Relationship between Periodontitis and Rheumatoid Arthritis: Review of the Literature

Exploring the Bidirectional Relationship Between Periodontitis and Rheumatoid Arthritis in a Large Danish Cohort

OBJECTIVE

We investigated the bidirectional relationship between rheumatoid arthritis (RA) and periodontitis and their cross-sectional association using national administrative health care data.

METHODS

The sample included 3,308,903 individuals aged 20 to 79 years who resided in Denmark in 2000 and had remained free of RA and periodontitis in the previous 10 years. RA and periodontitis were defined using diagnosis and treatment codes. Marginal structural survival models were employed to estimate the effects of RA on periodontitis incidence and vice versa from 2000 to 2017. Using a cross-sectional sample of 2,574,536 individuals from 2017, the association of periodontitis with RA was investigated using regression analyses and probabilistic quantitative bias analyses, simulating RA and periodontitis misclassification and unmeasured confounding of smoking.

RESULTS

Between 2000 and 2017, 20,348 individuals developed RA and 740,799 developed periodontitis. The estimated hazard ratio (HR) for the effect of periodontitis on incident RA was 1.05 (95% confidence interval [CI] 0.88-1.25), resulting in a restricted mean survival time difference of one day. The HR for the effect of RA on incident periodontitis was 0.84 (95% CI 0.80-0.88), corresponding to a restricted mean survival time difference of 151 days. Cross-sectionally, the unadjusted prevalence ratio for the association was 1.15 (95% CI 1.11-1.19), whereas the estimate adjusted for measured and simulated confounding was practically null (0.99, 95% simulation interval 0.93-1.04).

CONCLUSION

These findings challenge previously reported bidirectional relationships between periodontitis and RA, pointing to potential residual confounding as an important link and prompting reconsideration of the biologic plausibility and clinical significance of these associations.

The role of microbiota on rheumatoid arthritis onset

Rheumatoid arthritis (RA) is a chronic autoimmune disease that causes inflammation and pain, which can lead to the loss of normal joint function. Although the exact cause of the disease is not yet fully understood, both environmental factors and genetics may play a role in its development. Moreover, research suggests microbiota contributes to the onset and progression of RA. People with RA show higher quantities of bacteria such as Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Prevotella copri, Proteus mirabilis, and Lactobacillus salivarius compared to healthy individuals. Conversely, studies propose that Lactobacillus casei, a probiotic bacterium with immunomodulatory properties, has beneficial effects for RA in murine and human models. Therefore, this work reviews the potential role of the gut microbiota in the development of RA and explores the feasibility of using probiotic bacteria as a supplementary treatment for this disease.

Periodontal health status in systemic sclerosis patients: Systematic review and meta-analysis

OBJECTIVE

The present systematic review and meta-analysis aimed to evaluate the periodontal health of systemic sclerosis patients compared with non-systemic sclerosis controls.

MATERIALS AND METHODS

Online databases were searched for eligible studies on February 24, 2023. The primary outcomes of interest in systemic sclerosis patients and controls included the clinical attachment level, periodontal probing depth, recession depth, plaque index, bleeding on probing score, gingival index, number of teeth with periodontitis, prevalence of periodontitis and gingivitis, and extent and severity of periodontitis.

RESULTS

Fourteen studies met inclusion criteria and were incorporated in the qualitative and quantitative analysis. In comparison with the controls, systemic sclerosis patients had a higher prevalence of periodontitis (OR = 7.63 (1.74-33.50), p = 0.04, I2 = 69%), including more severe forms of periodontitis (OR = 6.68 (3.39-13.15), p = 0.85, I2 = 0%), as well as higher periodontal probing depth ((0.88 (0.45-1.31), p = 0.02, I2 = 99%)), clinical attachment level (1.22 (0.8-1.64), p = 0.003, I2 = 98%), and plaque presence (0.83 (0.13-1.53), p = 0.03, I2 = 96%). There was no statistically significant difference in gingival inflammation (1.14 (0.07-2.21), p = 0.04, I2 = 98%).

CONCLUSIONS

The systematic review and the meta-analysis showed that systemic sclerosis patients suffer from worse periodontal health than non-systemic sclerosis individuals.

The impact of arthritogenic viruses in oral tissues

Arthritis and periodontitis are inflammatory diseases that share several immunopathogenic features. The expansion in the study of virus-induced arthritis has shed light on how this condition could impact other parts of the human body, including the mouth. Viral arthritis is an inflammatory joint disease caused by several viruses, most notably the alphaviruses Chikungunya virus (CHIKV), Sindbis virus (SINV), Ross River virus (RRV), Mayaro virus (MAYV), and O'nyong'nyong virus (ONNV). These viruses can induce an upsurge of matrix metalloproteinases and immune-inflammatory mediators such as Interleukin-6 (IL6), IL-1β, tumor necrosis factor, chemokine ligand 2, and receptor activator of nuclear factor kappa-B ligand in the joint and serum of infected individuals. This can lead to the influx of inflammatory cells to the joints and associated muscles as well as osteoclast activation and differentiation, culminating in clinical signs of swelling, pain, and bone resorption. Moreover, several data indicate that these viral infections can affect other sites of the body, including the mouth. The human oral cavity is a rich and diverse microbial ecosystem, and viral infection can disrupt the balance of microbial species, causing local dysbiosis. Such events can result in oral mucosal damage and gingival bleeding, which are indicative of periodontitis. Additionally, infection by RRV, CHIKV, SINV, MAYV, or ONNV can trigger the formation of osteoclasts and upregulate pro-osteoclastogenic inflammatory mediators, interfering with osteoclast activation. As a result, these viruses may be linked to systemic conditions, including oral manifestations. Therefore, this review focuses on the involvement of alphavirus infections in joint and oral health, acting as potential agents associated with oral mucosal inflammation and alveolar bone loss. The findings of this review demonstrate how alphavirus infections could be linked to the comorbidity between arthritis and periodontitis and may provide a better understanding of potential therapeutic management for both conditions.

Exploring the presence of oral bacteria in non-oral sites of patients with cardiovascular diseases using whole metagenomic data

Cardiovascular diseases (CVDs) encompass various conditions affecting the heart and its blood vessels and are often linked with oral microbes. Our data analysis aimed to identify oral bacteria from other non-oral sites (i.e., gut, arterial plaque and cultured blood) that could be linked with CVDs. Taxonomic profiling identified bacteria to the species level and compared with the Human Oral Microbiome Database (HOMD). The oral bacteria in the gut, cultured blood and arterial plaque samples were catalogued, with their average frequency calculated for each sample. Additionally, data were filtered by comparison with the Human Microbiome Project (HMP) database. We identified 17,243 microbial species, of which 410 were present in the HOMD database and further denominated as "oral", and were found in at least one gut sample, but only 221 and 169 species were identified in the cultured blood and plaque samples, respectively. Of the 410 species, 153 were present solely in oral-associated environments after comparison with the HMP database, irrespective of their presence in other body sites. Our results suggest a potential connection between the presence of specific species of oral bacterial and occurrence of CVDs. Detecting these oral bacterial species in non-oral sites of patients with CVDs could help uncover the link between oral health and general health, including cardiovascular conditions via bacterial translocation.

Association between rheumatoid arthritis and pulpal-periapical pathology: a systematic review

OBJECTIVES

Rheumatoid arthritis (RA) is a debilitating disease where numerous pro-inflammatory cytokines have a proven role in its pathology. These cytokines are also involved in the pathogenesis of apical periodontitis (AP) where they have a pro-inflammatory role and induce bone resorption. Patients with RA may therefore be more prone to develop pulpal-periapical pathology (PPP). This study systematically reviewed the existing literature evaluating the association between RA and PPP.

MATERIALS AND METHODS

Studies including human participants with both RA and PPP were included. The search was performed in PubMed, Web of Science, and The Cochrane Library databases using keywords and Medical Subject Headings (MeSH) search terms. The risk of bias was assessed using Newcastle-Ottawa Quality Assessment Scale. The following parameters were extracted and analyzed by the reviewers; author, journal, year, design of the study, diagnostic criteria for periapical pathology, the association between rheumatoid arthritis and periapical pathology, and the evidence level.

RESULTS

The search identified 142 records. Inclusion criteria were as follows; studies in the English language, including human participants only, including patients with RA and PPP, cohort studies, cross-sectional studies, clinical trials, and case-control studies. According to the inclusion criteria, 5 studies were included in this systematic review. Three of the five studies reported significant association between RA and PPP.

CONCLUSIONS

Existing evidence suggests there may be an association between RA and PPP.

CLINICAL RELEVANCE

Clinicians should be aware that RA patients can be more prone to develop PPP which may result in a reduced quality of life.

