Relationship between cytokine levels in serum and gingival crevicular fluid (GCF) in pregnant women

Background: Periodontal disease has been linked to systemic diseases/disorders and a low-grade systemic inflammatory status originated from periodontitis has been proposed as a possible explanation for this association. This study evaluates the relationship, early in pregnancy, between gingival crevicular fluid (GCF) and serum levels of a panel of cytokines that have been implicated in PTB and periodontal disease. Methods: One hundred pregnant women aged 18-35. years old with a gestational age up to 20. weeks were included (mean ± SD gestational age:16.1 ± 3.5. weeks). Four periodontal sites per subject were randomly selected for GCF collection. Serum and GCF levels of IL-1β, IL-6, IL-8, IL-10, IL-12p70 and TNF-α were analyzed using a cytometric bead array. Regression and correlation analyses were used to assess the relationship between serum and GCF cytokine levels. Results: Participants had widespread periodontal inflammation but limited periodontal destruction. Cytokine levels were significantly higher in GCF than serum for all cytokines but IL-10. GCF levels had small but significant effect on serum levels for IL-10 (β= 0.34 ± 0.09, p< 0.01), IL-12p70 (β= 0.48 ± 0.08, p< 0.01) and TNF-α (β= 0.29 ± 0.09, p< 0.01). Periodontal probing depth and bleeding on probing were significantly associated with GCF levels for IL-1β, IL-6 and IL-8; however, they had negligible effect on serum cytokine levels. Correlation between GCF and serum levels was non-significant, except for IL-12p70, which showed a significant but small correlation between the two sources (r= 0.32, p= 0.001). Conclusions: GCF cytokine levels were not strongly associated with serum cytokine levels in pregnant women with widespread periodontal inflammation but limited periodontal destruction.