Matrix metalloproteinases (MMP-8 and -9) and neutrophil elastase in gingival crevicular fluid of cyclosporin-treated patients

BACKGROUND: Gingival overgrowth (GO) is one of the most important side effects of cyclosporin A (CsA) medication, but its pathogenesis is not completely understood. The aim of this study was to identify and compare collagenase-2 (MMP-8), gelatinase-B (MMP-9), and neutrophil (PMN)-elastase levels in gingival crevicular fluid (GCF) from 15 renal transplant patients receiving CsA therapy and exhibiting CsA GO, 14 patients with gingivitis, and 10 periodontally healthy subjects. METHODS: Clinical data were obtained on plaque index, papilla bleeding index, and hyperplastic index from each site studied. GCF samples and clinical data were collected 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. CsA GO+ and CsA GO- sites were divided into 2 subgroups as clinically not inflamed (PBI = 0) and inflamed (PBI > or =1). GCF MMP-8, MMP-9, and PMN-elastase levels were analyzed by immunofluorometric assay. RESULTS: GCF MMP-8 and -9 levels and clinical degrees of gingival inflammation in CsA GO+ sites were similar to those in diseased sites. However, GCF elastase levels were significantly lower in CsA GO+ sites compared to those in diseased sites. GCF MMP-8, -9 and PMN-elastase levels were not different between CsA GO- sites and healthy sites. Additionally, GCF MMP-8 and -9 levels in inflamed CsA GO+ sites were higher but not statistically significantly than those in diseased sites. In contrast, GCF PMN-elastase levels in inflamed CsA GO+ sites were significantly lower than the levels in diseased sites. CONCLUSIONS: These results show that CsA therapy does not have a significant effect on GCF MMP-8 and MMP-9 levels, but the gingival inflammation seems to be the main reason for their elevations. However, low GCF PMN-elastase levels can be an important factor in the pathogenesis of CsA-induced gingival overgrowth. CsA therapy does not eliminate the potential use of GCF MMP-8 and -9 as future diagnostic markers of gingival inflammation.