Interleukin-1 and IL-1 receptor antagonist in gingival crevicular fluid

BACKGROUND/AIMS: This study aimed to investigate the cytokine IL-1beta and its receptor antagonist IL-1ra in gingival crevicular fluid (GCF), in patients with adult periodontitis. METHOD: A total of 40 GCF samples were harvested from 10 subjects with moderate to severe adult periodontitis and 10 healthy controls. Subjects were selected from both genders, with all the upper anterior teeth present, and with no relevant systemic illness, pregnancy or recent medication. All subjects were non-smokers and had not received any periodontal therapy within the preceding 3 months. Deep bleeding sites, deep non-bleeding sites and healthy sites were investigated in relation to upper anterior teeth. Clinical measurements were recorded for each site, after obtaining a GCF sample. IL-1beta and IL-1ra were quantified using new commercially available ELISA kits (Quantikine), and could be detected in all samples. RESULTS: The mean concentration for IL-1beta was 0.11 (SD 0.14) pg/microl for bleeding periodontitis sites, 0.04 (0.05) pg/microl for non-bleeding periodontitis sites, and 0.01 (0.03) pg/microl for healthy sites (p<0.001). In contrast, the mean concentration for IL-1ra was 6.99 (9.78) pg/microl for healthy sites, 0.59 (0.44) pg/microl for non-bleeding periodontitis sites, and 0.44 (0.36) pg/microl for bleeding periodontitis sites (p<0.001, except for comparisons between bleeding and non-bleeding periodontitis sites, p>0.05). For healthy sites, a strong inverse relationship was found between IL-1beta and IL-1ra levels in GCE. CONCLUSIONS: The results suggest a strong relationship between the severity of adult periodontitis and the increasing GCF levels of IL-1beta and decreasing levels of IL-1ra.