IL-12 and IL-18 levels in serum and gingival tissue in aggressive and chronic periodontitis

Objective: The aim of this study was to compare the levels of interleukin-12 (IL-12) and IL-18 in gingival tissue and serum between patients with chronic (n = 18) or aggressive periodontitis (n = 12) and healthy subjects (HS) (n = 9). Methods: Gingival tissue biopsies and serum were obtained from all study subjects. The tissue was homogenized and cytokines IL-12 and IL-18 were quantified by enzyme-linked immunosorbent assay. Results: Interleukin-12 levels in gingival tissue were significantly higher in aggressive periodontitis patients than in HS; serum IL-12 was significantly elevated in aggressive periodontitis relative to both chronic periodontitis (CP) and HS. IL-18 levels in gingival tissue showed no significant differences between the groups. Patients with CP showed significantly elevated levels of serum IL-18 compared with HS; however, the aggressive periodontitis group showed no significant differences with either the CP group or the HS. Conclusions: Our results showed higher levels of IL-12 in gingival tissue and serum of patients with aggressive periodontitis, and IL-18 was elevated in the serum of CP patients. The patterns of IL-12 and IL-18 are different in chronic and aggressive periodontitis; this finding suggests distinctive mechanisms of immunopathogenesis between these forms of periodontitis.