A Preliminary Study on the Ability of the Trypsin-Like Peptidase Activity Assay Kit to Detect Periodontitis

The association between trypsin-like protease activity in the oral cavity and kidney function in Japanese workers

AIM

To evaluate the association between trypsin-like protease (TLP) activity in the oral cavity as an indicator of periodontal health status and kidney function in Japanese workers.

MATERIALS AND METHODS

This cross-sectional study included 1117 Japanese workers (mean age = 43.8 years). Tongue-swab TLP activity was quantified as a* value (the redness intensity of the matrix disc of the TLP activity assessment kit; a larger value indicates more intense enzymatic activity in the samples and poorer periodontal health status). Kidney function was assessed using the estimated glomerular filtration rate (eGFR; a lower value indicates poorer kidney function). We performed ordinal logistic regression analyses to assess the association of the a* value with three eGFR categories: ≥90, 60-89 and <60 mL/min/1.73 m2 .

RESULTS

The prevalence for each eGFR category was as follows: ≥90 (31.6%), 60-89 (63.8%) and <60 mL/min/1.73 m2 (4.6%). After adjusting for potential confounders, the a* value was found to be significantly associated with reduced kidney function. The multivariable-adjusted odds ratio (95% confidence interval) for reduced kidney function was 1.12 (1.02-1.22) per unit increase in the a* value.

CONCLUSIONS

Higher TLP activity was associated with reduced kidney function in Japanese workers.

Therapeutic effect of aged garlic extract on gingivitis in dogs

Periodontal disease is one of the most common dental health problems in dogs. Clinical studies in humans have shown that aged garlic extract (AGE), which contains stable and water-soluble sulfur-containing bioactive compounds, improves the symptoms of periodontal diseases. Our previous study demonstrated that oral administration of AGE in healthy Beagle dogs at 90 mg/kg/day for 12 weeks had no adverse effects such as hemolytic anemia, which is well known to occur as a result of ingestion of Allium species, including onions and garlic, in dogs. However, the therapeutic potential of AGE in canine periodontal disease remains unclear. Accordingly, we investigated the therapeutic effects of AGE in Beagle dogs with mild gingivitis. Feeding 18 mg/kg/day of AGE for 8 weeks resulted in the improvement of gingival index score, level of volatile sulfur compounds in exhaled air, and enzyme activity of periodontal pathogens without any adverse effects on clinical signs and hematological and serum biochemical parameters. Moreover, AGE increased the concentration of salivary cathelicidin, an antimicrobial peptide that contributes to the oral innate immune response. These results suggest that AGE could be a potential therapeutic agent for canine gingivitis.

Uncovering the potential role of oxidative stress in the development of periodontitis and establishing a stable diagnostic model via combining single-cell and machine learning analysis

Background

The primary pathogenic cause of tooth loss in adults is periodontitis, although few reliable diagnostic methods are available in the early stages. One pathological factor that defines periodontitis pathology has previously been believed to be the equilibrium between inflammatory defense mechanisms and oxidative stress. Therefore, it is necessary to construct a model of oxidative stress-related periodontitis diagnostic markers through machine learning and bioinformatic analysis.

Methods

We used LASSO, SVM-RFE, and Random Forest techniques to screen for periodontitis-related oxidative stress variables and construct a diagnostic model by logistic regression, followed by a biological approach to build a Protein-Protein interaction network (PPI) based on modelled genes while using modelled genes. Unsupervised clustering analysis was performed to screen for oxidative stress subtypes of periodontitis. we used WGCNA to explore the pathways correlated with oxidative stress in periodontitis patients. Networks. Finally, we used single-cell data to screen the cellular subpopulations with the highest correlation by scoring oxidative stress genes and performed a proposed temporal analysis of the subpopulations.

Results

We discovered 3 periodontitis-associated genes (CASP3, IL-1β, and TXN). A characteristic line graph based on these genes can be helpful for patients. The primary hub gene screened by the PPI was constructed, where immune-related and cellular metabolism-related pathways were significantly enriched. Consistent clustering analysis found two oxidative stress categories, with the C2 subtype showing higher immune cell infiltration and immune function ratings. Therefore, we hypothesized that the high expression of oxidative stress genes was correlated with the formation of the immune environment in patients with periodontitis. Using the WGCNA approach, we examined the co-expressed gene modules related to the various subtypes of oxidative stress. Finally, we selected monocytes for mimetic time series analysis and analyzed the expression changes of oxidative stress genes with the mimetic time series axis, in which the expression of JUN, TXN, and IL-1β differed with the change of cell status.

