Correlation between salivary IL-1β levels and periodontal clinical status

Salivary IL-1β, IL-6, and IL-10 Are Key Biomarkers of Periodontitis Severity

To explore severity and progression biomarkers, we examined the clinical relevance of multiple cytokines and mediators involved in the inflammatory response in periodontitis. A cohort of 68 patients was enrolled in the study and periodontal status assessed by the current classification of periodontal diseases. Immune mediators present in saliva, of both patients and healthy controls, were quantified using a Legendplex-13 panel. Clinic parameters were significantly higher in PD patients compared with HC, with a strong significant association with the disease severity (stage) (p < 0.001), but not with progression (grade). The panel of immune mediators evidenced elevated levels of pro-inflammatory cytokines IL-6 and IL-1β as disease established (p < 0.01). IL-1β/IL-1RA ratio was increased in PD patients, being associated with disease stage. An anti-inflammatory response was spotted by higher IL-10. Lower levels of IL-23 and IP-10 were associated with disease severity. No significant statistical differences were found by grade classification. Moreover, salivary IL-1β and IL-6 exhibited significant positive correlations with several clinical measurements (PI, BOP, PPD, CAL), while IP-10 showed a statistical negative correlation with BOP, PPD, and CAL. These insights highlight the complexity of the periodontitis inflammatory network and the potential of cytokines as biomarkers for refined diagnostic and therapeutic strategies.

Assessment of Salivary MMP-8 and IL-1β for the Diagnosis of Periodontal Diseases in Pakistani Population

OBJECTIVE

 Clinical methods use the subjective diagnosis of periodontal diseases by visual observation that could result in differences and variability of diagnosis. The addition of specific markers could aid in the accurate diagnosis of the local population. The objective of the study was to target two of the major proteins for possible significance in such an approach.

MATERIALS AND METHODS

 Unstimulated saliva samples were collected from 60 participants aged between 18 and 70 years. Three groups each with twenty participants were recruited into periodontitis, gingivitis, and healthy control.

STATISTICAL ANALYSIS

 The samples were analyzed using human enzyme-linked immunosorbent assay kits for matrix metalloproteinase-8 (MMP-8) and interleukin-1β (IL-1β).

RESULTS

 SPSS version 20 was used to analyze the result. Posthoc analysis by Tukey's test revealed that MMP-8 levels were higher in gingivitis and periodontitis groups as compared with healthy controls. The test also revealed that IL-1β levels were higher in the periodontitis group compared with the healthy control and gingivitis group. Additionally, one-way analysis of variance analysis showed a significant effect on probing depth in gingivitis and periodontitis patients. The mean age of periodontitis group was significantly higher than other groups.

CONCLUSION

 Salivary biomarkers may provide useful diagnostic information and could be utilized as tests for periodontal disease screening, prognosis, and prediction.

Evaluation of Salivary Il-38 Levels in Periodontitis: A Cross-Sectional Study

The goal of the current study was to assess levels of salivary interleukin (IL)-38, IL-1β, and IL-10 in various periodontal clinical conditions. In total, 60 (20 healthy, 20 gingivitis, and 20 stage II-III, grade A-B periodontitis) subjects were included in the study. Demographic and clinical periodontal parameters were recorded. Samples were examined for IL-38, IL-1β, and IL-10 levels by means of enzyme-linked immunosorbent assay. Results demonstrated that the periodontitis group had significantly lower salivary IL-38 levels (P < 0.05) than the healthy group. Salivary IL-10 levels did not differ significantly between the groups (P > 0.05). The salivary IL-1β levels of gingivitis (P < 0.001) and periodontitis groups (P < 0.01) were significantly higher than those of the healthy group. The present study indicated that IL-38 level is decreased in periodontal disease. The results suggested a possible role of IL-38 in the periodontal inflammation process. Clarifying the mechanisms of IL-38 in the inflammatory process may contribute to the development of novel treatment strategies in periodontal diseases.

Salivary Amylase and Mucin in Chronic Periodontitis: Pre- /Posttherapy

AIM

The study aims to investigate the potential of salivary amylase as a reliable biochemical marker for assessing periodontal disease progression, establishing a potential correlation between salivary amylase levels and periodontal disease severity.

MATERIALS AND METHODS

The study included 40 participants, aged 25-65, equally divided into a control and study group of 20 individuals each. Clinical parameters, such as oral hygiene index, gingival index, probing depth, and clinical attachment level were recorded. Saliva samples were collected and analyzed for amylase and mucin levels using a semi-auto analyzer and spectrophotometer, respectively. These clinical parameters and salivary biomarkers were evaluated before and after 45 days of phase I periodontal therapy. Statistical analysis, including independent samples t-test, paired samples t-test, and correlation analysis were performed to assess the treatment effectiveness and explore associations between clinical parameters and salivary biomarkers.

RESULTS

The study group with chronic generalized periodontitis showed significantly higher salivary amylase (27022.5 ± 8598.9) and mucin levels (3258 ± 724.2) and worse clinical parameters than the control group at baseline. However, after phase I periodontal therapy, the study group exhibited reduced salivary biomarkers amylase (17924.0 ± 4703.6) and mucin (1828.45 ± 314.07) and improved clinical parameters, indicating the effectiveness of the treatment in enhancing periodontal health compared with the control group. Positive correlations were found between clinical parameters and salivary amylase/mucin levels both before and after therapy (p < 0.001).

CONCLUSION

Salivary amylase and mucin levels hold promise as valuable biomarkers for diagnosing active periodontal disease and evaluating treatment outcomes after phase I therapy.

CLINICAL SIGNIFICANCE

Salivary biomarker comparison offers a noninvasive diagnostic tool for periodontal disease, improving early detection and personalized treatment planning. Further research is required to validate its clinical value fully.

Salivary interleukin-1β as a biomarker to differentiate between periodontal health, gingivitis, and periodontitis

BACKGROUND

Periodontal diagnosis is based on recording clinical parameters including bleeding on probing (BOP), probing pocket depth (PPD), and clinical attachment loss (CAL). These techniques may be prone to errors due to different factors. Available biomarkers in the oral biofluid such as interleukin (IL)-1β could provide solutions for these issues. The study aimed to determine the potential of salivary IL-1β to differentiate periodontal health from disease and between gingivitis and periodontitis.

METHODS

Patients with gingivitis (N.=25), periodontitis (N.=50), and healthy periodontium (N.=25) were recruited for this study. For each patient, whole unstimulated saliva was collected followed by recording periodontal parameters namely; Plaque Index (PI), BOP, PPD, CAL. Level of salivary IL-1β was assayed by using enzyme-linked immunosorbent assays. Sensitivity and specificity of IL-1β, to differentiate any given condition, was determined by Receiver operating characteristic curve and area under the curve (AUC).

