Smoking and inflammation: evidence for a synergistic role in chronic disease

Oral Microbiome Profiling in Smokers with and without Head and Neck Cancer Reveals Variations Between Health and Disease

While smoking is inextricably linked to oral/head and neck cancer (HNSCC), only a small fraction of smokers develop HNSCC. Thus, we have sought to identify other factors, which may influence the development of HNSCC in smokers including microbiology. To determine microbial associations with HNSCC among tobacco users, we characterized oral microbiome composition in smokers with and without HNSCC. 16S rRNA MiSeq sequencing was used to examine the oral mucosa microbiome of 27 smokers with (cases) and 24 without HNSCC (controls). In addition, we correlated previously reported levels of DNA damage with the microbiome data. Smokers with HNSCC showed lower microbiome richness compared with controls (q = 0.012). Beta-diversity analyses, assessed as UniFrac (weighted and unweighted) and Bray-Curtis distances, showed significant differences in oral mucosal microbiome signatures between cases and controls (r ² = 0.03; P = 0.03) and higher interindividual microbiome heterogeneity in the former (q ≤ 0.01). Higher relative abundance of Stenotrophomonas and Comamonadaceae and predicted bacterial pathways mainly involved in xenobiotic and amine degradation were found in cases compared with controls. The latter, in contrast, exhibited higher abundance of common oral commensals and predicted sugar degradation pathways. Finally, levels of DNA damage in the oral cavity were correlated with the microbiome profiles above. Oral microbiome traits differ in smokers with and without HNSCC, potentially informing the risk of eventual HNSCC and shedding light into possible microbially mediated mechanisms of disease. These findings present data that may be useful in screening efforts for HNSCC among smokers who are unable to quit.

Smoking behavior and smoking index as prognostic indicators for patients with esophageal squamous cell carcinoma who underwent surgery: A large cohort study in Guangzhou, China

INTRODUCTION

This study aimed to evaluate the association between smoking and smoking index with clinical outcomes of esophageal squamous cell carcinoma patients.

METHODS

This is a retrospective analysis conducted on consecutive patients with esophageal carcinoma who underwent esophagectomy from January 2005 to December 2010. All patients had pathologically confirmed esophageal squamous cell carcinoma. The association between smoking and sociodemographic characteristics with overall survival and disease-free survival was analyzed. Serum carcinoembryonic antigen was measured using an electrochemiluminescence immunoassay.

RESULTS

A total of 944 patients were enrolled. Kaplan-Meier analysis indicated that esophageal squamous cell carcinoma patients who smoked had a significantly worse prognosis in terms of both overall survival (p=0.007) and disease-free survival (p= 0.010). Multivariate analysis demonstrated that age (p=0.001), carcinoembryonic antigen (p=0.012), tumor-node-metastasis (TNM) staging (p<0.001) and smoking (p=0.048) were independently correlated with overall survival, while only TNM stage (p<0.001) and smoking (p=0.041) were identified as independent factors of disease-free survival. We divided the smoking population into two groups (smoking index <400 and ≥400). Kaplan-Meier survival analysis indicated that a smoking index <400 was associated with a significantly better prognosis in terms of both overall survival (p=0.003) and favorable disease-free survival (p=0.032). Multivariate analysis showed that age (p<0.001), TNM staging (p<0.001), and smoking index (p=0.025) were independent factors of overall survival, whereas for disease-free survival, only TNM stage (p=0.001) and smoking index (p=0.025) were identified.

CONCLUSIONS

Overall survival was significantly associated with smoking in esophageal squamous cell carcinoma patients. For esophageal squamous cell carcinoma patients who smoke, a higher smoking index is associated with worse clinical outcomes. Therefore, smoking may be used as a predictive indicator for pretreatment evaluation and adjustment of treatment regimen.

Higher Dietary Inflammatory Index Scores are Associated with Increased Odds of Benign Breast Diseases in a Case-Control Study

Purpose

Dietary inflammatory index (DII) is a new tool for assessing the inflammatory potential of diet. Since there is no study that has investigated the association of DII and benign breast diseases (BBD), the aim of our study was to compare DII scores in patients with and without BBD.

Methods

One hundred and eleven (111) subjects with BBD and 104 healthy women attending the Iranian Center for Breast Cancer affiliated with the Academic Center for Education, Culture and Research were enrolled in a case–control study. Dietary data collected using a 168‑item validated food frequency questionnaire (FFQ). Energy-adjusted DII was calculated based on FFQ. Socio demographic data were collected by interview. In addition, physical activity was measured by the International Physical Activity Questionnaire (IPAQ). Weight, height and waist circumference were also measured.

Results

After adjustment for multiple confounding variables, participants at the highest tertile of DII had increased OR for BBD (OR=1.7, 95% CI=0.75–3.95) (P-trend =0.04).

Conclusion

The increased chance of BBD was suggested with a higher consumption of diets with inflammatory potential. However, this result should be interpreted with caution as OR was not statistically significant. Interventional studies are warranted to elucidate the role of inflammatory diets in the development of BBD.

The Impact of Smoking on Subgingival Microflora: From Periodontal Health to Disease

Periodontal disease is one of the most common diseases of the oral cavity affecting up to 90% of the worldwide population. Smoking has been identified as a major risk factor in the development and progression of periodontal disease. It is essential to assess the influence of smoking on subgingival microflora that is the principal etiological factor of the disease to clarify the contribution of smoking to periodontal disease. Therefore, this article reviews the current research findings regarding the impact of smoking on subgingival microflora and discusses several potential mechanisms. Cultivation-based and targeted molecular approaches yield controversial results in determining the presence or absence of smoking-induced differences in the prevalence or levels of certain periodontal pathogens, such as the “red complex.” However, substantial changes in the subgingival microflora of smokers, regardless of their periodontal condition (clinical health, gingivitis, or periodontitis), have been demonstrated in recent microbiome studies. Available literature suggests that smoking facilitates early acquisition and colonization of periodontal pathogens, resulting in an “at-risk-for-harm” subgingival microbial community in the healthy periodontium. In periodontal diseases, the subgingival microflora in smokers is characterized by a pathogen-enriched community with lower resilience compared to that in non-smokers, which increases the difficulty of treatment. Biological changes in key pathogens, such as Porphyromonas gingivalis, together with the ineffective host immune response for clearance, might contribute to alterations in the subgingival microflora in smokers. Nonetheless, further studies are necessary to provide solid evidence for the underlying mechanisms.

