The relationship between concentrations of proinflammatory cytokines within gingiva and the adjacent sulcular depth

Cytokine levels in gingival tissues as an indicator to understand periodontal disease severity

Cytokines regulate periodontal pathogenesis and are relevant estimates of current disease activity. There is sparse information on status of cytokine protein levels in periodontal pocket (gingival) tissues. The current study analysed proteins and transcripts of selected cytokines in varying severity of periodontal disease and elucidated cytokine/cytokine ratios that best indicated periodontal disease severity, in gingival tissues. A total of 92 participants comprising of generalised moderate periodontitis (GMP, n = 18), generalised severe periodontitis (GSP, n = 46) and periodontally healthy controls (PHC, n = 25) were recruited for the study. Interproximal gingival tissue samples were utilised for cytokine protein estimation and mRNA quantification by qRT-PCR and ELISA respectively. Selected key pro and anti-inflammatory cytokines, also representative of various Th subsets were analysed. ROC curve analysis was performed and Youden index was calculated for individual cytokines and pro/anti-inflammatory cytokine ratio to estimate the best indicator of periodontal severity/progression in tissues. IL-1β, TGF-β and IFN-γ cytokine protein levels varied significantly (p ≤ 0.05) with severity of periodontal disease between groups. On comparison between deep and shallow sites within same participant, deep sites showed significant elevation of TGF-β (p ≤ 0.01) and IFN-γ (p ≤ 0.05) and IL-17 cytokines and shallow sites showed elevation of IL-4(p ≤ 0.01) and IL-1β (p ≤ 0.05) cytokines. Analysis of transcripts showed IFN-γ and IL-1β transcript predominance in GSP (p = 0.01) compared to PHC. ROC analysis illustrated 97% sensitivity, 93% specificity with Youden index of 90% for IL-1β cytokine and 81%sensitivity, 79% specificity with a Youden index of 60% for IL-1β/TGF-β ratio In periodontal pocket tissue, a lack of distinct predominance of specific cytokines between study groups or between shallow and deep sites affected by periodontal disease was observed. However, ROC analysis of cytokines revealed IL-1β cytokine and IL-1β/TGF-β ratio as promising indicators of periodontal disease severity in gingival tissues.

Local and Systemic Effects of Porphyromonas gingivalis Infection

Porphyromonas gingivalis, a gram-negative anaerobe, is a leading etiological agent in periodontitis. This infectious pathogen can induce a dysbiotic, proinflammatory state within the oral cavity by disrupting commensal interactions between the host and oral microbiota. It is advantageous for P. gingivalis to avoid complete host immunosuppression, as inflammation-induced tissue damage provides essential nutrients necessary for robust bacterial proliferation. In this context, P. gingivalis can gain access to the systemic circulation, where it can promote a prothrombotic state. P. gingivalis expresses a number of virulence factors, which aid this pathogen toward infection of a variety of host cells, evasion of detection by the host immune system, subversion of the host immune responses, and activation of several humoral and cellular hemostatic factors.

An Unusual Simultaneous Occurrence of Diabetes and Hypothyroidism in a Periodontitis Patient: A Case Report

Periodontal disease, diabetes mellitus, and hypothyroidism are commonly prevalent non-communicable diseases afflicting the human population all over the world, with the added burden on the health care system increasing the overall morbidity. It has been seen through various shreds of evidence that systemic diseases may influence the course of the localized disease and vice versa. Here, we report a case of 38-year-old female periodontitis patient also diagnosed with diabetes mellitus and hypothyroidism. Periodontitis is one of the complications of diabetes. But the occurrence of periodontal disease is a less common intra-oral finding in hypothyroidism as compared to diabetes. All these three chronic diseases were simultaneously observed in this patient, which is a rare occurrence and can adversely affect her overall prognosis. This case report highlights the need for a systematic interdisciplinary approach in the diagnosis and management of such cases.

Effect of Low-Level Laser Therapy on Peri-Miniscrew Fluid Prostaglandin E2 and Substance P Levels: A Controlled Clinical Trial

Objective

This study aims to evaluate the effect of low-level laser therapy on peri-miniscrew fluid prostaglandin E2 (PGE2) and substance P (SP) levels during orthodontic treatment.

Methods

A total of 15 individuals were included in this study. Miniscrews were inserted to the inter-radicular region of the maxillary right and left second premolar and the first molar teeth, and diode lasers were randomly applied to the right or left side. Irradiation was performed at 940 nm wavelength using a gallium-aluminum-arsenide diode laser with 100 mW power output, 0.125 cm2 spectral area, 8 J/cm2 energy density, and 10 seconds of exposure time. Peri-miniscrew fluid samples were collected on the 1st, 3rd, and 7th days, and PGE2 and SP levels were assessed. For statistical comparison, two-way (factors) analysis of variance with repeated measurements on one-factor levels was used at statistical significance (p) of <0.05.

Results

PGE2 levels on the 1st, 3rd, and 7th days were 160.64±10.05, 135.17±37.18, and 98.57±22.94, respectively, in the control group and 150.75±9.08, 87.17±40.67, and 78.10±16.50, respectively, in the laser group. SP levels on the 1st, 3rd, and 7th days were 79.90±12.05, 64.61±10.05, and 70.05±9.10, respectively, in the control group and 76.32±11.39, 60.25±9.08, and 65.71±5.59, respectively, in the laser group. The differences in PGE2 and SP levels between the laser and control groups were not statistically significant at all time intervals.

Conclusion

Low-level laser therapy cannot be recommended as a clinical adjunct therapy to reduce inflammation and pain around the miniscrews.

Periodontal Inflammation Primes the Systemic Innate Immune Response

The presence of periodontal diseases (PDs) often strongly correlates with other severe chronic inflammatory conditions, including cardiovascular disease, diabetes, and arthritis. However, the mechanisms through which these diseases interact are unclear. In PD, tissue and bone destruction in the mouth is driven by elevated recruitment of polymorphonuclear neutrophils (PMNs), which are primed and recruited from the circulation to sites of inflammation. We predicted that systemic effects on PMN mobilization or priming could account for the interaction between PD and other inflammatory conditions. We tested this using a mouse model of ligature-induced PD and found elevated PMN counts specifically in bone marrow, supporting a systemic effect of periodontal tissue inflammation on PMN production. In contrast, mice with induced peritonitis had elevated PMN counts in the blood, peritoneum, and colon. These elevated counts were further significantly increased when acute peritonitis was induced after ligature-induced PD in mice, revealing a synergistic effect of multiple inflammatory events on PMN levels. Flow cytometric analysis of CD marker expression revealed enhanced priming of PMNs from mice with both PD and peritonitis compared to mice with peritonitis alone. Thus, systemic factors associated with PD produce hyperinflammatory PMN responses during a secondary infection. To analyze this systemic effect in humans, we induced gingival inflammation in volunteers and also found significantly increased activation of blood PMNs in response to ex vivo stimulation, which reverted to normal following resolution of gingivitis. Together, these results demonstrate that periodontal tissue inflammation has systemic effects that predispose toward an exacerbated innate immune response. This indicates that peripheral PMNs can respond synergistically to simultaneous and remote inflammatory triggers and therefore contribute to the interaction between PD and other inflammatory conditions. This suggests larger implications of PD beyond oral health and reveals potential new approaches for treating systemic inflammatory diseases that interact with PD.

Periodontal status of hypothyroid patients on thyroxine replacement therapy: A comparative cross-sectional study

Background:

Thyroid hormones play a significant role in bone remodeling. However, there are few studies on the effect of these hormones on periodontium.

Aim:

The aim of this study was to evaluate the periodontal status of hypothyroid patients on thyroxine replacement therapy.

