However, the amount of LTB 4 and PAF elevation in CsA GO+ sites was not sig- nificantly higher than those in diseased sites. Clinical degrees of gingival inflammation were also similar between CsA GO+ and diseased sites. LTB 4 and PAF total amounts in GCF were higher in CsA GO+ sites compared to CsA GO- sites in the same subjects, but this difference just failed to reach significance. Sim- ilar findings were obtained with concentration data. Conclusions: The results of this study indicate that CsA therapy does not have a significant effect on GCF LTB 4 and PAF levels and that gingival inflammation seems to be the main reason for their elevation. In CsA-treated patients, alterations in LTB 4 and PAF levels might play a role in CsA GO through some as- yet unknown mechanism. To our knowledge, this is the first report describing the levels of lipid mediators in GCF of CsA-treated patients. We assume that further studies will contribute to the understanding of the pathogenesis of CsA-induced gingival overgrowth. J Periodontol 2000;71:50-57. KEY WORDS Cyclosporine A/adverse effects; lipid mediators; gingival crevicular fluid/analysis; gingival hyperplasia/pathogenesis; leukotriene; platelet activating factor. * Ege University, School of Dentistry, Department of Periodontology, Izmir, Turkey. † SSK Tepecik Hospital Yeni¸ sehir, Izmir, Turkey. ‡ Ege University, School of Medicine, Department of Pediatrics.