Lepr-Expressing PDLSCs Contribute to Periodontal Homeostasis and Respond to Mechanical Force by Piezo1

Periodontium supports teeth in a mechanically stimulated tissue environment, where heterogenous stem/progenitor populations contribute to periodontal homeostasis. In this study, Leptin receptor+ (Lepr+) cells are identified as a distinct periodontal ligament stem cell (PDLSC) population by single-cell RNA sequencing and lineage tracing. These Lepr+ PDLSCs are located in the peri-vascular niche, possessing multilineage potential and contributing to tissue repair in response to injury. Ablation of Lepr+ PDLSCs disrupts periodontal homeostasis. Hyper-loading and unloading of occlusal forces modulate Lepr+ PDLSCs activation. Piezo1 is demonstrated that mediates the mechanosensing of Lepr+ PDLSCs by conditional Piezo1-deficient mice. Meanwhile, Yoda1, a selective activator of Piezo1, significantly accelerates periodontal tissue growth via the induction of Lepr+ cells. In summary, Lepr marks a unique multipotent PDLSC population in vivo, to contribute toward periodontal homeostasis via Piezo1-mediated mechanosensing.

Increased risk of periodontitis in patients with rheumatoid arthritis: A nationwide register study in Norway

AIM

To investigate the risk of periodontitis in rheumatoid arthritis (RA) patients in a nationwide register-based study.

MATERIALS AND METHODS

Patients and controls were defined using ICD-10 codes registered in the Norwegian Patient Registry (NPR), from 2011 to 2017. The 324,232 included subjects had at least one registered diagnostic code for RA (33,040 patients) or diagnostic codes for non-osteoporotic fractures or hip or knee replacement due to osteoarthritis (controls). The outcome was periodontitis, defined by codes for periodontal treatment from the Norwegian Control and Payment of Health Reimbursements Database (KUHR). Hazard ratios (HRs) were calculated for periodontitis in RA patients compared to controls. Generalized additive model in Cox regressions was estimated to visualize periodontitis occurrences as a function of number of RA visits.

RESULTS

The risk of periodontitis increased with increasing number of RA visits. RA patients having 10 or more visits during the 7-year period had a 50% increased risk of periodontitis compared to controls (HR = 1.48, 95% confidence interval [CI]: 1.39-1.59); also, in patients with assumed new RA, an even higher risk estimate was seen (HR = 1.82, 95% CI: 1.53-2.17).

CONCLUSIONS

In this register-based study in which periodontal treatment was used as a surrogate marker for periodontitis, we found an increased risk of periodontitis in RA patients, particularly those with active disease and new RA.

Differential associations of rheumatoid arthritis and periodontitis or tooth loss: A cross-sectional study

AIM

To study the association between periodontitis, tooth loss, and rheumatoid arthritis (RA) by using a large national dataset.

MATERIALS AND METHODS

An observational cross-sectional study was performed using the National Health and Nutrition Examination Survey cycles (2009-2014). RA status was detected using a questionnaire. Periodontal status was assigned on the basis of the clinical attachment level and periodontal pocket depth. Dentition status was assessed by the number of permanent teeth observed. We examined the association between RA as exposure and moderate/severe periodontitis and non-functional dentition as outcomes. We progressively adjusted our models for different sets of potential confounders.

RESULTS

Moderate/severe periodontitis was more prevalent in participants reporting RA (53% vs. 41.5%, p = .0003). Non-functional dentition was more prevalent in participants with RA (41% vs. 15.5%, p = .0001). The fully adjusted model showed that participants with RA had higher odds of having non-functional dentition (odds ratio 1.8, 95% confidence interval [CI] 1.3-2.3, p = .0001) but no association with moderate/severe periodontitis (prevalence ratio 1.01, 95% CI 0.9-1.1, p = .9).

CONCLUSION

RA was associated with a higher likelihood of having non-functional dentition but did not show any association with periodontitis after adjusting for the risk factors to control their confounding effect.

Immune dysregulation and pathogenic pathways mediated by common infections in rheumatoid arthritis

Rheumatoid arthritis (RA) is one of the world's most prevalent inflammatory autoimmune diseases, affecting between 0.4 and 1.3% of the population. The susceptibility to RA appears to be influenced by a complex interaction between a favorable genetic background and the existence of a specific immune reaction against a wide range of environmental variables. Among the known environmental variables, infections are believed to have a significant role in promoting the formation of autoimmune disorders, which are frequently caused by specific microorganisms. Infections have been linked to RA in recent medical studies. In this study, we selected the most prevalent infections associated with RA from the literature and described the data confirming their pathogenic role in RA. Our investigation included Mycobacterium, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Proteus mirabilis, Epstein-Barr virus, parvovirus, and Prevotella copri.

Salivary Antioxidant Profile in Patients with Systemic Sclerosis and Periodontitis

Objective

The aim of the present study was to compare periodontal status and antioxidant profile in unstimulated saliva of systemic sclerosis (SSc) patients with periodontitis and systemically healthy periodontitis patients.

Design

Twenty patients with established diagnoses of systemic sclerosis and periodontitis (SSc group) and 20 systemically healthy individuals with periodontitis (P group) were enrolled in the study. Clinical periodontal parameters (clinical attachment level (CAL), gingival recession (GR), periodontal probing depth (PPD), and gingival index (GI)) and concentration of uric acid (UA), superoxide dismutase (SOD), and glutathione peroxidase (GPX) in unstimulated saliva samples were assessed.

Results

There were significantly higher mean values of CAL (4.8 ± 0.21 mm versus 3.18 ± 0.17 mm; p ≤ 0.001) and GR (1.66 ± 0.90 mm versus 0.46 ± 0.54 mm; p ≤ 0.001) in the SSc group when compared to the P group. Significantly higher level of GPX (p ≤ 0.001) and SOD (p ≤ 0.001) in unstimulated saliva was detected in the SSc group in comparison with the P group. The specific activity of UA did not significantly differ between the two groups (p = 0.083).

Conclusion

The results may indicate higher periodontal destruction and antioxidant perturbations in unstimulated saliva of SSc patients with periodontitis compared to systemically healthy periodontitis patients.

Nanoparticulate cell-free DNA scavenger for treating inflammatory bone loss in periodontitis

Periodontitis is a common type of inflammatory bone loss and a risk factor for systemic diseases. The pathogenesis of periodontitis involves inflammatory dysregulation, which represents a target for new therapeutic strategies to treat periodontitis. After establishing the correlation of cell-free DNA (cfDNA) level with periodontitis in patient samples, we test the hypothesis that the cfDNA-scavenging approach will benefit periodontitis treatment. We create a nanoparticulate cfDNA scavenger specific for periodontitis by coating selenium-doped hydroxyapatite nanoparticles (SeHANs) with cationic polyamidoamine dendrimers (PAMAM-G3), namely G3@SeHANs, and compare the activities of G3@SeHANs with those of soluble PAMAM-G3 polymer. Both G3@SeHANs and PAMAM-G3 inhibit periodontitis-related proinflammation in vitro by scavenging cfDNA and alleviate inflammatory bone loss in a mouse model of ligature-induced periodontitis. G3@SeHANs also regulate the mononuclear phagocyte system in a periodontitis environment, promoting the M2 over the M1 macrophage phenotype. G3@SeHANs show greater therapeutic effects than PAMAM-G3 in reducing proinflammation and alveolar bone loss in vivo. Our findings demonstrate the importance of cfDNA in periodontitis and the potential for using hydroxyapatite-based nanoparticulate cfDNA scavengers to ameliorate periodontitis.

Periodontitis is a common type of inflammatory bone loss, and cell-free DNA (cfDNA) can be a major source that enhances the periodontal tissue destruction. Here, the authors show that a cfDNA-scavenging approach is able to ameliorate periodontitis by using nanoparticulate cfDNA scavenger.

Periodontitis in Italian patients with established rheumatoid arthritis: A cross-sectional study

OBJECTIVE

To assess the prevalence and severity of periodontitis (P) among Italian patients affected by rheumatoid arthritis (RA).

MATERIALS AND METHODS

A full-mouth periodontal examination and a rheumatologic examination were performed. RA disease activity was scored using the DAS28. Serum analyses investigated levels of rheumatoid factor, anti-citrullinated protein antibodies (ACPAs), C-reactive protein, erythrocyte sedimentation rate and fibrinogen. Information concerning smoking, body mass index and RA medical therapy was collected. Data were analysed by Student's t test, chi-square test, binary logistic regression and Spearman's rank.