Materials and Methods:

Clinical parameters (plaque index, bleeding index, probing pocket depth [PPD], and clinical attachment level [CAL]) and radiographic parameters (Mandibular cortical width and panoramic mandibular index) were recorded in 52 hypothyroid patients on thyroxine replacement therapy (Study group) and 50 individuals without signs and symptoms of thyroid dysfunction (Control group). The effect of dosage and duration of therapy on clinical and radiographical parameters were also assessed in the study group.

Results:

Statistically significant higher PPD (P = 0.008) and clinical attachment loss (P = 0.032) were observed in the study group in comparison to the control group. However, no significant differences were observed within the hypothyroid group with varying doses and duration of therapy. Furthermore, there was no correlation between the dosage and duration of therapy with periodontal status. Regression analysis showed that hypothyroidism and thyroxine replacement therapy was a significant predictor of PPD and CAL even after controlling for the effect of age in hypothyroid patients.

Conclusion:

Hypothyroid patients on thyroxine replacement therapy may be at increased risk for periodontal destruction. However, this needs to be validated through longitudinal studies.

[Cytokine dysregulation in children with chronic catarrhal gingivitis living in polluted areas with fluoride and iodine deficiency]

The aim of the research was to study the state of oral liquid immunity in children with chronic catarrhal gingivitis living in unfavorable environmental conditions. The study included 190 children with chronic catarrhal gingivitis (CCG): 110 children aged 7, 12 and 15 years and residing in ecologically unfavorable areas of Lviv region and 80 children living in 'conditionally clean' region which constituted comparison group. Children with CCG from polluted areas had increased content of pro-inflammatory cytokines and reduction of anti-inflammatory cytokines compared to controls. The level of pro-inflammatory cytokines was age-depended in both groups but in children from ecologically unfavorable region this tendency was more pronounced. Thus, changes of indicators of interleukin spectrum in children with CCG depend not only on age and degree of severity of periodontium pathology but also on ecological living conditions.

Effect of 1.2% of simvastatin gel as a local drug delivery system on Gingival Crevicular Fluid interleukin-6 & interleukin-8 levels in non surgical treatment of chronic periodontitis patients

AIM

The present study was carried out to evaluate the effect of 1.2% simvastatin gel as local drug delivery (LDD) system on Gingival Crevicular Fluid (GCF) Interleukin -6 (IL-6) and Interleukin-8 (IL-8) levels in chronic periodontitis patients, in addition to scaling and root planing (SRP).

METHODS

A total of 46 chronic periodontitis patients were equally divided into two groups. Group I patients were treated by SRP; Group II patients were treated by SRP followed by LDD of 1.2% simvastatin (SMV) gel. Plaque index (PI), Gingival index(GI), Sulcus Bleeding Index (SBI), Probing pocket depth (PPD) and Relative clinical attachment level (CAL) were recorded & GCF samples were collected at baseline (0day) and at 45th day from both the groups. The collected GCF samples were analysed for IL-6 and IL-8 levels with enzyme-linked immunosorbent assay (ELISA).

RESULTS

Both the groups showed significant reduction in all the clinical parameters scores and IL-6 and IL-8 levels after non-surgical periodontal therapy (SRP for group I/SRP+1.2% SMV gel for group II) in contrast to baseline values. However, a greater reduction was observed in group II. A non-significant positive correlation was observed between clinical parameters and IL-6 and IL-8 levels except at baseline, a significant correlation was observed between PPD &IL 6 levels in group II.

CONCLUSIONS

In adjunct to SRP, 1.2% Simvastatin gel acts as an effective local drug delivery agent for the management of chronic periodontitis.

Association between interleukin-8 levels and chronic periodontal disease: A PRISMA-compliant systematic review and meta-analysis

BACKGROUND

Current publications present contradictory findings regarding interleukin-8 (IL-8) levels in patients with chronic periodontitis (CP). This systematic review compile evidences of the IL8 mRNA and protein levels in gingival tissue, saliva, and gingival crevicular fluid (GCF) investigated in patients with CP. Moreover, 2 meta-analyses were made focusing on the IL-8 levels in GCF and saliva of patients with or without CP.

METHODS

Electronic searches of the PubMed, Web of Science, and Scopus databases were conducted for publications up to February 2016 that investigated the levels of IL-8 detected in individuals with CP compared with health individuals. A total of 31 publications were included in the systematic review. For meta-analyses, the strength of association was calculated by pooled odds ratios with 95% confidence intervals using RevMan 5.1 software. Heterogeneity was examined using Higgins I-squared, tau-squared, and χ tests.

RESULTS

In biopsies of gingival tissue of CP patients, all studies found higher IL8 mRNA levels, and the majority of studies showed higher IL-8 protein levels in this tissue of individuals with moderate to severe CP. Four studies investigating the IL-8 levels in saliva showed inconclusive results. In spite of some studies seemed to indicate higher levels of IL-8 in GCF of CP patients, the meta-analysis results showed significantly lower IL-8 levels (pg/μL) in GCF of CP patients in comparison with periodontally healthy subjects.

CONCLUSIONS

We concluded that IL8 gene expression and IL-8 protein levels were higher in gingival tissues of CP patients when compared to periodontally health individuals. Meta-analysis of studies that measured IL-8 (pg/uL) in GCF found lower levels in CP patients. There are conflicting evidences regarding IL-8 levels in saliva.

[Dynamics of immunological features of oral liquid in children with chronic catarrhal gingivitis living on polluted territories with fluoride and iodine deficiency]

The aim of the study was to assess the state of oral liquid (OL) immunity in children with chronic catarrhal gingivitis (CCG) living in adverse environmental conditions. 120 children aged 7-15 residing in ecologically unfavorable areas of Lviv region were examined, while 75 children living in 'relatively clean' region were involved in the control group. Chronic catarrhal gingivitis was diagnosed according to Danilevskiy classification (1994). The level of cytokines in oral liquid of 7-years-old children living in ecologically polluted region (EPR), was (198.19±4.11)·106/l, which was 1.4 times more than in the conditionally clean region (CCR): (141.09±4.10)·106/l (p<0.01). Analysis of cytokine profile in 7-years-old from EPR showed increased levels of IL-6 proinflammatory cytokines by 11.22% (13.78±0.38 pg/ml vs 12.39±0.50 pg/ml in controls, p<0.05) and the decrease of IL-4 anti-inflammatory cytokine by 26.9% (7.12±0.62 pg/ml vs 9.74±0.58 pg/ml, p<0.01). In 12 years-old from EPR quantity of leukocytes in OL was 1.3 times higher than in controls ((246.81±4.16)·106/l vs (190.02±4.11)·106/l, p<0.01), the increase of the IL-6 content of 27.1% (p<0.01) and reduce of the IL-4 of 21.5% (p<0.05) compared to controls was also seen. At the age of 15 further increase of leucocytes in children from EPR was revealed: (297.53±4.15)·106/l, which was 1.2 times higher than in controls (p<0.01). Changes of cytokine profile in this age group were characterized by increased content of IL-6 of 26.41% (p<0.05) and IL-4 drop of 28.53% (p>0.05). Thus the age-dependent trend for the increase of leukocytes count in OL and pro-inflammatory cytokine IL-6 with the decrease of anti-inflammatory cytokine IL-4 is noted in children with CCG living in EPR.

Investigating the Effects of Systemically Administered Strontium Ranelate on Alveolar Bone Loss Histomorphometrically and Histopathologically on Experimental Periodontitis in Rats

BACKGROUND

The aim of this study is to investigate effects of strontium ranelate (SR) on alveolar bone loss (ABL) in rats with experimental periodontitis.