Inflammation has synergistic effect with nicotine in periodontitis by up-regulating the expression of α7 nAChR via phosphorylated GSK-3β

Periodontitis is the leading cause of adult tooth loss, and those who smoke are at an increased risk of developing periodontitis. α7 nicotinic acetylcholine receptor (α7 nAChR) is proposed to mediate the potential synergistic effect of nicotine and inflammation in smoking‐related periodontitis. However, this has not been experimentally demonstrated. We isolated and cultured human periodontal ligament stem cells (PDLSCs) from healthy and inflamed tissues. PDLSCs were treated with either inflammatory factors or nicotine. We measured expression of genes that are associated with osteogenic differentiation and osteoclast formation using RT‐qPCR and Western blot analyses. Besides, immunohistochemical staining, micro‐CT analysis and tartaric acid phosphatase staining were used to measure α7 nAChR expression and function. Inflammation up‐regulated α7 nAChR expression in both periodontal ligament tissues and PDLSCs. The up‐regulated α7 nAChR contributed to the synergistic effect of nicotine and inflammation, leading to a decreased capability of osteogenic differentiation and increased capability of osteoclast formation‐induction of PDLSCs. Moreover, the inflammation‐induced up‐regulation of α7 nAChR was partially dependent on the level of phosphorylated GSK‐3β. This study provides experimental evidence for the pathological development of smoking‐related periodontitis and sheds new light on developing inflammation and α7 nAChR‐targeted therapeutics to treat and prevent the disease.

Carotenoids and their role in cancer prevention

Approximately two of every five people will develop cancer in their lifetime. Dietary modifications are one of the most promising lifestyle changes that can adjust the risk of developing cancer by nearly 40%. Carotenoids are a diverse group of natural pigments and are present in many fruits and vegetables. The data surrounding carotenoids and their potential roles in carcinogenesis have been rapidly growing over the past two decades. This review summarizes the literature surrounding the associations between the most six common carotenoids in the diet and ten of the most commonly diagnosed cancers. In this study, preclinical, epidemiological, and toxicology data were reviewed. Data from these studies suggest that several carotenoids might provide a beneficial impact on reducing carcinogenesis. Further studies are needed to determine the causal relationships between individual carotenoids and cancer incidence and progression. This article is part of a Special Issue entitled Carotenoids recent advances in cell and molecular biology edited by Johannes von Lintig and Loredana Quadro.

Association between leucocyte telomere length and cardiovascular disease in a large general population in the United States

Leucocyte telomere length (LTL) has been reported to be linked to ageing, cancer and cardiovascular disease (CVD). This study aimed to explore the association between LTL and CVD risk in a nationally representative sample of U.S. adults. Complex associations, including nonlinearity and interaction, were also examined. A total of 7,378 subjects from the National Health and Nutrition Examination Survey (NHANES) 1999-2002 were collected. Telomere length was detected from DNA samples and expressed as the mean T/S ratio (telomere repeats per single-copy gene). We performed multiple logistic regression models and interactive analysis to explore the associations between LTL and CVD risk by adjusting for potential confounders. We also performed a sensitivity analysis to investigate the robustness of our results. Among all participants, LTL was associated with the risk of CVD (OR = 0.79, 95% CI: 0.63~0.98, P = 0.033) in a linear manner rather than in a nonlinear manner (P = 0.874). Interaction effects of LTL with both education (P = 0.017) and hypertension (P = 0.007) were observed. Furthermore, using subgroup analyses, protective effects of LTL on CVD risk were found in females and in individuals who were college graduates or above, had serum cotinine >10 ng/ml, did not have hypertension, or had normal white blood cell levels. LTL is linearly inversely associated with CVD risk in the general population of the United States.

Exposure to Cigarette Smoke Augments Post-ischemic Brain Injury and Inflammation via Mobilization of Neutrophils and Monocytes

Cigarette smoke is a major preventable risk factor of ischemic stroke. Cigarette smoke induces a significant increase in circulating leukocytes. However, it remains unclear to what extent and by what mechanisms smoke priming influences stroke severity. Here we report that exposure to cigarette smoke exacerbated ischemic brain injury in mice subjected to transient middle cerebral artery occlusion (MCAO). The augmentation of neurodeficits and brain infarction was accompanied by increased production of pro-inflammatory factors and brain infiltration of neutrophils and monocytes. Prior to brain ischemia, exposure to cigarette smoke induced mobilization of peripheral neutrophils, and monocytes. Furthermore, the detrimental effects of smoke priming on ischemic brain injury were abolished either by pharmacological inhibition of the recruitment of neutrophils and monocytes or by blockade of the NLRP3 inflammasome, an effector protein of neutrophils and monocytes. Our findings suggest that cigarette smoke-induced mobilization of peripheral neutrophils and monocytes augments ischemic brain injury.

The effect of smoking on gingival crevicular fluid peptidoglycan recognition protein-1 level following initial periodontal therapy in chronic periodontitis

OBJECTIVE

To determine the effect of smoking on peptidoglycan recognition protein (PGRP)-1 levels in gingival crevicular fluid (GCF) in smokers and non-smokers with chronic periodontitis (CP) following initial periodontal therapy.

SUBJECTS AND METHODS

A total of 40 patients with CP (20 smokers (S + CP) and 20 non-smokers (S-CP)) and 40 subjects with healthy periodontium (20 smokers (S + PH) and 20 non-smokers (S-PH)), comprising 80 subjects, were included in this study. Baseline GCF samples were obtained from all subjects, and clinical periodontal measurements were recorded. In patients who had received initial periodontal therapy, GCF samples were obtained and all clinical periodontal measurements were recorded again during the 6th-8th weeks. GCF PGRP-1 levels were analyzed by enzyme-linked immunosorbent assay.

RESULTS

At baseline, GCF PGRP-1 levels were significantly higher in both groups with CP than in both groups with healthy periodontium, whereas these levels were significantly lower in S + CP than in S-CP. GCF PGRP-1 levels decreased significantly in both CP groups after periodontal therapy, and this reduction was significantly greater in non-smokers than in smokers.

CONCLUSION

Smoking might have a suppressive effect on GCF PGRP-1 levels in CP. Initial periodontal therapy is effective in decreasing GCF PGRP-1 levels in both smokers and non-smokers with CP.

Impact of smoking on gingival inflammation in representative samples of three South American cities

The aim of this study was to investigate the impact of smoking on gingival inflammation in a representative sample of 1,650 adults from Santiago (Chile), Porto Alegre (Brazil), and Tucumán (Argentina). A questionnaire was administered to participants to gather demographic and behavioral characteristics, including smoking habits. The participants were clinically examined to obtain gingival index (GI), gingival bleeding index (GBI), visible plaque index (VPI), and calculus presence values. Gingival inflammation was defined as a mean GI > 0.5. Heavy smokers presented significantly lower levels of gingival inflammation, as reflected by both GI and GBI, than both light and moderate smokers, despite their having increased amounts of plaque and calculus. Being 50 years old or older [odds ratio (OR), 1.93], a VPI ≥ 30% (OR, 28.1), and self-reported diabetes (OR, 2.79) were positively associated with detection of gingival inflammation. In conclusion, the occurrence of clinically detectable gingival inflammation was lower in heavy smokers than light and moderate smokers. Older age, diabetes, and visible plaque emerged as risk indicators of gingivitis. Plaque and gingival indices are significantly associated regardless of the smoking status.