RESULTS

Both BOP and PI were significantly higher in association with gingivitis and periodontitis groups as compared to controls. Concentration of salivary IL-1β in periodontal health was significantly lower than gingivitis and periodontitis groups. The biochemical analyses showed that salivary IL-1β differentiated periodontal health from gingivitis (AUC 0.949) and periodontitis (AUC 0.852) but could not discriminate gingivitis from periodontitis (AUC 0.532). The proposed cut-off points to differentiate periodontal health from gingivitis was 103.8 pg/mL, while the value of the biomarker to differentiate periodontal health from periodontitis was 102.0 pg/mL.

CONCLUSIONS

Salivary IL-1β could be a reliable biomarker with a good level of accuracy to differentiate periodontal health from disease but not to discriminate gingivitis from periodontitis.

Salivary levels of NLRC4 inflammasome in different periodontal clinical status

OBJECTIVE

Nucleotide-binding and oligomerization domain (NOD)-like receptor family CARD domain-containing protein 4 (NLRC4) has a critical role in the regulation of interleukin-1β (IL-1β), an important cytokine in the pathogenesis of the periodontal diseases. In this study, we aimed to evaluate levels of salivary NLRC4 inflammasomes in different periodontal clinical statuses.

METHODS

The individuals with 20 periodontally healthy (healthy), 20 gingivitis, and 20 periodontitis were periodontally examined. Saliva samples were collected, after the clinical measurements (plaque index, gingival index, gingival bleeding index, probing depth, and clinical attachment level). The levels of salivary NLRC4, IL-1β, and interleukin 10 (IL-10) were examined by enzyme-linked immunosorbent assay.

RESULTS

The results demonstrated that levels of salivary NLRC4 (p < 0.01), and IL-1β (p < 0.001) were significantly higher in gingivitis and periodontitis than in the healthy group. No significant difference was salivary IL-10 levels between the groups (p > 0.05). Positive significant correlations among NLRC4 and IL-1β salivary levels and clinical parameters were detected (p < 0.05).

CONCLUSION

The findings of this study suggest that the NLRC4 is elevated in periodontal disease. Larger randomized controlled clinical studies are needed to use salivary NLRC4 levels as a potential marker for detecting the presence and/or severity of the periodontal disease.

Salivary bactericidal/permeability-increasing protein: A novel inflammatory marker associated with periodontitis

OBJECTIVES

The present case-control study aims to investigate the salivary levels of bactericidal/permeability-increasing protein (BPI) and interleukin-1beta (IL-1ß) in systemically healthy individuals with periodontitis and periodontally healthy for the evaluation of BPI's relation with periodontal inflammation and clinical diagnosis of periodontitis.

MATERIALS AND METHODS

A total of 100 participants were enrolled in this study and divided into periodontitis (P group) (n = 50) and periodontally healthy (H group) (n = 50) groups based on their full-mouth periodontal examination results including plaque index, probing pocket depth, gingival index, bleeding on probing, and clinical attachment level. Unstimulated whole saliva was collected. Salivary BPI and IL-1β levels were determined using an enzyme-linked immunosorbent assay. Receiver operating characteristic (ROC) curves were created to determine the diagnostic value of BPI.

RESULTS

The levels of BPI and IL-1ß in saliva were significantly higher in the P group than in the H group (p<0.001). Moreover, salivary BPI and IL-1ß levels correlated significantly with all clinical periodontal parameters (all p<0.001). Interestingly, there was a strong positive correlation between salivary levels of BPI and IL-1ß (r=0.544, p<0.001). In addition, the results of the ROC curve analysis showed that BPI had a high diagnostic potential to distinguish periodontitis from healthy controls with an area under the curve value of 0.94% (p<0.000).

CONCLUSION

The significantly higher salivary levels of BPI in periodontitis patients together with strong positive correlations between all periodontal parameters and salivary IL-1ß levels suggest that BPI may be involved in the inflammatory process of periodontal disease.

CLINICAL RELEVANCE

The present study for the first time report that salivary BPI levels may serve as a potential biomarker of inflammation in periodontal disease.

TRIAL REGISTRATION NUMBER

Thai Clinical Trials.gov (TCTR20211222008) (22 December 2021).

Analysis of Salivary Levels of IL-1β, IL17A, OPG and RANK-L in Periodontitis Using the 2017 Classification of Periodontal Diseases-An Exploratory Observational Study

Periodontitis is a chronic disease with a high overall prevalence. It involves a complex interplay between the immune-inflammatory pathways and biofilm changes, leading to periodontal attachment loss. The aims of this study were (i) to assess whether the salivary IL-1β, IL-17A, RANK-L and OPG levels have the potential to discriminate between the mild and severe periodontitis conditions; and (ii) to enable diagnostic/prognostic actions to differentiate between distinct levels of the disease. The analysis of the clinical parameters and the evaluation of the salivary immunomediators levels by means of a multiplex flow assay revealed a statistically significantly higher level of IL-1β in the periodontitis III/IV patients, as well as a higher level of RANK-L in the periodontitis III/IV and I/II patients, when compared to the healthy controls. Furthermore, the grade C periodontitis patients presented a significantly higher level of RANK-L compared to the grade B and grade A patients. In the grade C patients, IL-1β had a positive correlation with the PPD and CAL indices and RANK_L had a positive correlation with CAL. The evidence emerging from this study associates the salivary IL-1β and RANK-L levels with an advanced stage of periodontitis, stage III/IV, and with grade C, suggesting the possible cooperative action of both in the inflammatory and bone loss events. In addition to IL-1β, RANK-L could be considered a combined diagnostic biomarker for periodontitis.

IL-1/IL-1R Signaling in Head and Neck Cancer

Decades ago, the study of cancer biology was mainly focused on the tumor itself, paying little attention to the tumor microenvironment (TME). Currently, it is well recognized that the TME plays a vital role in cancer development and progression, with emerging treatment strategies focusing on different components of the TME, including tumoral cells, blood vessels, fibroblasts, senescent cells, inflammatory cells, inflammatory factors, among others. There is a well-accepted relationship between chronic inflammation and cancer development. Interleukin-1 (IL-1), a potent pro-inflammatory cytokine commonly found at tumor sites, is considered one of the most important inflammatory factors in cancer, and has been related with carcinogenesis, tumor growth and metastasis. Increasing evidence has linked development of head and neck squamous cell carcinoma (HNSCC) with chronic inflammation, and particularly, with IL-1 signaling. This review focuses on the most important members of the IL-1 family, with emphasis on how their aberrant expression can promote HNSCC development and metastasis, highlighting possible clinical applications.

A review of T helper 17 cell-related cytokines in serum and saliva in periodontitis

Periodontitis is a chronic inflammatory disease with a complex underlying immunopathology. Cytokines, as molecular mediators of inflammation, play a role in all stages of disease progression. T helper 17 (Th17) cells are thought to play a role in periodontitis. Th17 cell development and maintenance requires a pro-inflammatory cytokine milieu, with many of the cytokines implicated in the pathogenesis of periodontitis. Serum and saliva are easily accessible biofluids which can represent the systemic and local environment to promote the development of Th17 cells. Here we review human clinical studies that investigate IL-1β, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-25, IL-31, IL-33, IFN-γ, sCD40L and TNF-α in serum and saliva in periodontitis. We highlight their putative role in the pathogenesis of periodontitis and place them within a wider context of animal and other clinical studies.