Conclusion

This study identifies a diagnostic model of 3-OSRGs from which patients can benefit and explores the importance of oxidative stress genes in building an immune environment in patients with periodontitis.

The Ability of a Novel Trypsin-like Peptidase Activity Assay Kit to Detect Red-Complex Species

The trypsin-like peptidase activity assay kit measures the trypsin-like protease produced by three red-complex species, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola, causing periodontitis, and detects the presence of these bacteria in samples. The purpose of this study was to investigate the relationship between the detection of TLPs by a novel TLP-AA, ADCHECK and the detection of red-complex pathogens by real-time PCR using tongue swabs from patients with periodontitis. The detection limit of trypsin-like protease activity by ADCHECK was validated using the culture supernatants of two different Porphyromonas gingivalis bacterial strains. Real-time PCR was performed to determine the number of red-complex species in the tongue coatings of patients with periodontal disease. Trypsin-like protease activity in tongue-swab samples was scored using ADCHECK. ADCHECK successfully detected trypsin-like protease activity in 103 Porphyromonas gingivalis bacterial strains. The specificity, positive predictive value, negative predictive value, and accuracy of ADCHECK for the presence of red-complex pathogens determined by real-time PCR were 90%, 97%, 98%, and 92%, respectively. ADCHECK is an effective tool for the detection of red-complex pathogens.

The Association between Tannerella forsythia and the Onset of Fever in Older Nursing Home Residents: A Prospective Cohort Study

Background: Periodontal pathogens are related to the incidence of systemic diseases. This study aimed to examine whether periodontal pathogen burden is associated with the risk of fever onset in older adults. Methods: Older adults in nursing homes, aged ≥65 years, were enrolled. The study was set in Kitakyushu, Japan. The body temperatures of participants were ≥37.2 °C and were recorded for eight months. As periodontal pathogens, Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia were qualified by a real-time polymerase chain reaction at the baseline. For statistical analysis, the number of bacterial counts was logarithmically conversed to 10 as a base. Results: Data from 56 participants with a median age of 88 (62−98) years were available for analysis. The logarithmic-conversed bacterial counts of T. forsythia, but not P. gingivalis or T. denticola, were associated with the onset of fever in older residents. The Kaplan−Meier method revealed that the group with <104 of T. forsythia had significantly less cumulative fever incidence than the group with ≥104 of T. forsythia. The group with ≥104 of T. forsythia was associated with an increased risk of fever onset (hazard ratio, 3.7; 98% confidence interval, 1.3−10.2; p = 0.012), which was adjusted for possible confounders. Conclusions: Bacterial burden of T. forsythia in the oral cavity was associated with the risk of the onset of fever in older nursing homes residents.

Evaluation of the ability of the trypsin-like peptidase activity assay to detect severe periodontitis

Objectives

N-benzoyl-DL-arginine peptidase (trypsin-like peptidase) is specifically produced by certain strains of periodontitis-associated bacteria. We aimed to examine the effectiveness of an objectively quantified trypsin-like peptidase activity assay (TLP-AA) for detecting severe periodontitis.

Methods

The study population included 347 adults (108 men and 239 women; average age, 43.3 years) who underwent a full-mouth periodontal examination. Specimens for the TLP-AA were obtained using tongue swabs. Using a color reader, the TLP-AA results were obtained as a* values, with higher positive a* values indicating an increased intense enzymatic activity. The predictive validity of the TLP-AA results for severe periodontitis was assessed using receiver operating characteristic curve analysis and the periodontitis case definition provided by the Centers for Disease Control and Prevention/American Academy of Periodontology as the gold standard. Furthermore, multivariable logistic regression analyses were performed to predict severe periodontitis using the TLP-AA results and health characteristics, as the exposure variables.