Periodontal disease, smoking, cardiovascular complications and mortality in type 1 diabetes

AIM

To assess the role of periodontal disease (PD) as a predictor of coronary artery disease (CAD) and mortality in a prospective type 1 diabetes (T1D) cohort and to evaluate the role of smoking in this relationship.

METHODS

Data were based on 320 participants of the Pittsburgh Epidemiology of Diabetes Complications study of T1D who, during 1992-94, received a partial mouth periodontal exam, and who were followed for up to 19 years to ascertain complication incidence. PD was defined as clinical attachment loss of ≥4 mm for at least 10% of the examined sites. Predictors of all-cause mortality; Hard CAD (CAD death, myocardial infarction or revascularization), and Total CAD (Hard CAD, angina, ischemic ECG) were assessed using Cox models.

RESULTS

During 19 years of follow-up, 33.7% (97/288) developed CAD, 27.3% (83/304) developed Hard CAD, and 16.9% (54/320) died. Among current smokers, 46.4% (26/56) developed CAD, 42.7% (24/56) developed Hard CAD and 29.5% (18/61) died. PD was not associated with all-cause mortality, although it was a significant predictor of both CAD (HR = 1.12, CI = 1.01-1.23) and Hard CAD (HR = 1.30, CI = 1.11-1.51). As smoking modified the PD-CAD and PD-Hard CAD associations, analyses were stratified by smoking status. PD was associated with an increased risk of CAD (HR = 1.25, CI = 1.03-1.50) and Hard CAD (HR = 1.85, CI = 1.17-2.93) only among smokers.

CONCLUSION

PD was a significant predictor of CAD and Hard CAD among current smokers with T1D.

Periodontal and chronic kidney disease association: A systematic review and meta-analysis

AIM

Chronic kidney disease (CKD) and kidney failure is increasing globally and evidence from observational studies suggest periodontal disease may contribute to kidney functional decline.

METHODS

Electronic searches of the PubMed, EMBASE, Web of Science, Scopus and Cochrane Library databases were conducted for the purposes of conducting a systematic review. Hand searching of reference lists was also performed. Meta-analysis of observational studies involving periodontal disease and chronic kidney disease in adults was performed.

RESULTS

A total of 17 studies was selected from an initial 4055 abstracts. Pooled estimates indicated the odds of having CKD were 60% higher among patients with periodontitis: pooled OR 1.60 (95% CI 1.44-1.79, I² 35.2%, P = 0.11) compared to those without. Conversely, a similar magnitude but non-significant higher odds of having periodontal disease was found among people with CKD 1.69 (95% CI: 0.84, 3.40, I² = 89.8%, P < 0.00) versus non-CKD. Meta-regression revealed study quality based on the Newcastle-Ottawa Scale and statistical adjustment for potential confounders explained almost 35% of the heterogeneity in the studies investigating the association between CKD and periodontitis.

CONCLUSIONS

Moderate evidence for a positive association between periodontitis and CKD exists. Evidence for the opposite direction is extremely weak based on significant heterogeneity between studies.

Effects of Lactobacillus reuteri as an adjunct to the treatment of periodontitis in smokers: randomised clinical trial

The aim of this randomised clinical trial was to evaluate the effect of Lactobacillus reuteri in chewable tablets as an adjunct to non-surgical periodontal treatment of chronic periodontitis in smoking patients. 34 patient smokers were selected and randomly divided into two groups. The SRP group (n=17) received scaling and root planing (SRP) in one session and a placebo; the PRO group (n=17) received SRP in one session and 2 probiotic tablets 2× per day, for 21 days. Bleeding on probing (BOP), probing depth (PD), clinical attachment level (CAL), gingival recession (GR), and pockets with PD≥5 mm and bleeding were measured at baseline and 90 days. After 90 days of treatment, the PD and pockets with PD≥5 mm and bleeding were significantly lower in both groups compared to baseline (P<0.05). In the PRO group, the BOP had significantly reduced at 90 days when compared with the baseline (P<0.05). There was statistically significant reduction in PD between baseline and 90 days in the PRO group in deep pockets (P<0.05). There was no statistically significant difference between the groups in the reduction in PD (P=0.95) or gain in CAL (P=0.97) in moderate and deep pockets. The adjuvant use of L. reuteri in the treatment of chronic periodontitis was effective in controlling gingival inflammation because reduced bleeding on probing which means reduced gingival inflammation and was effective in reducing deep pocket in manner clinically relevant.

Subgingivally delivered coenzyme Q10 in the treatment of chronic periodontitis among smokers: A randomized, controlled clinical study

Background

Coenzyme Q10 is an antioxidant whose efficacy in periodontal diseases is well known. However studies regarding its efficacy in smokers with periodontitis are few. Coenzyme Q10 serves as an endogenous antioxidant and its increased concentration in the diseased gingiva effectively suppresses advanced periodontal inflammation.

Objectives

The aim of this study is to evaluate the efficacy of coenzyme Q10 as an adjunct to scaling and root planing in smokers with chronic periodontitis.

Methods

Total of 40 patients were enrolled for the study. The subjects were divided into control (Scaling and root planing only) and test group (Coenzyme Q10 plus Scaling and root planing). Clinical parameters such as plaque index, modified sulcular bleeding index, probing pocket depth and clinical attachment level. These were assessed at baseline, at 1 month and 3 month. The results were subjected to appropriate statistical analysis.

Results

There was a significant improvement in all clinical parameters in the test sites seen at the end of the 1 month and 3 month period.

Conclusions

Coenzyme Q10 can be said to have a beneficial effect on smokers with periodontitis when used as an adjunct to scaling and root planing.

Adult Patient Risk Stratification Using a Risk Score for Periodontitis

Background: There is a need for analytical tools predicting the risk of periodontitis. The purpose of this study was to estimate and evaluate a risk score for prediction of periodontitis. Materials and methods: This case-cohort study included a random sample of 155 cases (with periodontitis) and 175 controls (randomly sampled from the study population at baseline) that were followed for 3-year. A logistic regression model was used with estimation of the risk ratio (RR) for each potential predictor. Results: The risk model included the predictors “age > 53 years” (RR = 0.53), “smoking” (RR = 2.9), “gingivitis at baseline” (RR = 3.1), “subgingival calculus at baseline” (RR = 1.9), “history of periodontitis” (RR = 2.3), and “less than 2 observations in the first year of follow-up” (RR = 3.7). Patients were distributed into three risk groups based on the preanalysis risk: low risk, moderate risk, and high risk. The risk score discrimination (95% confidence interval (CI)) was 0.75 (0.70; 0.80) (p < 0.001, C-statistic). Conclusions: The risk score estimated in the present study enabled to identify patients at higher risk of experiencing periodontitis and may be considered a useful tool for both clinicians and patients.

Association between C-reactive protein, neutrophil to lymphocyte ratio and the burden of apical periodontitis: a case-control study

OBJECTIVE

Endodontic originated chronic apical periodontitis (AP) is an inflammatory disease of periapical tissue. High-sensitivity C-reactive protein (hsCRP) as an inflammatory marker and hemogram indexes provide valuable information to clinicians for diagnosis, screening and follow-up of various diseases. The aim of this study was to investigate AP in terms of its association with hemogram indices and hsCRP levels.