Salivary Biomarkers and Their Application in the Diagnosis and Monitoring of the Most Common Oral Pathologies

Saliva is a highly versatile biological fluid that is easy to gather in a non-invasive manner—and the results of its analysis complement clinical and histopathological findings in the diagnosis of multiple diseases. The objective of this review was to offer an update on the contribution of salivary biomarkers to the diagnosis and prognosis of diseases of the oral cavity, including oral lichen planus, periodontitis, Sjögren’s syndrome, oral leukoplakia, peri-implantitis, and medication-related osteonecrosis of the jaw. Salivary biomarkers such as interleukins, growth factors, enzymes, and other biomolecules have proven useful in the diagnosis and follow-up of these diseases, facilitating the early evaluation of malignization risk and the monitoring of disease progression and response to treatment. However, further studies are required to identify new biomarkers and verify their reported role in the diagnosis and/or prognosis of oral diseases.

Changes in salivary microbial sensing proteins CD14 and TLR2 with aging

OBJECTIVE

Soluble toll-like receptor-2 (sTLR2) and soluble CD14 (sCD14) in saliva are defense proteins that bind specific microbe-associated molecular patterns. Since the oral flora changes with aging, the objective of this study is to determine and compare the concentration of sTLR2 and sCD14 in the saliva of healthy individuals in age groups from the first to the sixth decade of life.

METHODS

Unstimulated whole saliva was collected after obtaining informed consent. The concentration of sCD14 and sTLR-2 was measured by enzyme-linked immunosorbent assay. Statistical differences between the age groups were determined by analysis of variance. The relationship between the two markers in each age group was evaluated by Pearson's correlation coefficient and linear regression analyses.

RESULTS

The concentration of salivary sTLR2 was highest in the youngest, and that of the sCD14 was highest in the oldest age group. While the salivary sCD14 and the sTLR2 exhibited a moderate negative correlation in the youngest, the relationship between the two markers was inversed in the oldest age group.

CONCLUSIONS AND CLINICAL RELEVANCE

The results of our exploratory study suggest a need to adjust for age-dependent changes in sCD14 and sTLR2 in healthy saliva while assessing the two proteins as biomarkers.

Effects of Sulfonylureas on Periodontopathic Bacteria-Induced Inflammation

Interleukin-1β (IL-1β) is an inflammatory cytokine produced by monocytes/macrophages and is closely associated with periodontal diseases. The NLRP3 inflammasome is involved in IL-1β activation through pro-IL-1β processing and pyroptotic cell death in bacterial infection. Recently, glyburide, a hypoglycemic sulfonylurea, has been reported to reduce IL-1β activation by suppressing activation of the NLRP3 inflammasome. Therefore, we evaluated the possibility of targeting the NLRP3 inflammasome pathway by glyburide to suppress periodontal pathogen-induced inflammation. THP-1 cells (a human monocyte cell line) were differentiated to macrophage-like cells by treatment with phorbol 12-myristate 13-acetate and stimulated by periodontopathic bacteria, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, or Fusobacterium nucleatum, in the presence of glyburide. IL-1β and caspase-1 expression in the cells and culture supernatants were analyzed by Western blotting and enzyme-linked immunosorbent assay, and cell death was analyzed by lactate dehydrogenase assay. Stimulation of THP-1 macrophage-like cells with every periodontopathic bacteria induced IL-1β secretion without cell death, which was suppressed by the NLRP3 inhibitor, MCC950, and caspase-1 inhibitor, z-YVAD-FMK. Glyburide treatment suppressed IL-1β expression in culture supernatants and enhanced intracellular IL-1β expression, suggesting that glyburide may have inhibited IL-1β secretion. Subsequently, a periodontitis rat model was generated by injecting periodontal bacteria into the gingiva, which was analyzed histologically. Oral administration of glyburide significantly suppressed the infiltration of inflammatory cells and the number of osteoclasts in the alveolar bone compared with the control. In addition to glyburide, glimepiride was shown to suppress the release of IL-1β from THP-1 macrophage-like cells, whereas other sulfonylureas (tolbutamide and gliclazide) or other hypoglycemic drugs belonging to the biguanide family, such as metformin, failed to suppress IL-1β release. Our results suggest that pharmacological targeting of the NLRP3 pathway may be a strategy for suppressing periodontal diseases.

Comparative evaluation of Gingival Crevicular Fluid (GCF) levels of Interleukin-34 levels in periodontally healthy and in patients with chronic and aggressive periodontitis- A cross-sectional study

Background and objectives

Proinflammatory cytokines appear to have a central role in the destruction of periodontal tissues. By binding to Receptor Activator of Nuclear Factor κb (RANK) on osteoclast progenitor cells, these cytokines are locally responsible for the activation of bone resorbing osteoclasts differentiation and function. Interleukin-34 (IL-34) is a proinflammatory cytokine derived from the osteoblasts and plays an important role in osteoclastogenesis. The present study was carried out to assess the levels of IL-34 in Gingival Crevicular Fluid (GCF) in periodontally healthy patients, chronic periodontitis and aggressive periodontitis.

Materials and method

A total of 90 patients were recruited in the study and were divided into 3 groups: Periodontally healthy patients (Group I), Chronic periodontitis (Group II) and Aggressive periodontitis (Group III). Clinical Parameters like plaque index, gingival index, probing depth, clinical attachment levels were recorded and GCF samples were collected at baseline for the assessment of IL-34 levels in all the three groups. IL-34 levels were calculated using Enzyme-Linked Immune-Sorbent Assay (ELISA).

Results

The mean GCF levels of IL-34 in Group I was 47.22 ± 18.04 pg/ml, Group II was 103.76 ± 26.61 pg/ml and in Group III was 191.71 ± 49.24 pg/ml. The mean GCF IL-34 level was found to be higher in Group III followed by Group II and Group I. The IL-34 levels correlated with clinical parameters like plaque index, gingival index, probing depth, clinical attachment levels. But correlation with probing depth and clinical attachment level were significantly higher in Group III followed by Group II and Group I.

Interpretation and conclusion

The study demonstrated higher levels of IL-34 in aggressive periodontitis when compared with chronic periodontitis. IL-34, a novel diagnostic marker which was found to be at higher level in GCF of aggressive and chronic periodontitis patients.

Pregnancy-induced periodontal inflammation: Influence of salivary cytokines and antimicrobial proteins

The aim of this study was to evaluate the association between pregnancy-induced periodontal inflammation and levels of some salivary cytokines and antimicrobial proteins (AMPs). The study was a cohort longitudinal study that included pregnant women attending a secondary health facility. Consented participants had oral examination and saliva sampling during pregnancy and post-partum (three months after pregnancy). Saliva samples were used for the analysis of cytokines (TNF-α, IFN-gamma and IL-1β) and AMPs (Lactoferin, Lysozyme, and β defensin-1) using ELISA. Data are presented as median with interquartile range and compared using related sample Wilcoxon signed rank test. Correlations between levels of the salivary factors and indices of periodontal inflammation were determined using Spearman’s correlation test. Salivary flow rate, pH, levels of salivary IL-1β and IFN-gamma were significantly lower; while gingival index, periodontal index and level of salivary TNF-α were significantly higher during pregnancy compared with postpartum period. However, salivary lactoferin, lysozyme and β defensin-1 did not show significant difference comparing during pregnancy and postpartum period. Level of salivary IFN-gamma showed negative correlation with gingival index while level of salivary TNF-α showed positive correlation with gingival and periodontal indices. Lower levels of salivary IL-1β and IFN-gamma along with higher TNF-α concentration during pregnancy suggest their contributions to the pathophysiology of pregnancy-induced periodontal inflammation.

