Gingival crevicular interleukin‐1 and interleukin‐1 receptor antagonist levels in periodontally healthy and diseased sites

Abstract

Interleukin‐l (IL‐1) molecules, IL‐lα and IL‐lβ are cytokines involved in the acute‐phase response against infection and in the pathogenesis of periodontal destruction. Administration of exogenous IL‐1 receptor antagonist (IL‐1ra) is effective in reducing the inflammatory reactions mediated by IL‐1. However, the relationship between these three naturally occurring IL‐1 molecules and periodontal diseases has been poorly characterized. We investigated the correlation of gingival crevicular IL‐1 molecules and the clinical status of patients with different severities of periodontitis. IL‐lα, IL‐1β, IL‐1ra and the total IL‐1/IL‐1ra ratio (IL‐1 activity index; IL‐1AI) were measured in 75 gingival crevicular fluid (GCF) samples from non‐inflamed gingiva sites in 2 healthy subjects and diseased sites in 7 patients with several types of periodontitis. IL‐lα, IL‐1bT and IL‐1ra were measured by specific non‐cross‐reactive enzyme linked immunosorbent assay. The probing depth, gingival index and alveolar bone loss of each site was recorded at the time of GCF sampling. The total amount of IL‐lα, IL‐1β and the IL‐1AI, but not total IL‐1ra, were found to be correlated with alveolar bone loss score. Three IL‐1 molecules were also measured in the gingival tissue of patients with periodontitis. A similar progressive decrease of the IL‐1AI was detected in gingival tissue with periodontitis. These results suggest that the amounts of both crevicular IL‐1 and IL‐1AI are closely associated with periodontal disease severity.