METHODS

Forty Wistar rats were randomly divided into five groups: 1) control (n = 8); 2) ligated (n = 8); 3) 300 mg/kg SR (SR300, n = 8); 4) 625 mg/kg SR (SR625, n = 8); and 5) 900 mg/kg SR (SR900, n = 8). To create experimental periodontitis, 4/0 silk ligatures were inserted submarginally around first molars at the right mandible. After 11 days, rats were sacrificed. ABL was calculated by measuring cemento-enamel junction and alveolar crest distance. Interleukin (IL)-1β, osteoprotegerin (OPG), and bone-specific alkaline phosphatase (BALP) serum levels were determined by enzyme-linked immunosorbent assay. Histopathologic analysis was used to evaluate inflammatory cell infiltration, numbers of osteoblasts and osteoclasts, and receptor activator of nuclear factor-kappa B ligand (RANKL) activity.

RESULTS

ABL was significantly lower in SR900 group than in the ligated group (P <0.05). Osteoclast numbers in ligated group were significantly higher than in the control, SR300, and SR900 groups (P <0.05). In ligated, SR625, and SR900 groups, significantly higher osteoblast numbers were detected than in control group (P <0.05). Osteoblast numbers in SR625 group were significantly higher than in the SR300 group (P <0.05). RANKL activities in SR900 and control groups were close to each other (P >0.05). Serum IL-1β, OPG, and BALP levels revealed no significant difference (P >0.05).

CONCLUSION

It can be concluded that SR can reduce RANKL activity and osteoclast numbers, as well as ABL.

Clinical and biochemical comparison of guided tissue regeneration versus guided tissue regeneration plus low-level laser therapy in the treatment of class II furcation defects: A clinical study

OBJECTIVE

The present study was aimed to compare the clinical and biochemical effectiveness of guided tissue regeneration (GTR) alone and combined with low-level laser therapy (LLLT) application in the treatment of furcation II periodontal defects, over a period of 6 months.

MATERIAL AND METHODS

Thirty-three furcation defects were included in the study. Seventeen of these defects were treated with GTR plus LLLT, and sixteen of them were treated with GTR alone. Probing pocket depth (PPD), clinical attachment level (CAL), horizontal probing depth (HPD), and alkaline phosphatase (ALP) and osteocalcin (OC) levels in the gingival crevicular fluid (GCF) were recorded at baseline and at postoperative 3rd and 6th months.

RESULTS

Healing was uneventful in all cases. At the 3rd and 6th months, both treatment modalities-GTR and GTR plus LLLT--showed improved PPD, CAL, and HPD values compared to their baseline values. ALP and OC levels in GCF increased after the treatment in both groups (p < 0.05). When compared the two groups, at the 6th month, PPD, CAL, HPD, and ALP values showed significantly more improvement in laser group than non-laser group (p < 0.05).

CONCLUSIONS

The results of this study showed that both treatments led to significantly favorable clinical improvements in furcation periodontal defects. LLLT plus GTR may be a more effective treatment modality compared to GTR alone.

Periodontitis and systemic lupus erythematosus

A large number of studies have shown a potential association between periodontal and autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus (SLE). Similar mechanisms of tissue destruction concerning periodontitis and other autoimmune diseases have stimulated the study of a possible relationship between these conditions. This study aims to review the literature about this potential association and their different pathogenic mechanisms. Considering that periodontal disease is a disease characterized by inflammation influenced by infectious factors, such as SLE, it is plausible to suggest that SLE would influence periodontal disease and vice versa. However, this issue is not yet fully elucidated and several mechanisms have been proposed to explain this association, as deregulation mainly in innate immune system, with action of phagocytic cells and proinflammatory cytokines such as IL-1β and IL-18 in both conditions' pathogenesis, leading to tissue destruction. However, studies assessing the relationship between these diseases are scarce, and more studies focused on common immunological mechanisms should be conducted to further understanding.

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

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

The association between inflammatory bowel disease and periodontitis among Jordanians: a case-control study

BACKGROUND AND OBJECTIVE

Inflammatory bowel disease (IBD) is hypothesized to involve immuno-inflammatory alterations, and the condition has been related to increased susceptibility to oral challenges. The objective of the study was to determine the association between the prevalence, severity and extent of periodontitis and both ulcerative colitis (UC) and Crohn's disease (CD).

MATERIAL AND METHODS

A case-control study was conducted among patients who attended outpatient clinics at King Hussein Medical City in Jordan during the study period. All participants completed the questionnaire and underwent thorough oral and periodontal examinations. Periodontitis was defined as presence of four or more teeth with one or more sites with probing pocket depth ≥ 4 mm and clinical attachment level ≥ 3 mm. The general linear model multivariate procedure and multivariate binary logistic regression were used to analyse the data.

RESULTS

This case-control study included 260 Jordanian adults (101 with UC, 59 with CD and 100 with no IBD) with a mean (SD) age of 39.4 (0.7) years. The prevalence of periodontitis was much higher among patients with CD and those with UC compared with subjects having no IBD in the age groups < 36 and 36-45 years old only. After adjusting for age and number of missing teeth, patients with CD (odds ratio 4.9, 95% confidence interval 1.8-13.2) and patients with UC (odds ratio 7.00, 95% confidence interval 2.8-17.5) had significantly higher odds of periodontitis than subjects with no IBD. In multivariate analysis, the severity of periodontitis was significantly higher among patients with CD and patients with UC when compared with subjects having no IBD. Ulcerative colitis patients but not CD patients had significantly higher prevalence of deep ulcers in oral soft tissues than the non-IBD group (p = 0.004).

CONCLUSION

Patients with IBD have higher prevalence, severity and extent of periodontitis compared with those having no IBD.

Effect of periodontal therapy on crevicular fluid interleukin-6 and interleukin-8 levels in chronic periodontitis

Purpose. The aim of this study was to analyse the levels of interleukin-6 (IL-6) and interleukin-8 (IL-8) in gingival crevicular fluid (GCF) of patients with chronic periodontitis prior to and following surgical and/or nonsurgical periodontal therapy for a period of 32 weeks. Methods. GCF samples were obtained from 24 nondiseased and 72 diseased sites of 12 periodontal patients prior to as well as at 6, 16, and 32 weeks following non-surgical and surgical periodontal therapy. IL-6 and IL-8 levels were determined by enzyme-linked immunosorbent assay (ELISA). Results. Periodontal treatment improved all clinical parameters. Both treatment modalities resulted in similar IL-6 as well as IL-8 levels. Mean IL-6 and IL-8 concentrations were significantly higher in non-diseased compared to diseased sites and increased significantly following treatment in diseased sites. Mean total amounts of IL-6 and IL-8 (TAIL-6, TAIL-8) did not differ significantly between diseased and nondiseased sites, while following therapy TAIL-8 levels decreased significantly. Conclusions. The data suggest that periodontal therapy reduced the levels of IL-8 in GCF. However, a strong relationship between IL-6, IL-8 amounts in GCF and periodontal destruction and inflammation was not found.

Vascular endothelial growth factor in gingival crevicular fluid around dental implants

INTRODUCTION

Angiogenesis occurs under physiological and pathological conditions and is regulated by cytokines and growth factors. Vascular endothelial growth factor (VEGF) is a multifunctional angiogenic cytokine that plays a significant role in inflammation and immune responses implicated in the pathogenesis of inflammatory processes in the implant- surrounding tissues.

OBJECTIVE

The study investigated the concentration of VEGF in gingival crevicular fluid (GCF) in healthy and diseased soft tissues surrounding implants.

MATERIAL AND METHODS

Clinical examinations were focused on assessing the periodontal status of soft tissues around dental implants with the use of Florida Probe. Bone loss was examined radiologically. VEGF concentrations were assessed by enzyme-linked immunoabsorbent assay (ELISA).