Local application of IGFBP5 protein enhanced periodontal tissue regeneration via increasing the migration, cell proliferation and osteo/dentinogenic differentiation of mesenchymal stem cells in an inflammatory niche

Background

Periodontitis is a widespread infectious disease ultimately resulting in tooth loss. The number of mesenchymal stem cells (MSCs) in patients with periodontitis is decreased, and MSC functions are impaired. Rescuing the impaired function of MSCs in periodontitis is the key for treatment, especially in a manner independent of exogenous MSCs. Our previous study found that overexpressed insulin-like growth factor binding protein 5 (IGFBP5) could promote exogenous MSC-mediated periodontal tissue regeneration. Here, we investigate the role of IGFBP5 protein in MSCs and periodontal tissue regeneration independent of exogenous MSCs in an inflammatory niche.

Methods

TNFα was used to mimic the inflammatory niche. Lentiviral IGFBP5 shRNA was used to silence IGFBP5 and recombinant human IGFBP5 protein (rhIGFBP5) was used to stimulate the periodontal ligament stem cells (PDLSCs) and bone marrow stem cells (BMSCs). The effects of IGFBP5 on PDLSCs were evaluated using the scratch-simulated wound migration, Transwell chemotaxis, alkaline phosphatase (ALP) activity, Alizarin red staining, Cell Counting Kit-8, Western blot, Real-time PCR, Co-IP and ChIP assays. The swine model of periodontitis was used to investigate the functions of IGFBP5 for periodontal regeneration and its anti-inflammation effect.

Results

We discovered that 0.5 ng/ml rhIGFBP5 protein enhanced the migration, chemotaxis, osteo/dentinogenic differentiation and cell proliferation of MSCs under the inflammatory condition. Moreover, 0.5 ng/ml rhIGFBP5 application could rescue the impaired functions of IGFBP5-silenced-MSCs in the inflammatory niche. Furthermore, local injection of rhIGFBP5 could promote periodontal tissue regeneration and relieve the local inflammation in a minipig model of periodontitis. Mechanistically, we found that BCOR negatively regulated the expression of IGFBP5 in MSCs. BCOR formed a protein complex with histone demethylase KDM6B and raised histone K27 methylation in the IGFBP5 promoter.

Conclusions

This study revealed that rhIGFBP5 could activate the functions of MSCs in an inflammatory niche, provided insight into the mechanism underlying the activated capacities of MSCs, and identified IGFBP5 as a potential cytokine for improving tissue regeneration and periodontitis treatment independent of exogenous MSCs and its potential application in dental clinic.

Electronic supplementary material

The online version of this article (doi:10.1186/s13287-017-0663-6) contains supplementary material, which is available to authorized users.

Salivary Levels of NLRP3 Inflammasome-Related Proteins as Potential Biomarkers of Periodontal Clinical Status

BACKGROUND

Emerging evidence suggests that activation of inflammasomes plays a central mechanism in pathogenesis of periodontitis. This study aims to compare salivary levels of nod-like receptor family pyrin domain containing protein (NLRP) 3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), cysteine aspartase (caspase)-1, and interleukin (IL)-1β from individuals with aggressive (AgP) or chronic periodontitis (CP) and healthy controls (HC), as well as elucidate its association with periodontal clinical status.

METHODS

Saliva samples from individuals with CP (n = 75), AgP (n = 20), and HC (n = 69) were collected. Periodontal status was assessed by measurement of probing depth, clinical attachment level, and extent and severity of disease. Salivary levels of analytes were analyzed by enzyme-linked immunosorbent assay. Association between biomarkers with CP or AgP was analyzed using multivariate binary logistic regression models.

RESULTS

Significantly higher levels of NLRP3, ASC, and IL-1β were detected in periodontitis groups in comparison to the periodontally HC group. However, no significant differences were observed for caspase-1 levels between clinical groups, and only NLRP3 salivary concentration was significantly higher in AgP compared with CP patients. Also, positive significant correlations among NLRP3, ASC, and IL-1β salivary concentrations and clinical parameters were observed. Logistic regression analyses revealed a strong/independent association of NLRP3, ASC, and IL-1β salivary levels with CP and AgP.

CONCLUSION

Although the concentration of caspase-1 in saliva samples makes its determination useless for detection of periodontal disease and/or its severity, salivary levels of NLRP3, ASC, and IL-1β may act as strong/independent indicators of amount and extent of periodontal breakdown in both CP and AgP and could potentially be used for prevention and therapy of this group of diseases.

HIV Infection and Compromised Mucosal Immunity: Oral Manifestations and Systemic Inflammation

Mucosal surfaces account for the vast majority of HIV transmission. In adults, HIV transmission occurs mainly by vaginal and rectal routes but rarely via oral route. By contrast, pediatric HIV infections could be as the result of oral route by breastfeeding. As such mucosal surfaces play a crucial role in HIV acquisition, and spread of the virus depends on its ability to cross a mucosal barrier. HIV selectively infects, depletes, and/or dysregulates multiple arms of the human immune system particularly at the mucosal sites and causes substantial irreversible damage to the mucosal barriers. This leads to microbial products translocation and subsequently hyper-immune activation. Although introduction of antiretroviral therapy (ART) has led to significant reduction in morbidity and mortality of HIV-infected patients, viral replication persists. As a result, antigen presence and immune activation are linked to “inflammaging” that attributes to a pro-inflammatory environment and the accelerated aging process in HIV patients. HIV infection is also associated with the prevalence of oral mucosal infections and dysregulation of oral microbiota, both of which may compromise the oral mucosal immunity of HIV-infected individuals. In addition, impaired oral immunity in HIV infection may predispose the patients to periodontal diseases that are associated with systemic inflammation and increased risk of cardiovascular diseases. The purpose of this review is to examine existing evidence regarding the role of innate and cellular components of the oral cavity in HIV infection and how HIV infection may drive systemic hyper-immune activation in these patients. We will also discuss current knowledge on HIV oral transmission, HIV immunosenescence in relation to the oral mucosal alterations during the course of HIV infection and periodontal disease. Finally, we discuss oral manifestations associated with HIV infection and how HIV infection and ART influence the oral microbiome. Therefore, unraveling how HIV compromises the integrity of the oral mucosal tissues and innate immune components of the oral cavity and its association with induction of chronic inflammation are critical for the development of effective preventive interventions and therapeutic strategies.