MATERIAL AND METHODS

Study includes 104 patients with AP and 40 participants as the control group. 160 teeth were diagnosed as AP through digital radiographic images and scored with respect to Periapical Index (PAI) scoring. Afterwards, patients were categorized into 3 grades in accordance with both the number and the severity of AP. AP grade 0 was considered for the control group with regard to a new scoring system. Patients with only one tooth involved with AP with a PAI score of 3 or 4 were categorized as an AP Grade 1, when a patient had more than one tooth with a PAI score of 3 or 4 he was classified as an AP Grade 2 and a patient with at least one tooth scored as a PAI 5 was rated as an AP Grade 3. Hemograms and hsCRP levels were measured for each individual to establish a correlation with inflammatory markers.

RESULTS

The neutrophil/lymphocyte ratio (NLR) levels of patients with AP Grade 3 were significantly higher than all other AP grades (p < .05). hsCRP levels in patients with an AP Grade 2 and 3 were higher than both AP Grade 0 and 1 (p < .05).

CONCLUSIONS

hsCRP levels of patients were reliable predictive indicators for AP severity in correlation with the new proposed scoring system for AP.

Cytokine Research in Depression: Principles, Challenges, and Open Questions

Cytokines have been implicated in the pathology of depression. Currently, the evidence is based on cross-sectional studies and meta-analytic research comparing blood concentrations of T helper type 1 (TH1), T helper type 2 (TH2), pro-inflammatory or anti-inflammatory cytokines of patients with a depressive disorder to those of healthy controls. Additionally, multiple longitudinal studies have investigated cytokine levels during antidepressant treatment. According to the current literature, it seems that peripheral levels of interleukin (IL)-6, IL-10, IL-12, IL-13, and tumor necrosis factor (TNF)-α are elevated and that interferon (IFN)-γ levels are lower in patients with depression compared to healthy controls. However, the overlap of cytokine values between acutely depressed patients, remitted and recovered patients and healthy controls is considerable. Thus, the discriminative power of cytokine concentrations between depressed and non-depressed people is likely weak. Treatment with certain antidepressants appears to decrease peripheral levels of IL-6, IL-10, and TNF-α. However, weight gain-inducing psychopharmacological substances, such as the antidepressant mirtazapine, have been reported to potentially increase the production of pro-inflammatory cytokines. Even though cytokines are often discussed as biomarkers for depression, they have also been shown to be altered in other psychiatric disorders. Moreover, many environmental, social, psychological, biological, and medical factors are also associated with cytokine changes. Thus, cytokine alterations seem extremely unspecific. The interpretation of the results of these studies remains a challenge because it is unknown which type of cells are most responsible for cytokine changes measured in the blood nor have the main target cells or target tissues been identified. The same cytokine can be produced by multiple cell types, and the same cell can produce various cytokines. Additionally, redundancy, synergy, antagonism, and signaling cascades of cytokine signaling must be considered. Cytokines might not be associated with the diagnosis of depression according to the currently used diagnostic manuals, but rather with specific subtypes of depression, or with depressive symptoms across different psychiatric diagnoses. Therefore, the currently available diagnostic systems may not be the ideal starting point for psychiatric cytokine research.

Dental caries are positively associated with periodontal disease severity

OBJECTIVES

To examine associations between periodontal disease severity and clinical and microbiological measures of caries in adults.

MATERIALS AND METHODS

A cross-sectional study of 94 healthy adults ((mean ± SD) 55.4 ± 13.0 years) was conducted. Data were collected by means of questionnaire and a clinical examination that included the Decayed, Missing, Filled teeth Surfaces (DMFS) index, probing depth (PD), clinical attachment level (CAL), and gingival bleeding and plaque scores. Supra- and subgingival plaque samples were collected to assess the presence of Streptococcus mutans and six periodontal pathogens. Participants were subsequently categorized using Center for Disease Control and Prevention/American Academy of Periodontology (CDC-AAP) definitions and tertiles of percentage of sites with CAL ≥ 3mm.

RESULTS

Significant positive associations were found between the periodontal disease severity (CDC-AAP) and the DMFS (aOR = 1.03; 95% CI 1.01-1.05) and DS indices (aOR = 1.18; 95% CI 1.05-1.32) as well as between the tertiles of percentage of sites with CAL ≥ 3 mm and DMFS (aOR = 1.03; 95% CI 1.00-1.05) and DS indices (aOR = 1.12; 95% CI 1.00-1.25). A significant positive association was also found between oral levels of F. nucleatum and S. mutans (aOR = 6.03; 95% CI 1.55-23.45).

CONCLUSIONS

A small but positive association was found between clinical measures of caries and periodontal disease severity. Further research is warranted to examine the association between these two common oral diseases.

CLINICAL RELEVANCE

Periodontal diseases and caries are the two most common oral diseases. There was a positive association between clinical and microbiological markers of both diseases. Therefore, strategies in oral health education should involve both caries and periodontitis prevention.

Dysregulation of miR-146a by periodontal pathogens: A risk for acute coronary syndrome

BACKGROUND

Periodontitis is a polymicrobial, chronic inflammatory disease leading to loss of tooth-supporting structures. The bacteremia, endotoxemia, and systemic low-grade inflammation associate periodontitis with systemic illnesses such as diabetes mellitus and coronary artery disease. Periodontal pathogens have been detected from atheromatous plaque by amplification of the genetic material by using specific oligonucleotide primers in polymerase chain reaction. Though the association between periodontitis and cardiovascular diseases has been ascertained by systematic reviews and meta-analyses, its pathophysiology is not lucid. MicroRNAs are currently implicated in the regulation of many cellular processes including inflammation and may play a vital role in our understanding of this disease association. In this case-control study, we explored the role of the inflammatory microRNA, miR-146a, in acute coronary syndrome (ACS) subjects with and without chronic periodontitis (CP) and its regulation of the innate immune host response to periodontal pathogens.

METHODS

Three groups each comprising 66 patients each, namely group 1 (ACS patients without CP), group 2 (ACS patients with CP) and group 3 (CP only) formed the study population. Subgingival plaque samples and serum samples were subjected to quantitative Polymerase Chain Reaction (qPCR) for detection of Porphyromonas gingivalis, a keystone pathogen and to assess the levels of circulating miR-146a and associated proinflammatory cytokines.

RESULTS

miR-146a associated significantly in group 2 subjects with an odds ratio 1.434, 95% confidence interval 1.013-2.030, P < 0.042, and a predictive percentage of 83.3% and group 1 with a predictive percentage of 76.0.% The associated cytokines interleukin-6 (IL-6), tumor necrosis factor-α, and IL-1β also showed an upregulation with statistical significance (P < 0.05).