RESULTS

VEGF concentrations were found higher in crevicular fluid around implants than in clinically healthy sites. They were also strongly correlated with the pocket depth.

CONCLUSIONS

The presence of VEGF in gingival crevicular fluid in patients with peri-implants can be implicated in the progression of peri-implantitis, possibly by promoting the formation of new blood vessels during angiogenic processes.

M, O'Connell PA, Nóbrega PBD, Costa PP, Kawata VKDS, Trevisan GL, Novaes Jr. AB, Souza SLSD, Palioto DB, Grisi MFDM. Inflammation markers in healthy and periodontitis patients: a preliminary data screening

Advances in diagnostic research are moving towards methods whereby the periodontal risk can be identified and quantified by objective measures using biomarkers. Patients with periodontitis may have elevated circulating levels of specific inflammatory markers that can be correlated to the severity of the disease. The purpose of this study was to evaluate whether differences in the serum levels of inflammatory biomarkers are differentially expressed in healthy and periodontitis patients. Twenty-five patients (8 healthy patients and 17 chronic periodontitis patients) were enrolled in the study. A 15 mL blood sample was used for identification of the inflammatory markers, with a human inflammatory flow cytometry multiplex assay. Among 24 assessed cytokines, only 3 (RANTES, MIG and Eotaxin) were statistically different between groups (p<0.05). In conclusion, some of the selected markers of inflammation are differentially expressed in healthy and periodontitis patients. Cytokine profile analysis may be further explored to distinguish the periodontitis patients from the ones free of disease and also to be used as a measure of risk. The present data, however, are limited and larger sample size studies are required to validate the findings of the specific biomarkers.

IL-1beta secretion induced by Aggregatibacter (Actinobacillus) actinomycetemcomitans is mainly caused by the leukotoxin

Aggregatibacter (Actinobacillus) actinomycetemcomitans forms a leukotoxin that selectively lyses primate neutrophils, monocytes and triggers apoptosis in promyeloic cells and degranulation of human neutrophils. Recently, we showed that the leukotoxin causes activation of caspase-1 and abundant secretion of bio-active IL-1beta from human macrophages. In this study, we show that high levels of IL-beta correlated with a high proportion of A. actinomycetemcomitans in clinical samples from a patient with aggressive periodontitis. To determine the relative contribution of leukotoxin to the overall bacteria-induced IL-1beta secretion, macrophages were isolated from peripheral blood and exposed to different concentrations of live A. actinomycetemcomitans strains with either no, low or high production of leukotoxin. Cell lysis and levels of IL-1beta, IL-6, TNF-alpha and caspase-1 were measured by ELISA and flow cytometry. Leukotoxin was the predominant cause of IL-1beta secretion from macrophages, even in the A. actinomycetemcomitans strain with low leukotoxin production. Macrophages exposed to non-leukotoxic bacteria accumulated cytosolic pro-IL-1beta, which was secreted by a secondary exposure to leukotoxic bacteria. In conclusion, the present study shows for the first time that A. actinomycetemcomitans-induced IL-1beta secretion from human macrophages in vitro is mainly caused by leukotoxin.

Anti-inflammatory effects of Lactobacillus brevis (CD2) on periodontal disease

OBJECTIVES

To analyze the anti-inflammatory effects of Lactobacillus brevis extracts on periodontitis patients and to investigate the involved mechanisms in vitro on activated macrophages.

METHODS

Eight healthy subjects and 21 patients with chronic periodontitis were enrolled to analyze the effect of L. brevis-containing lozenges on periodontitis-associated symptoms and signs. Before and after the treatment, the patients received a complete periodontal examination. Saliva samples, collected before and after treatment, were analyzed for metalloproteinase and nitric oxide synthase (NOS) activity, immunoglobulin-A (IgA), prostaglandin E(2) (PGE(2)) and gamma-interferon (IFN-gamma) levels. Arginine deiminase (AD) and NOS activities were determined through a radiometric assay. Metalloproteinases were assayed by zymogram and Western blotting, whereas IgA, PGE(2) and IFN-gamma were assayed by enzyme-linked imunosorbent assay tests.

RESULTS

The treatment led to the total disappearance or amelioration of all analyzed clinical parameters in all patients. This was paralleled to a significant decrease of nitrite/nitrate, PGE(2), matrix metalloproteinase, and IFN-gamma levels in saliva samples.

CONCLUSION

Our results suggest that the anti-inflammatory effects of L. brevis could be attributed to the presence of AD which prevented nitric oxide generation. Our findings give further insights into the knowledge of the molecular basis of periodontitis and have a potential clinical significance, giving the experimental ground for a new innovative, simple and efficacious therapeutical approach of periodontal disease.

Gingival Concentrations of Interleukin-23 and -17 at Healthy Sites and at Sites of Clinical Attachment Loss

BACKGROUND

The presence of interleukin (IL)-23 has not been reported within inflamed gingiva, so we evaluated its concentration within gingiva from normal sites and sites of chronic periodontal disease.

METHODS

Gingiva was obtained prior to extraction of teeth. It was grouped based on clinical attachment loss (CAL): 0 to 2 mm (normal-slight), 3 to 4 mm (moderate), and >5 mm (severe). Tissues were solubilized, and IL-12, -23, -6, -17, and -1beta; interferon-gamma (IFN-gamma); and tumor necrosis factor-alpha (TNF-alpha) concentrations were assessed by enzyme-linked immunosorbent assay. Data were compared by factorial analysis of variance, post hoc Tukey test, and Pearson correlation test. Groups were defined as significantly different when P <0.05.

RESULTS

The gingival concentrations of IL-23, -17, -1beta, and -6 and IFN-gamma were significantly greater at moderate CAL sites than at normal-slight CAL sites. Gingival concentrations of IL-23, -1beta, -17, and -6 and TNF-alpha were significantly greater at severe CAL sites than at normal-slight CAL sites. In addition, the gingival concentrations of IL-23, -17, and -6 and TNF-alpha were significantly greater and the gingival concentrations of IL-12 and IFN-gamma were significantly lower at severe CAL sites than at moderate CAL sites. Gingival concentrations of IL-23, -17, -6, and -1beta and TNF-alpha correlated positively with CAL. The IL-23 gingival concentration correlated significantly with IL-17, -1beta, and -6 and TNF-alpha concentrations and correlated negatively with IL-12 and IFN-gamma concentrations.

CONCLUSIONS

Our results suggested the possibility that the IL-23/IL-17 immune response was present within chronically inflamed gingiva. This is a host response that had not been reported previously in periodontal disease and may be an important factor in the chronic nature of the disease.

Levels of gingival tissue platelet activating factor after conventional and regenerative periodontal surgery

The hypothesis, a relationship between gingival tissue platelet activating factor (PAF) levels and healing after periodontal surgery, was tested by measuring PAF levels in gingival tissues collected from sites that had undergone flap surgery and guided tissue regeneration (GTR) or flap surgery alone. Using a split-mouth design, 20 intrabony defects were randomly assigned to treatment with flap surgery and GTR (group 1) or with flap surgery alone (group 2). Gingival tissue samples were obtained at surgery (baseline) and at 6-month follow-up evaluation visit. One half of each sample was used for analysis of PAF levels by high-performance liquid chromatography, and the other half of the sample was used for histomorphometric analysis that included measurements of number and diameter of blood vessels. PAF levels and diameter of blood vessels were significantly decreased (p < 0.01), and the number of blood vessels was significantly increased (p < 0.05) in both groups after 6 months compared to the baseline values. Postoperative number of blood vessels were significantly higher in group 1 (p < 0.05), whereas there was no significant difference in postoperative PAF levels between the two groups (p > 0.05). Based on the reported results, it is suggested that a decrease in gingival PAF levels might be found after conventional and regenerative periodontal surgery.