HIV Infection and Compromised Mucosal Immunity: Oral Manifestations and Systemic Inflammation

Mucosal surfaces account for the vast majority of HIV transmission. In adults, HIV transmission occurs mainly by vaginal and rectal routes but rarely via oral route. By contrast, pediatric HIV infections could be as the result of oral route by breastfeeding. As such mucosal surfaces play a crucial role in HIV acquisition, and spread of the virus depends on its ability to cross a mucosal barrier. HIV selectively infects, depletes, and/or dysregulates multiple arms of the human immune system particularly at the mucosal sites and causes substantial irreversible damage to the mucosal barriers. This leads to microbial products translocation and subsequently hyper-immune activation. Although introduction of antiretroviral therapy (ART) has led to significant reduction in morbidity and mortality of HIV-infected patients, viral replication persists. As a result, antigen presence and immune activation are linked to "inflammaging" that attributes to a pro-inflammatory environment and the accelerated aging process in HIV patients. HIV infection is also associated with the prevalence of oral mucosal infections and dysregulation of oral microbiota, both of which may compromise the oral mucosal immunity of HIV-infected individuals. In addition, impaired oral immunity in HIV infection may predispose the patients to periodontal diseases that are associated with systemic inflammation and increased risk of cardiovascular diseases. The purpose of this review is to examine existing evidence regarding the role of innate and cellular components of the oral cavity in HIV infection and how HIV infection may drive systemic hyper-immune activation in these patients. We will also discuss current knowledge on HIV oral transmission, HIV immunosenescence in relation to the oral mucosal alterations during the course of HIV infection and periodontal disease. Finally, we discuss oral manifestations associated with HIV infection and how HIV infection and ART influence the oral microbiome. Therefore, unraveling how HIV compromises the integrity of the oral mucosal tissues and innate immune components of the oral cavity and its association with induction of chronic inflammation are critical for the development of effective preventive interventions and therapeutic strategies.

Trends in Laboratory Diagnostic Methods in Periodontology

This work presents a summary of current knowledge on the laboratory diagnosis of periodontitis. It focuses on the theoretical foundations and is supplemented with new knowledge. It subsequently describes specifically the laboratory diagnosis methods of periodontitis: the protein expression of inflammation, oral microbiology and molecular diagnostics. Periodontitis is a serious disease worldwide and its confirmed association with systemic diseases means its severity is increasing. Its laboratory diagnosis has the potential to rise to the level of clinical and diagnostic imaging. The transfer of diagnostic methods from laboratory to clinical use is increasingly used in the prevention and monitoring of the exacerbation and treatment of periodontal disease, as well as of its impact on systemic disease.

Temporal Stability of the Salivary Microbiota in Oral Health

Objectives

Saliva is a biological fluid suitable for biomarker analysis, and differences in the salivary microbiota in oral health and disease have been reported. For such comparative analyses, time of sampling is critical since the bacterial composition may vary throughout the day, i.e., diurnal variation. The purpose of this study is to compare the salivary microbiome over time to determine the optimal time for sampling.

Design

Stimulated saliva samples were collected from 5 orally healthy individuals in 4 h intervals for 24 h, and collection was repeated 7 days later (number of samples per person, n = 12, total number of samples, n = 60). Salivary microbiota was analyzed using the Human Oral Microbe Identification using Next Generation Sequencing (HOMINGS), and statistical analysis was performed using the Kruskal-Wallis test with Benjamini-Hochberg’s correction for multiple comparisons, cluster analysis, principal component analysis and correspondence analysis.

Results

From a total of 60 saliva samples, 477 probe targets were collectively identified with a mean number of probes per sample of 207 (range: 153–307). Little or no variation in microbial profiles within subjects was observed over time.

Conclusions

Although there was considerable variation between subjects, microbial profiles within subjects were stable throughout a 24 hour period and after 1 week. Since there is little or no evidence of diurnal variation of the salivary microbiome, time of sampling of saliva is not critical for perturbation or other microbial studies.

Salivary biomarkers in a biofilm overgrowth model

BACKGROUND

The purpose of this study is to determine whether baseline salivary inflammatory biomarkers could discriminate between different clinical levels of disease and/or detect clinical changes over a 3-week stent-induced biofilm overgrowth (SIBO) period.

METHODS

A total of 168 participants were enrolled in a 21-day experimental gingivitis investigation and grouped according to clinical measures of periodontal status of health and diseased individuals representing each of five biofilm gingival interface (BGI) periodontal groups: 1) health, all probing depth (PD) <3 mm and bleeding on probing (BOP) <10%; 2) gingivitis, all PD <3 mm and BOP ≥10%; 3) periodontitis (P)1, ≥1 site with PD >3 mm and BOP ≤10%; 4) P2, ≥1 site with PD >3 mm and BOP >10% but ≤50%; and 5) P3, ≥1 site with PD >3 mm and BOP >50%. Stents were used to prevent plaque removal during brushing over one maxillary and one mandibular posterior dental sextant for 21 days. Clinical periodontal parameters and unstimulated saliva were collected at screening, baseline, and each week during SIBO. Saliva samples were assessed for levels of 13 different biomarkers by multiplex immunoassay.

RESULTS

Higher salivary levels of interleukin (IL)-1β, matrix metalloproteinase (MMP)-3, MMP-8, MMP-9, and neutrophil gelatinase-associated lipocalin (NGAL) were found in diseased groups compared with the healthy group at baseline. Conversely, higher IL-1 receptor antagonist (ra) levels were found in healthy patients at baseline. In addition, during SIBO, MMP-1, tissue inhibitor of metalloproteinase (TIMP)-1, and TIMP-2 levels increased across all participant groups. A stepwise linear regression model using all salivary biomarkers demonstrated that, at baseline, increased IL-1ra (P = 0.004) and IL-6 (P = 0.009) were significantly associated with change in PDs during SIBO.

CONCLUSIONS

In summary, this investigation supports salivary levels of IL-1ra and IL-6 as potential indicators for PD changes during induced gingival inflammation. In addition, participants from the BGI-P3 group (severe periodontitis) demonstrated elevated baseline levels of IL-1β, MMP-3, MMP-8, MMP-9, and NGAL compared with the other study groups, strengthening the relevance of participants' biologic phenotype on expression of salivary biomarkers.

