Significance of elevated gingival crevicular fluid tumor necrosis factor-α and interleukin-8 levels in chronic hemodialysis patients with periodontal disease

Abstract
The prevalence of chronic renal disease in industrialized countries is increasing, and chronic renal disease and periodontitis can have significant, reciprocal effects. The aim of this study was to evaluate the associations between specific clinical parameters and the levels of tumor necrosis factor-alpha (TNF-alpha) and interleukin-8 (IL-8) in the gingival crevicular fluid of hemodialysis (HD) patients with periodontal disease. Forty-three HD patients and 43 systemically healthy subjects were enrolled in this study. Plaque index (PI), gingival index (GI) and pocket depth were used to determine periodontal status. Venous blood samples were obtained from each patient in the morning before the dialysis session and analyzed to determine the levels of inflammatory, biochemical and hematological parameters. Gingival crevicular fluid was collected from all subjects, and the levels of TNF-alpha and IL-8 were determined in the gingival crevicular fluid samples. The following results were obtained from HD patients and controls: TNF-alpha (pg/mL), 31.40 +/- 1.46 and 3.06 +/- 0.15 (p < 0.001); IL-8 (pg/mL), 90.98 +/- 94.03 and 35.05 +/- 16.86 (p < 0.001); PI, 1.69 +/- 1.02 and 0.04 +/- 0.02 (p < 0.001); GI, 0.82 +/- 0.06 and 0.04 +/- 0.02 (p < 0.001); and pocket depth, 2.23 +/- 0.63 and 1.51 +/- 0.05 (p < 0.001), respectively. In addition, there were positive correlations between TNF-alpha and PI (r = 0.642, p < 0.001), between TNF-alpha and GI (r = 0.565, p < 0.001), between TNF-alpha and pocket depth (r = 0.522, p < 0.001), between IL-8 and PI (r = 0.402, p = 0.002), between IL-8 and GI (r = 0.396, p = 0.002), and between IL-8 and pocket depth (r = 0.326, p = 0.012). There were negative correlations between albumin and PI (r = -0.491, p < 0.001), albumin and GI (r = -0.406, p < 0.001), albumin and pocket depth (r = -0.464, p < 0.001) and albumin and CRP (r = -0.467, p = 0.002) and between the gingival crevicular fluid levels of TNF-alpha and IL-8, TNF-alpha and hemoglobin (r = -0.745, p < 0.001; r = -0.285, p < 0.05) (respectively). The levels of TNF-alpha and IL-8 in gingival crevicular fluid were significantly higher in HD patients than in controls. There were strong, positive correlations between clinical periodontal parameters and the levels of inflammatory cytokines in gingival crevicular fluid from the HD patients.