Interleukin-18 Concentrations and the Pathogenesis of Periodontal Disease

BACKGROUND

Interleukin-18 (IL-18) is reported as an important regulatory cytokine in non-oral inflammation. Our objective was to compare the concentrations of IL-18 within diseased and healthy human gingiva with concentrations of other T(H)1 and T(H)2 cytokines to determine possible effects of IL-18 on gingival inflammation.

METHODS

Gingival biopsies were obtained prior to routine tooth extraction. Gingiva was grouped by the depth of the adjacent gingival sulcus: < or =3 healthy (featuring no bleeding on probing) and > or =3 mm diseased (featuring bleeding on probing). Diseased gingiva was subdivided into 3, 4 to 6 and >6 mm groups. Gingival interleukin (IL)-2, IL-4, IL-6, IL-10, IL-12, IL-18, and interferon (IFN)-gamma concentrations were assessed by enzyme linked immunosorbent assay (ELISA). Data were compared by factorial analysis of variance and the Pearson's correlation test.

RESULTS

Concentrations of IL-2, IL-4, IL-6, IL-10, IL-18, and IFN-gamma adjacent to 4 to 6 mm diseased sites were greater than adjacent to < or =3 mm healthy sites (P <0.001). IL-12 concentrations were lower within diseased than within healthy gingiva (P <0.001). IL-6 and IL-18 concentrations were greater adjacent to >6 mm sites compared to healthy sites (P <0.001); the concentrations of the other cytokines (except IL-12) were similar to healthy sites. IL-6 and IL-18 concentrations were positively correlated, and IFN-gamma and IL-12 negatively correlated, with the adjacent gingival sulcular depth.

CONCLUSIONS

Periodontal inflammation may not successfully resolve because of accumulation of IL-6 and IL-18, and decreased concentrations of IL-12, within diseased gingiva. Because of the highly significant correlation between IL-18 concentration and gingival sulcular depth, IL-18 may be a useful target for either preventive or palliative therapy for periodontitis.

Abundant secretion of bioactive interleukin-1beta by human macrophages induced by Actinobacillus actinomycetemcomitans leukotoxin

Actinobacillus actinomycetemcomitans produces a leukotoxin that selectively kills human leukocytes. Recently, we reported that macrophages are highly sensitive to leukotoxin and that their lysis involves activation of caspase 1. In this study, we show that leukotoxin also induces the production and release of proinflammatory cytokines from human macrophages. The macrophages were challenged with leukotoxin or lipopolysaccharide (LPS) from A. actinomycetemcomitans or LPS from Escherichia coli, and the production and secretion of interleukin-1beta (IL-1beta), IL-6, and tumor necrosis factor alpha (TNF-alpha) were determined at the mRNA and protein levels by reverse transcription-PCR and enzyme-linked immunosorbent assay, respectively. Leukotoxin (1 to 30 ng/ml) induced abundant production and secretion of IL-1beta, while the effects on IL-6 and TNF-alpha production were limited. Leukotoxin (1 ng/ml) caused a 10-times-higher release of IL-1beta than did LPS (100 ng/ml). The secreted IL-1beta was mainly the bioactive 17-kDa protein. At higher concentrations (>30 ng/ml), leukotoxin caused secretion of mainly inactive cytokine, the 31-kDa pro-IL-1beta. The presence of specific antibodies to IL-1beta or of a caspase 1 inhibitor blocked the secretion and production of the cytokine. Supernatants of leukotoxin-challenged macrophages stimulated bone resorption when tested in a mouse calvarial model. The activity could be blocked by an IL-1 receptor antagonist or specific antibodies to IL-1beta. We concluded that A. actinomycetemcomitans leukotoxin can trigger abundant production and secretion of bioactive IL-1beta by human macrophages, which is mediated by activation of caspase 1.

The effects of a tea tree oil-containing gel on plaque and chronic gingivitis

BACKGROUND

[corrected] This clinical study assessed the effects of topically applied tea tree oil (TTO)-containing gel on dental plaque and chronic gingivitis.

METHODS

This was a double-blind, longitudinal, non-crossover study in 49 medically fit non-smokers (24 males and 25 females) aged 18-60 years with severe chronic gingivitis. Subjects were randomly assigned to three groups and given either TTO-gel (2.5 per cent), chlorhexidine (CHX) gel (0.2 per cent), or a placebo gel to apply with a toothbrush twice daily. Treatment effects were assessed using the Gingival Index (GI), Papillary Bleeding Index (PBI) and plaque staining score (PSS) at four and eight weeks.

RESULTS

No adverse reactions to any of the gels were reported. The data were separated into subsets by tooth (anterior and posterior) and tooth surface (buccal and lingual). The TTO group had significant reduction in PBI and GI scores. However,,TTO did not reduce plaque scores, which tended to increase over the latter weeks of the study period.

CONCLUSION

Although further studies are required, the anti-inflammatory properties of TTO-containing gel applied topically to inflamed gingival tissues may prove to be a useful non-toxic adjunct to chemotherapeutic periodontal therapy.

Relationship between clinical parameters and cytokine profiles in inflamed gingival tissue and serum samples from patients with chronic periodontitis

OBJECTIVE

The purpose of the present study was to assess the relation between clinical parameters and concentrations of the key (IL-1beta, TNF-alpha, IL-2, IFN-gamma, IL-4, IL-10) cytokines, important in the initiation and progression of periodontal diseases, within inflamed gingival tissues and serum samples from patients with severe chronic periodontitis.

MATERIAL AND METHODS

Twenty-five patients with severe chronic periodontitis, who had sites with probing depths (PD) > 5 mm, and 25 periodontally healthy persons were included in the study. Clinical examinations including PD, clinical attachment loss, plaque index, and bleeding index were performed before periodontal treatment. Gingival tissue biopsies were collected from one active site of each patient and from healthy individuals, and blood samples were withdrawn on the day of tissue biopsy. The concentrations of cytokines were determined by an enzyme-linked immunosorbent assay, and the relationship between their profiles in situ and in circulation with clinical parameters was analysed.

RESULTS

The concentrations of IL-1beta, TNF-alpha, IL-2, IFN-gamma were, on average, significantly higher in serum samples and gingival tissue biopsies from periodontitis patients than in healthy controls. However, serum samples from both groups showed high individual variability of cytokine profiles, and no association between cytokine concentrations and clinical parameters of periodontitis was found. On the contrary, the levels of IL-4 and IL-10 in both kinds of samples obtained from patients and controls were generally low or even undetectable, and remained, on average, on the same level. However, the frequency of IL-4 (88% positive samples) and IL-10 (72%) was much higher in healthy gingival tissues. High concentrations of TNF-alpha, IFN-gamma and IL-2 and, especially, a high ratio of IL-1beta/IL-10 and TNF-alpha/IL-4 found in tissue biopsies from periodontitis patients, strongly correlated with the severity of periodontitis.

CONCLUSION

These results indicate that high variability of cytokine concentrations and low frequency of their detection in serum samples from periodontitis patients make these determinations useless for the detection of disease presence and/or its severity. In contrast, high absolute levels of IL-1beta, TNF-alpha, IL-2 and IFN-gamma and, especially their high ratios to IL-4 and IL-10 found in inflamed tissue biopsies, were closely associated with periodontal disease severity.

Interleukin-11 and IL-17 and the Pathogenesis of Periodontal Disease

BACKGROUND

Interleukin (IL)-11 and IL-17 are cytokines that modulate the inflammatory process and have not been assessed within normal or inflamed gingival tissues. Our purpose was to compare concentrations of human IL-11 and IL-17 within healthy and diseased human gingiva to determine their possible role in the initiation or progression of periodontal diseases.

