The association between rheumatoid arthritis and periodontal disease

The Influence of Interleukin 17A and IL17F Polymorphisms on Chronic Periodontitis Disease in Brazilian Patients

A case-control study was conducted on patients with chronic periodontitis (CP) and healthy controls with the aim of evaluating possible association between interleukin 17A (IL17A) G197A (rs2275913) and IL17F T7488C (rs763780) polymorphisms and periodontitis. Genotypes were determined by PCR-RFLP method. Statistical analyses were conducted using the OpenEpi and SNPStas software to calculate Chi-square with Yates correction or Fisher's exact tests, odds ratios (OR), and 95% confidence intervals (CIs). SNPStas software was used to calculate Hardy-Weinberg equilibrium. IL17A AA genotype was more frequent in patients with chronic periodontitis (CP) in the codominant and recessive models (P = 0.09; OR = 2.53 and P = 0.03; OR = 2.46, resp.), the females with CP (P = 0.01, OR = 4.34), Caucasoid patients with CP (P = 0.01, OR = 3.45), and nonsmoking Caucasian patients with CP (P = 0.04, OR = 3.51). The IL17A A allele was also more frequent in Caucasians with CP (P = 0.04, OR = 1.59). IL17F T7488C polymorphism was not associated with chronic periodontitis. In these patients from Southern Brazil, the IL17A rs2275913 polymorphisms, IL17A AA genotype, and the A allele were associated with a susceptibility to chronic periodontitis.

Diabetic Lactoferrin Deficient Mice Demonstrates Greater Susceptibility to Experimental Periodontal Disease

The objective of this study is to detrmine whether alloxan-induced diabetic Lactoferrin knockout (LFKO^-/-) mice are more susceptible to periodontal disease caused by Aggregatibacter actinomycetemcomitans compared to the diabetic wild-type (WT) mice. Diabetes was induced in mice by a single dose of alloxan (60 mg/kg) injected intravenously. Mice were categorized as diabetic when blood glucose levels >250 mg/dL were measured on the 7^th day after the injection. Periodontal disease was experimentally induced by A. actinomycetemcomitans infection in alloxan induced diabetic WT and LFKO^-/- mice. Fasting blood glucose levels and body weight were monitored throughout the study. At the end of the 12^th week of infection, mice were sacrificed and bone loss among the groups was estimated by measuring the distance between cemento-enamel junction (CEJ) to the alveolar bone crest (ABC) at 12 sites on the molars. A. actinomycetemcomitans infected mice groups developed more alveolar bone loss than sham-infected animals. Diabetic LFKO^-/- infected mice exhibited significant bone loss (P<0.01) and a higher mean fasting blood glucose level (P<0.05) when compared to diabetic WT infected mice. No statistically significant difference in fasting blood glucose level was found between the infected and sham-infected groups. Peripheral blood analysis at the end of the 12^th week revealed a significant reduction in the platelet counts in LFKO^-/- mice when compared to WT mice. Furthermore, diabetic LFKO^-/- presented with lower counts than non-diabetic LFKO^-/- mice (P<0.01). In conclusion, diabetic lactoferrin deficient mice are at a higher risk of developing periodontal infection induced by A. actinomycetemcomitans when compared to diabetic WTI mice.

Structural and mutational analyses of dipeptidyl peptidase 11 from Porphyromonas gingivalis reveal the molecular basis for strict substrate specificity

The dipeptidyl peptidase 11 from Porphyromonas gingivalis (PgDPP11) belongs to the S46 family of serine peptidases and preferentially cleaves substrates with Asp/Glu at the P1 position. The molecular mechanism underlying the substrate specificity of PgDPP11, however, is unknown. Here, we report the crystal structure of PgDPP11. The enzyme contains a catalytic domain with a typical double β-barrel fold and a recently identified regulatory α-helical domain. Crystal structure analyses, docking studies, and biochemical studies revealed that the side chain of Arg673 in the S1 subsite is essential for recognition of the Asp/Glu side chain at the P1 position of the bound substrate. Because S46 peptidases are not found in mammals and the Arg673 is conserved among DPP11s, we anticipate that DPP11s could be utilised as targets for antibiotics. In addition, the present structure analyses could be useful templates for the design of specific inhibitors of DPP11s from pathogenic organisms.

The dormant blood microbiome in chronic, inflammatory diseases

Blood in healthy organisms is seen as a ‘sterile’ environment: it lacks proliferating microbes. Dormant or not-immediately-culturable forms are not absent, however, as intracellular dormancy is well established. We highlight here that a great many pathogens can survive in blood and inside erythrocytes. ‘Non-culturability’, reflected by discrepancies between plate counts and total counts, is commonplace in environmental microbiology. It is overcome by improved culturing methods, and we asked how common this would be in blood. A number of recent, sequence-based and ultramicroscopic studies have uncovered an authentic blood microbiome in a number of non-communicable diseases. The chief origin of these microbes is the gut microbiome (especially when it shifts composition to a pathogenic state, known as ‘dysbiosis’). Another source is microbes translocated from the oral cavity. ‘Dysbiosis’ is also used to describe translocation of cells into blood or other tissues. To avoid ambiguity, we here use the term ‘atopobiosis’ for microbes that appear in places other than their normal location. Atopobiosis may contribute to the dynamics of a variety of inflammatory diseases. Overall, it seems that many more chronic, non-communicable, inflammatory diseases may have a microbial component than are presently considered, and may be treatable using bactericidal antibiotics or vaccines.

Atopobiosis of microbes (the term describing microbes that appear in places other than where they should be), as well as the products of their metabolism, seems to correlate with, and may contribute to, the dynamics of a variety of inflammatory diseases.

Periodontitis and Porphyromonas gingivalis in preclinical stage of arthritis patients

Purpose

To determine whether the presence of periodontitis (PD) and Porphyromonas gingivalis (Pg) in the subgingival biofilm associates with the development of rheumatoid arthritis (RA) in treatment naïve preclinical stage of arthritis patients.

Methods

We conducted a prospective cohort study of 72 consecutive patients with arthralgia who had never been treated with any anti-rheumatic drugs or glucocorticoids. Periodontal status at baseline was assessed by dentists. PD was defined stringently by the maximal probing depth≧4 mm, or by the classification by the 5th European Workshop in Periodontology (EWP) in 2005 using attachment loss. Up to eight plaque samples were obtained from each patient and the presence of Pg was determined by Taqman PCR. The patients were followed up for 2 years and introduction rate of methotrexate (MTX) treatment on the diagnosis of RA was compared in patients with or without PD or Pg.

Results

Patients with PD (probing depth≧4mm) had higher arthritis activity (p = 0.02) and higher risk for future introduction of MTX treatment on the diagnosis of RA during the follow up than patients without PD (Hazard ratio 2.68, p = 0.03). Arthritis activity and risk for MTX introduction increased with the severity of PD assessed by EWP, although not statistically significant. On the other hand, presence of Pg was not associated with arthritis activity (p = 0.72) or the risk for MTX introduction (p = 0.45).

Conclusion

In treatment naïve arthralgia patients, PD, but not the presence of Pg, associates with arthritis activity and future requirement of MTX treatment on the diagnosis of RA.

Could early rheumatoid arthritis resolve after periodontitis treatment only?: case report and review of the literature

Rheumatoid arthritis (RA) is an immune-mediated polyarthritis; currently no pathogenic agent has been identified as a disease trigger. A patient with RA, presumably caused by periodontal infection, whose remission has been observed after periodontitis treatment in absence of specific RA therapy, is reported here for the first time, to our knowledge. A 61-year-old male patient presented migrant arthritis associated with antibodies against citrullinated protein antigens positivity. The clinical features allowed to make RA diagnosis according to the 2010 European League against Rheumatism/American College of Rheumatology RA classification criteria. X-ray of the second upper molar showed chronic apical periodontitis. After its treatment, arthritis remission has been observed in the absence of specific RA therapy. It has been suggested that periodontitis may have a trigger role in RA pathogenesis. This could be explained by the enzymatic action of Porphyromonas gingivalis, probably leading to break tolerance to collagen. The identification and subsequent treatment of periodontitis should therefore be considered pivotal in RA prophylaxis and management.

