The long-term effect of periodontitis treatment on changes in blood inflammatory markers in patients with generalized aggressive periodontitis

BACKGROUND

Periodontitis is characterized by local inflammatory conditions in the periodontium, its severe form has been associated with elevated systemic inflammatory markers. However, the long-term effects of periodontal inflammation control on systemic inflammatory markers are unclear.

OBJECTIVE

This study aimed to investigate the long-term effects of periodontal therapy on the levels of peripheral venous blood inflammatory markers in patients with generalized aggressive periodontitis (GAgP), all of whom were now diagnosed as Stage III or IV Grade C periodontitis.

METHODS

Patients with GAgP were consecutively recruited from April 2013 to August 2014 (T0). Active periodontal treatment (APT) was provided, and follow-ups were conducted over a 3- to 5-year period (T1). Clinical parameters were assessed and fasting venous blood was collected at T0 and T1. Complete blood cell counts were obtained, and biochemical analyses were performed to evaluate the levels of serum components. The correlations between probing depth (PD) and hematological parameters were analyzed.

RESULTS

A total of 49 patients with GAgP completed APT and follow-ups. Probing depth (PD) reduced from 5.10 ± 1.07 mm at T0 to 3.15 ± 0.65 mm at T1. For every 1-mm reduction in PD after treatment, the neutrophil count, neutrophil-lymphocyte ratio, and total protein concentration were reduced by 0.33 × 109/L, 0.26, and 1.18 g/L, respectively. In contrast, the albumin/globulin ratio increased by 0.10.

CONCLUSION

This study indicated that periodontal therapy may have beneficial effects on peripheral venous blood inflammatory markers in patients with GAgP during long-term observation.

J-shaped association between systemic immune-inflammation index and periodontitis: Results from NHANES 2009-2014

BACKGROUND

To examine the relationship between the systemic immune-inflammation index (SII) and periodontitis and to investigate possible effect modifiers.

METHODS

Data used in the present cross-sectional study are from the National Health and Nutrition Examination Survey (NHANES) 2009-2014 (N = 10,301). The SII was calculated using the following formula: (neutrophils count × platelet count)/lymphocytes count. The category of periodontitis was defined by the Centers for Disease Control and Prevention and American Academy of Periodontology (CDC/AAP) classification. We employed natural cubic spline and multivariable logistic regression analyses to evaluate the associations of the SII with periodontitis.

RESULTS

The associations between SII and periodontal health followed a J-shape (p < 0.001). The risk of periodontitis tended to reduce with the increment of log2(SII) in participants with log2(SII) ≤ 8.66 (odds radio [OR] = 0.83; 95% CI: 0.69-0.999), especially among non-Hispanic Whites (OR = 0.70; 95% CI: 0.52-0.95), and increased with the increment of log2(SII) in participants with log2(SII) > 8.66 (OR = 1.19; 95% CI: 1.02-1.38). A similar trend was also observed between the SII and the number of sites with probing pocket depth (PPD) ≥4 mm and clinical attachment loss (CAL) ≥ 3 or 5 mm. Furthermore, we found a significantly stronger correlation between lymphocytes and either neutrophils or platelets in individuals with log2(SII) > 8.66, as opposed to those with log2(SII) ≤ 8.66.

CONCLUSIONS

There is a J-shaped association between SII and periodontitis in US adults, with an inflection point of log2(SII) at 8.66, which may provide potential adjunctive treatment strategies for periodontitis with different immune response states. Further prospective trials are still required to confirm our findings.

PI3Kγ controls IL-17A expression and attenuates alveolar bone loss in an experimental periodontitis model

OBJECTIVE

In this study, we investigated the modulatory effects of PI3Kγ on IL-17A expression and the progression of experimental periodontitis in vivo.

METHODS

Ligature-induced periodontitis was developed around the first molar of mice. Animals were treated with anti-mouse IL-17A or IPI-549 (PI3Kγ inhibitor). In addition, PI3Kγ-deficient mice (PI3Kγ^-/-) were used in the study. Alveolar bone loss was measured and real-time PCR of Il17a and Rankl genes was performed. A bioinformatics analysis was carried out using the Gene Set Enrichment Analysis computational tool.

RESULTS

Nine days after ligature placement, alveolar bone loss scores were significantly increased, with upregulation of Il17a and Rankl genes in the gingival tissues. Treatment with anti-mouse IL-17A (100 µg/mice) significantly attenuated alveolar bone loss. Mice with ligature-induced periodontitis treated with IPI-549 (3 mg/kg) or PI3Kγ^-/- mice showed reduced alveolar bone loss and downregulation of Il17a and Rankl gene expression in the gingival tissues. Consistent with this, the bioinformatics analysis showed upregulation of IL17F, IL17A, IL17D, and STAT3 genes, as well as greater activation of IL-17 and PI3KCI pathways (upregulation of PIK3CG gene) in the gingival tissue of patients with periodontitis.