METHODS

Biopsies from healthy (non-hemorrhagic gingiva adjacent to a < or = 3 mm gingival sulcus) and diseased gingiva (hemorrhagic gingiva adjacent to a > or = 3 mm periodontal pocket) were studied. IL-11, IL-17, RANTES, and IL-6 concentrations were assessed within solubilized gingival biopsies by enzyme-linked immunosorbent assay. Data were compared by factorial analysis of variance and a post-hoc Tukey honestly significant difference (HSD) test. Regression analysis and partial correlation analysis (adjusted for sample weight) were also used to determine correlations between the variables.

RESULTS

Interleukin-11 concentrations were highest within gingiva adjacent to 3 mm diseased pockets (P < 0.001), and IL-17 concentrations were highest at 4 to 5 mm sites compared to other sites (P < 0.001). Gingival concentrations of both cytokines were significantly lower in gingiva adjacent to a > or = 6 mm pocket. RANTES concentrations were significantly greater in gingiva adjacent to > or = 6 mm pockets than in tissues derived from other sites (P < 0.001). IL-11, IL-6, and RANTES concentrations were significantly correlated with sulcular depth.

CONCLUSIONS

Gingival concentrations of IL-11 and IL-17 are different in diseased gingiva adjacent to 3, 4 to 5, and > or = 6 mm pockets, suggesting that their concentrations change as a consequence of the progression of gingivitis to periodontitis and that both cytokines could have a significant role in this progression. These data may be useful for the design of procedures for prevention of periodontal disease.

Activation of human matrix metalloproteinase 2 by gingival crevicular fluid and Porphyromonas gingivalis

AIM

To assess the potential of gingival crevicular fluid (GCF) from adult periodontitis patients and Porphyromonas gingivalis proteases to activate matrix metalloproteinase 2 (MMP-2) in vitro.

MATERIAL AND METHODS

GCF samples were collected from each of 15 adult periodontitis patients, from a clinically healthy site, a deep (>6 mm) bleeding site, and a deep nonbleeding site. The GCF samples were examined for general proteolytic activity, gelatinolytic activity and ability to activate pro-MMP-2 by zymography. Ultrasonic extracts of a range of clinical isolates of P. gingivalis cells and purified arg- and lys-gingipains were also assessed for their ability to activate pro-MMP-2.

RESULTS

GCF from deep nonbleeding sites showed higher general proteolytic activity than samples from deep bleeding and healthy sites but this did not reach statistical significance. Pefabloc, a general serine protease inhibitor, inhibited the majority (92%) of the proteolytic activity. GCF samples contained neutrophil MMP-9 in its latent form in 93% of the samples, and in its activated form in 40% of the samples. In contrast, MMP-2 was present in only trace amounts in 9% of the samples. When latent MMP-2 was added to these GCF samples, it was converted to the activated form (59 kDa) in 68% of the samples. Lower molecular weight (55 and 45 kDa) activated forms also appeared in 53% of the samples, particularly those from deep sites. Activation to the 55 and 45 kDa forms was inhibited by MSAAPket (a neutrophil elastase inhibitor), whereas Pefabloc completely inhibited the activation of latent MMP-2. All ultrasonic extracts of P. gingivalis activated latent MMP-2 in a concentration- and time-dependent manner. Also, latent MMP-2 was activated by purified arg-gingipain but less efficiently by lys-gingipain.

CONCLUSION

These findings suggest that P. gingivalis arg-gingipain and neutrophil elastase present in GCF can activate latent MMP-2, which may contribute in vivo to local periodontal tissue destruction.

The role of gingipains in the pathogenesis of periodontal disease

Gingipains are trypsin-like cysteine proteinases produced by Porphyromonas gingivalis, a major causative bacterium of adult periodontitis. HRgpA (95 kDa) and RgpB (50 kDa), products of 2 distinct but related genes, rgpA and rgpB, respectively, are specific for Arg-Xaa peptide bonds. Kgp, a product of the kgp gene, is specific for Lys-Xaa bonds. HRgpA and Kgp are non-covalent complexes containing separate catalytic and adhesion/ hemagglutinin domains, while RgpB has only a catalytic domain with a primary structure essentially identical to that of the catalytic subunit of HRgp. HRgpA and RgpB induce vascular permeability enhancement through activation of the kallikrein/kinin pathway and activate the blood coagulation system, which, respectively, are potentially associated with gingival crevicular fluid production and progression of inflammation leading to alveolar bone loss in the periodontitis site. Kgp is the most potent fibrinogen/fibrin degrading enzyme of the 3 gingipains in human plasma and is involved in the bleeding tendency at the diseased gingiva. HRgpA activates coagulation factors and degrades fibrinogen/fibrin more efficiently than RgpB due to the adhesion/hemagglutinin domains, which have affinity for phospholipids and fibrinogen. Gingipains degrade macrophage CD14, thus inhibiting activation of the leukocytes through the lipopolysaccharide (LPS) receptor, and thereby facilitating sustained colonization of P. gingivalis. Gingipains play a role in bacterial housekeeping and infection, including amino acid uptake from host proteins and fimbriae maturation. Based on the important activities of gingipains in the bacterial infection and the pathogenesis of periodontitis, the bacterial proteinases can be targets for periodontal disease therapy. Immunization with RgpB, HRgpA, or a portion of HRgpA catalytic domain attenuated P. gingivalis induced disorders in mice. In addition, a trypsin-like proteinase inhibitor retarded P. gingivalis growth specifically. Gingipains are potent virulence factors of P. gingivalis, and are likely to be associated with the development of periodontitis. It is, therefore, suggested that gingipain inhibition by vaccination and gingipain-specific inhibitors is a useful therapy for adult periodontitis caused by P. gingivalis infection.

Localization of the chemokine interleukin-8 and interleukin-8 receptors in human gingiva and cultured gingival keratinocytes

Interleukin-8 (IL-8) has been implicated in a wide variety of diseases. Previous studies have demonstrated the expression of IL-8 in periodontal tissues, yet little is known about the exact source(s), mechanisms and factors involved in gingival expression of IL-8. Additionally, nothing is known about the presence and distribution of IL-8 receptors (IL-8R) in gingival cells. Therefore it was hypothesized that, in vivo, periodontal pathogens induce IL-8 expression from gingival keratinocytes (GK) which enhances leukocyte, microvascular endothelial cell (MVEC) and GK migration via specific IL-8 receptors present on these cells. The objective of the present study was to determine the distribution of IL-8 and IL-8R in gingival tissues and cultured human GK in vitro. Standard immunohistochemical and immunocytochemical techniques were utilized in order to localize IL-8 and its receptors CXCR-1 and CXCR-2 in archival gingival specimens (eight periodontitis and four non-inflamed controls) and in cultured gingival keratinocytes. It was demonstrated that, in vivo, IL-8 and IL-8R were present in gingival epithelium, MVEC and leukocytes. In vitro studies verified the above results, by showing expression of IL-8 and IL-8R in cultured gingival keratinocytes. It is concluded that IL-8 and IL-8 receptors are expressed in gingival epithelium both in vivo and in vitro. This new evidence indicates that epithelium plays a critical role in the host defense against invading pathogens and that keratinocytes can actively respond to IL-8 and other host cytokines, via specific receptors.