A large candidate-gene association study suggests genetic variants at IRF5 and PRDM1 to be associated with aggressive periodontitis

AIM

Epidemiological and clinical studies indicated a relationship of periodontitis with rheumatoid arthritis (RA). We aimed to identify shared genetic susceptibility loci of RA and periodontitis.

MATERIALS AND METHODS

Forty-seven risk genes of genome-wide significance of RA and SLE were genotyped in a German case-control sample of aggressive periodontitis (AgP), using Immunochip genotyping arrays (Illumina, 600 cases, 1440 controls) and Affymetrix 500 K Genotyping Arrays (280 cases and 983 controls). Significant associations were replicated in 168 Dutch AgP cases and 679 controls and adjusted for the confounders smoking and sex.

RESULTS

Variants at IRF5 and PRDM1 showed association with AgP. Upon covariate adjustment for smoking and sex, the most strongly associated variant at IRF5 was the rare variant rs62481981 (ppooled  = 0.0012, odds ratio [OR] = 3.1, 95% confidence interval [95% CI] = 1.6-6.1; 801 cases, 1476 controls).Within PRDM1 it was rs6923419 (ppooled  = 0.004, OR = 0.7, 95% CI = 0.6-0.9; 833 cases, 1440 controls). The associations lost significance after correction for multiple testing in the replication. Both genes are implicated in beta-interferon signalling and are also genome-wide associated with SLE and inflammatory bowel disease.

CONCLUSION

The study gives no definite evidence for a pathogenic genetic link of periodontitis and RA but suggests IRF5 and PRDM1 as shared susceptibility factors.

The link between periodontal disease and rheumatoid arthritis: an updated review

Porphyromonas gingivalis is a leading pathogen in chronic periodontitis, a disease process involving progressive destruction of the tissues that support the teeth. Recently, the organism has been reported to produce a unique bacterial enzyme, P. gingivalis peptidyl-arginine deiminase (PPAD), which has the ability to convert arginine residues in proteins to citrulline. Protein citrullination alters protein structure and function; hence, PPAD may be involved in deregulation of the host’s signalling network and immune evasion. Further, accumulating evidence suggests a role for autoimmunity against citrullinated proteins in the development of rheumatoid arthritis (RA). As inflammatory conditions in the lungs of cigarette smokers contribute to the breakdown of immune tolerance to citrullinated epitopes, chronic exposure to citrullinated proteins at periodontitis sites may also predispose susceptible individuals to the development of autoantibodies and the initiation of RA. In this review, we discuss evidence that PPAD may represent a mechanistic link between periodontitis and RA, diseases that are known to be significantly associated at the epidemiological level.

Involvement of PG2212 zinc finger protein in the regulation of oxidative stress resistance in Porphyromonas gingivalis W83

The adaptation of Porphyromonas gingivalis to H2O2-induced stress while inducible is modulated by an unknown OxyR-independent mechanism. Previously, we reported that the PG_2212 gene was highly upregulated in P. gingivalis under conditions of prolonged oxidative stress. Because this gene may have regulatory properties, its function in response to H2O2 was further characterized. PG2212, annotated as a hypothetical protein of unknown function, is a 10.3-kDa protein with a cysteine 2-histidine 2 (Cys2His2) zinc finger domain. The isogenic mutant P. gingivalis FLL366 (ΔPG_2212) showed increased sensitivity to H2O2 and decreased gingipain activity compared to the parent strain. Transcriptome analysis of P. gingivalis FLL366 revealed that approximately 11% of the genome displayed altered expression (130 downregulated genes and 120 upregulated genes) in response to prolonged H2O2-induced stress. The majority of the modulated genes were hypothetical or of unknown function, although some are known to participate in oxidative stress resistance. The promoter region of several of the most highly modulated genes contained conserved motifs. In electrophoretic mobility shift assays, the purified rPG2212 protein did not bind its own promoter region but bound a similar region in several of the genes modulated in the PG_2212-deficient mutant. A metabolome analysis revealed that PG2212 can regulate a number of genes coding for proteins involved in metabolic pathways critical for its survival under the conditions of oxidative stress. Collectively, our data suggest that PG2212 is a transcriptional regulator that plays an important role in oxidative stress resistance and virulence regulation in P. gingivalis.

Characterization of wheat germ agglutinin lectin-reactive glycosylated OmpA-like proteins derived from Porphyromonas gingivalis

Glycosylation is one of the common posttranslational modifications in eukaryotes. Recently, glycosylated proteins have also been identified in prokaryotes. A few glycosylated proteins, including gingipains, have been identified in Porphyromonas gingivalis, a major pathogen associated with chronic periodontitis. However, no other glycosylated proteins have been found. The present study identified glycoproteins in P. gingivalis cell lysates by lectin blotting. Whole-cell lysates reacted with concanavalin A (ConA), Lens culinaris agglutinin (LCA), Phaseolus vulgaris erythroagglutinin (PHA-E4), and wheat germ agglutinin (WGA), suggesting the presence of mannose-, N-acetylgalactosamine-, or N-acetylglucosamine (GlcNAc)-modified proteins. Next, glycoproteins were isolated by ConA-, LCA-, PHA-E4-, or WGA-conjugated lectin affinity chromatography although specific proteins were enriched only by the WGA column. Mass spectrometry analysis showed that an OmpA-like, heterotrimeric complex formed by Pgm6 and Pgm7 (Pgm6/7) was the major glycoprotein isolated from P. gingivalis. Deglycosylation experiments and Western blotting with a specific antibody indicated that Pgm6/7 was modified with O-GlcNAc. When whole-cell lysates from P. gingivalis mutant strains with deletions of Pgm6 and Pgm7 were applied to a WGA column, homotrimeric Pgm7, but not Pgm6, was isolated. Heterotrimeric Pgm6/7 had the strongest affinity for fibronectin of all the extracellular proteins tested, whereas homotrimeric Pgm7 showed reduced binding activity. These findings suggest that the heterotrimeric structure is important for the biological activity of glycosylated WGA-binding OmpA-like proteins in P. gingivalis.

Citrullination and proteolytic processing of chemokines by Porphyromonas gingivalis

The outgrowth of Porphyromonas gingivalis within the inflammatory subgingival plaque is associated with periodontitis characterized by periodontal tissue destruction, loss of alveolar bone, periodontal pocket formation, and eventually, tooth loss. Potential virulence factors of P. gingivalis are peptidylarginine deiminase (PPAD), an enzyme modifying free or peptide-bound arginine to citrulline, and the bacterial proteases referred to as gingipains (Rgp and Kgp). Chemokines attract leukocytes during inflammation. However, posttranslational modification (PTM) of chemokines by proteases or human peptidylarginine deiminases may alter their biological activities. Since chemokine processing may be important in microbial defense mechanisms, we investigated whether PTM of chemokines by P. gingivalis enzymes occurs. Upon incubation of interleukin-8 (IL-8; CXCL8) with PPAD, only minor enzymatic citrullination was detected. In contrast, Rgp rapidly cleaved CXCL8 in vitro. Subsequently, different P. gingivalis strains were incubated with the chemokine CXCL8 or CXCL10 and their PTMs were investigated. No significant CXCL8 citrullination was detected for the tested strains. Interestingly, although considerable differences in the efficiency of CXCL8 degradation were observed with full cultures of various strains, similar rates of chemokine proteolysis were exerted by cell-free culture supernatants. Sequencing of CXCL8 incubated with supernatant or bacteria showed that CXCL8 is processed into its more potent forms consisting of amino acids 6 to 77 and amino acids 9 to 77 (the 6-77 and 9-77 forms, respectively). In contrast, CXCL10 was entirely and rapidly degraded by P. gingivalis, with no transient chemokine forms being observed. In conclusion, this study demonstrates PTM of CXCL8 and CXCL10 by gingipains of P. gingivalis and that strain differences may particularly affect the activity of these bacterial membrane-associated proteases.

