Soluble Triggering Receptor Expressed on Myeloid Cells 1 (sTREM-1) in Gingival Crevicular Fluid: Association With Clinical and Microbiologic Parameters

Background: Soluble triggering receptor expressed on myeloid cells 1 (sTREM-1) belongs to the immunoglobulin superfamily and is involved in amplification of the inflammatory response to bacterial infection. This cross-sectional study aims to investigate the levels of sTREM-1 in gingival crevicular fluid (GCF) of individuals without periodontitis and with chronic periodontitis (CP) or generalized aggressive periodontitis (GAgP) and their association with the levels of key periodontal pathogens in subgingival plaque. Methods: GCF and subgingival plaque samples were obtained from healthy sites of participants without periodontitis (n = 20) and periodontitis sites of patients with CP (n = 22) and GAgP (n = 20). sTREM-1 levels in GCF were measured by enzyme-linked immunosorbent assay. Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, and Aggregatibacter actinomycetemcomitans levels in subgingival plaque were analyzed by quantitative real-time polymerase chain reaction. Results: sTREM-1 levels in GCF were higher in CP and GAgP than healthy sites by 3.6- and 4.4-fold, respectively, with no significant differences between the two forms of periodontitis. Moreover, sTREM-1 levels in GCF were positively correlated with site-specific clinical periodontal parameters and levels of P. gingivalis, T. denticola, and T. forsythia, but not A. actinomycetemcomitans, in subgingival plaque. Conclusion: Increased GCF levels of sTREM-1 at diseased sites and their positive correlation with clinical and microbiologic parameters strengthen the association of this inflammatory marker with periodontitis.