The relationship between periodontal diseases and diabetes: an overview

Diabetes mellitus, caused by the malfunction of insulin-dependent glucose and lipid metabolism, presents with the classical triad of symptoms: polydypsia, polyuria, and polyphagia which are often accompanied by chronic fatigue and loss of weight. Complications of diabetes mellitus include retinopathy, nephropathy, neuropathy, and cardiovascular disease. Periodontal diseases are infections affecting the periodontium and resulting in the loss of tooth support. The association between diabetes mellitus and periodontitis has long been discussed with conflicting conclusions. Both of these diseases have a relatively high incidence in the general population (diabetes 1% to 6% and periodontitis 14%) as well as a number of common pathways in their pathogenesis (both diseases are polygenic disorders with some degree of immunoregulatory dysfunction). On the one hand, numerous reports indicate a higher incidence of periodontitis in diabetics compared to healthy controls, while other reports fail to show such a relationship. Clarification of this dilemma is occurring as the diagnostic criteria for periodontitis and diabetes mellitus improve, controlled studies with increased sample sizes are carried out, and the studies take into account major confounding variables that impact on the pathogenesis of both diseases. Current studies tend to support a higher incidence and severity of periodontitis in patients with diabetes mellitus. The overview looks at the bidirectional relationship between periodontitis and diabetes. An analysis of the National Health and Nutrition Examination Survey (NHANES) III data set confirms the previously reported significantly higher prevalence of periodontitis in diabetics than in non-diabetics (17.3% versus 9%). The analysis of the data also shows that the prevalence of diabetes in patients with periodontitis is double that seen in the non-periodontitis patients (12.5% versus 6.3%) and that this difference is also statistically significant. The pathogenesis of the 2 diseases is reviewed with an emphasis on common genetic and immune mechanisms. On the basis of the overview, 2 hypotheses for testing the relationship between periodontitis and diabetes are discussed. The first proposes a direct causal or modifying relationship in which the hyperglycemia and hyperlipidemia of diabetes result in metabolic alterations that may then exacerbate bacteria-induced inflammatory periodontitis. The second hypothesis proposes that a fortuitous combination of genes (gene sets) could result in a host who, under the influence of a variety of environmental stressors, could develop either periodontitis or diabetes or both.

Immunohistological study of interferon-gamma- and interleukin-4-bearing cells in human periodontitis gingiva

The purpose was to investigate the balance between interferon (IFN)-gamma- and interleukin (IL)-4-bearing cells in various human inflamed gingiva by immunohistochemistry. Gingival tissues obtained from patients with gingivitis or periodontitis were divided into three groups based on the degree of histopathological inflammation, mild, moderate and severe. The tissues were also divided into four groups according to the clinical probing depth (PD). IFN-gamma- and IL-4-bearing cells in gingival tissues were stained immunohistologically and counted. The ratio of IL-4-bearing cells to IFN-gamma-bearing cells was calculated for each section. IFN-gamma-bearing cells were widespread in the connective tissue and their number increased significantly with the severity of inflammation and an increase of PD. IL-4-bearing cells were located beneath the pocket epithelium and their number showed no significant differences among the inflammation or PD groups. The ratios of IL-4-bearing cells to IFN-gamma-bearing cells in the severe inflammation or deep PD groups were significantly lower than those in the moderate inflammation or shallow PD groups. These results suggest that a low ratio of IL-4-bearing cells to IFN-gamma-bearing cells might be involved in the destruction of periodontal tissue.

Leptin within healthy and diseased human gingiva

BACKGROUND

Plasma leptin concentrations are reported to be elevated in patients with inflammatory diseases. There is no consensus concerning the biological mechanism for this phenomenon. To date, tissue leptin concentrations have not been assessed within normal or inflamed gingiva. The purpose of this study was to assess concentrations of human leptin within healthy and diseased gingiva to define its possible role in periodontal disease progression.

METHODS

Healthy (non-hemorrhagic gingiva adjacent to a < or =3 mm gingival sulcus) and inflamed gingiva (hemorrhagic gingiva adjacent to a > or =3 mm periodontal pocket) were studied. Leptin, vascular endothelial growth factor (VEGF; to assess potential vascular expansion), and interleukin-6 (IL-6; to assess periodontal disease activity and severity) concentrations were assessed within solubilized gingival biopsies by enzyme-linked immunosorbent assay. Data were grouped by sulcular depth and compared by factorial analysis of variance, regression analysis, and Scheffé comparisons.

RESULTS

Leptin concentrations were highest within gingiva adjacent to a < or =3 mm sulcus and progressively declined within gingiva adjacent to a > or =3 mm sulcus. VEGF concentrations were highest within gingiva adjacent to 4 to 6 mm pockets and nearly equivalent in healthy (< or =3 mm sulcus) and severely diseased gingiva (>6 mm sulcus). IL-6 was positively correlated and leptin negatively correlated with adjacent probing depth; IL-6 concentration was significantly higher and leptin significantly lower in gingiva adjacent to >6 mm pockets compared to sites adjacent to <6 mm pockets (P<0.001).

CONCLUSIONS

Human leptin is present within healthy and marginally inflamed gingiva and decreases in concentration as the adjacent probing depth increases. When leptin concentrations decreased (> or =3 mm sulcus), VEGF concentrations increased, suggesting that leptin could be released from gingiva coincident to vascular expansion. Thus, gingiva, in addition to adipose tissue, could be a source of circulating leptin in patients with periodontal disease. This possibility requires further investigation.

Relationship between interleukin-6 levels in gingival crevicular fluid and periodontal status in patients with rheumatoid arthritis and adult periodontitis

BACKGROUND

The aim of this study was to determine and compare interleukin-6 (IL-6) levels in gingival crevicular fluid (GCF) and clinical periodontal findings in patients with rheumatoid arthritis (RA) and adult periodontitis (AP).

METHODS

A total of 45 patients divided into 3 groups (15 patients with RA and AP, 15 patients with AP, and 15 periodontally healthy subjects) were included in this study. Plaque index (PI), gingival index (GI), sulcus bleeding index (SBI), probing depth (PD), and attachment level (AL) values for each patient were recorded. Enzyme-linked immunosorbent assay for quantitative detection of IL-6 in each GCF sample was employed.

RESULTS

No significant difference could be detected between the RA and AP groups in the mean clinical parameter data except PI. Although the mean GCF IL-6 level in the RA group was the highest, no significant difference could be found among the groups. There was only a strong negative correlation between GCF IL-6 levels and GI scores in the RA group.

CONCLUSIONS

In the patients with RA, despite increased local tissue destruction potential due to autoimmunity and higher PI levels than in the AP patients, our findings suggest that medication including corticosteroid and non-steroidal anti-inflammatory drugs may decrease gingival inflammation, but the synthesis and degradation of IL-6 in gingival tissue of RA patients may be different. To our knowledge, this study is the first report determining GCF IL-6 levels in RA patients.

Levels of interleukin-1 beta, -8, and -10 and RANTES in gingival crevicular fluid and cell populations in adult periodontitis patients and the effect of periodontal treatment

BACKGROUND

Various cytokines have been identified at sites of chronic inflammation such as periodontitis. Cytokines are synthesized in response to bacteria and their products, inducing and maintaining an inflammatory response in the periodontium. The purpose of the present study was to investigate the involvement of interleukin-1 beta (IL-1 beta), IL-8, and IL-10 and RANTES (regulated on activation, normally T cell expressed and secreted) and the cell populations associated with the immune response in destructive periodontitis, as well as the effect of periodontal therapy on cytokine levels in gingival crevicular fluid (GCF).