RESULTS

This cross-sectional study included 120 subjects, 77 had both diseases while 43 only had RA. The number of teeth present was statistically lower in the RA-P compared to the RA group (p < .05). There were statistically more subjects seropositive for ACPAs in the RA-P group (62.3% vs. 32.6%, p < .05). RA-P patients had an adjusted OR = 2.9 of presenting a moderate-severe DAS28 score (DAS28 ≥ 3.2).

CONCLUSIONS

Higher prevalence of severe P was noted among RA subjects. The clinical severity of RA was strongly correlated with the clinical periodontal parameters, and RA subjects also affected by P had an OR of 2.9 for presenting with a moderate-severe RA (DAS28 score ≥ 3.2).

Oral health associated with incident diabetes but not other chronic diseases: A register-based cohort study

Introduction

Oral infectious diseases are common chronic oral diseases characterized by a chronic inflammatory condition. We investigated chronic oral diseases as potential risk factors for systemic chronic diseases, diabetes mellitus, connective tissue diseases, seropositive rheumatoid arthritis, ulcerative colitis, and Crohn's disease, as well as severe psychotic and other severe mental disorders.

Methods

The cohort comprised 68,273 patients aged ≥ 29 years with at least one dental visit to the Helsinki City Health Services between 2001 and 2002. The cohort was linked to the data on death (Statistics Finland), cancer (Finnish Cancer Registry), and drug reimbursement (Finnish Social Insurance Institution) and followed until death or the end of 2013. The outcomes of interest were the incidences of chronic diseases measured starting with special refund medication, which means Social Insurance Institution partly or fully reimburses medication costs. Outcomes of interest were diabetes mellitus, connective tissue diseases, seropositive rheumatoid arthritis, ulcerative colitis and Crohn's disease, and severe mental disorders.

Results

The mean follow-up time was 9.8 years. About 25% of the study population had periodontitis, 17% caries, over 70% apical periodontitis, and 9% <24 teeth at the start of follow-up. Diabetes was the only chronic systemic condition associated with oral health variables. Having 24 to 27 teeth was associated with a higher incidence rate ratio (IRR) (1.21, 95% confidence interval 1.09-1.33) compared to having 28 or more teeth; the IRR for having 23 or less was 1.40 (1.22-1.60). Having periodontitis (1.10, 1.01-1.20), caries (1.12, 1.01-1.23), or apical periodontitis (1.16, 1.04-1.30) is also associated with a higher risk of diabetes.

Conclusion

Our epidemiological 10 years follow-up study suggests that the association exists between chronic oral diseases and diabetes, warranting close collaboration among patient's healthcare professionals.

Oral health-related quality of life and dental caries in rheumatoid arthritis patients: a cross-sectional observational study

Rheumatoid arthritis (RA) is a systemic, chronic, and inflammatory joint disease with oral complications. This research aimed to compare the oral health-related quality of life and decayed, missing and filled teeth (DMFT) index in rheumatoid arthritis patients over 18 years with healthy individuals. In this study, 45 rheumatoid arthritis cases were assigned to the experimental group, and 45 healthy individuals were assigned to the control group. After completing biography forms, the participants filled out two questionnaires. These questionnaires included the Oral Health Impact Profile-14 (OHIP-14) and the Oral Health Assessment Index (GOHAI). Next, their teeth were clinically examined to check for caries. Finally, the data were analyzed statistically. RA and control groups were similar in gender, marital status, age, occupation, and level of education. However, a significant difference was observed between the two groups concerning DMFT (P<0.001) and total OHIP-14 score (P<0.001). Moreover, no significant difference was observed between the groups concerning the total GOHAI score (P=0.526). The oral health-related quality of life in rheumatoid arthritis patients was lower than that in the general population, with the rate of dental caries being higher in these patients.

Managing the Systemic Impact of Periodontitis

Periodontitis is a microbially driven host-mediated disease that leads to loss of periodontal attachment and bone. It is associated with elevation of systemic inflammatory markers and with the presence of systemic co-morbidities. Furthermore, periodontal treatment leads to a 24-48 h-long acute local and systemic inflammatory response. This systemic response might increase the burden of patients with compromised medical history and/or uncontrolled systemic diseases. The correlation between periodontitis and systemic diseases, the impact of periodontitis on the quality of life and public health, the effects of periodontal treatment on systemic health and disease, and the available methods to manage systemic inflammation after periodontal therapy are discussed. The main focus then shifts to a description of the existing evidence regarding the impact of periodontitis and periodontal treatment on systemic health and to the identification of approaches aiming to reduce the effect of periodontitis on systemic inflammation.

Study of Alveolar Bone Remodeling Using Deciduous Tooth Stem Cells and Hydroxyapatite by Vascular Endothelial Growth Factor Enhancement and Inhibition of Matrix Metalloproteinase-8 Expression in vivo

Background

Periodontitis progression is characterized by alveolar bone loss, and its prevention is a major clinical problem in periodontal disease management. Matrix metalloproteinase-8 (MMP-8) has been shown to adequately monitor the treatment of chronic periodontitis patients as gingival crevicular fluid MMP-8s were positively associated with the severity of periodontal disease. Moreover, modulating the vascular endothelial growth factor (VEGF) levels in bones could be a good way to improve bone regeneration and cure periodontitis as VEGF promotes endothelial cell proliferation, proteolytic enzyme release, chemotaxis, and migration; all of which are required for angiogenesis.

Purpose

The aim of this study was to determine the effect of hydroxyapatite incorporated with stem cells from exfoliated deciduous teeth (SHED) in Wistar rats’ initial alveolar bone remodeling based on the findings of MMP-8 and VEGF expressions.

Methods

A hydroxyapatite scaffold (HAS) in conjunction with SHED was transplanted into animal models with alveolar mandibular defects. A total of 10 Wistar rats (Rattus norvegicus) were divided into two groups: HAS and HAS + SHED. Immunohistochemistry staining was performed after 7 days to facilitate the examination of MMP-8 and VEGF expressions.

Results

The independent t-test found significant downregulation of MMP-8 and upregulation VEGF expressions in groups transplanted with HAS in conjunction with SHED compared with the HAS group (p < 0.05).

Conclusion

The combination of SHED with HAS on alveolar bone defects may contribute to initial alveolar bone remodeling as evident through the assessments of MMP-8 and VEGF expressions.

Aggregatibacter actinomycetemcomitans as the Aetiological Cause of Rheumatoid Arthritis: What Are the Unsolved Puzzles?

Leukotoxin A (LtxA) is the major virulence factor of an oral bacterium known as Aggregatibacter actinomycetemcomitans (Aa). LtxA is associated with elevated levels of anti-citrullinated protein antibodies (ACPA) in rheumatoid arthritis (RA) patients. LtxA targets leukocytes and triggers an influx of extracellular calcium into cytosol. The current proposed model of LtxA-mediated hypercitrullination involves the dysregulated activation of peptidylarginine deiminase (PAD) enzymes to citrullinate proteins, the release of hypercitrullinated proteins through cell death, and the production of autoantigens recognized by ACPA. Although model-based evidence is yet to be established, its interaction with the host’s immune system sparked interest in the role of LtxA in RA. The first part of this review summarizes the current knowledge of Aa and LtxA. The next part highlights the findings of previous studies on the association of Aa or LtxA with RA aetiology. Finally, we discuss the unresolved aspects of the proposed link between LtxA of Aa and RA.

The Periodontopathic Pathogen, Porphyromonas gingivalis, Involves a Gut Inflammatory Response and Exacerbates Inflammatory Bowel Disease

Periodontal disease (PD) is one of the most prevalent disorders globally and is strongly associated with many other diseases. Inflammatory bowel disease (IBD), an inflammatory condition of the colon and the small intestine, is reported to be associated with PD through undetermined mechanisms. We analyzed taxonomic assignment files from the Crohn’s Disease Viral and Microbial Metagenome Project (PRJEB3206). The abundance of Porphyromonadaceae in fecal samples was significantly different between patients with Crohn’s disease and control volunteers. Dextran sulfate sodium was used to induce colitis in mice to reveal the effect of this periodontopathic pathogen in vivo. After intrarectal implantation of Porphyromonas gingivalis (Pg)—the primary pathogen causing PD—the disease activity index score, colonic epithelial loss, and inflammatory cell infiltration were intensified. In addition, tumor necrosis factor-α and interleukin-6 showed the highest levels in Pg-infected colons. This revealed the importance of Pg in the exacerbation of IBD. Thus, simultaneous treatment of PD should be considered for people with IBD. Moreover, implantation of Pg in the rectum worsened the clinical symptoms of colitis in mice. Because Pg participates in the pathogenesis of IBD, reducing the chances of it entering the intestine might prevent the worsening of this disorder.