CONCLUSION

microRNA-146a is a key molecule associating periodontitis with acute coronary syndrome.

Genetic and clinical markers for predicting treatment responsiveness in rheumatoid arthritis

Although many drugs and therapeutic strategies have been developed for rheumatoid arthritis (RA) treatment, numerous patients with RA fail to respond to currently available agents. In this review, we provide an overview of the complexity of this autoimmune disease by showing the rapidly increasing number of genes associated with RA.We then systematically review various factors that have a predictive value (predictors) for the response to different drugs in RA treatment, especially recent advances. These predictors include but are certainly not limited to genetic variations, clinical factors, and demographic factors. However, no clinical application is currently available. This review also describes the challenges in treating patients with RA and the need for personalized medicine. At the end of this review, we discuss possible strategies to enhance the prediction of drug responsiveness in patients with RA.

Influence of anti-inflammatory diet and smoking on mortality and survival in men and women: two prospective cohort studies

BACKGROUND

The associations between an anti-inflammatory diet and both all-cause and cause-specific mortality have been studied previously; however, the influence of an anti-inflammatory diet on survival time has not been investigated. Moreover, the potential modification of these associations by smoking status remains unclear.

OBJECTIVE

The aims of this study were to examine the associations between an anti-inflammatory diet index (AIDI) and all-cause and cause-specific mortality, to determine the association between the AIDI and differences in survival time and to assess effect modification by smoking status.

METHODS

The study population included 68 273 Swedish men and women (aged 45-83 years) at baseline. The anti-inflammatory potential of the diet was estimated using the validated AIDI, which includes 11 potential anti-inflammatory and five potential pro-inflammatory foods. Cox proportional hazards and Laplace regression were used to estimate hazard ratios and differences in survival time.

RESULTS

During 16 years of follow-up (1 057 959 person-years), 16 088 deaths [5980 due to cardiovascular disease (CVD) and 5252 due to cancer] were recorded. Participants in the highest versus lowest quartile of the AIDI had lower risks of all-cause (18% reduction, 95% CI: 14-22%), CVD (20%, 95% CI: 14-26%) and cancer (13%, 95% CI: 5-20%) mortality. The strongest inverse associations between the highest and lowest quartiles of AIDI and risk of mortality were observed in current smokers: 31%, 36% and 22% lower risks of all-cause, CVD and cancer mortality, respectively. The difference in survival time between current smokers in the lowest AIDI quartile and never smokers in the highest quartile was 4.6 years.

CONCLUSION

Adherence to a diet with high anti-inflammatory potential may reduce all-cause, CVD and cancer mortality and prolong survival time especially amongst smokers.

Exposure to cigarette smoke via respiratory system may induce abnormal alterations of reproductive organs in female diabetic rats

Cigarette smoke (CS) has harmful effects on human fertility, reproduction, and development as well as on patients suffering from metabolic diseases such as diabetes than on healthy individuals. This study was conducted to investigate the relationship between CS exposure and histological alterations of reproductive organs in female diabetic rats. We evaluated the histology of uteruses and ovaries obtained from female rats exposed to smoke from standard cigarettes for 4 weeks (28 hours a week). After CS exposure, tissue slides were made from uterine and ovarian samples and examined after hematoxylin and eosin staining. Immunohistochemistry was used for detection of matrix metallopeptidase 9 (MMP9), C-X-C chemokine receptor type 4 (CXCR4), and estrogen receptor (ER)α in the uterus and ovary. MMP9 is an inflammatory biomarker that increases during progression to endometriosis. As a chemokine receptor, CXCR4 is involved in development of the inner wall of the uterus and cell adhesion. In the uterus, the occurrence of MMP9, CXCR4, and ERα and the number of endometrial glands were increased by CS exposure, while in the ovary, occurrence of MMP9, CXCR4, ERα, proliferating cell nuclear antigen and the number of corpus lutea or cyst follicles were increased by CS exposure. Collectively, this study indicates that CS induced abnormal development of the uterus and ovary under induced diabetes, leading to adverse effects on normal function of reproductive organs in female rats. HIGHLIGHTS: Cigarette smoke (CS) exposure adversely affected reproductive organs of diabetic female rats. In the uterus, expression of matrix metallopeptidase 9 (MMP9), C-X-C chemokine receptor type 4 (CXCR4), estrogen receptor (ER)α, and the number of endometrial glands were increased by CS exposure, In the ovary, the expression of MMP9, CXCR4, ERα, and proliferating cell nuclear antigen and the number of corpus lutea or cyst follicles were increased by CS exposure. Exposure to CS via the respiratory system exerted a harmful impact on the uterus and ovary in female rats with diabetes.

Cytokine Thresholds in Gingival Crevicular Fluid with Potential Diagnosis of Chronic Periodontitis Differentiating by Smoking Status

The objective of the present study was to determine cytokine thresholds derived from predictive models for the diagnosis of chronic periodontitis, differentiating by smoking status. Seventy-five periodontally healthy controls and 75 subjects affected by chronic periodontitis were recruited. Sixteen mediators were measured in gingival crevicular fluid (GCF) using multiplexed bead immunoassays. The models were obtained using binary logistic regression, distinguishing between non-smokers and smokers. The area under the curve (AUC) and numerous classification measures were obtained. Model curves were constructed graphically and the cytokine thresholds calculated for the values of maximum accuracy (ACC). There were three cytokine-based models and three cytokine ratio-based models, which presented with a bias-corrected AUC > 0.91 and > 0.83, respectively. These models were (cytokine thresholds in pg/ml for the median ACC using bootstrapping for smokers and non-smokers): IL1alpha (46099 and 65644); IL1beta (4732 and 5827); IL17A (11.03 and 17.13); IL1alpha/IL2 (4210 and 7118); IL1beta/IL2 (260 and 628); and IL17A/IL2 (0.810 and 1.919). IL1alpha, IL1beta and IL17A, and their ratios with IL2, are excellent diagnostic biomarkers in GCF for distinguishing periodontitis patients from periodontally healthy individuals. Cytokine thresholds in GCF with diagnostic potential are defined, showing that smokers have lower threshold values than non-smokers.

Smoking confounds the periodontal diagnostics using saliva biomarkers

BACKGROUND

Smoking is a risk factor for periodontal disease because of its complex impact on the inflammatory response in the periodontium. We investigated the effect of smoking on salivary periodontal biomarkers, matrix metalloproteinase (MMP)-8, MMP-9, tissue inhibitor of metalloproteinase (TIMP)-1 and myeloperoxidase (MPO).

METHODS

Saliva biomarkers were analyzed in the Parogene population (n = 480) comprising a random cohort of patients that have undergone coronary angiography and oral examination. The effect of time since cessation and pack years of smoking on biomarkers were investigated.