METHODS

Data were obtained from 12 patients with moderate to advanced periodontitis and 6 healthy controls. Patients presenting at least 2 sites with > or =2 mm clinical attachment loss were included in the destructive periodontitis group. After monitoring for 4 months, only 6 patients showed destructive periodontitis and GCF samples and soft tissues biopsies were collected from these patients. GCF samples and biopsies were collected both from active (12 CGF samples and 6 biopsies) and inactive (12 CGF samples and 6 biopsies) sites. The comparison with healthy controls was carried out by collecting GCF samples from 6 healthy volunteers (12 samples) and biopsies during the surgical removal of wisdom teeth. In periodontal patients, clinical data and GCF samples were obtained prior to periodontal treatment (72 samples) and 2 months after periodontal therapy (72 samples). GCF was collected using a paper strip; eluted and enzyme-linked immunoabsorbent assays (ELISA) were performed to determine cytokine levels. The inflammatory infiltrate was analyzed by immunohistochemistry of gingival biopsy samples with monoclonal antibodies against CD3, CD8, CD4, CD11c, and CD19 antigens.

RESULTS

Cellular components of the inflammatory infiltrate include B and T lymphocytes and monocyte/macrophages. Active sites contained a higher number of B lymphocytes and macrophages. IL-8 and IL-1 beta and RANTES in GCF were detected in the majority of sites from periodontal patients (100%, 94% and 87%, respectively); IL-10 was found in only 43%. IL-8 was the only cytokine detected in the GCF (75%) of the control group. Moreover, IL-1 beta levels were significantly higher in active sites versus inactive sites (P <0.05). IL-8 and IL-10 and RANTES were increased in active sites; however, differences were not significant (P>0.05). A positive correlation between the IL-8 and RANTES (r = 0.677, P<0.05) was observed in periodontitis patients. Periodontal therapy reduced the total amount of IL-1 beta, IL-8, and IL-10 and RANTES. Data showed a weak correlation between the clinical parameters and the total amount of cytokines in periodontitis.

CONCLUSIONS

These data suggest that the amount of crevicular IL-1 beta, IL-8, and IL-10 and RANTES is associated with periodontal status. Removal of the bacterial plaque reduces the antigenic stimuli and consequently could modulate the chemokines present in GCF. We propose that the dynamic interactions between cytokines, their production rates, and their quantity could represent factors controlling the induction, perpetuation, and collapse of the cytokine network present in the periodontal disease.

Enhanced interleukin-1beta, interleukin-6 and tumor necrosis factor-alpha production by LPS stimulated human monocytes isolated from HIV+ patients

Periodontal disease and tooth loss is a common finding among advanced HIV+ patients. In addition to local oral lipopolysaccharide (LPS) stimulation, systemic up-regulation of monocyte pro-inflammatory cytokine secretion may also be involved in the pathogenesis of HIV disease. A study was undertaken to investigate IL-1beta, IL-6 and TNF-alpha production by resting and LPS stimulated monocytes isolated from HIV+ patients and also to investigate the relationship of the patient's HIV viral load status to the cytokine production. Whole blood samples in EDTA were collected from 39 HIV-1 infected patients and 20 age and sex matched uninfected controls. Plasma was separated by centrifugation. Viral load was determined using a quantitative RT-PCR. Monocytes were isolated by Ficoll-hypaque gradient separation followed by overnight plastic adherence. Cultured monocytes (1x10(6)/ml) were stimulated with LPS (1 microg/ml) of either P. gingivalis or F. nucleatum for 2, 8, 24 and 48 h and supernatant fluids were collected. IL-1beta, IL-6, and TNF-alpha levels in supernatant fluids were estimated by ELISA. Increased overall production of IL-1beta, IL-6 and TNF-alpha by LPS stimulated monocytes isolated from HIV-1 infected patients was observed when compared to HIV-1 uninfected controls. LPS stimulated monocytes from HIV-1 infected patients with high viral load (HVL) produced significant (p<0.05) elevations in these pro-inflammatory cytokines when compared to HIV-1 uninfected controls. Both LPS of P. gingivalis and F. nucleatum produced a comparable cytokine production by monocytes after 8 h of stimulation. These data suggest that enhanced IL-1beta, IL-6 and TNF-alpha is produced by monocytes/macrophages isolated from HVL HIV+ patients and may be involved in the overall pathogenesis of HIV-1 infection.

Enhanced interleukin 1 beta, interleukin 6 and tumor necrosis factor alpha in gingival crevicular fluid from periodontal pockets of patients infected with human immunodeficiency virus 1

Loss of periodontal support and eventually tooth loss is a common finding among acquired immunodeficiency syndrome (AIDS) patients. The cause of this destruction may be an increase in periodontal disease activity at sites within the same individual and also may be related to an increase in the pro-inflammatory cytokines, diffused through the gingival crevicular sulcus in AIDS patients. A study was undertaken to determine the relative levels of the pro-inflammatory cytokines, interleukin 1 beta (IL-1 beta), IL-6, and tumor necrosis factor alpha (TNF-alpha), in gingival crevicular fluid collected from the deep (> 5 mm periodontal pocket depth) and shallow (< or = 3 mm periodontal pocket depth) periodontal pockets of 39 HIV-1-infected patients and 20 age-, race- and sex-matched uninfected controls. Complete medical history including risk factors such as intravenous drug abuse was taken. Gingival crevicular fluid samples were collected on periopaper strips. Cytokines were estimated by solid-phase enzyme-linked immunosorbent assay. To assess the degree of HIV activity, the viral load of these patients was determined by an Amplicor HIV-1 monitor kit using reverse transcriptase polymerase chain reaction. Gingival crevicular fluid from HIV-1-infected patients showed a two-fold increase in both IL-1 beta and TNF-alpha in deep periodontal pockets in comparison to shallow pockets, whereas IL-6 increased 1.8-fold. There was a significant (P < 0.05) increase in IL-1 beta, IL-6 and TNF-alpha in gingival crevicular fluid (both shallow and deep pockets) from HIV-1-infected patients in comparison to uninfected controls and also significantly elevated in deep versus shallow pockets in these patients. Although IL-1 beta, L-6 and TNF-alpha levels among HIV-1-infected patients with a high viral load (> 10,000 copies/ml) were higher than those from patients with a low viral load (< 400 copies/ml), only the increase in IL-1 beta level associated with deep pockets was significant (P < 0.05). There was also a trend of an increase in all the three cytokines among intravenous drug-abusing HIV-1-infected patients in comparison to non-intravenous drug abusers, but only the difference in IL-1 beta levels from deep pockets reached significance (P < 0.05). These enhanced pro-inflammatory cytokine levels in the gingival crevicular fluid of HIV-positive patients may be an important factor in causing the advanced periodontal lesions sometimes observed in HIV-positive patients.

Rapid and efficient inactivation of IL-6 gingipains, lysine- and arginine-specific proteinases from Porphyromonas gingivalis

Deregulation of the cytokine network is an important adaptation of pathogenic bacteria to modulate and evade a host immune response. Here we describe that IL-6 is rapidly and efficiently cleaved and inactivated by the arginine- and lysine-specific proteinases from Porphyromonas gingivalis, referred to as RGP-A, RGP-B, and KGP. One of the primary cleavage sites for RGPs has been mapped between R18 and Q19 within the N-terminal region of the IL-6 polypeptide chain; however, both KGP and RGPs cleave IL-6 within the C-terminal region of the polypeptide chain. After these initial proteolytic cleavages, IL-6 is further degraded by each of the enzymes tested. Although KGP is the most potent IL-6-degrading proteinase, the initial C-terminal cleavage of IL-6 mediated by all gingipains is already sufficient to inactivate this cytokine. Our data are consistent with the observation that in periodontitis the IL-6 concentration is lowest in the gingival tissue adjacent to bacterial plaque, whereas significantly elevated concentrations of this cytokine are detected around the infected area. Degradation of IL-6 by gingipains may, therefore, represent an additional mechanism which influences the balance between pro- and anti-inflammatory reactions at distal versus proximal sites from the periodontal plaque.