Patient-Specific Variations in Biomarkers across Gingivitis and Periodontitis

This study investigates the use of saliva, as an emerging diagnostic fluid in conjunction with classification techniques to discern biological heterogeneity in clinically labelled gingivitis and periodontitis subjects (80 subjects; 40/group) A battery of classification techniques were investigated as traditional single classifier systems as well as within a novel selective voting ensemble classification approach (SVA) framework. Unlike traditional single classifiers, SVA is shown to reveal patient-specific variations within disease groups, which may be important for identifying proclivity to disease progression or disease stability. Salivary expression profiles of IL-1ß, IL-6, MMP-8, and MIP-1α from 80 patients were analyzed using four classification algorithms (LDA: Linear Discriminant Analysis [LDA], Quadratic Discriminant Analysis [QDA], Naïve Bayes Classifier [NBC] and Support Vector Machines [SVM]) as traditional single classifiers and within the SVA framework (SVA-LDA, SVA-QDA, SVA-NB and SVA-SVM). Our findings demonstrate that performance measures (sensitivity, specificity and accuracy) of traditional classification as single classifier were comparable to that of the SVA counterparts using clinical labels of the samples as ground truth. However, unlike traditional single classifier approaches, the normalized ensemble vote-counts from SVA revealed varying proclivity of the subjects for each of the disease groups. More importantly, the SVA identified a subset of gingivitis and periodontitis samples that demonstrated a biological proclivity commensurate with the other clinical group. This subset was confirmed across SVA-LDA, SVA-QDA, SVA-NB and SVA-SVM. Heatmap visualization of their ensemble sets revealed lack of consensus between these subsets and the rest of the samples within the respective disease groups indicating the unique nature of the patients in these subsets. While the source of variation is not known, the results presented clearly elucidate the need for novel approaches that accommodate inherent heterogeneity and personalized variations within disease groups in diagnostic characterization. The proposed approach falls within the scope of P4 medicine (predictive, preventive, personalized, and participatory) with the ability to identify unique patient profiles that may predict specific disease trajectories and targeted disease management.

Evaluation of the effect of nicotine and metabolites on the periodontal status and the mRNA expression of interleukin-1β in smokers with chronic periodontitis

Background and Objective:

Smoking is an important environmental risk factor involved in the causation and progression of periodontal disease. Smoking can impair various components of the host immune response and immune system. The virulence factors of periodontal pathogens stimulate inflammatory cytokine expression by mononuclear cells. IL-1β is the key mediator involved in the pathogenesis and disease progression. Therefore, whole gingival biopsy samples are assessed for this increased expression of IL-1.

Materials and Methods:

29 male subjects’ age and gender matched were divided into three groups based on the periodontal and smoking status (Group A:healthy, Group B: non-smokers suffering from chronic periodontitis, Group C: smokers suffering from chronic periodontitis). Periodontal parameters like plaque index, gingival index, probing pocket depth and clinical attachment level were recorded at baseline and post scaling. The mRNA expression of IL-1β was determined by real time polymerase chain reaction and correlated with the periodontal and smoking status.

Results:

The improvement in the periodontal parameters was statistically significant in the non- smokers (Group B) and there was a 2 fold increase in the mRNA expression in this group. The smokers (Group C) showed lesser improvement in the periodontal parameters and there was an 8 fold increase in the mRNA expression of IL-1β.

Conclusion:

Association of smoking status with periodontal destruction can thus be correlated with the increased mRNA expression of IL-1β in chronic periodontitis patients.

Point-of-care diagnosis of periodontitis using saliva: technically feasible but still a challenge

Periodontitis is a chronic inflammation of the periodontium caused by persistent bacterial infection that leads to the breakdown of connective tissue and bone. Because the ability to reconstruct the periodontium is limited after alveolar bone loss, early diagnosis and intervention should be the primary goals of periodontal treatment. However, periodontitis often progresses without noticeable symptoms, and many patients do not seek professional dental care until the periodontal destruction progresses to the point of no return. Furthermore, the current diagnosis of periodontitis depends on time-consuming clinical measurements. Therefore, there is an unmet need for near-patient testing to diagnose periodontitis. Saliva is an optimal biological fluid to serve as a near-patient diagnostic tool for periodontitis. Recent developments in point-of-care (POC) testing indicate that a diagnostic test for periodontitis using saliva is now technically feasible. A number of promising salivary biomarkers associated with periodontitis have been reported. A panel of optimal biomarkers must be carefully selected based on the pathogenesis of periodontitis. The biggest hurdle for the POC diagnosis of periodontitis using saliva may be the process of validation in a large, diverse patient population. Therefore, we propose the organization of an International Consortium for Biomarkers of Periodontitis, which will gather efforts to identify, select, and validate salivary biomarkers for the diagnosis of periodontitis.

Targeted salivary biomarkers for discrimination of periodontal health and disease(s)

Generally, clinical parameters are used in dental practice for periodontal disease, yet several drawbacks exist with the clinical standards for addressing the needs of the public at large in determining the current status/progression of the disease, and requiring a significant amount of damage before these parameters can document disease. Therefore, a quick, easy and reliable method of assessing and monitoring periodontal disease should provide important diagnostic information that improves and speeds treatment decisions and moves the field closer to individualized point-of-care diagnostics.

OBJECTIVE

This report provides results for a saliva-based diagnostic approach for periodontal health and disease based upon the abundance of salivary analytes coincident with disease, and the significant progress already made in the identification of discriminatory salivary biomarkers of periodontitis.

METHODS

We evaluated biomarkers representing various phases of periodontitis initiation and progression (IL-1ß, IL-6, MMP-8, MIP-1α) in whole saliva from 209 subjects categorized with periodontal health, gingivitis, and periodontitis.

RESULTS

Evaluation of the salivary analytes demonstrated utility for individual biomarkers to differentiate periodontitis from health. Inclusion of gingivitis patients into the analyses provided a more robust basis to estimate the value of each of these analytes. Various clinical and statistical approaches showed that pairs or panels of the analytes were able to increase the sensitivity and specificity for the identification of disease.

CONCLUSIONS

Salivary concentrations of IL-1ß, IL-6, MMP-8, MIP-1α alone and in combination are able to distinguish health from gingivitis and periodontitis. The data clearly demonstrated a heterogeneity in response profiles of these analytes that supports the need for refinement of the standard clinical classifications if we are to move toward precision/personalized dentistry for the twenty-first century.

Inflammatory Mediators of Leprosy Reactional Episodes and Dental Infections: A Systematic Review

Reactional episodes in leprosy are a result of complex interactions between the immune system, Mycobacterium leprae, and predisposing factors, including dental infections. To determine the main inflammatory mediators in the immunopathological process of dental infections and leprosy reactions, we conducted a systematic review of primary literature published between 1996 and 2013. A three-stage literature search was performed (Stage I, "leprosy reactions" and "inflammatory mediators"; Stage II, "dental infections" and "inflammatory mediators"; and Stage III, "leprosy reactions," "dental infections," and "inflammatory mediators"). Of the 911 eligible publications, 10 were selected in Stage I, 68 in Stage II, and 1 in Stage III. Of the 27 studied inflammatory mediators, the main proinflammatory mediators were IL-6, IFN-γ, TNF-α, IL-1β, and IL-17; the main anti-inflammatory mediators were IL-10 and IL-4. Serum IL-6 and TNF-α concentrations were significant during periodontal and reactional lesion evolution; IFN-γ and IL-1β were associated with types 1 and 2 reactions and chronic periodontal disease. The proinflammatory mediators in dental infections and leprosy reactions, especially IL-6 and TNF-α, were similar across studies, regardless of the laboratory technique and sample type. IFN-γ and IL-1β were significant for leprosy reactions and periodontal diseases. This pattern was maintained in serum.