Identification of the catalytic triad of family S46 exopeptidases, closely related to clan PA endopeptidases

The exopeptidases of family S46 are exceptional, as the closest homologs of these enzymes are the endopeptidases of clan PA. The three-dimensional structure of S46 enzymes is unknown and only one of the catalytic residues, the serine, has been identified. The catalytic histidine and aspartate residues are not experimentally identified. Here we present phylogenetic and experimental data that identify all residues of the catalytic triad of S46 peptidase, dipeptidyl aminopeptidase BII (DAP BII) from Pseudoxanthomonas mexicana WO24. Phylogenetic comparison with the protein and S46 peptidases, revealed His-86, Ser-657, and five aspartate residues as possible catalytic residues. Mutation studies identified the catalytic triad of DAP BII as His-86, Asp-224, and Ser-657, while secondary structure analysis predicted an extended alpha-helical domain in between Asp-224 and Ser-657. This domain is unique for family S46 exopeptidases and its absence from the endopeptidases of clan PA might be key to their different hydrolysis activities.

Identification and characterization of prokaryotic dipeptidyl-peptidase 5 from Porphyromonas gingivalis

Porphyromonas gingivalis, a Gram-negative asaccharolytic anaerobe, is a major causative organism of chronic periodontitis. Because the bacterium utilizes amino acids as energy and carbon sources and incorporates them mainly as dipeptides, a wide variety of dipeptide production processes mediated by dipeptidyl-peptidases (DPPs) should be beneficial for the organism. In the present study, we identified the fourth P. gingivalis enzyme, DPP5. In a dpp4-7-11-disrupted P. gingivalis ATCC 33277, a DPP7-like activity still remained. PGN_0756 possessed an activity indistinguishable from that of the mutant, and was identified as a bacterial orthologue of fungal DPP5, because of its substrate specificity and 28.5% amino acid sequence identity with an Aspergillus fumigatus entity. P. gingivalis DPP5 was composed of 684 amino acids with a molecular mass of 77,453, and existed as a dimer while migrating at 66 kDa on SDS-PAGE. It preferred Ala and hydrophobic residues, had no activity toward Pro at the P1 position, and no preference for hydrophobic P2 residues, showed an optimal pH of 6.7 in the presence of NaCl, demonstrated Km and kcat/Km values for Lys-Ala-MCA of 688 μM and 11.02 μM(-1) s(-1), respectively, and was localized in the periplasm. DPP5 elaborately complemented DPP7 in liberation of dipeptides with hydrophobic P1 residues. Examinations of DPP- and gingipain gene-disrupted mutants indicated that DPP4, DPP5, DPP7, and DPP11 together with Arg- and Lys-gingipains cooperatively liberate most dipeptides from nutrient oligopeptides. This is the first study to report that DPP5 is expressed not only in eukaryotes, but also widely distributed in bacteria and archaea.

Genetic dysbiosis: the role of microbial insults in chronic inflammatory diseases

Thousands of bacterial phylotypes colonise the human body and the host response to this bacterial challenge greatly influences our state of health or disease. The concept of infectogenomics highlights the importance of host genetic factors in determining the composition of human microbial biofilms and the response to this microbial challenge. We hereby introduce the term ‘genetic dysbiosis’ to highlight the role of human genetic variants affecting microbial recognition and host response in creating an environment conducive to changes in the normal microbiota. Such changes can, in turn, predispose to, and influence, diseases such as: cancer, inflammatory bowel disease, rheumatoid arthritis, psoriasis, bacterial vaginosis and periodontitis. This review presents the state of the evidence on host genetic factors affecting dysbiosis and microbial misrecognition (i.e. an aberrant response to the normal microbiota) and highlights the need for further research in this area.

Looking in the Porphyromonas gingivalis cabinet of curiosities: the microbium, the host and cancer association

The past decades of biomedical research have yielded massive evidence for the contribution of the microbiome in the development of a variety of chronic human diseases. There is emerging evidence that Porphyromonas gingivalis, a well-adapted opportunistic pathogen of the oral mucosa and prominent constituent of oral biofilms, best known for its involvement in periodontitis, may be an important mediator in the development of a number of multifactorial and seemingly unrelated chronic diseases, such as rheumatoid arthritis and orodigestive cancers. Orodigestive cancers represent a large proportion of the total malignancies worldwide, and include cancers of the oral cavity, gastrointestinal tract and pancreas. For prevention and/or enhanced prognosis of these diseases, a good understanding of the pathophysiological mechanisms and the interaction between P. gingivalis and host is much needed. With this review, we introduce the currently accumulated knowledge on P. gingivalis's plausible association with cancer as a risk modifier, and present the putative cancer-promoting cellular and molecular mechanisms that this organism may influence in the oral mucosa.

Periodontal disease bacteria specific to tonsil in IgA nephropathy patients predicts the remission by the treatment

Background

Immunoglobulin (Ig)A nephropathy (IgAN) is the most common form of primary glomerulonephritis in the world. Some bacteria were reported to be the candidate of the antigen or the pathogenesis of IgAN, but systematic analysis of bacterial flora in tonsil with IgAN has not been reported. Moreover, these bacteria specific to IgAN might be candidate for the indicator which can predict the remission of IgAN treated by the combination of tonsillectomy and steroid pulse.

Methods and Findings

We made a comprehensive analysis of tonsil flora in 68 IgAN patients and 28 control patients using Denaturing gradient gel electrophoresis methods. We also analyzed the relationship between several bacteria specific to the IgAN and the prognosis of the IgAN. Treponema sp. were identified in 24% IgAN patients, while in 7% control patients (P = 0.062). Haemophilus segnis were detected in 53% IgAN patients, while in 25% control patients (P = 0.012). Campylobacter rectus were identified in 49% IgAN patients, while in 14% control patients (P = 0.002). Multiple Cox proportional-hazards model revealed that Treponema sp. or Campylobactor rectus are significant for the remission of proteinuria (Hazard ratio 2.35, p = 0.019). There was significant difference in remission rates between IgAN patients with Treponema sp. and those without the bacterium (p = 0.046), and in remission rates between IgAN patients with Campylobacter rectus and those without the bacterium (p = 0.037) by Kaplan-Meier analysis. Those bacteria are well known to be related with the periodontal disease. Periodontal bacteria has known to cause immune reaction and many diseases, and also might cause IgA nephropathy.

Conclusion

This insight into IgAN might be useful for diagnosis of the IgAN patients and the decision of treatment of IgAN.

Porphyromonas Gingivalis and E-coli induce different cytokine production patterns in pregnant women

Objective

Pregnant individuals of many species, including humans, are more sensitive to various bacteria or their products as compared with non-pregnant individuals. Pregnant individuals also respond differently to different bacteria or their products. Therefore, in the present study, we evaluated whether the increased sensitivity of pregnant women to bacterial products and their heterogeneous response to different bacteria was associated with differences in whole blood cytokine production upon stimulation with bacteria or their products.

