Local and Plasma Biomarker Profiles in Localized Aggressive Periodontitis

Localized aggressive periodontitis (LAP) patients possess a systemic hyperinflammatory response after lipopolysaccharide stimulation. However, the levels of inflammatory and bone biomarkers in plasma, as well as possible associations between local and plasma biomarkers, are unknown in LAP. This cross-sectional study aimed to characterize gingival crevicular fluid (GCF) and plasma biomarker profiles in LAP patients, their healthy siblings (HS), and healthy unrelated controls (HC). Fifty-eight LAP subjects, 33 HS, and 49 HC (African Americans, aged 5 to 25 y) were included. Following collection of clinical parameters with GCF and plasma samples, levels of 16 inflammatory and bone resorption biomarkers were determined with Milliplex. Univariate and correlation analyses were performed among all clinical and laboratorial parameters. Discriminant analyses were used to investigate groups of biomarkers discriminating LAP from HS and HC in GCF and plasma. GCF levels of multiple cytokines and chemokines and RANKL:OPG ratio (receptor activator of nuclear factor kappa-B ligand:osteoprotegerin) were higher in LAP disease, most of which positively correlated with probing depth and attachment loss of sampled sites. A group of IL-12p40, IL-6, IL-12p70, IL-2, and MIP-1α discriminated LAP diseased sites from twheir healthy sites, as well as from HS and HC healthy sites. In plasma, only RANKL levels were increased in LAP versus controls, which positively correlated with the percentage of affected sites and deep/bleeding sites. A plasma inflammatory profile including MIP-1α, IL-8, IL-10, and INF-γ could significantly discriminate LAP patients from HS and HC. No correlations were found between GCF and plasma levels of biomarkers. In conclusion, an inflammatory profile including groups of specific biomarkers in GCF and plasma may significantly discriminate LAP from healthy individuals. The hyperinflammatory response previously found in the peripheral blood of LAP patients is dependent on lipopolysaccharide stimulation, apparently resulting mostly in local tissue destruction and changes in biomarker profile, with a slight influence in the systemic inflammatory profile (ClinicalTrials.gov NCT01330719). Knowledge Transfer Statement: The results of this study can be possibly used by clinicians in the future as diagnostic tools for localized aggressive periodontitis. Thus, in the future, with proper consideration of cost, patient preference, chair-side feasibility and ultimately further studies validating the role of GCF markers for disease progression and response to treatment, this information could lead to more appropriate therapeutic decisions and the development of preventive approaches for susceptible patients.