RESULTS

Saliva MMP-8, MMP-9, TIMP-1, and MPO concentrations distinguished periodontitis patients significantly from patients without periodontitis. When the time since cessation was considered, the area-under-the-curve values (p-value) for periodontitis were 0.76 (<0.001), 0.74 (<0.001), 0.70 (<0.001), and 0.76 (<0.001), respectively. Adding information about smoking habits in the models improved slightly the sensitivities of all biomarkers. In logistic regression model saliva, MMP-8 was mainly affected by pack years of smoking, whereas saliva MMP-9, TIMP-1, and MPO were mostly affected by time since cessation, especially if smoking currently or quit recently (<1 year ago).

CONCLUSION

Smoking confounds the salivary diagnostics of periodontitis and should be considered when interpreting the results obtained by potential diagnostic tests.

Personalized periodontal treatment for the tobacco- and alcohol-using patient

The use of various forms of tobacco is one of the most important preventable risk factors for the incidence and progression of periodontal disease. Tobacco use negatively affects treatment outcomes for both periodontal diseases and conditions, and for dental implants. Tobacco-cessation programs can mitigate these adverse dental treatment outcomes and may be the most effective component of a personalized periodontal treatment approach. In addition, heavy alcohol consumption may exacerbate the adverse effects of tobacco use. In this review, the microbiology, host/inflammatory responses and genetic characteristics of the tobacco-using patient are presented as a framework to aid the practitioner in developing personalized treatment strategies for these patients. These personalized approaches can be used for patients who use a variety of tobacco products, including cigarettes, cigars, pipes, smokeless tobacco products, e-cigarettes and other tobacco forms, as well as patients who consume large amounts of alcohol. In addition, principles for developing personalized tobacco-cessation programs, using both traditional and newer motivational and pharmacological approaches, are presented.

Activity of rheumatoid arthritis correlates with oral inflammatory burden

To study oral health in patients with rheumatoid arthritis (RA) with emphasis on disease activity and treatment of RA. In this prospective cohort study 81 RA patients [53 early untreated RA (EURA) and 28 chronic RA (CRA) patients with inadequate response to synthetic disease modifying antirheumatic drugs (DMARDs)], underwent rheumatological [Disease Activity Score (28-joint) DAS28] and dental examinations [Total Dental Index (TDI), Decayed Missing Filled Teeth (DMFT) and Decayed Missing Filled Surfaces (DMFS)]. For controls, 43 volunteers were examined. After the examinations, EURA patients started treatment with synthetic DMARDs, oral and intra-articular glucocorticoids. CRA patients were candidates for biological DMARDs. The patients were re-examined mean 16 months later. Results were analyzed with descriptive statistics and logistic regression. TDI was higher in both RA groups at baseline compared to controls [EURA: 2 (2-3); CRA: 2 (1-3); controls 1 (1-3), p = 0.045]. DMFT [r_s 0.561 (p = 0.002)] and DMFS [r_s 0.581 (p = 0.001)] associated with DAS28 at baseline in CRA patients. After follow-up, DAS28 associated positively with DMFT [r_s 0.384 (p = 0.016)] and DMFS [r_s 0.334 (p = 0.038)] in EURA patients; as well as in CRA patients DMFT [r_s 0.672 (p = 0.001)], DMFS [r_s 0.650 (p = 0.001)]. RA patients already in the early phase of the disease had poorer oral health compared to controls. The caries indices associated with the activity of RA in both patient groups. Oral status may thus contribute to the development and further relate to the activity of RA.

Elevated levels of 8-OHdG and PARK7/DJ-1 in peri-implantitis mucosa

BACKGROUND

Reactive oxygen species contribute to periodontal tissue homeostasis under control of anti-oxidative responses. Disruption in this balance induces severe inflammation and extended tissue degradation.

PURPOSE

Aim of this study was to identify the expression levels of nuclear factor, erythroid 2 like 2 (NFE2L2/NRF2), Parkinsonism associated deglycase (PARK7/DJ-1), kelch-like ECH associated protein 1 (KEAP1), and 8-hydroxy-deoxyguanosine (8-OHdG) in peri-implant mucosal tissues affected by peri-implantitis, and to compare the levels to those of periodontally diseased and healthy tissue samples.

METHODS

Tissue biopsies were collected from systemically healthy, non-smoking 12 peri-implantitis patients, 13 periodontitis patients, and 13 periodontally healthy controls. Expression levels of NFE2L2/NRF2, PARK7/DJ-1, KEAP1, and 8-OHdG in tissue samples were analyzed immunohistochemically. Statistical analysis was performed by one-way ANOVA with Tukey's HSD test.

RESULTS

Inflammatory cell infiltration in the connective tissue and loss of architecture in the spinous layer of the epithelium were prominent in peri-implantitis. Proportions of 8-OHdG and PARK7/DJ-1 expressing cells were elevated in both peri-implantitis (P = .025 for 8-OHdG and P = .014 for PARK7/DJ-1) and periodontitis (P = .038 for 8-OHdG and P = .012 for PARK7/DJ-1) groups in comparison with controls. Staining intensities of 8-OHdG and PARK7/DJ-1 were higher in the periodontitis and peri-implantitis groups than in the control (P < .01) groups. There was no difference in the expression levels of NFE2L2/NRF2 between the groups. KEAP1 was not observed in any tissue sample.

CONCLUSIONS

Peri-implantitis is characterized by severe inflammation and architectural changes in the epithelium and connective tissue. The expressions of 8-OHdG and PARK7/DJ-1 are elevated in both peri-implantitis and periodontitis.

Assessment of the impact of aerosol from a potential modified risk tobacco product compared with cigarette smoke on human organotypic oral epithelial cultures under different exposure regimens

Cigarette smoke (CS) is affecting considerably the oral mucosa. Heating, instead of burning, tobacco reduces consistently the amount of toxic compounds and may exert a lower impact on oral health than combusted cigarettes. The carbon-heated tobacco product 1.2 (CHTP1.2) is a potential modified risk tobacco product (MRTP) based on heat-not-burn technology. Using a systems toxicology assessment framework, we compared the effects of exposure to CHTP1.2 aerosol with those of CS from a reference cigarette (3R4F). Human organotypic cultures derived from buccal and gingival epithelia were exposed acutely (28-min) or repeatedly (28 min/day for 3 days), respectively, to two matching concentrations of CHTP1.2 aerosol or 3R4F CS, and a non-diluted (100%) CHTP1.2 aerosol. The results showed an absence of cytotoxicity, reduction in pathophysiological alterations, toxicological marker proteins, and inflammatory mediators following exposure to CHTP1.2 aerosol compared with 3R4F CS. Changes in mRNA and miRNA expression were linked by an integrative analysis approach, suggesting a regulatory role of miRNAs in several smoke/disease-relevant biological processes induced by 3R4F CS. The identification of mechanisms by which potential MRTPs can reduce the impact of tobacco use on biological systems is of great importance in understanding the molecular basis of the smoking harm reduction paradigm.

Ageing effects on humoral immune responses in chronic periodontitis

Periodontal disease is a dominant global bacterial infection that increases with ageing.