Oral health-related quality of life in patients with early rheumatoid arthritis is associated with periodontal inflammation and painful temporomandibular disorders: a cross-sectional study

OBJECTIVES

To evaluate oral health-related quality of life (OHRQoL) in early rheumatoid arthritis (ERA) patients and individuals at risk of rheumatoid arthritis (RA) compared to healthy controls, and to explore possible associated factors.

MATERIALS AND METHODS

Fifty ERA patients, 50 at-risk individuals, and 50 age and gender matched healthy controls were recruited. OHRQoL (Oral Health Impact Profile-14 (OHIP-14)); number of decayed, missing, and filled teeth (DMFT); denture use; periodontal inflamed surface area (PISA); xerostomia (xerostomia inventory (XI)); and possible TMD (-pain) diagnoses were recorded. The groups were compared on these variables. Subsequently, backward multiple regression analyses were performed for the ERA and at-risk groups, with OHRQoL as the dependent variable and gender, age, DMFT, denture use, PISA, XI, non-painful TMD, and TMD pain as independent variables.

RESULTS

At-risk individuals had higher XI scores (U = 789.5, z = -3.181, p = 0.001, r = -0.32) and higher prevalence of TMD pain (p = 0.046, OR = 4.57; 95% CI 0.92-22.73) than healthy controls and higher OHIP-14 scores than the ERA group (U = 894.5, z = -2.418, p = 0.016, r = -0.24), while no difference in OHIP-14 was found between the control group and both other groups. For ERA patients, OHRQoL was associated with PISA and TMD pain (R2 = 0.498, p < 0.001). For at-risk individuals, OHRQoL was associated with XI score (R2 = 0.410, p < 0.001).

CONCLUSIONS

Alertness of health professionals to TMD pain and periodontal inflammation in ERA patients and to xerostomia and TMD pain in at-risk individuals is recommended.

CLINICAL RELEVANCE

The results of this study address orofacial aspects that require attention of health professionals in the timeframe around RA onset.

TRIAL REGISTRATION

Dutch National Trial Register (NTR, NTR6362).

Genome-wide association study of periodontal pocketing in Finnish adults

Background

A genome‐wide association study is an analytical approach that investigates whether genetic variants across the whole genome contribute to disease progression. The aim of this study was to investigate genome-wide associations of periodontal condition measured as deepened periodontal pockets (≥ 4 mm) in Finnish adults.

Methods

This study was based on the data of the national Health 2000 Survey (BRIF8901) in Finland and the Northern Finland Birth Cohort 1966 Study totalling 3,245 individuals. The genotype data were analyzed using the SNPTEST v.2.4.1. The number of teeth with deepened periodontal pockets (≥ 4 mm deep) was employed as a continuous response variable in additive regression analyses performed separately for the two studies and the results were combined in a meta-analysis applying a fixed effects model.

Results

Genome-wide significant associations with the number of teeth with ≥ 4 mm deep pockets were not found at the p-level of < 5 × 10⁻⁸, while in total 17 loci reached the p-level of 5 × 10⁻⁶. Of the top hits, SNP rs4444613 in chromosome 20 showed the strongest association (p = 1.35 × 10⁻⁷).

Conclusion

No statistically significant genome-wide associations with deepened periodontal pockets were found in this study.

Serum miR-224, miR-760, miR-483-5p, miR-378 and miR-375 as potential novel biomarkers in rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is an inflammatory autoimmune disease which affects various tissues and organs mainly joints. Serum microRNAs are considered a new class of non-coding RNA which plays a vital role in pathogenesis of RA.

METHODS

The current study was conducted on 80 RA patients and 80 healthy participants. Serum expression levels of miR-224, miR-760, miR-483-5p, miR-378 and miR-375 were evaluated via real-time quantitative polymerase chain reaction (PCR).

RESULTS

Significant upregulation of miR-224, miR-760, miR-483-5p, miR-378 and miR-375 was reported in the present study with respect to the control group (P = .031, P = .017, P = .026, P = .036 and P = .05, respectively). Furthermore, significant positive correlation between the abovementioned microRNAs with DAS28 score (P < .001, each) was demonstrated.

CONCLUSION

Early detection of RA could be achieved through evaluation of serum expression of miR-224, miR-760, miR-483-5p, miR-378 and miR-375 which also may be used as targets for treatment of patients with RA.

Exploring the Oral Microbiome in Rheumatic Diseases, State of Art and Future Prospective in Personalized Medicine with an AI Approach

The oral microbiome is receiving growing interest from the scientific community, as the mouth is the gateway for numerous potential etiopathogenetic factors in different diseases. In addition, the progression of niches from the mouth to the gut, defined as "oral-gut microbiome axis", affects several pathologies, as rheumatic diseases. Notably, rheumatic disorders (RDs) are conditions causing chronic, often intermittent pain affecting the joints or connective tissue. In this review, we examine evidence which supports a role for the oral microbiome in the etiology and progression of various RDs, including rheumatoid arthritis (RA), Sjogren's syndrome (SS), and systemic lupus erythematosus (SLE). In addition, we address the most recent studies endorsing the oral microbiome as promising diagnostic biomarkers for RDs. Lastly, we introduce the concepts of artificial intelligence (AI), in particular, machine learning (ML) and their general application for understanding the link between oral microbiota and rheumatic diseases, speculating the application of a possible AI approach-based that can be applied to personalized medicine in the future.

Periodontal disease in seropositive rheumatoid arthritis: scoping review of the epidemiological evidence

The link between periodontal disease (PD) and rheumatoid arthritis (RA) has been hypothesized to lie in the anti-cyclic citrullinated protein antibody (ACPA) molecules present in seropositive RA. This review aimed to discuss how RA and specifically ACPA-positive RA link to PD, and appraise the epidemiological evidence on the relationship between ACPA-positive RA and PD. Articles were searched following the PRISMA guideline across the MEDLINE, Web of Science, Scopus and Cochrane Library databases. A total of 21 articles met the inclusion criteria of reporting the epidemiological data on the different ACPA status of the subjects with RA and PD (or periodontitis) parameters. A discrepancy is noted in the epidemiological evidence on the difference in the prevalence and severity of PD between ACPA-positive and ACPA-negative RA patients. Although the link between RA and PD is mostly discussed in terms of ACPA, reports on the different manifestations of PD between the two RA subsets remains inconclusive.

Lipid, fatty acid, carnitine- and choline derivative profiles in rheumatoid arthritis outpatients with different degrees of periodontal inflammation

Rheumatoid arthritis (RA) and periodontitis are chronic inflammatory diseases with several pathogenic pathways in common. Evidence supports an association between the diseases, but the exact underlying mechanisms behind the connection are still under investigation. Lipid, fatty acid (FA) and metabolic profile alterations have been associated with several chronic inflammatory diseases, including RA and periodontitis. Mitochondria have a central role in regulating cellular bioenergetic and whole-body metabolic homeostasis, and mitochondrial dysfunction has been proposed as a possible link between the two disorders. The aim of this cross-sectional study was to explore whole-blood FA, serum lipid composition, and carnitine- and choline derivatives in 78 RA outpatients with different degrees of periodontal inflammation. The main findings were alterations in lipid, FA, and carnitine- and choline derivative profiles. More specifically, higher total FA and total cholesterol concentrations were found in active RA. Elevated phospholipid concentrations with concomitant lower choline, elevated medium-chain acylcarnitines (MC-AC), and decreased ratios of MC-AC and long-chain (LC)-AC were associated with prednisolone medication. This may indicate an altered mitochondrial function in relation to the increased inflammatory status in RA disease. Our findings may support the need for interdisciplinary collaboration within the field of medicine and dentistry in patient stratification to improve personalized treatment. Longitudinal studies should be conducted to further assess the potential impact of mitochondrial dysfunction on RA and periodontitis.

Prediction of Chronic Periodontitis Severity Using Machine Learning Models Based On Salivary Bacterial Copy Number

Periodontitis is a widespread chronic inflammatory disease caused by interactions between periodontal bacteria and homeostasis in the host. We aimed to investigate the performance and reliability of machine learning models in predicting the severity of chronic periodontitis. Mouthwash samples from 692 subjects (144 healthy controls and 548 generalized chronic periodontitis patients) were collected, the genomic DNA was isolated, and the copy numbers of nine pathogens were measured using multiplex qPCR. The nine pathogens are as follows: Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Treponema denticola (Td), Prevotella intermedia (Pi), Fusobacterium nucleatum (Fn), Campylobacter rectus (Cr), Aggregatibacter actinomycetemcomitans (Aa), Peptostreptococcus anaerobius (Pa), and Eikenella corrodens (Ec). By adding the species one by one in order of high accuracy to find the optimal combination of input features, we developed an algorithm that predicts the severity of periodontitis using four machine learning techniques. The accuracy was the highest when the models classified “healthy” and “moderate or severe” periodontitis (H vs. M-S, average accuracy of four models: 0.93, AUC = 0.96, sensitivity of 0.96, specificity of 0.81, and diagnostic odds ratio = 112.75). One or two red complex pathogens were used in three models to distinguish slight chronic periodontitis patients from healthy controls (average accuracy of 0.78, AUC = 0.82, sensitivity of 0.71, and specificity of 0.84, diagnostic odds ratio = 12.85). Although the overall accuracy was slightly reduced, the models showed reliability in predicting the severity of chronic periodontitis from 45 newly obtained samples. Our results suggest that a well-designed combination of salivary bacteria can be used as a biomarker for classifying between a periodontally healthy group and a chronic periodontitis group.