Association study between salivary levels of interferon (IFN)-gamma, interleukin (IL)-17, IL-21, and IL-22 with chronic periodontitis

OBJECTIVE

To investigate if the salivary levels of IL-17, IL-21, IL-22, and its ratio regarding salivary IFN-γ may be linked with the periodontal clinical status.

DESIGN

One hundred and five chronic periodontitis (CP) subjects and 44 healthy controls (HC) were recruited. Periodontal status was assessed based on full-mouth clinical periodontal measurements. Cytokine salivary levels were analyzed by ELISA. The association between the analytes with CP was analyzed using a binary logistic regression model.

RESULTS

A statistically significant increase in salivary levels of IFN-γ and IFN-γ/IL-22 ratio in CP group could be detected, but there was no significant domination of any Th17 cytokine that could be of predictive value for health/disease status. Univariate and binary logistic regression analyses revealed a strong and independent association of IFN-γ salivary levels and IFN-γ/IL-22 ratio with disease status. An interaction effect of ageing on IFN-γ levels also could be noted.

CONCLUSION

While salivary levels of IFN-γ and IFN-γ/IL-22 ratio may act as strong/independent indicators of the amount and extent of periodontal breakdown, the low detection frequency of Th17 cytokines in saliva samples make these determinations useless for the detection of disease presence and/or its severity.

Cytokine production by leukocytes in patients with periodontitis

In the present study, we investigated the relation between clinical parameters and levels of interleukin (IL) -4 and -5, and tumour necrosis factor-α (TNF-α) in the leukocyte incubation medium (LIM) obtained from 26 patients with chronic periodontitis (P) and 26 control group subjects (C). The levels of cytokines IL-4 and IL -5 produced by the LIM stimulated with non-opsonised E. coli were determined using the Enzyme-Linked Immunosorbent Assay (ELISA) method and the levels of TNF-α were evaluated by applying Enzyme Amplified Sensitivity Immunoassay (EASIA). TNF-α levels in stimulated LIM were strongly positively correlated with clinical parameters such as the pocket probing depths (PPD), the clinical attachment level (CAL), the bleeding on probing (BOP) and oral hygiene index (OHI), whereas the IL-4 and IL-5 levels in the analogous medium were strongly negatively correlated with the clinical parameters. IL-4 and IL-5 levels in stimulated LIM of P group patients were significantly lower, whereas TNF-α levels were significantly higher than that in analogous medium of C group subjects. These differences were associated with the severity of periodontal disease.

Saliva versus peri-implant inflammation: quantification of IL-1β in partially and totally edentulous patients

The aim of this study was to investigate the potential use of salivary IL1β in early-stage diagnostics of peri-implant inflammation in partially and totally edentulous patients rehabilitated with dental implants. Patients were classified according to peri-implant probing depth and bleeding upon probing in groups of healthy individuals or in groups of individuals with peri-implant inflammation. Data on plaque index, clinical attachment loss, suppuration, and mobility were also assessed. Saliva was collected without stimulation, and the levels of IL-1β were determined by ELISA. Healthy groups demonstrated significantly lower levels of IL-1β compared with the inflammation groups. No difference in IL-1β levels was observed between partially edentulous or totally edentulous patients. Salivary IL-1β may be useful for the diagnosis and monitoring of early peri-implant inflammation, particularly in edentulous patients.

Protein biomarkers of periodontitis in saliva

Periodontitis is a chronic inflammatory condition of the tissues that surround and support the teeth and is initiated by inappropriate and excessive immune responses to bacteria in subgingival dental plaque leading to loss of the integrity of the periodontium, compromised tooth function, and eventually tooth loss. Periodontitis is an economically important disease as it is time-consuming and expensive to treat. Periodontitis has a worldwide prevalence of 5-15% and the prevalence of severe disease in western populations has increased in recent decades. Furthermore, periodontitis is more common in smokers, in obesity, in people with diabetes, and in heart disease patients although the pathogenic processes underpinning these links are, as yet, poorly understood. Diagnosis and monitoring of periodontitis rely on traditional clinical examinations which are inadequate to predict patient susceptibility, disease activity, and response to treatment. Studies of the immunopathogenesis of periodontitis and analysis of mediators in saliva have allowed the identification of many potentially useful biomarkers. Convenient measurement of these biomarkers using chairside analytical devices could form the basis for diagnostic tests which will aid the clinician and the patient in periodontitis management; this review will summarise this field and will identify the experimental, technical, and clinical issues that remain to be addressed before such tests can be implemented.

Expression of IL-1β, IL-6, TNF-α, and iNOS in pregnant women with periodontal disease

Periodontal disease is one of the most prevalent oral diseases. An association between this disease and pregnancy has been suggested, but available findings are controversial. We evaluated the expression levels of interleukins (IL-1β and IL-6), tumor necrosis factor-alpha (TNF-α), and inducible nitric oxide synthase (iNOS) in pregnant women with and without periodontal disease in comparison with non-pregnant women with and without periodontal disease since studies have suggested a relationship between periodontitis and the expression levels of these genes. The women in the sample were distributed into four groups: pregnant and non-pregnant women, with or without periodontal disease, a total of 32 women. The periodontal condition was evaluated according to the probing depth, clinical attachment level and bleeding on probing. Analysis of gene expression was performed by real-time PCR. Comparisons were made of the level of gene expression among the four groups. Expression of IL-1β in the non-pregnant women with periodontal disease was 12.6 times higher than in the non-pregnant women without periodontal disease (P < 0.01), while expression of TNF-α in the non-pregnant women without periodontal disease was 3.5 times higher than in the pregnant women with periodontal disease (P < 0.05). Despite these differences, our overall findings indicate no differences in the expression levels of the cytokines IL-1β, IL-6, TNF-α, and iNOS in pregnant women with and without periodontal disease in comparison with expression of the same genes in non-pregnant women with and without periodontal disease, suggesting that periodontal disease is not influenced by pregnancy.

Salivary biomarkers of periodontal disease in response to treatment

BACKGROUND

Salivary biomarkers of periodontitis were assessed longitudinally to determine response to therapy.

METHODS

A 6-month case-controlled study of adults with chronic periodontitis was performed, with 33 participants receiving oral hygiene instructions (OHI) alone and 35 with scaling and root planing (SRP) combined with OHI. Saliva samples collected at week 0, 16 and 28 were analysed for interleukin (IL)-1β, IL-8, macrophage inflammatory protein (MIP)-1α, matrix metalloproteinase-8 (MMP-8), osteoprotegerin (OPG), and tumour necrosis factor-α (TNF)-α. Clinical measures of periodontal disease were recorded at each visit.

RESULTS

All parameters of periodontal health improved significantly in both groups by week 16 (p<0.0001) with the SRP group demonstrating greater benefit at week 16 and 28. Baseline OPG and TNF-α levels changed significantly at both follow-up visits (p<0.03), regardless of treatment group. IL-1β and MMP-8 levels decreased significantly from baseline (p<0.04) in the SRP group only. OPG, MMP-8, and MIP-1α were significantly reduced in responders compared with non-responders (p=0.04, 0.01, 0.05, respectively). In receiver-operating characteristic analyses, MMP-8 produced the highest area under the curve (0.7; p=0.01).