AIM

This report focuses on host adaptive immune responses in periodontitis. While experimental models and humans diagnosed with periodontitis demonstrate an antigenic specificity for particular oral bacteria, we have a limited understanding of (i) how ageing affects the adaptive immune responses to these bacteria that chronically colonize the oral cavity for decades prior to disease expression and (ii) how the magnitude and specificity of the response interface with pathogens that emerge within the bacterial ecology during exacerbations of disease.

MATERIALS AND METHODS

Serum antibody levels to a group of pathogenic and commensal oral bacteria were measured in a population of individuals from 21 to 74 years of age, stratified based on clinical status of the periodontium, smoking and sex.

RESULTS

Clinical parameters were not significantly different within health, gingivitis or periodontitis groups related to age. Antibody to oral pathogens and commensals was similar in different age groups in each of the clinical categories, with no age correlation noted in the periodontitis patients.

CONCLUSIONS

The adaptive immune responses to oral bacteria that chronically colonize the oral cavity appear generally unaffected by age, but clearly are linked to the extent of disease.

Disability and the impact of need for periodontal care on quality of life: A cross-sectional study

Objective

The need for periodontal care may negatively impact daily life. We compared the need for periodontal care and its impact on daily life between disabled and healthy adults in the Eastern Province, Saudi Arabia.

Methods

In this cross-sectional study of 819 adults, a questionnaire was used to assess personal background factors; the impact of periodontitis on pain, avoiding foods, embarrassment, sleeplessness, work absence, and discontinuing daily activities; and risk factors (smoking, diabetes, toothbrushing, insurance, professional tooth cleaning, and dental visits). The outcome was clinically assessed need for periodontal care impacting daily life. The relationship between the outcome and risk factors adjusted for personal background and disability was assessed using ordinal regression.

Results

Healthy and disabled persons had a high need for periodontal care (66.8%). Current smokers had a higher likelihood and health-insured persons had a lower likelihood of need for periodontal care impacting daily life regardless of whether disability was considered.

Conclusions

Most adults needed periodontal care, and disabled persons experienced a greater impact on life. Current smokers and uninsured persons were more likely to need periodontal care impacting daily life. Our findings are important for the prevention of periodontitis through tobacco cessation and extending insurance coverage.

The combined and individual impact of diabetes and smoking on key subgingival periodontal pathogens in patients with chronic periodontitis

BACKGROUND AND OBJECTIVE

Comprehension of the similarities and differences in the composition of the subgingival microbiota of patients with diabetes mellitus (DM), smokers or smokers with DM is an important step in developing therapies specific for these groups at risk for periodontitis. Therefore, the aim of this study was to compare the combined and individual effects of DM and smoking on the levels and prevalence of key subgingival periodontal pathogens in patients with chronic periodontitis.

MATERIAL AND METHODS

One hundred patients with generalized chronic periodontitis were allocated into one of the following groups: DM (n = 25, non-smokers with type 2 DM); S (n = 25, non-diabetic smokers); SDM (n = 25, smokers with type 2 DM); and control (n = 25, non-diabetic non-smokers). Two subgingival biofilm samples from healthy sites (probing depth and clinical attachment level ≤3 mm and no bleeding) and 2 from diseased sites (probing depth and clinical attachment level ≥5 mm and bleeding on probing) were analyzed by quantitative polymerase chain reaction for Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Eubacterium nodatum, Parvimonas micra, Fusobacterium nucleatum ssp. and Prevotella intermedia.

RESULTS

There were no differences among groups in the mean counts of the bacterial species studied, considering all sampled sites (healthy plus diseased sites). There were also no differences among groups regarding the prevalence of any bacteria species in healthy and diseased sites (P > .05). The mean P. micra count was significantly higher in the healthy sites of both smoking groups, than in those of the control group (P < .05).

CONCLUSION

The subgingival levels and prevalence of the bacterial species studied are not significantly different in subjects with chronic periodontitis presenting DM, smokers or smokers with DM. In addition, DM and smoking, jointly and individually, do not considerably affect the subgingival levels of target periodontal pathogens in patients with chronic periodontitis.

Cytokine-based Predictive Models to Estimate the Probability of Chronic Periodontitis: Development of Diagnostic Nomograms

Although a distinct cytokine profile has been described in the gingival crevicular fluid (GCF) of patients with chronic periodontitis, there is no evidence of GCF cytokine-based predictive models being used to diagnose the disease. Our objectives were: to obtain GCF cytokine-based predictive models; and develop nomograms derived from them. A sample of 150 participants was recruited: 75 periodontally healthy controls and 75 subjects affected by chronic periodontitis. Sixteen mediators were measured in GCF using the Luminex 100™ instrument: GMCSF, IFNgamma, IL1alpha, IL1beta, IL2, IL3, IL4, IL5, IL6, IL10, IL12p40, IL12p70, IL13, IL17A, IL17F and TNFalpha. Cytokine-based models were obtained using multivariate binary logistic regression. Models were selected for their ability to predict chronic periodontitis, considering the different role of the cytokines involved in the inflammatory process. The outstanding predictive accuracy of the resulting smoking-adjusted models showed that IL1alpha, IL1beta and IL17A in GCF are very good biomarkers for distinguishing patients with chronic periodontitis from periodontally healthy individuals. The predictive ability of these pro-inflammatory cytokines was increased by incorporating IFN gamma and IL10. The nomograms revealed the amount of periodontitis-associated imbalances between these cytokines with pro-inflammatory and anti-inflammatory effects in terms of a particular probability of having chronic periodontitis.

Factors Associated With Need for Revascularisation in Non-coronary Arterial Occlusive Lesions Secondary to Takayasu's Arteritis

OBJECTIVE/BACKGROUND

Takayasu's arteritis (TA) is rare inflammatory large vessel form of vasculitis. The objective of this study was to evaluate experience in the management of TA patients and to identify the influence of inflammatory markers and clinical variables associated with disease progression, worsening ischaemic symptoms, and the need for interventions.

METHODS

Demographics, and laboratory and clinical variables in patients that required revascularisation procedures were compared with those who had adequate symptomatic control with medical management. Categorical data were analysed with Fisher's exact test, continuous variables with two-sample t test, and a life table analysis was used to study the recurrence of symptoms in intervened patients.

RESULTS

From January 1995 to May 2016, 47 patients (mean age 30 years; range 14-59 years) were managed; 44 (94%) were female. During the mean follow-up period of 120 months, 21 (45%) underwent 23 procedures (17 of these [74%] open, six [26%] endovascular). From the intervened group, eight (38%) patients presented with transient ischaemic attacks, five (24%) with renovascular hypertension, and four (19%) with upper extremity and four (19%) lower extremity claudication. Comparative analysis demonstrated that elevation of erythrocyte sedimentation rate (ESR) at the time of the diagnosis (revascularisation group: median value 28 mm/hour; medical management group: median value 15 mm/hour) was associated with progression of the disease, worsening symptoms, and subsequent need for intervention (p = .04). Active smoking was a factor connected with the need for revascularisation (p = .05). Immediate symptomatic improvement occurred in 19 (90%) patients that underwent surgical or endovascular revascularisation.