Methods

Blood samples were taken from healthy pregnant and age-matched non-pregnant women and ex vivo stimulated with bacteria or LPS from Porphyromonas Gingivalis (Pg) or E-coli for 24 hrs. TNFα, IL-1ß, IL-6, IL-12 and IL-10 were measured using a multiplex Luminex system.

Results

We observed a generally lower cytokine production after stimulation with Pg bacteria or it’s LPS as compared with E-coli bacteria. However, there was also an effect of pregnancy upon cytokine production: in pregnant women the production of IL-6 upon Pg stimulation was decreased as compared with non-pregnant women. After stimulation with E-coli, the production of IL-12 and TNFα was decreased in pregnant women as compared with non-pregnant women.

Conclusion

Our results showed that cytokine production upon bacterial stimulation of whole blood differed between pregnant and non-pregnant women, showing that the increased sensitivity of pregnant women may be due to differences in cytokine production. Moreover, pregnancy also affected whole blood cytokine production upon Pg or E-coli stimulation differently. Thus, the different responses of pregnant women to different bacteria or their products may result from variations in cytokine production.

Residual Salivary Secretion Ability May Be a Useful Marker for Differential Diagnosis in Autoimmune Diseases

Background. We have elucidated decreased resting salivary flow in approximately 60% of patients with autoimmune diseases not complicated by Sjögren syndrome (SjS). In this study, salivary stimulation tests using capsaicin were performed to examine residual salivary secretion ability in patients with autoimmune diseases. Materials and Methods. Fifty-eight patients were divided into three groups: patients with primary or secondary SjS (SjS group), patients with systemic sclerosis not complicated by SjS (SSc group), and patients with other autoimmune diseases (non-SjS/non-SSc group). Simple filter paper and filter paper containing capsaicin were used to evaluate salivary flow rates. Results. Resting salivary flow rates were significantly lower in the SjS and SSc groups than in the non-SjS/non-SSc group but did not differ significantly between the SjS and SSc groups. Capsaicin-stimulated salivary flow rates were significantly lower in the SjS and SSc groups than in the non-SjS/non-SSc group, but not significantly different between the SjS and SSc groups. In the non-SjS/non-SSc group, salivary flow rates increased after capsaicin stimulation to the threshold level for determination of salivary gland dysfunction, whereas no improvement was observed in the SjS and SSc groups. Conclusion. Residual salivary secretion ability may be a useful marker for differential diagnosis in autoimmune diseases.

Kartagener's syndrome and rheumatoid arthritis

We herein present the case of a 47-year-old woman with rheumatoid arthritis (RA) complicated by Kartagener's syndrome (KS). Although her RA disease activity score (DAS28-CRP) decreased following the administration of periodontitis treatment and etanercept, she did not achieve symptom relief or DAS28-CRP remission. After undergoing surgery for chronic sinusitis, her articular symptoms improved and the DAS28-CRP declined to the level of remission. Patients with KS may develop respiratory infections due to an impaired defense mechanism against microbes in the airway. Therefore, in patients with RA complicated by KS, comprehensive management of infection, including surgical therapy for sinusitis, is needed to reduce the RA disease activity.

Oral lichen planus may enhance the expression of Th17-associated cytokines in local lesions of chronic periodontitis

OBJECTIVES

This study aims to compare the expression levels of interleukin (IL)-17 and IL-23 in local periodontal tissues from patients with both chronic periodontitis and oral lichen planus (CP-OLP), patients with chronic periodontitis (CP) only, patients with oral lichen planus (OLP) only, and healthy controls (HC).

MATERIALS AND METHODS

The periodontal tissues were collected from 15 CP-OLP patients, 15 CP patients, 15 OLP patients, and 10 healthy controls. Immunohistochemistry (IHC) and real-time quantitative PCR (qPCR) was performed to investigate the protein and mRNA expression level of IL-17 and IL-23 in periodontal lesions from these four groups.

RESULTS

IHC statistical analysis showed that the expression level of IL-17- and IL-23p19-positive cells significantly increased in CP-OLP group compared with that in CP (P < 0.01) and OLP groups (P < 0.05), showing intense staining reaction in local lamina propria lesions. Meanwhile, qPCR result showed higher IL-17 mRNA level in CP-OLP compared with that in CP and OLP groups and demonstrated a significant increase than OLP group (P < 0.05). Moreover, it was found that IL-17 mRNA expression level in erosive CP-OLP patients was significantly correlated with probing depth and attachment loss (P < 0.05).

CONCLUSIONS

This study indicated that there was an increased expression level of IL-17 and IL-23 in periodontal tissues from periodontitis patients with oral lichen planus, which might aggravate the inflammatory response in local lesions.

CLINICAL RELEVANCE

Oral lichen planus and chronic periodontitis may have interaction in disease pathogenesis, while IL-17 detection in local lesions may be helpful in identifying the disease severity in periodontitis patients with oral lichen planus.

Periodontal disease and rheumatoid arthritis: the evidence accumulates for complex pathobiologic interactions

PURPOSE OF REVIEW

This review was conducted to focus on the recent clinical and translational research related to the associations between periodontal disease and rheumatoid arthritis.

RECENT FINDINGS

There is a growing interest in the associations between oral health and autoimmune and inflammatory diseases. A number of epidemiologic studies have described associations between rheumatoid arthritis and periodontal disease. Recent clinical studies continue to support these reports, and are increasingly linked with biological assessments to better understand the nature of these relationships. A number of recent studies have evaluated the periopathogenic roles of Porphyromonas gingivalis, the oral microbiome, and mechanisms of site-specific and substrate-specific citrullination. These are helping to further elucidate the interactions between these two inflammatory disease processes.

SUMMARY

Studies of clinical oral health parameters, the gingival microenvironment, autoantibodies and biomarkers, and rheumatoid arthritis disease activity measures are providing a better understanding of the potential mechanisms responsible for rheumatoid arthritis and periodontal disease associations. The cumulative results and ongoing studies have the promise to identify novel mechanisms and interventional strategies to improve patient outcomes for both conditions.

Periodontal disease and risk of preeclampsia: a meta-analysis of observational studies

Background

Many epidemiological studies have found a positive association between periodontal disease (PD) and the risk of preeclampsia, but the magnitude of this association varies and independent studies have reported conflicting findings. We performed a meta-analysis to ascertain the relationship between PD and preeclampsia.

Methods

The PubMed database was searched up to January 12, 2013, for relevant observational studies on an association between PD and the risk of preeclampsia. Data were extracted and analyzed independently by two authors. The meta-analysis was performed using comprehensive meta-analysis software.

Results

Thirteen observational case-control studies and two cohort studies, involving 1089 preeclampsia patients, were identified. Based on a random-effects meta-analysis, a significant association between PD and preeclampsia was identified (odds ratio = 2.79, 95% confidence interval CI, 2.01–3.01, P<0.0001).

Conclusions

Although the causality remains unclear, the association between PD and preeclampsia may reflect the induction of PD by the preeclamptic state, or it may be part of an overall exaggerated inflammatory response to pregnancy. Larger randomized controlled trials with preeclampsia as the primary outcome and pathophysiological studies are required to explore causality and to dissect the biological mechanisms involved.

Association between a history of periodontitis and the risk of rheumatoid arthritis: a nationwide, population-based, case-control study

OBJECTIVE

To investigate the association between the risk of rheumatoid arthritis (RA) and a history of periodontitis.

METHODS

This nationwide, population-based, case-control study used administrative data to identify 13 779 newly diagnosed patients with RA (age ≥16 years) as the study group and 137 790 non-patients with RA matched for age, sex, and initial diagnosis date (index date) as controls. Using conditional logistic regression analysis after adjustment for potential confounders, including geographical region and a history of diabetes and Sjögren's syndrome, ORs with 95% CI were calculated to quantify the association between RA and periodontitis. To evaluate the effects of periodontitis severity and the lag time since the last periodontitis visit on RA development, ORs were calculated for subgroups of patients with periodontitis according to the number of visits, cumulative cost, periodontal surgery and time interval between the last periodontitis-related visit and the index date.