The roles of osteocytes in alveolar bone destruction in periodontitis

Periodontitis, a bacterium-induced inflammatory disease that is characterized by alveolar bone loss, is highly prevalent worldwide. Elucidating the underlying mechanisms of alveolar bone loss in periodontitis is crucial for understanding its pathogenesis. Classically, bone cells, such as osteoclasts, osteoblasts and bone marrow stromal cells, are thought to dominate the development of bone destruction in periodontitis. Recently, osteocytes, the cells embedded in the mineral matrix, have gained attention. This review demonstrates the key contributing role of osteocytes in periodontitis, especially in alveolar bone loss. Osteocytes not only initiate physiological bone remodeling but also assist in inflammation-related changes in bone remodeling. The latest evidence suggests that osteocytes are involved in regulating bone anabolism and catabolism in the progression of periodontitis. The altered secretion of receptor activator of NF-κB ligand (RANKL), sclerostin and Dickkopf-related protein 1 (DKK1) by osteocytes affects the balance of bone resorption and formation and promotes bone loss. In addition, the accumulation of prematurely senescent and apoptotic osteocytes observed in alveolar bone may exacerbate local destruction. Based on their communication with the bloodstream, it is noteworthy that osteocytes may participate in the interaction between local periodontitis lesions and systemic diseases. Overall, further investigations of osteocytes may provide vital insights that improve our understanding of the pathophysiology of periodontitis.

Hypothesis: Rheumatoid arthritis and periodontitis: A new possible link via prolactin hormone

Rheumatoid arthritis and periodontitis are two common chronic inflammatory diseases affecting human population worldwide. The association between the two conditions have been the focus of many researches, trying to explore the possible mechanisms underlying this association. Prolactin hormone, besides its known lactogenic effects acts as a cytokine secreted from various tissues other than the pituitary gland with multiple pleotropic actions in immunity and inflammation. Several data showed that prolactin levels are increased significantly in the synovial and periodontal tissues, and this increase is correlated with disease activity and tissue destruction. Our hypothesis suggests that local prolactin can represent a link between the two conditions. In this work, we suggest a possible mechanistic interactions, hypothesized to form a common path linking between rheumatoid arthritis, periodontitis and prolactin. This is because of the need to develop new treatment strategies for the most effective long term control of inflammation in both conditions.

Downregulating microRNA-152-3p promotes the viability and osteogenic differentiation of periodontal ligament stem cells via targeting integrin alpha 5

OBJECTIVE

The aim of this study was to investigate the role of microRNA-152-3p (miR-152-3p) in the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs).

DESIGN

HPDLSCs were isolated and identified using immunofluorescence staining, and their osteogenic differentiation capability was evaluated by alkaline phosphatase staining and Alizarin Red staining. HPDLSC viability was measured using cell counting kit-8. alkaline phosphatase level in hPDLSCs was measured by enzyme-linked immunosorbent assay. Target gene and potential binding sites between miR-152-3p and integrin alpha 5 (ITGA5) were predicted using TargetScan and confirmed by dual-luciferase reporter assay. Relative expressions of miR-152-3p and factors related to hPDLSC osteogenic differentiation were measured by quantitative real-time polymerase chain reaction and Western blot as needed.

RESULTS

Collected cells were observed and identified as hPDLSCs. MiR-152-3p expression was downregulated during hPDLSC osteogenic differentiation in a time-dependent manner, and downregulating miR-152-3p promoted cell viability, enhanced alkaline phosphatase level, and increased the expressions of genes related to hPDLSC osteogenic differentiation. ITGA5 was the target gene of miR-152-3p and ITGA5 expression was upregulated during osteogenic differentiation in a time-dependent manner. Silencing ITGA5 partially reversed the effects of downregulating miR-152-3p on hPDLSCs.

CONCLUSION

Downregulating miR-152-3p may promote hPDLSC viability and osteogenic differentiation via targeting ITGA5, and have potential effects on periodontal and alveolar bone regeneration.

Relationship between periodontitis and rheumatoid arthritis in Vietnamese patients

Objective: This study aimed to survey periodontal status of Vietnamese patients with rheumatoid arthritis (RA) and investigates the association between periodontitis and RA in these patients.Materials and methods: We conducted a cross-sectional descriptive study on 150 RA patients and another 150 patients with osteoarthritis (OA). RA was evaluated using the DAS28 disease activity score based on C-reactive protein levels (DAS28-CRP), disease activity classification, and serum levels of RA biomarkers. Periodontal status was determined using periodontal indices.Results: The proportion of periodontitis cases in the RA group was significantly higher than the OA group (67 and 28%, respectively). The rate of severe periodontitis observed in the RA group was also significantly higher than that in the OA group (22.7 and 8%, respectively). RA patients with periodontitis had higher DAS28-CRP scores, disease activity levels, ACPA positivity and higher serum levels of CRP and ACPAs. Periodontitis is associated with an increased risk for RA (odds ratio [OR]: 5.14, 95% confidence interval [CI]: 3.14 - 8.41) and with higher disease activity classification (OR: 2.7, 95% CI: 1.14 - 6.42).Conclusions: Vietnamese RA patients often presented with a more serious periodontal condition than OA patients. We observed an association between periodontal disease (PD) status and clinic symptoms and biochemical/immunological characteristics of RA.

Bacterial citrullinated epitopes generated by Porphyromonas gingivalis infection-a missing link for ACPA production

OBJECTIVES

Porphyromonas gingivalis (P.g.) is discussed to be involved in triggering self-reactive immune responses. The aim of this study was to investigate the autocitrullinated prokaryotic peptidylarginine deiminase (PPAD) from P.g. CH2007 (RACH2007-PPAD) from a rheumatoid arthritis (RA) patient and a synthetic citrullinated PPAD peptide (CPP) containing the main autocitrullination site as potential targets for antibody reactivity in RA and to analyse the possibility of citrullinating native human proteins by PPAD in the context of RA.

METHODS

Recombinant RACH2007-PPAD was cloned and expressed in Escherichia coli. Purified RACH2007-PPAD and its enzymatic activity was analysed using two-dimensional electrophoresis, mass spectrometry, immunoblot and ELISA. Autoantibody response to different modified proteins and peptides was recorded and bioinformatically evaluated.

RESULTS

RACH2007-PPAD was capable to citrullinate major RA autoantigens, such as fibrinogen, vimentin, hnRNP-A2/B1, histone H1 and multiple peptides, which identify a common RG/RGG consensus motif. 33% of RA patients (n=30) revealed increased reactivity for α-cit-RACH2007-PPAD before RA onset. 77% of RA patients (n=99) presented α-cit-specific signals to CPP amino acids 57-71 which were positively correlated to α-CCP2 antibody levels. Interestingly, 48% of the α-CPP-positives were rheumatoidfactor IgM/anti-citrullinated peptide/protein antibodies (ACPA)-negative. Anti-CPP and α-RACH2007-PPAD antibody levels increase with age. Protein macroarrays that were citrullinated by RACH2007-PPAD and screened with RA patient sera (n=6) and controls (n=4) uncovered 16 RACH2007-PPAD citrullinated RA autoantigens and 9 autoantigens associated with lung diseases. We showed that the α-CPP response could be an important determinant in parenchymal changes in the lung at the time of RA diagnosis (n=106; p=0.018).

CONCLUSIONS

RACH2007-PPAD induced internal citrullination of major RA autoantigens. Anti-RACH2007-PPAD correlates with ACPA levels and interstitial lung disease autoantigen reactivity, supporting an infection-based concept for induction of ACPAs via enzymatic mimicry.

The Porphyromonas gingivalis inhibitory effects, antioxidant effects and the safety of a Sri Lankan traditional betel quid - an in vitro study

Background

The Sri Lankan traditional betel quid (TBQ) which had been extensively used in the country before its colonization is claimed to have antiperiodontopathic effects in the Sri Lankan folklore. However, there is no reported scientific evidence to support the claimed antiperiodontopathic effects mediated by this TBQ. The present study was carried out to investigate the protective effect of the Sri Lankan TBQ in the pathogenesis of periodontitis.