CONCLUSION

Patients with TA who underwent interventions had higher ESR at the time of diagnosis; this factor and active smoking were associated with progression of the disease and worsening ischaemic symptoms despite medical therapy. Revascularisation procedures are effective at relieving symptoms; lifelong surveillance is necessary.

The Inflammatory Potential of the Diet Is Associated with Depressive Symptoms in Different Subgroups of the General Population

Background: Low-grade chronic inflammation, which can be modulated by diet, has been suggested as an important risk factor for depression, but few studies have investigated the association between the inflammatory potential of the diet and depression.Objective: We investigated the prospective association between the inflammatory potential of the diet, measured by the Dietary Inflammatory Index (DII), and incident depressive symptoms and tested the potential modulating effect of sex, age, physical activity, and smoking status.Methods: This study included 3523 participants (aged 35-60 y) from the SU.VI.MAX (Supplémentation en Vitamines et Minéraux Antioxydants) cohort, who were initially free of depressive symptoms. Baseline DII (1994-1996) was computed by using repeated 24-h dietary records. Incident depressive symptoms were defined by a Center for Epidemiologic Studies-Depression Scale score ≥17 for men and ≥23 for women in 2007-2009. We used multivariable logistic regression models to estimate ORs and 95% CIs, and modeled the DII as a continuous variable and as sex-specific quartiles.Results: A total of 172 cases of incident depressive symptoms were identified over a mean follow-up of 12.6 y. The DII was not associated with incident depressive symptoms in the full sample. In sex-specific models, men with a higher DII had a higher risk of incident depressive symptoms (quartile 4 compared with quartile 1-OR: 2.32; 95% CI: 1.01, 5.35), but the association was only marginally significant (P-trend = 0.06). When analyses were performed across smoking status, current and former smokers with a higher DII had a higher risk of incident depressive symptoms (quartile 4 compared with quartile 1-OR: 2.21; 95% CI: 1.08, 4.52). A positive association was also observed among less physically active participants (quartile 4 compared with quartile 1-OR: 2.07; 95% CI: 1.05, 4.07).Conclusion: The promotion of a healthy diet with anti-inflammatory properties may help to prevent depressive symptoms, particularly among men, smokers, or physically inactive individuals. This trial was registered at clinicaltrials.gov as NCT0027242.

The effect of smoking on inflammatory and bone remodeling markers in gingival crevicular fluid and subgingival microbiota following periodontal therapy

BACKGROUND AND OBJECTIVE

Periodontal health is mediated by suppressing microorganisms inducing a local inflammatory host response. Smoking may impair this process. This study compares gingival crevicular fluid levels of inflammatory and bone remodeling markers in heavy smokers and non-smokers following active and supportive periodontal therapy in patients with chronic periodontitis.

MATERIAL AND METHODS

Gingival crevicular fluid and subgingival plaque were collected from the deepest periodontal pocket in 50 patients, 25 smokers and 25 non-smokers, at baseline (T0), following active (T1) and 12 mo of supportive periodontal therapy (T2). Smoking status was validated measuring serum cotinine levels. Gingival crevicular fluid levels of 27 inflammatory and two bone remodeling markers were analyzed using multiplex and singleplex micro-bed immunoassays, and subgingival plaque samples using checkerboard DNA-DNA hybridization. Amounts of markers in smokers and non-smokers were compared calculating the effect size.

RESULTS

Expression of inflammatory and bone-remodeling markers in smokers demonstrated an overall reduced effect size at T0 and T2 (p < 0.001). In particular, proinflammatory markers (p < 0.001), chemokines (p = 0.007) and growth factors (p = 0.003) at T0, osteoprotegerin (p = 0.003) at T1, proinflammatory markers (p = 0.019) and chemokines (p = 0.005) at T2. At T2, interleukin-8 was detected in significantly higher levels in smokers. Ten different markers in non-smokers and none in smokers responded to periodontal therapy (p < 0.05). An overall negative association was revealed between smoking and subgroups of markers at sites presenting ≥ 10⁵ red complex periodontal microbial species.

CONCLUSION

Except for an upregulation of interleukin-8, smokers exhibited reduced gingival crevicular fluid levels of several inflammatory markers at baseline and following active and supportive periodontal therapy. Only inflammatory responses in non-smokers adapted to periodontal therapy. Apparently, there seems to be an immunosuppressant effect of smoking regulating the local inflammatory response and bone remodeling markers captured in gingival crevicular fluid following periodontal therapy.

Integrated biomarker profiling of smokers with periodontitis

BACKGROUND

In the context of precision medicine, understanding patient-specific variation is an important step in developing targeted and patient-tailored treatment regimens for periodontitis. While several studies have successfully demonstrated the usefulness of molecular expression profiling in conjunction with single classifier systems in discerning distinct disease groups, the majority of these studies do not provide sufficient insights into potential variations within the disease groups.

AIM

The goal of this study was to discern biological response profiles of periodontitis and non-periodontitis smoking subjects using an informed panel of biomarkers across multiple scales (salivary, oral microbiome, pathogens and other markers).

MATERIAL & METHODS

The investigation uses a novel ensemble classification approach (SVA-SVM) to differentiate disease groups and patient-specific biological variation of systemic inflammatory mediators and IgG antibody to oral commensal and pathogenic bacteria within the groups.

RESULTS

Sensitivity of SVA-SVM is shown to be considerably higher than several traditional independent classifier systems. Patient-specific networks generated from SVA-SVM are also shown to reveal crosstalk between biomarkers in discerning the disease groups. High-confidence classifiers in these network abstractions comprised of host responses to microbial infection elucidated their critical role in discerning the disease groups.

CONCLUSIONS

Host adaptive immune responses to the oral colonization/infection contribute significantly to creating the profiles specific for periodontitis patients with potential to assist in defining patient-specific risk profiles and tailored interventions.

Genetic and environmental risk factors for rheumatoid arthritis

Multiple genetic and environmental factors have been associated with an increased risk for rheumatoid arthritis (RA). Of these, the strongest associations have been seen with female sex, a family history of RA, the genetic factor the "shared epitope," and exposure to tobacco smoke. There is also renewed interest in mucosal inflammation and microbial factors as contributors to the development of RA. However, the identification of a "preclinical" period of RA that can be defined as local or systemic autoimmunity as measured by autoantibodies and other biomarkers prior to the development of clinically apparent synovitis suggests that the risk factors for RA are acting long prior to first clinical evidence of IA. As such, a major challenge to the field will be to investigate the full spectrum of the development of RA, from initiation and propagation of autoimmunity during preclinical RA and transition to clinically apparent synovitis and classifiable RA, to determine which genetic and environmental factors are important at each stage of disease development. Understanding the exact role and timing of action of risk factors for RA is especially important given the advent of prevention trials in RA, and the hope that a full understanding of genetic and environmental factors in RA could lead to effective preventive interventions.