Results

Severe periodontitis was observed in 5.2% of the participants. TLP-AA had high diagnostic accuracy for severe periodontitis, with an area under the curve of 0.83 (95% confidence interval [CI]: 0.75–0.92). The cut-off score for the a* value that best differentiated individuals with severe periodontitis was 0.09, with a sensitivity of 83% and specificity of 77%. Multivariable logistic regression analyses revealed that the TLP-AA results were significantly associated with severe periodontitis after adjusting for health characteristics (adjusted odds ratios: 1.90 [95% CI: 1.37–2.62] for the a* value).

Conclusions

Objectively quantified TLP-AA results are potentially useful for detecting severe periodontitis in epidemiological surveillance.

Validation of a self-report questionnaire for periodontitis in a Japanese population

We aimed to assess the validity of the self-report questionnaire for periodontitis in a Japanese population. A Japanese 9-item self-report questionnaire, developed by translating English-version questions that were used to detect periodontitis, was validated against full-mouth clinically-assessed periodontitis in 949 Japanese adults (average age = 43.2 years). Multivariable logistic regression modeling was used to calculate the area under the receiver operating characteristic curve (AUC), wherein the periodontitis case definition of the Centers for Disease Control and Prevention/American Academy of Periodontology was considered the gold standard. Severe, moderate, and mild periodontitis were identified in 6.2%, 30.0%, and 6.7% of the study population, respectively. Self-reported oral health questions combined with socio-demographic and health-related variables had an AUC > 0.70 (range, 0.71-0.87) for any periodontitis category. Four oral health questions ("have gum disease," "loose tooth," "lost bone," and "bleeding gums") were selected in the parsimonious model for severe periodontitis. The periodontitis screening score generated by the responses to these four questions had an AUC, sensitivity, and specificity of 0.82, 73.1%, and 74.3%, respectively, where the cut-off was set at 2 points. In conclusion, a locally adapted version of the self-report questionnaire had an acceptable diagnostic capacity for the detection of periodontitis in this study population.

The Chairside Periodontal Diagnostic Toolkit: Past, Present, and Future

Periodontal diseases comprise a group of globally prevalent, chronic oral inflammatory conditions caused by microbial dysbiosis and the host immune response. These diseases specifically affect the tooth-supporting tissues (i.e., the periodontium) but are also known to contribute to systemic inflammation. If left untreated, periodontal diseases can ultimately progress to tooth loss, lead to compromised oral function, and negatively impact the overall quality of life. Therefore, it is important for the clinician to accurately diagnose these diseases both early and accurately chairside. Currently, the staging and grading of periodontal diseases are based on recording medical and dental histories, thorough oral examination, and multiple clinical and radiographic analyses of the periodontium. There have been numerous attempts to improve, automate, and digitize the collection of this information with varied success. Recent studies focused on the subgingival microbiome and the host immune response suggest there is an untapped potential for non-invasive oral sampling to assist clinicians in the chairside diagnosis and, potentially, prognosis. Here, we review the available toolkit available for diagnosing periodontal diseases, discuss commercially available options, and highlight the need for collaborative research initiatives and state-of-the-art technology development across disciplines to overcome the challenges of rapid periodontal disease diagnosis.

Trypsin-Like Activity in Oral Cavity Is Associated with Risk of Fever Onset in Older Residents of Nursing Homes: An 8-Month Longitudinal Prospective Cohort Pilot Study

This study aimed to evaluate the association between trypsin-like activity in the oral cavity and the onset of fever in independent older residents of nursing homes. Independent older residents aged ≥ 65 years in 10 nursing homes were included in this study, which was conducted in Kitakyushu, Japan. For 8 months, follow-up dates on which the body temperatures of participants were more than 37.2 °C were noted. Trypsin-like activity in the oral cavity was detected by ADCHECK® with five-grade evaluation at baseline. Data from 53 independent participants with median age 89.0 (67–102) years were available for analysis. ADCHECK® scores were associated with fever days (r = 0.312, p = 0.029). The average periods until the onset of fever in participants with ADCHECK® Scores 1 and 2, Score 3, and Scores 4 and 5 were 6.6 ± 0.5, 5.0 ± 0.7, and 4.1 ± 1.0 months, respectively. ADCHECK® Scores 4 and 5 signified a higher risk of fever compared to ADCHECK® Scores 1 and 2 (hazards ratio 5.9, 95% confidence interval 1.4–23.9, p = 0.013), adjusted for possible confounders. We concluded that trypsin-like activity in the oral cavity was associated with the risk of fever in independent older residents of nursing homes.