CONCLUSION

Salivary levels of IL-1β, MMP-8, OPG, and MIP-1α reflected disease severity and response to therapy suggesting their potential utility for monitoring periodontal disease status.

Salivary interleukin-1β levels in patients with chronic periodontitis before and after periodontal phase I therapy and healthy controls: a case-control study

BACKGROUND

The role of interleukin (IL)-1β in periodontal disease pathogenesis is well researched. This study aimed to assess and compare the salivary IL-1β levels in patients with chronic periodontitis before and after periodontal phase I therapy and periodontally healthy controls. Further, relationships between IL-1β levels and various clinical parameters were explored.

METHODS

Twenty-eight patients with moderate-to-severe generalized chronic periodontitis and 24 age-, race-, and ethnicity-matched controls participated in this study. Saliva samples were obtained from all patients. The clinical parameters recorded were clinical attachment loss (AL), probing depth, bleeding on probing, periodontal index, and gingival index. Clinical evaluation and sample collection were repeated 1 month after periodontal phase I therapy in patients with periodontitis. IL-1β levels were assessed using enzyme-linked immunosorbent assay.

RESULTS

Mean IL-1β levels in patients with periodontitis at baseline (1,312.75 pg/mL) were significantly higher (P <0.0001; eight-fold) than in controls (161.51 pg/mL). Although treatment in patients with periodontitis resulted in significant reduction in IL-1β levels (mean: 674.34 pg/mL; P = 0.001), they remained significantly higher (P <0.0001; four-fold) than control levels. There were significant correlations between IL-1β levels and all clinical parameters (P <0.01) except percentage sites with clinical AL >2 mm (P >0.05).

CONCLUSIONS

The data indicate that IL-1β levels are raised in the saliva of patients with chronic periodontitis, which are reduced after phase I therapy, suggesting a close association between salivary IL-1β and periodontitis. Additional longitudinal studies are needed to validate salivary IL-1β as a marker for periodontal disease.

Rheumatoid arthritis and salivary biomarkers of periodontal disease

AIM

To test the hypothesis that rheumatoid arthritis (RA) influenced levels of salivary biomarkers of periodontal disease.

METHODS

Medical assessments, periodontal examinations and pain ratings were obtained from 35 RA, 35 chronic periodontitis and 35 age- and gender-matched healthy controls in a cross-sectional, case-controlled study. Unstimulated whole saliva samples were analysed for interleukin-1β (IL-1β), matrix metalloproteinase-8 (MMP-8) and tumour necrosis factor-α (TNF-α) concentrations.

RESULTS

The arthritis and healthy groups had significantly less oral disease than the periodontitis group (P<0.0001), with the arthritis group having significantly more sites bleeding on probing (BOP) than matched controls (P=0.012). Salivary levels of MMP-8 and IL-1β were significantly elevated in the periodontal disease group (P<0.002), and IL-1β was the only biomarker with significantly higher levels in the arthritis group compared with controls (P=0.002). Arthritis patients receiving anti-TNF-α antibody therapy had significantly lower IL-1β and TNF-α levels compared with arthritis patients not on anti-TNF-α therapy (P=0.016, 0.024) and healthy controls (P<0.001, P=0.011), respectively.

CONCLUSION

RA patients have higher levels of periodontal inflammation than healthy controls, i.e., an increased BOP. Systemic inflammation appears to influence levels of select salivary biomarkers of periodontal disease, and anti-TNF-α antibody-based disease-modifying therapy significantly lowers salivary IL-1β and TNF-α levels in RA.

Current developments in salivary diagnostics

Salivary diagnostics is an emerging field that has progressed through several important developments in the past decade, including the publication of the human salivary proteome and the infusion of federal funds to integrate nanotechnologies and microfluidic engineering concepts into developing compact point-of-care devices for rapid analysis of this secretion. In this article, we discuss some of these developments and their relevance to the prognosis, diagnosis and management of periodontitis, as an oral target, and cardiovascular disease, as a systemic example for the potential of these biodiagnostics. Our findings suggest that several biomarkers are associated with distinct biological stages of these diseases and demonstrate promise as practical biomarkers in identifying and managing periodontal disease, and acute myocardial infarction. The majority of these studies have progressed through biomarker discovery, with the identified molecules requiring more robust clinical studies to enable substantive validation for disease diagnosis. It is predicted that with continued advances in this field the use of a combination of biomarkers in multiplex panels is likely to yield accurate screening tools for these diagnoses in the near future.

ATP-dependent activation of an inflammasome in primary gingival epithelial cells infected by Porphyromonas gingivalis

Production of IL-1beta typically requires two-separate signals. The first signal, from a pathogen-associated molecular pattern, promotes intracellular production of immature cytokine. The second signal, derived from a danger signal such as extracellular ATP, results in assembly of an inflammasome, activation of caspase-1 and secretion of mature cytokine. The inflammasome component, Nalp3, plays a non-redundant role in caspase-1 activation in response to ATP binding to P2X(7) in macrophages. Gingival epithelial cells (GECs) are an important component of the innate-immune response to periodontal bacteria. We had shown that GECs express a functional P2X(7) receptor, but the ability of GECs to secrete IL-1beta during infection remained unknown. We find that GECs express a functional Nalp3 inflammasome. Treatment of GECs with LPS or infection with the periodontal pathogen, Porphyromonas gingivalis, induced expression of the il-1beta gene and intracellular accumulation of IL-1beta protein. However, IL-1beta was not secreted unless LPS-treated or infected cells were subsequently stimulated with ATP. Conversely, caspase-1 is activated in GECs following ATP treatment but not P. gingivalis infection. Furthermore, depletion of Nalp3 by siRNA abrogated the ability of ATP to induce IL-1beta secretion in infected cells. The Nalp3 inflammasome is therefore likely to be an important mediator of the inflammatory response in gingival epithelium.

When grief heats up: pro-inflammatory cytokines predict regional brain activation

BACKGROUND

Pro-inflammatory cytokines are associated with sickness behaviors, a set of behaviors including low mood, which are orchestrated by the brain and described as shift in motivational state. The present study investigated the hypothesis that local inflammation is associated with greater subgenual anterior cingulate cortex (sACC) activation in persons undergoing chronic stress.

METHODS

Women undergoing the emotional stress of bereavement had fMRI scans during a grief elicitation task. Local inflammation was measured by salivary concentrations of two markers of pro-inflammatory cytokine activity (e.g., interleukin-1beta and soluble tumor necrosis factor receptor II).

RESULTS

Analyses revealed that both inflammatory markers were positively associated with ventral prefrontal activation (e.g., sACC and orbitofrontal cortex) as well as other regions important in the emotional task such as noun retrieval (e.g., temporal cortex), and visual processing (e.g., cuneus and fusiform gyrus). In separate analyses, the ventral prefrontal activations correlated with free recall of grief-related word stimuli, but not neutral word stimuli.

CONCLUSIONS

This is the first study to demonstrate the relationship between emotional processing, regional brain activation and localized inflammation in a chronically stressed population of adults.