Methods

We investigate the ethyl acetate extract of the Sri Lankan TBQ for its antibacterial effects against the keystone periodontopathic bacterium, P. gingivalis and also its antioxidant potential, which is important to protect the periodontium from oxidative stress. Further, its safety was analyzed using the cytokinesis block micronucleus assay on human peripheral blood lymphocytes (PBLs).

Results

Ethyl acetate extract of this TBQ inhibited the growth of P. gingivalis with a minimum bactericidal concentration (MBC) of 125 μg/ml. It was found to be a rich source of polyphenols and displayed considerable DPPH and ABTS radical scavenging activities and a strong ferric reducing antioxidant power. This extract could protect the cultured human gingival fibroblasts from H₂O₂ induced oxidative stress. In addition, this TBQ extract was not genotoxic to human PBLs even at a concentration of 2.5 mg/ml. Moreover, it exhibited protective effects against bleomycin induced genotoxicity in PBLs.

Conclusion

Ethyl acetate extract of the Sri Lankan TBQ is a source of natural antibacterial compounds against P. gingivalis. It is also a source of natural antioxidants which can protect human gingival fibroblasts from H₂O₂ induced oxidative stress. These properties of the TBQ may have contributed to its claimed antiperiodontopathic effects. Besides, it was found to be relatively non-toxic to human cells. Thus this TBQ extract has a huge potential to be developed as a novel adjunctive therapeutic lead against periodontitis.

Perception of Gingival Bleeding by People and Healthcare Professionals: A Multicentre Study in an Adult French Population

Gingival bleeding (GB) is a common sign of gingival inflammation, which indicates the presence of periodontal diseases. This study aimed to describe the perception of French adults about their self-reported GB and answers of healthcare professionals regarding the GB reported by these interviewees. A questionnaire administered by one investigator in each of three public settings of four cities in France from September 2016 to November 2017. Among 794 adults interviewed, 502 (63.2%) reported a GB. Among them, 414 (82.5%) believed that GB is benign, and 309 (61.6%) declared one or more responses. The three main responses were to use mouthwash (29.3%), to change to a soft-bristle toothbrush (20.1%) and to modify the brushing technique (19.3%). Almost half (49.0%) questioned at least one healthcare professional concerning their GB: a dentist (43.0%), a physician (14.1%), and a pharmacist (8.0%). The main response of each healthcare professional was: for dentists: a "prescription of mouthwash", for physicians to say "gingival bleeding is not serious"; and for pharmacists: "to sell a mouthwash". Most of the participants considered their GB as benign and had inappropriate responses, which indicates their lack of knowledge regarding periodontal health. The same conclusions can be drawn for healthcare professionals, as reported by interviewees.

Effect of interleukin-22 on osteogenic differentiation and the osteoclastogenic response of human periodontal ligament fibroblasts in vitro

BACKGROUND

Interleukin-22 (IL-22) exerts extensive biological effects, playing both protective and pathological roles in autoimmune and infectious diseases. However, the specific role and mechanism of IL-22 in the pathogenesis of periodontitis have not been clarified. The aim of this study was to analyze the possible roles of IL-22 in the osteoclastogenesis and osteogenesis of periodontitis.

METHODS

Human periodontal ligament fibroblasts (hPDLFs) were treated with IL-22 and/or lipopolysaccharide from Porphyromonas gingivalis (Pg-LPS), and the mRNA and protein expression of RANKL and OPG were measured by qRT-PCR and Western blotting, respectively. Western blotting was also used to examine the phosphorylated and total protein expression of MAPK signaling molecules. The role of the MAPK pathway in osteoclastogenesis marker expression was further confirmed by inhibition assays. For osteogenic assays, the mRNA expression of osteoblastic markers was quantified by qRT-PCR, the alkaline phosphatase (ALP) activity of hPDLFs was measured by an ALP assay, and the mineralized nodules formed by hPDLFs were determined by Alizarin Red S staining.

RESULTS

IL-22 promoted the expression of RANKL in hPDLFs via the MAPK signaling pathway and further upregulated RANKL expression together with Pg-LPS via the p38 MAPK pathway. IL-22 could enhance the ALP activity and mineralized nodule formation of hPDLFs in the early period of osteogenic induction, while exhibiting no profound effect on the expression of osteoblastic markers.

CONCLUSION

IL-22 plays regulatory roles in bone homeostasis, and it is likely to contribute to osteoclastogenesis as a proinflammatory cytokine in the pathogenesis of periodontitis.

Effect of VEGFC on lymph flow and inflammation-induced alveolar bone loss

The lymphatic system plays a crucial role in the maintenance of tissue fluid homeostasis and the immunological response to inflammation. The effects of lymphatic drainage dysfunction on periodontitis have not been well studied. Here we show that lymphatic vessel endothelial receptor 1 (LYVE1)+ /podoplanin (PDPN)+ lymphatic vessels (LVs) are increased in the periodontal tissues, with accumulation close to the alveolar bone surface, in two murine periodontitis models: rheumatoid arthritis (RA)-associated periodontitis and ligature-induced periodontitis. Further, PDPN+ /alpha-smooth muscle actin (αSMA)- lymphatic capillaries are increased, whereas PDPN+ /αSMA+ collecting LVs are decreased significantly in the inflamed periodontal tissues. Both mouse models of periodontitis have delayed lymph flow in periodontal tissues, increased TRAP-positive osteoclasts, and significant alveolar bone loss. Importantly, the local administration of adeno-associated virus for vascular endothelial growth factor C, the major growth factor that promotes lymphangiogenesis, increases the area and number of PDPN+ /αSMA+ collecting LVs, promotes local lymphatic drainage, and reduces alveolar bone loss in both models of periodontitis. Lastly, LYVE1+ /αSMA- lymphatic capillaries are increased, whereas LYVE1+ /αSMA+ collecting LVs are decreased significantly in gingival tissues of patients with chronic periodontitis compared with those of clinically healthy controls. Thus, our findings reveal an important role of local lymphatic drainage in periodontal inflammation-mediated alveolar bone loss. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Increase in the Number of Bone Marrow Osteoclast Precursors at Different Skeletal Sites, Particularly in Long Bone and Jaw Marrow in Mice Lacking IL-1RA

Recently, it was shown that interleukin-1β (IL-1β) has diverse stimulatory effects on different murine long bone marrow osteoclast precursors (OCPs) in vitro. In this study, interleukin-1 receptor antagonist deficient (Il1rn^-/-) and wild-type (WT) mice were compared to investigate the effects of enhanced IL-1 signaling on the composition of OCPs in long bone, calvaria, vertebra, and jaw. Bone marrow cells were isolated from these sites and the percentage of early blast (CD31^hi Ly-6C^-), myeloid blast (CD31⁺ Ly-6C⁺), and monocyte (CD31^- Ly-6C^hi) OCPs was assessed by flow cytometry. At the time-point of cell isolation, Il1rn^-/- mice showed no inflammation or bone destruction yet as determined by histology and microcomputed tomography. However, Il1rn^-/- mice had an approximately two-fold higher percentage of OCPs in long bone and jaw marrow compared to WT. Conversely, vertebrae and calvaria marrow contained a similar composition of OCPs in both strains. Bone marrow cells were cultured with macrophage colony stimulating factor (M-CSF) and receptor of NfκB ligand (RANKL) on bone slices to assess osteoclastogenesis and on calcium phosphate-coated plates to analyze mineral dissolution. Deletion of Il1rn increased osteoclastogenesis from long bone, calvaria, and jaw marrows, and all Il1rn^-/- cultures showed increased mineral dissolution compared to WT. However, osteoclast markers increased exclusively in Il1rn^-/- osteoclasts from long bone and jaw. Collectively, these findings indicate that a lack of IL-1RA increases the numbers of OCPs in vivo, particularly in long bone and jaw, where rheumatoid arthritis and periodontitis develop. Thus, increased bone loss at these sites may be triggered by a larger pool of OCPs due to the disruption of IL-1 inhibitors.

Upregulation of circulating inflammatory biomarkers under the influence of periodontal disease in rheumatoid arthritis patients

OBJECTIVES

Periodontal disease (PD) and rheumatoid arthritis (RA) are chronic immuno-inflammatory conditions with osteolysis being a hallmark feature. The influence of PD on RA's systemic inflammatory status and disease activity remains unclear. The objective of this study was to assess the systemic inflammation and disease activity of RA under the influence of PD.