RESULTS

An association was found between a history of periodontitis and newly diagnosed RA (OR=1.16; 95% CI 1.13 to 1.21). The strength of this association remained statistically significant after adjustment for potential confounders (OR=1.16; 95% CI 1.12 to 1.20), and after variation of periodontitis definitions. The association was dose- and time-dependent and was strongest when the interval between the last periodontitis-related visit and the index date was <3 months (OR=1.64; 95% CI 1.49 to 1.79).

CONCLUSIONS

This study demonstrates an association between periodontitis and incident RA. This association is weak and limited to lack of individual smoking status.

Propeptide-mediated inhibition of cognate gingipain proteinases

Porphyromonas gingivalis is a major pathogen associated with chronic periodontitis. The organism’s cell-surface cysteine proteinases, the Arg-specific proteinases (RgpA, RgpB) and the Lys-specific proteinase (Kgp), which are known as gingipains have been implicated as major virulence factors. All three gingipain precursors contain a propeptide of around 200 amino acids in length that is removed during maturation. The aim of this study was to characterize the inhibitory potential of the Kgp and RgpB propeptides against the mature cognate enzymes. Mature Kgp was obtained from P. gingivalis mutant ECR368, which produces a recombinant Kgp with an ABM1 motif deleted from the catalytic domain (rKgp) that enables the otherwise membrane bound enzyme to dissociate from adhesins and be released. Mature RgpB was obtained from P. gingivalis HG66. Recombinant propeptides of Kgp and RgpB were produced in Escherichia coli and purified using nickel-affinity chromatography. The Kgp and RgpB propeptides displayed non-competitive inhibition kinetics with K_i values of 2.04 µM and 12 nM, respectively. Both propeptides exhibited selectivity towards their cognate proteinase. The specificity of both propeptides was demonstrated by their inability to inhibit caspase-3, a closely related cysteine protease, and papain that also has a relatively long propeptide. Both propeptides at 100 mg/L caused a 50% reduction of P. gingivalis growth in a protein-based medium. In summary, this study demonstrates that gingipain propeptides are capable of inhibiting their mature cognate proteinases.

Periodontal disease immunology: 'double indemnity' in protecting the host

During the last two to three decades our understanding of the immunobiology of periodontal disease has increased exponentially, both with respect to the microbial agents triggering the disease process and the molecular mechanisms of the host engagement maintaining homeostasis or leading to collateral tissue damage. These foundational scientific findings have laid the groundwork for translating cell phenotype, receptor engagement, intracellular signaling pathways and effector functions into a 'picture' of the periodontium as the host responds to the 'danger signals' of the microbial ecology to maintain homeostasis or succumb to a disease process. These findings implicate the chronicity of the local response in attempting to manage the microbial challenge, creating a 'Double Indemnity' in some patients that does not 'insure' health for the periodontium. As importantly, in reflecting the title of this volume of Periodontology 2000, this review attempts to inform the community of how the science of periodontal immunology gestated, how continual probing of the biology of the disease has led to an evolution in our knowledge base and how more recent studies in the postgenomic era are revolutionizing our understanding of disease initiation, progression and resolution. Thus, there has been substantial progress in our understanding of the molecular mechanisms of host-bacteria interactions that result in the clinical presentation and outcomes of destructive periodontitis. The science has embarked from observations of variations in responses related to disease expression with a focus for utilization of the responses in diagnosis and therapeutic outcomes, to current investigations using cutting-edge fundamental biological processes to attempt to model the initiation and progression of soft- and hard-tissue destruction of the periodontium. As importantly, the next era in the immunobiology of periodontal disease will need to engage more sophisticated experimental designs for clinical studies to enable robust translation of basic biologic processes that are in action early in the transition from health to disease, those which stimulate microenvironmental changes that select for a more pathogenic microbial ecology and those that represent a rebalancing of the complex host responses and a resolution of inflammatory tissue destruction.

Identification of Magnolia officinalis L. Bark Extract as the Most Potent Anti-Inflammatory of Four Plant Extracts

This study was designed to compare the anti-inflammatory potential of a Magnolia officinalis L. bark extract solely or in combination with extracts prepared from either Polygonum aviculare L., Sambucus nigra L., or Isodon japonicus L. in bacterial lipopolysaccharide (LPS) stimulated human gingival fibroblasts (HGF-1) and human U-937 monocytes, as cell models of periodontal disease. HGF-1 and U-937 cells were incubated with LPS from either Porphyromonas gingivalis or Escherichia coli together with the four plant extracts alone or in combination. Secretion of anti-inflammatory cytokines from HGF-1 and U-937 cells was measured by means of a multiplexed bead assay system. Magnolia officinalis L. bark extract, at concentrations of 1 μg/mL and 10 μg/mL, reduced interleukin 6 (IL-6) and interleukin-8 (IL-8) secretion from HGF-1 cells to 72.5 ± 28.6% and reduced matrix metalloproteinase 2 (MMP-2) and matrix metalloproteinase 9 (MMP-9) secretion from U-937 cells to 8.87 ± 7.97% compared to LPS-treated cells (100%). The other three extracts also reduced secretion of these inflammatory markers but were not as effective. Combination of 9 μg/mL Magnolia officinalis L. extract with 1 μg/mL of each of the other extracts maintained the anti-inflammatory effect of Magnolia officinalis L. extract. Combination of 5 μg/mL Magnolia officinalis L. extract with 5 μg/mL Isodon japonicus L. extract also maintained the anti-inflammatory potential of the Magnolia officinalis L. extract, whereas increasing concentrations of any of the other plant extracts in the combination experiments reduced the Magnolia officinalis L. extract efficacy in U-937 cells.

Influence of adult height on rheumatoid arthritis: association with disease activity, impairment of joint function and overall disability

Objectives

To investigate whether normal variation of adult height is associated with clinical characteristics in rheumatoid arthritis (RA), including disease activity (DAS28), impairment of joint function (mechanical joint score, MJS) and overall disability (health assessment questionnaire, HAQ).

Methods

A cohort (134 males, 287 females) of consecutively recruited RA patients of Northern European origin was studied. Height, weight and demographic information were obtained. A core set of disease measurements, including DAS28, MJS and HAQ, were recorded at baseline, 12 and 24 months. Other clinical variables (e.g. disease duration, IgM rheumatoid factor, antibodies to cyclic citrullinated peptide, C-reactive protein, erythrocyte sedimentation rate) were recorded at baseline. Socioeconomic status, smoking status, comorbid condition, other autoimmune conditions and drug therapy were also recorded. Associations were analyzed using univariate statistics and multivariate linear regression models. Mediation tests were also carried out for evaluating the relationship between gender, height and disease measures.

Results

In males, height was inversely associated with DAS28, MJS and HAQ (at baseline and over 24 months) independent of other factors (e.g. weight, body mass index, age, disease duration, osteoporosis, autoantibodies, erosive disease, joint replacement, steroid use, smoking status, socioeconomic status and comorbid disease). In females, a similar trend was seen but the relationships were non significant. In the whole population, the association of female gender with more active disease and poor function disappeared after adjustment for height. Mediation analysis indicated that height served as a full mediator in the relationship of gender with disease activity and overall disability. Confirmation of these findings was demonstrated in a second RA population (n = 288).

Conclusion

Adult height is inversely associated with disease activity, impairment of joint function and overall disability in RA, particularly in males. The association of female sex with more severe disease activity and disability appears to be mediated by smaller stature.