CONCLUSION

PI3Kγ plays an important role in modulating IL-17A expression and alveolar bone loss in vivo and can be considered a promising pathway for the management of periodontal disease and the development of new therapies.

Platelet factor 4 (CXCL4/PF4) upregulates matrix metalloproteinase-2 (MMP-2) in gingival fibroblasts

Periodontitis is a chronic inflammatory disease characterized by the release of matrix metalloproteinases (MMPs) from resident connective tissue cells in tooth-supporting tissues (periodontium). Platelet activation, and the attendant release of pro-inflammatory chemokines such as platelet factor 4 (CXCL4/PF4), are associated with periodontitis although the associated biochemical pathways remain undefined. Here we report that recombinant PF4 is internalized by cultured human gingival fibroblasts (hGFs), resulting in significant (p < 0.05) upregulation in both the production and release of MMP-2 (gelatinase A). This finding was corroborated by elevated circulating levels of MMP-2 (p < 0.05) in PF4-overexpressing transgenic mice, relative to controls. We also determined that PF4 induces the phosphorylation of NF-κB; notably, the suppression of NF-κB signaling by the inhibitor BAY 11-7082 abrogated PF4-induced MMP-2 upregulation. Moreover, the inhibition of surface glycosaminoglycans (GAGs) blocked both PF4 binding and NF-κB phosphorylation. Partial blockade of PF4 binding to the cells was achieved by treatment with either chondroitinase ABC or heparinase III, suggesting that both chondroitin sulfate and heparan sulfate mediate PF4 signaling. These results identify a novel pathway in which PF4 upregulates MMP-2 release from fibroblasts in an NF-κB- and GAG-dependent manner, and further our comprehension of the role of platelet signaling in periodontal tissue homeostasis.

Application of Ligature-Induced Periodontitis in Mice to Explore the Molecular Mechanism of Periodontal Disease

Periodontitis is an inflammatory disease characterized by the destruction of the periodontium. In the last decade, a new murine model of periodontitis has been widely used to simulate alveolar bone resorption and periodontal soft tissue destruction by ligation. Typically, 3-0 to 9-0 silks are selected for ligation around the molars in mice, and significant bone loss and inflammatory infiltration are observed within a week. The ligature-maintained period can vary according to specific aims. We reviewed the findings on the interaction of systemic diseases with periodontitis, periodontal tissue destruction, the immunological and bacteriological responses, and new treatments. In these studies, the activation of osteoclasts, upregulation of pro-inflammatory factors, and excessive immune response have been considered as major factors in periodontal disruption. Multiple genes identified in periodontal tissues partly reflect the complexity of the pathogenesis of periodontitis. The effects of novel treatment methods on periodontitis have also been evaluated in a ligature-induced periodontitis model in mice. This model cannot completely represent all aspects of periodontitis in humans but is considered an effective method for the exploration of its mechanisms. Through this review, we aimed to provide evidence and enlightenment for future studies planning to use this model.

Identification of the different salivary Interleukin-6 profiles in patients with periodontitis: A cross-sectional study

OBJECTIVE

The aim of this study was to analyze and identify the association among salivary interleukin-6 (IL-6) levels and periodontitis (PT) and to determine the significant trend of this association in PT patients.

STUDY DESIGN

For the present study, 49 patients with PT and 47 healthy subjects (HS) were enrolled and assessed for clinical parameters, blood samples and salivary IL-6 analyses. Clinical differences among groups were recorded and evaluated. The Spearman Correlation and the Jonckheere-Terpstra Test were applied in order to assess the interdependence between salivary IL-6 and PT.

RESULTS

Patients in the PT group had significantly higher median salivary IL-6 levels [195.4 (184.6-205.9 pg/mL)] compared to the HS group [101.9 (89.5-115.4 pg/mL) (p < 0.001). Salivary IL-6 levels were negatively correlated with C-reactive protein, with the number of teeth and with clinical attachment loss (CAL), probing pocket depth (PPD), and bleeding sites (FMBS) (p < 0.001). Furthermore, in patients with PT, salivary IL-6 levels were inversely associated (P-trend) with the number of teeth (p < 0.001), and directly associated with the proportional extent of PT (CAL, p = 0.006; PPD, p = 0.009; FMBS, p < 0.001).

CONCLUSIONS

The results of this study showed that PT patients presented significant higher salivary IL-6 levels compared to HS. Moreover, in the analyzed sample a significant p-trend among PT, tooth loss and increased salivary IL-6 levels was found.