Studies on onset and lesion characteristics of periodontitis

Will early forms of periodontitis in childhood predict future risk for severe periodontitis? At what age may onset of periodontitis be detected in subjects with severe periodontitis? Are there differences in cell composition between lesions representing longstanding gingivitis and severe periodontitis? In study I, 11 children (7–13 years) with localized aggressive periodontitis (LAP) were re-examined after 14-19 years. While bleeding on probing was a general finding in the group, only two of the subjects exhibited recurrence of disease with probing pocket depth ≥ 6mm and 3-4 mm of bone loss at several teeth. The age of onset of disease in 42 patients, 30-45 years of age, diagnosed with severe, generalized periodontitis was assessed in study II. The earliest age at which a radiographic examination revealed distance between the cement-enamel junction (CEJ) and alveolar bone crest (BC) ≥ 3 mm (F3) at any site was recorded, as well as the highest patient age at which a radiographic examination revealed absence of sites with CEJ-BC ≥ 3 mm (L0). Onset of disease, i.e. the interval between L0 and F3, occurred on the average between 22 and 28 years. In study III and IV differences between lesions representing longstanding gingivitis and severe periodontitis were analyzed. Gingival biopsies were collected and prepared for histological examination and RT-qPCR analysis. Periodontitis lesions were twice as large as gingivitis and contained significantly larger proportions and higher numbers of plasma cells and macrophages than gingivitis lesions. T cells were not the dominating cell type in gingivitis lesions, as B cells together with their subset plasma cells comprised a larger number and proportion than T cells. In addition, the total number and density of IL-17 producing T cells were larger and expression of IL-17mRNA was higher in periodontitis than in gingivitis lesions. Conclusions: Children treated for LAP do not always exhibit recurrence of periodontitis in the absence of supportive periodontal therapy over periods of 14–19 years. Disease in the current sample of 30-45 year-old subjects with severe, generalized periodontitis, commenced mainly between 22 and 28 years of age. Large number and high density of plasma cells are the hallmarks of advanced periodontitis lesions and the most conspicuous difference in relation to longstanding gingivitis lesions. IL-17 producing T cells represent a significant feature in the detection of differences between destructive and non-destructive lesions

The neutrophil subset defined by CD177 expression is preferentially recruited to gingival crevicular fluid in periodontitis

In recent years, the concept of distinct subpopulations of human neutrophils has attracted much attention. One bona fide subset marker, exclusively expressed by a proportion of circulating neutrophils in a given individual, and therefore dividing neutrophils in two distinct subpopulations, is the glycoprotein CD177. CD177 is expressed on the plasma and granule membranes of 0-100% of circulating neutrophils depending on the donor. Several in vitro studies have linked CD177 to neutrophil transmigration, yet very few have looked at the role of CD177 for tissue recruitment in vivo. We investigate whether the CD177(+)and CD177(-)neutrophil subsets differ in their propensity to migrate to both aseptic- and microbe-triggered inflamed human tissues. Microbe-triggered neutrophil migration was evaluated in samples of gingival crevicular fluid (GCF) from patients with periodontitis, whereas neutrophil migration to aseptic inflammation was evaluated in synovial fluid from patients with inflammatory arthritis, as well as in exudate from experimental skin chambers applied on healthy donors. We found that the proportion of CD177(+)neutrophils was significantly higher in GCF from patients with periodontitis, as compared to blood from the same individuals. Such accumulation of CD177(+)neutrophils was not seen in the two models of aseptic inflammation. Moreover, the proportion of CD177(+)neutrophils in circulation was significantly higher in the periodontitis patient group, as compared to healthy donors. Our data indicate that the CD177(+)neutrophil subset is preferentially recruited to the gingival crevice of periodontitis patients, and may imply that this subtype is of particular importance for situations of microbe-driven inflammation.Funding Agencies|Swedish Research CouncilSwedish Research Council [201600982]; Swedish Heart-Lung FoundationSwedish Heart-Lung Foundation [20180218]; King Gustaf V Memorial Foundation [FAI-2017-0368]; Patent Revenue Fund Research in Preventive Odontology; Swedish state under the TUA agreement [TUAGBG-628751]</p