Oral manifestations of systemic autoimmune and inflammatory diseases: diagnosis and clinical management

CONTEXT

Systemic autoimmune and inflammatory diseases often manifest oral lesions in their earliest stages, and early diagnosis, which may be spurred by a dental examination, is key for improved outcomes. After systemic diagnosis, oral lesions benefit from specialized care by dentists in collaboration with the medical team. This review aims to educate dental clinicians about the most relevant systemic autoimmune and inflammatory conditions with accompanying oral lesions, their implications for health, and management strategies supported by the biomedical literature and clinical experience. Ulcerative conditions including Behcet and Crohn diseases are discussed, along with rheumatic conditions including Sjögren syndrome, lupus erythematosus, and rheumatoid arthritis.

EVIDENCE ACQUISITION

Evidence was accumulated through PubMed searches using pertinent keywords for each subsection. References were reviewed and original publications examined to verify the accuracy of the information. We focused on evidence included in current reviews and randomized trials. Recommendations were supported by multiple studies and consensus expert opinion.

EVIDENCE SYNTHESIS

Disease phenotypes described and clinical recommendations were synthesized from best-quality evidence available for each disease. Efforts were made to describe evidence selection within each disease section.

CONCLUSIONS

Dentists play an important role in the early detection and multidisciplinary medical management of complex autoimmune diseases. It is important to recognize prevalent medical and dental issues and special needs of patients with autoimmune conditions. The management of many inflammatory conditions is similar, and often begins with the use of topical steroids, analgesics, and antimicrobial treatments, in addition to careful attention to oral hygiene and appropriate fluoride usage. In this brief review, we aim to discuss the presentation/prevalence, diagnosis, and treatment of oral manifestations encountered in autoimmune, autoinflammatory and systemic chronic inflammatory diseases. Systemic autoimmune conditions are estimated to affect 5% to 8% of Americans.(1) Oral manifestations are encountered with high frequency, and are often the first clinical signs or symptoms of the general disease. Optimal management of complex autoimmune diseases requires a multidisciplinary medical team including dentists to care for lesions of the oral cavity. The dental practitioner may be asked to play a primary role in the diagnosis of such conditions and to participate with other health professionals working together to achieve effective clinical management. To aid in this process, we discuss in this article the current general knowledge of systemic autoimmune conditions that present with prevalent oral manifestations. The focus is on the diagnosis and management of the oral component of each disease. Importantly, whereas the etiology and pathogenesis and systemic clinical presentation may vary, presentation in the oral cavity is often similar and many conditions involve oral ulcerations. For this reason, we discuss the differential diagnosis and management of the most common oral ulcerations in a general section and subsequently address individual conditions that present with oral ulcerations. Similarly, treatment of various autoimmune/inflammatory oral conditions is often common and involves modulation or suppression of the immune response locally and/or systemically and will be therefore addressed in a common section as well as individually for each disease when unique treatment regimens are recommended. We present here our general treatment recommendations based on clinical experience and literature review; however, it is critical that good clinical judgment and specifics of an individual case should determine the appropriate dental/oral medicine intervention for a specific patient.

Neutrophils alter epithelial response to Porphyromonas gingivalis in a gingival crevice model

A gingival crevice model (epithelial cell-Porphyromonas gingivalis-neutrophil) was established and used to profile gingipain, matrix metalloproteinase (MMP), MMP mediators [neutrophil gelatinase-associated lipocalin (NGAL) and tissue inhibitor of metalloproteinases 1 (TIMP-1)] and cytokine networks. Smoking is the primary environmental risk factor for periodontitis. Therefore, the influence of cigarette smoke extract (CSE) was also monitored in the same model. Porphyromonas gingivalis alone induced low levels of interleukin-1β and interleukin-8 from epithelial cells, but high levels of both cytokines were produced on the addition of neutrophils. Exposure to CSE (100 and 1000 ng ml(-1) nicotine equivalency) significantly compromised P. gingivalis-induced cytokine secretion (both P < 0.05). P. gingivalis induced impressive secretion of NGAL (P < 0.05) that was not influenced by CSE. The influence of CSE on gingipain production was strain-specific. Purified gingipains effectively and rapidly degraded both TIMP-1 and MMP-9. Induction of large amounts of NGAL, degradation of TIMP-1, and increased gingipain activity would each be expected to prolong collagen degradation and promote disease progression. However, gingipains also degrade MMP-9. Hence, P. gingivalis exerts a complex influence on the proteolytic balance of a gingival crevice model. Exposure to CSE reduces the proinflammatory cytokine burden, which may be expected to promote P. gingivalis survival. In addition to novel findings that provide mechanistic insight into periodontal disease progression, these results are in keeping with the recognized clinical dogma of decreased inflammation/increased disease in smokers. This straightforward gingival crevice model is established as a suitable vehicle for the elucidation of mechanisms that contribute to susceptibility to periodontitis.

Rheumatoid arthritis in the elderly: recent advances in understanding the pathogenesis, risk factors, comorbidities and risk–benefit of treatments

Rheumatoid arthritis (RA) increases in incidence and prevalence with age, with a peak in the sixth decade of life. Elderly onset RA (EORA) may be genetically different from younger onset RA, and with immune dysfunction associated with aging, environmental factors may also influence EORA onset. Smoking, periodontitis and viral infections are examples of environmental factors that have been shown to be associated with development of EORA, and even hormonal changes with menopause may be a source of RA activation in older patients. EORA can be distinguished from polymyalgia rheumatica, inflammatory hand osteoarthritis or psoriatic arthritis by rheumatoid factor or anticitrullinated protein antibodies. Comorbidities influence treatment risk–benefit and require proactive management; these include arteriosclerotic cardiovascular disease, obesity, diabetes, GI tract conditions, lung disease, renal disease or malignancies, as well as susceptibility to infection. As inclusion of older RA patients is lower in clinical trials, safety data in this group are limited and this influences treatment choice, especially for biologics. Despite the efficacy of biologics, they are less likely to be used in older RA patients. This is problematic as glucocorticoids, when used in the elderly, are associated with serious infections, cardiovascular and fracture risk, among other side effects. Similarly, analgesics and NSAIDs should be used cautiously. Taking into account comorbidities, treat-to-target strategies with nonbiologic disease-modifying antirheumatic drugs and biologics can be applied with an expectation of acceptable risk–benefit in these patients.

Phenylalanine 664 of dipeptidyl peptidase (DPP) 7 and Phenylalanine 671 of DPP11 mediate preference for P2-position hydrophobic residues of a substrate

Dipeptidyl peptidases (DPPs) are crucial for the energy metabolism in Porphyromonas gingivalis, a Gram-negative proteolytic and asaccharolytic anaerobic rod causing chronic periodontitis. Three DPPs, DPPIV specific for Pro, DPP7 for hydrophobic residues and DPP11 for Asp/Glu at the P1 position, are expressed in the bacterium. Like DPP7, DPP11 belongs to the S46 protease family, and they share 38.7% sequence identity. Although DPP11 is preferential for hydrophobic residues at the P2 position, it has been reported that DPP7 has no preference at the P2 position. In the present study, we defined the detailed P2 substrate preference of DPP7 and the amino acid residue responsible for the specificity. DPP7 most efficiently hydrolyzed Met-Leu-dipeptidyl-4-methylcoumaryl-7-amide (MCA) carrying hydrophobic residues at the P1 position with k cat/Km of 10.62 ± 2.51 μM(-1) s(-1), while it unexpectedly cleaved substrates with hydrophilic (Gln, Asn) or charged (Asp, Arg) residues. Examination with 21 dipeptidyl MCA demonstrated that DPP7-peptidase activity was dependent on hydrophobicity of the P2- as well as P1-position residue, thus it correlated best with the sum of the hydrophobicity index of P1- and P2-amino acid residues. Hydrophobicity of the P1 and P2 positions ensured efficient enzyme catalysis by increasing k cat and lowering Km values, respectively. Substitution of hydrophobic residues conserved in the S46 DPP7/DPP11 family to Ala revealed that Phe664 of DPP7 and Phe671 of DPP11 primarily afforded hydrophobic P2 preference. A modeling study suggested that Phe664 and Gly666 of DPP7 and Phe671 and Arg673 of DPP11 being associated with the P2- and P1-position residues, respectively, are located adjacent to the catalytic Ser648/Ser655. The present results expand the substrate repertoire of DPP7, which ensures efficient degradation of oligopeptides in asaccharolytic bacteria.