METHODS

In this case-control study, 38 RA patients (19 with PD and 19 without PD) were compared to 38 non-RA patients and 12 healthy controls. Periodontal parameters (bleeding on probing (BOP), probing pocket depth (PPD), PPD Total, PPD Disease and marginal bone loss (MBL) were determined. Serological analyses included quantification of 92 inflammatory biomarkers using a multiplex proximity extension assay, anti-citrullinated protein antibodies (ACPA), rheumatoid factor (IgM-RF) and erythrocyte sedimentation rate (ESR). RA disease activity was determined using Disease Activity Score for 28 joints (DAS28). All RA patients were on medication.

RESULTS

IgM-RF was higher in RA patients with PD. PD conditions were more severe in the non-RA group. Inflammatory biomarkers (IL-10RB, IL-18, CSF-1, NT-3, TRAIL, PD-L1, LIF-R, SLAMF1, FGF-19, TRANCE, CST5, STAMPB, SIRT2, TWEAK, CX3CL1, CXCL5, MCP-1) were significantly higher in RA patients with PD than RA without PD. DAS28 associated with twice as many inflammatory biomarkers in RA patients with PD whereas IgM-RF and ACPA associated more frequently with biomarkers in the RA without PD group. IgM-RF correlated inversely with BOP.

CONCLUSION

Periodontal disease augments systemic inflammation in RA. A profound influence exists independent of autoimmune status.

Association of cytokine patterns and clinical/laboratory parameters, medication and periodontal burden in patients with rheumatoid arthritis (RA)

To evaluate serum levels of the following cytokines in rheumatoid arthritis subjects with periodontal disease: Interleukin-6, -10, -17, and -23. Patients with rheumatoid arthritis frequently suffer from periodontal disease. Both diseases partly result from a dysregulated immune response. The current study aimed to quantify Interleukin-6, -10, -17, and -23 levels in rheumatoid arthritis. It should be investigated if the periodontal disease would have additional modifying effects. A total of 157 patients were included. Serum levels of IL-6, -10, -17, and -23 were measured by ELISA. Serum IL-10 increased with longer duration of morning stiffness and with higher rheumatoid factor and anti-cyclic citrullinated peptide titres. IL-10 was also elevated with longer duration of prednisolone (< 5 mg daily) and leflunomide therapy. Subjects with lower erythrocyte sedimentation rate/longer leflunomide therapy displayed more missing teeth/more clinical attachment loss. IL-17 was higher in subjects with fewer missing teeth if the following criteria were fulfilled: shorter prednisolone (< 5 mg) and methotrexate therapy, more swollen joints, longer morning stiffness. IL-23 finally was increased in subjects with higher rheumatoid factor and in those with higher periodontal probing depth/clinical attachment loss in the following situations: lower rheumatoid factor and shorter leflunomide therapy. Subjects suffering from dental/periodontal burden show an aberrant systemic cytokine availability of serum IL-6, IL-10, IL-17 and IL-23 related to disease activity and medication. This examination underlines the complexity of potential interactions between disease activity and medication related to periodontal burden.

Comprehensive Assessment of Orofacial Health and Disease Related Parameters in Adolescents with Juvenile Idiopathic Arthritis-A Cross-Sectional Study

Background: The aim of this cross-sectional study was to investigate oral health and functional status of adolescents with juvenile idiopathic arthritis (JIA) and its possible link to disease specific parameters. Methods: Patients with JIA were recruited (November 2012–October 2014) and disease specific information was extracted from patients’ records. Oral examination included: dental findings (decayed-, missing- and filled-teeth-index (dmf-t/DMF-T)), gingival inflammation (papilla-bleeding-index (PBI)) and periodontal screening index (PSI). Functional examination followed Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). Additionally, modified Helkimo’s Clinical Dysfunction Index and radiographic scoring were recorded. Results: 59 JIA patients were included. The mean dmf-t/DMF-T was 2.6. Only one patient showed no signs of gingival inflammation, while 57.6% had a maximum PSI of 2 or less. Positive functional findings were assessed clinically in more than half of the patients. Major diagnosis by RDC/TMD was osteoarthrosis. Patients with at least one positive anamnestic or clinical functional finding revealed significantly higher radiographic scores (CI = 0.440, p = 0.022). Patients with increased c-reactive-protein had a significantly higher PBI (Z = –2.118, p = 0.034) and increased radiographic scores (CI = 0.408, p = 0.043). Conclusions: Adolescents suffering from JIA show high levels of caries experience and gingival inflammation. Temporomandibular joint dysfunction is often seen in JIA patients. Consequently, special dental care programs would be recommendable.

Relationship between hypothyroidism and periodontitis: A scoping review

AIM

The objective of this study was to assess the existing literature to determine if a relationship exists between hypothyroidism and periodontitis.

METHODS

We used a modified approach to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses by searching five databases in addition to the gray literature. Keywords in the title and abstract fields, as well as subject headings for both periodontal disease and hypothyroidism, were used to search the existing literature for publications relevant to evaluation of the thyroid-periodontitis relationship.

RESULTS

The authors screened 847 unique publications which, after applying inclusion and exclusion criteria, yielded 29 publications, which were further analyzed for relevance and applicability. Most of the included papers were cross-sectional studies and retrospective chart reviews. Following critical analysis, four publications, including one abstract, were used to further assess the hypothyroid-periodontitis relationship.

CONCLUSIONS

There are very few high-quality studies describing the potential association between hypothyroidism and periodontitis. In general, and among the included papers with the fewest confounding factors, a positive relationship between hypothyroidism and periodontitis was found. Further well-controlled, prospective clinical and immunologic studies will be required to confirm that relationship.

Oral health and plaque microbial profile in juvenile idiopathic arthritis

BACKGROUND

The oral microbiota has been implicated in the pathogenesis of rheumatoid arthritis through activation of mucosal immunity. This study tested for associations between oral health, microbial communities and juvenile idiopathic arthritis (JIA).

METHODS

A cross-sectional exploratory study of subjects aged 10-18 years with oligoarticular, extended oligoarticular and polyarticular JIA was conducted. Control groups included pediatric dental clinic patients and healthy volunteers. The primary aim was to test for an association between dental health indices and JIA; the secondary aim was to characterize the microbial profile of supragingival plaque using 16S rRNA gene sequencing.

RESULTS

The study included 85 patients with JIA, 62 dental patients and 11 healthy child controls. JIA patients overall had significantly more gingival inflammation compared to dental patients, as evidenced by bleeding on probing of the gingiva, the most specific sign of active inflammation (p = 0.02). Overall, however, there was a trend towards better dental hygiene in the JIA patients compared to dental patients, based on indices for plaque, decay, and periodontitis. In the JIA patients, plaque microbiota analysis revealed bacteria belonging to genera Haemophilus or Kingella elevated, and Corynebacterium underrepresented. In poly JIA, bacteria belonging to the genus Porphyromonas was overrepresented and Prevotella was underrepresented.

CONCLUSION

Increased gingival inflammation in JIA was independent of general oral health, and thus cannot be attributed to poor dental hygiene secondary to disability. The variation of microbial profile in JIA patients could indicate a possible link between gingivitis and synovial inflammation.

Active matrix metalloproteinase-8 and periodontal bacteria-interlink between periodontitis and inflammatory bowel disease?

BACKGROUND

The aim of this study was the investigation of concentration and prevalence of selected periodontal pathogenic bacteria and concentration of active matrix metalloproteinase-8 (aMMP-8) within a group of patients with inflammatory bowel diseases (IBD) and to compare the results with a group of healthy control subjects (HC).

METHODS

Fifty-nine IBD patients with Crohn`s disease (CD, n = 30) or ulcerative colitis (UC, n = 29) and 59 HC were included in this cross-sectional study. Based on periodontal probing depth (PD) and clinical attachment level (CAL), periodontitis was classified as healthy/mild, moderate, or severe. aMMP-8 was analyzed from gingival crevicular fluid using enzyme linked immunosorbent assay. Eleven selected periodontal pathogenic bacteria were analyzed in subgingival plaque samples using polymerase chain reaction.

RESULTS

IBD patients showed higher CAL (P < 0.01), more severe periodontitis (P = 0.04), gingival bleeding (P < 0.01) and aMMP-8 concentration (P < 0.01) than HC. Only in CD, increasing severity of periodontitis was associated with an increase in aMMP-8 concentration (P = 0.02). The prevalences of Eubacterium nodatum and Eikenella corrodens were significantly lower in IBD compared to HC (P = 0.01). Additionally, the prevalence of Eikenella corrodens was significantly higher in CD compared to the UC group (P = 0.04). Further statistically significant differences in selected bacteria between IBD and HC or CD and UC groups could not be found (P > 0.05).

