Interleukin-33 levels in gingival crevicular fluid, saliva, or plasma do not differentiate chronic periodontitis

Background: This study investigates whether gingival crevicular fluid (GCF), saliva, and plasma levels of interleukin‐33 (IL‐33) can differentiate individuals with chronic periodontitis from individuals with healthy periodontium. Methods: GCF, whole saliva, and plasma samples together with full‐mouth clinical periodontal recordings were obtained from 32 otherwise healthy, non‐smoker chronic periodontitis individuals and 25 systemically and periodontally healthy, non‐smoker individuals. IL‐33 levels in the biofluid samples were determined by enzyme‐linked immunosorbent assay. Data were tested statistically by Mann‐Whitney U test. Results: The GCF concentrations of IL‐33 were significantly lower in chronic periodontitis individuals than in healthy individuals (P <0.0001), whereas the total amounts in GCF samples were similar (P >0.05). The salivary and plasma contrations of IL‐33 were indifferent in the two study groups (P >0.05). Conclusions: According to the present findings, the GCF, saliva or plasma levels of IL‐33 could not differentiate chronic periodontitis individuals and periodontally healthy individuals. Larger‐scale intervention studies may better clarify this issue.