Rheumatoid arthritis in the elderly and its relationship with periodontitis: a review

Periodontitis and rheumatoid arthritis are chronic inflammatory diseases commonly seen in the elderly. It has been proposed that the two conditions are interrelated and influence the severity of each other. Recently, the role of Porphyromonas gingivalis, a periodontopathogen, has been explained in the pathogenesis and progression of rheumatoid arthritis. It can be inferred from the present review that the two conditions share a common pathobiology, genetics and environmental risk factors. Furthermore, a thorough understanding of the aforementioned mechanisms might enable the development of conjoint treatment modalities beneficial in treating the geriatric population afflicted by both the disorders.

Periodontal disease and rheumatoid arthritis: a systematic review

This systematic review considers the evidence available for a relationship between periodontal disease and rheumatoid arthritis. MEDLINE/PubMed, CINAHL, DOSS, Embase, Scopus, Web of Knowledge, MedNar, and ProQuest Theses and Dissertations were searched from the inception of the database until June 2012 for any quantitative studies that examined the association between periodontal disease and rheumatoid arthritis. Nineteen studies met our inclusion criteria. Good evidence was found to support an association between these conditions with regard to tooth loss, clinical attachment levels, and erythrocyte sedimentation rates. Moderate evidence was noted for C-reactive protein and interleukin-1β. Some evidence for a positive outcome of periodontal treatment on the clinical features of rheumatoid arthritis was noted. These results provide moderate evidence based on biochemical markers and stronger evidence with regard to clinical parameters that common risk factors or common pathologic processes may be responsible for an association between rheumatoid arthritis and periodontal disease. Further studies are required to fully explore both the biochemical processes and clinical relationships between these 2 chronic inflammatory conditions. There is a need to move from case-control studies to more rigorous studies using well-defined populations and well-defined biochemical and clinical outcomes as the primary outcome measures with consideration of potential confounding factors.

Human Endogenous Retroviruses (HERVs) and Autoimmune Rheumatic Disease: Is There a Link?

Autoimmune rheumatic diseases, such as RA and SLE, are caused by genetic, hormonal and environmental factors. Human Endogenous Retroviruses (HERVs) may be triggers of autoimmune rheumatic disease. HERVs are fossil viruses that began to be integrated into the human genome some 30-40 million years ago and now make up 8% of the genome. Evidence suggests HERVs may cause RA and SLE, among other rheumatic diseases. The key mechanisms by which HERVS are postulated to cause disease include molecular mimicry and immune dysregulation. Identification of HERVs in RA and SLE could lead to novel treatments for these chronic conditions. This review summarises the evidence for HERVs as contributors to autoimmune rheumatic disease and the clinical implications and mechanisms of pathogenesis are discussed.

Level of information about the relationship between diabetes mellitus and periodontitis--results from a nationwide diabetes information program

Background

A comprehensive knowledge about the mutual influence between diabetes and periodontitis is decisive for the successful treatment of both diseases. The present investigation aimed at assessing the diabetic and periodontal conditions and, in particular, the degree of knowledge about the relationship between diabetes and periodontitis.

Methods

During a diabetes information program, 111 nondiabetics (ND), 101 type 1 diabetics (T1D), and 236 type 2 diabetics (T2D) were subject to a medical and dental examination and completed a self-administered questionnaire. Medical examination included measurements of glycated hemoglobin (HbA1c), blood glucose (BG), and body mass index (BMI). Full-mouth examination consisted of the assessment of the decayed, missing, filled teeth index (DMFT) and the periodontal screening index (PSI). Chi-square test, ANOVA, t test of independent samples, univariate and multivariate logistic regression models with variable selection strategies were used for statistical analyses. Due to the exploratory character of the investigation a value of P ≤0.05 was considered to be statistically substantial.

Results

T2D had a significantly higher PSI when compared to T1D and ND (t test: P <0.001; P = 0.005). Approximately 90% of T2D suffered from periodontitis. In addition, diabetics with periodontitis showed a significantly higher BMI when compared to diabetics without periodontitis (multivariate logistic regression: P = 0.002). Almost 60% of all investigated subjects were not informed about the mutual influence between diabetes and periodontitis. T2D had almost as little information about the increased risk for periodontitis as ND.

Conclusions

The data of the present investigation suggest that there is a strong association between type 2 diabetes and chronic periodontitis. The lack of awareness of the mutual influence between diabetes and periodontitis, especially in T2D, demonstrates that this topic is still neglected in dental and diabetic treatment.

Hyposalivation in autoimmune diseases

We have investigated the prevalence of dry mouth among patients with autoimmune diseases other than Sjögren's syndrome. One hundred and forty-four patients, excluding patients with primary Sjögren's syndrome, were enrolled in this study. The volume of saliva secreted was measured with the screening technique for estimation of salivary flow, which uses a filter paper for diagnosing dry mouth. Disturbed salivary secretion was observed in 84 (58.3 %) of the 144 patients. In the case of patients free of Sjögren's syndrome, the prevalence of disturbed salivary secretion differed significantly among the disease groups (P < 0.05), with the prevalence being over 50 % in all disease groups other than the rheumatoid arthritis group and the highest in the systemic sclerosis group. There was significant positive correlation between the number of colored spots and oral visual analog scale score (r = 0.45, P < 0.0001). Autoimmune diseases can be accompanied by salivary gland dysfunction, regardless of the presence/absence of complication by Sjögren's syndrome. In the present study, the screening technique for estimation of salivary flow, which uses a filter paper for diagnosing dry mouth, was shown to be a useful means of detecting salivary gland dysfunction.

The association between periodontitis and obstructive sleep apnea: a preliminary study

BACKGROUND AND OBJECTIVE

Periodontitis is becoming a highly prevalent disease worldwide. Obstructive sleep apnea (OSA) is a common disorder that is characterized by repeated disruptions in breathing during sleep, and mouth breathing is a common characteristic among patients with OSA. We aimed to assess the hypothesis that OSA is associated with the onset and progression of periodontal disease.

MATERIAL AND METHODS

This is a cross-sectional study of a total of 687 participants (460 men and 227 women), 47-77 years of age, who were examined between August 2009 and September 2010 as part of the Korean Genome and Epidemiology Study. The participants underwent standard polysomnography, clinical periodontal examination and health-screening examinations. Periodontitis was defined as clinical attachment level (CAL) ≥ 6 mm and probing pocket depth ≥ 4 mm. OSA was determined using the apnea-hypopnea index (AHI), and an AHI score of ≥ 5 was the cut-off used to indicate the presence of OSA.

RESULTS

The results showed that 17.5% of the participants had periodontitis, 46.6% had OSA and 60.0% who were diagnosed with periodontitis had OSA. In our study, old age, male gender, current smoking status, mouth breathing during sleep and high AHI were identified as risk factors for periodontitis. OSA was positively associated with periodontitis [odds ratio (OR) = 1.84, 95% confidence interval (CI) = 1.18-2.87], probing pocket depth (OR = 2.22, 95% CI = 1.30-3.77) and CAL (OR = 1.86, 95% CI = 1.07-3.21) in a dose-response manner. Additionally, OSA was positively associated with periodontitis (OR = 2.51, 95% CI = 1.37-4.62) in subjects ≥ 55 years of age, but not in subjects < 55 years of age.