CONCLUSIONS

The results reveal changes in host immune response of IBD patients in terms of aMMP-8. Only in CD increasing aMMP-8 was associated with severity of periodontal disease. The role of periodontal pathogenic bacteria in the interrelationship between IBD and periodontitis remains unclear.

The microbiome in autoimmune diseases

The microbiome is represented by microorganisms which live in a symbiotic way with the mammalian. Microorganisms have the ability to influence different physiological aspects such as the immune system, metabolism and behaviour. In recent years, several studies have highlighted the role of the microbiome in the pathogenesis of autoimmune diseases. Notably, in systemic lupus erythematosus an alteration of the intestinal flora (lower Firmicutes/Bacteroidetes ratio) has been described. Conversely, changes to the gut commensal and periodontal disease have been proposed as important factors in the pathogenesis of rheumatoid arthritis. At the same time, other autoimmune diseases (i.e. systemic sclerosis, Sjögren's syndrome and anti-phospholipid syndrome) also share modifications of the microbiome in the intestinal tract and oral flora. Herein, we describe the role of the microbiome in the maintenance homeostasis of the immune system and then the alterations of the microorganisms that occur in systemic autoimmune diseases. Finally, we will consider the use of probiotics and faecal transplantation as novel therapeutic targets.

Periodontal Pathogens as Risk Factors of Cardiovascular Diseases, Diabetes, Rheumatoid Arthritis, Cancer, and Chronic Obstructive Pulmonary Disease-Is There Cause for Consideration?

Cardiovascular diseases, chronic obstructive pulmonary diseases, diabetes, rheumatoid arthritis, and cancer are the most common noncommunicable diseases (NCDs). These NCDs share risk factors with periodontal disease (PD), a preventable risk factor linked to lifestyle. The discussion regarding the association between these chronic diseases is more complex. There is still a significant knowledge gap particularly of the causal relationship between PD and NCDs. In this paper, we present fundamental knowledge of the mechanisms and roles of putative periodontal bacteria to gather several hypotheses, evidence that clinical studies thus far have not produced. Although the causal hypotheses are not yet clearly established on a biological basis, prevention and prophylactic measures are recommended to prevent even the possibility of such potential risk factors.

Periodontitis and Rheumatoid Arthritis in sub-Saharan Africa, gaps and way forward: a systematic review and meta-analysis

BACKGROUND

This review identified papers that described periodontitis and rheumatoid arthritis in sub-Saharan Africa. Only English language publications from January 2010 to December 2017 describing original research in sub-Saharan Africa on the association between periodontitis and rheumatoid arthritis were considered for this study.

METHODS

Published databases: PubMed, Science direct and Google scholar, were searched using terms "periodontitis", "rheumatoid arthritis" and "Sub-Saharan Africa" to generate a set of putative studies. Articles with data on both rheumatoid arthritis and periodontitis compared to controls were selected. Studies on the association of periodontitis with cardiovascular disease, arthritis or rheumatoid arthritis alone were excluded. Data were extracted, critically appraised, and analyzed using a random-effect Mantel-Haenszel meta-analysis on plaque index, gingival index, pocket depth and clinical attachment loss.

RESULTS

Three publications were selected for the systematic review and 2 for the meta-analysis. Two studies were from Sudan, and one was from Burina Faso. There was a significant increase in pocket depth (mean difference: 0.31; 95% CI: 0.21, 0.41; N= 274; (p ≤ 0.001) and clinical attachment loss (mean difference: 0.47; 95% CI: 0.22, 0.75; N= 274; (p ≤ 0.001) in participants with rheumatoid arthritis compared to normal controls.

CONCLUSION

Findings from these combined studies show a significant relationship between periodontal disease and rheumatoid arthritis with increased periodontal pocket depth and clinical attachment loss. They also highlight the need for additional work especially in the area of associating rheumatoid arthritis with P. gingivalis, the oral microbiome and treating periodontal diseases to help in the management of rheumatoid arthritis.

Oral health and orofacial function in patients with rheumatoid arthritis

The aim of the study was to describe the oral health and orofacial function of Mexican patients with rheumatoid arthritis (RA) and their association with clinical and radiological aspects of the disease. Patients with RA received a complete odontological exam, which also included a clinical and radiographic assessment of the temporomandibular joint (TMJ). The rheumatologic assessment included detailed profiling of the disease and serological and radiographic parameters. The study included 62 RA patients; the median (min-max) age was 51 (18-72) years old and 8.5 (1-39) years of disease duration. The 63.6% of the patients had DAS28 ≥ 3.2, and a median (min-max) of Sharp/van der Heijde score (SvdHS) of 41 (0-214). 98.3% of the patients presented caries, which were severe in 53.3% of the cases. The 73.8% of the patients were missing teeth due to caries, with a median (min-max) of 4 (0-32) teeth missing per patient. Oral hygiene was classified as bad in 49.1% of patients and only 15.3% of them had a healthy periodontium. The TMJ function was abnormal in 98.4% of the patients and 62.9% of them presented moderate or severe TMJ disorder (TMD). The radiographic damage of the TMJ correlated positively with the SvdHS. No correlations were found between disease activity or structural progression and orofacial variables, including periodontitis. There are severe oral and orofacial health problems in RA patients despite having medical attention for their disease. Multidisciplinary management remains an area of opportunity for both the medical specialists and the health system in our country.

Linkage of Periodontitis and Rheumatoid Arthritis: Current Evidence and Potential Biological Interactions

The association between rheumatoid arthritis (RA) and periodontal disease (PD) has been the focus of numerous investigations driven by their common pathological features. RA is an autoimmune disease characterized by chronic inflammation, the production of anti-citrullinated proteins antibodies (ACPA) leading to synovial joint inflammation and destruction. PD is a chronic inflammatory condition associated with a dysbiotic microbial biofilm affecting the supporting tissues around the teeth leading to the destruction of mineralized and non-mineralized connective tissues. Chronic inflammation associated with both RA and PD is similar in the predominant adaptive immune phenotype, in the imbalance between pro- and anti-inflammatory cytokines and in the role of smoking and genetic background as risk factors. Structural damage that occurs in consequence of chronic inflammation is the ultimate cause of loss of function and disability observed with the progression of RA and PD. Interestingly, the periodontal pathogen Porphyromonas gingivalis has been implicated in the generation of ACPA in RA patients, suggesting a direct biological intersection between PD and RA. However, more studies are warranted to confirm this link, elucidate potential mechanisms involved, and ascertain temporal associations between RA and PD. This review is mainly focused on recent clinical and translational research intends to discuss and provide an overview of the relationship between RA and PD, exploring the similarities in the immune-pathological aspects and the possible mechanisms linking the development and progression of both diseases. In addition, the current available treatments targeting both RA and PD were revised.

Periodontal disease in Chinese patients with rheumatoid arthritis: A case-control study

OBJECTIVE

To evaluate the prevalence and severity of periodontal disease in Chinese rheumatoid arthritis patients.

SUBJECTS AND METHODS

This cross-sectional study included 128 RA and 109 healthy controls. Two dentists conducted periodontal status including Plaque index (PI), Gingival index (GI), pocket probing depths (PPDs), Clinical attachment level (CAL) and Bleeding on probing (BOP) independently. Sociodemographic, lifestyle, clinical parameters and use of medication were assessed. Data were analyzed by Student's t test, χ² test, Wilcoxin-Mann- Whitney's test, Correlational Analysis, univariate or multivariate logistic regression.

RESULTS

The periodontal status was significantly worse in RA, especially the condition of dental and gingival status. RA had 4.68-fold. After adjusted potential risk factors, RA had 10.26-fold. The independent variable related to GI was DAS28 (p = .05) negatively, to the contrary, ESR (p = .013) was positively associated; the independent variable positively and related to periodontitis was educational level (p = .021) and anti-CCP positivity (p = .002). Through multivariate logistic regression, age and swollen joint were the independent variable related to periodontitis of RA (OR 1.087, p = .044) and (OR 1.560, p = .008) respectively.

CONCLUSIONS

Chinese RA patients show higher odds of PD. It is important to take early interventions in combination with medical therapy.

Rheumatoid Arthritis-Associated Mechanisms of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans

Rheumatoid arthritis (RA) is an autoimmune disease of unknown etiology characterized by immune-mediated damage of synovial joints and antibodies to citrullinated antigens. Periodontal disease, a bacterial-induced inflammatory disease of the periodontium, is commonly observed in RA and has implicated periodontal pathogens as potential triggers of the disease. In particular, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans have gained interest as microbial candidates involved in RA pathogenesis by inducing the production of citrullinated antigens. Here, we will discuss the clinical and mechanistic evidence surrounding the role of these periodontal bacteria in RA pathogenesis, which highlights a key area for the treatment and preventive interventions in RA.