CONCLUSION

There is a significant association between OSA and periodontal disease. Further research is needed to clarify the causal relationship between the two conditions.

A phage display selected 7-mer peptide inhibitor of the Tannerella forsythia metalloprotease-like enzyme Karilysin can be truncated to Ser-Trp-Phe-Pro

Tannerella forsythia is a gram-negative bacteria, which is strongly associated with the development of periodontal disease. Karilysin is a newly identified metalloprotease-like enzyme, that is secreted from T. forsythia. Karilysin modulates the host immune response and is therefore considered a likely drug target. In this study peptides were selected towards the catalytic domain from Karilysin (Kly18) by phage display. The peptides were linear with low micromolar binding affinities. The two best binders (peptide14 and peptide15), shared the consensus sequence XWFPXXXGGG. A peptide15 fusion with Maltose Binding protein (MBP) was produced with peptide15 fused to the N-terminus of MBP. The peptide15-MBP was expressed in E. coli and the purified fusion-protein was used to verify Kly18 specific binding. Chemically synthesised peptide15 (SWFPLRSGGG) could inhibit the enzymatic activity of both Kly18 and intact Karilysin (Kly48). Furthermore, peptide15 could slow down the autoprocessing of intact Kly48 to Kly18. The WFP motif was important for inhibition and a truncation study further demonstrated that the N-terminal serine was also essential for Kly18 inhibition. The SWFP peptide had a Ki value in the low micromolar range, which was similar to the intact peptide15. In conclusion SWFP is the first reported inhibitor of Karilysin and can be used as a valuable tool in structure-function studies of Karilysin.

Periodontal disease and risk of chronic obstructive pulmonary disease: a meta-analysis of observational studies

BACKGROUND

Many epidemiological studies have found a positive association between periodontal disease (PD) and risk of chronic obstructive pulmonary disease (COPD), but this association is varied and even contradictory among studies. We performed a meta-analysis to ascertain the relationship between PD and COPD.

METHODS

PubMed and Embase database were searched up to January 10, 2012, for relevant observational studies on the association between PD and risk of COPD. Data from the studies selected were extracted and analyzed independently by two authors. The meta-analysis was performed using the Comprehensive Meta-Analysis software.

RESULTS

Fourteen observational studies (one nested case-control, eight case-control, and five cross-sectional) involving 3,988 COPD patients were yielded. Based on random-effects meta-analysis, a significant association between PD and COPD was identified (odds ratio = 2.08, 95% confidence interval = 1.48-2.91; P<0.001), with sensitivity analysis showing that the result was robust. Subgroups analyses according to study design, ethnicity, assessment of PD/COPD, and adjusted/unadjusted odds ratios also revealed a significant association. Publication bias was detected.

CONCLUSIONS

Based on current evidence, PD is a significant and independent risk factor of COPD. However, whether a causal relationships exists remains unclear. Morever, we suggest performing randomized controlled trails to explore whether periodontal interventions are beneficial in regulating COPD pathogenesis and progression.

Periodontitis in established rheumatoid arthritis patients: a cross-sectional clinical, microbiological and serological study

Introduction

The association between rheumatoid arthritis (RA) and periodontitis is suggested to be linked to the periodontal pathogen Porphyromonas gingivalis. Colonization of P. gingivalis in the oral cavity of RA patients has been scarcely considered. To further explore whether the association between periodontitis and RA is dependent on P. gingivalis, we compared host immune responses in RA patients with and without periodontitis in relation to presence of cultivable P. gingivalis in subgingival plaque.

Methods

In 95 RA patients, the periodontal condition was examined using the Dutch Periodontal Screening Index for treatment needs. Subgingival plaque samples were tested for presence of P. gingivalis by anaerobic culture technique. IgA, IgG and IgM antibody titers to P. gingivalis were measured by ELISA. Serum and subgingival plaque measures were compared to a matched control group of non-RA subjects.

Results

A higher prevalence of severe periodontitis was observed in RA patients in comparison to matched non-RA controls (27% versus 12%, p < 0.001). RA patients with severe periodontitis had higher DAS28 scores than RA patients with no or moderate periodontitis (p < 0.001), while no differences were seen in IgM-RF or ACPA reactivity. Furthermore, RA patients with severe periodontitis had higher IgG- and IgM-anti P. gingivalis titers than non-RA controls with severe periodontitis (p < 0.01 resp. p < 0.05), although subgingival occurrence of P. gingivalis was not different.

Conclusions

Severity of periodontitis is related to severity of RA. RA patients with severe periodontitis have a more robust antibody response against P. gingivalis than non-RA controls, but not all RA patients have cultivable P. gingivalis.

Pregnancy and the risk of rheumatoid arthritis in a highly predisposed North American Native population

OBJECTIVE

To examine reproductive history and rheumatoid arthritis (RA) risk in a highly predisposed population of North American Natives (NAN) with unique fertility characteristics.

METHODS

The effect of pregnancy on the risk of RA was examined by comparing women enrolled in 2 studies: a study of RA in NAN patients and their unaffected relatives; and NAN patients with RA and unrelated healthy NAN controls enrolled in a study of autoimmunity. All participants completed questionnaires detailing their reproductive history.

RESULTS

Patients with RA (n = 168) and controls (n = 400) were similar overall in age, education, shared epitope frequency, number of pregnancies, age at first pregnancy, smoking, and breastfeeding history. In multivariate analysis, for women who had ≥ 6 births the OR for developing RA was 0.43 (95% CI 0.21-0.87) compared with women who had 1-2 births (p = 0.046); for women who gave birth for the first time after age 20 the OR for developing RA was 0.33 (95% CI 0.16-0.66) compared with women whose first birth occurred at age ≤ 17 (p = 0.001). The highest risk of developing RA was in the first postpartum year (OR 3.8; 95% CI 1.45-9.93) compared with subsequent years (p = 0.004).

CONCLUSION

In this unique population, greater parity significantly reduced the odds of RA; an early age at first birth increased the odds, and the postpartum period was confirmed as high risk for RA onset. The protective effect of repeated exposure to the ameliorating hormonal and immunological changes of pregnancy may counterbalance the effect of early exposure to the postpartum reversal of these changes.

Effects of periodontal therapy on disease activity and systemic inflammation in rheumatoid arthritis patients

OBJECTIVE

This observational prospective cohort study aimed to evaluate the effects of non-surgical periodontal treatment on clinical periodontal measurements and systemic inflammatory mediator levels in low or moderate to highly active rheumatoid arthritis (RA) patients with chronic periodontitis.

SUBJECTS AND METHODS

Rheumatoid arthritis activity was assessed with disease activity score test (DAS28). Thirty patients with RA with moderate to high disease activity (DAS28 ≥ 3.2) and chronic periodontitis (MHDA group) and thirty patients with RA with low disease activity (DAS28 < 3.2) and chronic periodontitis (LDA group) were enrolled in the study. The patients were monitored at the beginning and 3 months after undergoing periodontal therapy. Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), tumour necrosis factor-alpha (TNF-α) levels in serum, DAS28 and periodontal parameters were evaluated.

RESULTS

Erythrocyte sedimentation rate, CRP, TNF-α levels in serum, DAS28 and periodontal parameters exhibited similar and significant reduction 3 months after the non-surgical periodontal treatment.

CONCLUSION

Non-surgical periodontal treatment may prove beneficial in reducing RA severity as measured by ESR, CRP, TNF-α levels in serum and DAS28 in low or moderate to highly active RA patients with chronic periodontitis.