Clinical, Histological, and Microbiological Findings in Peri-Implant Disease: A Pilot Study

Objectives: This study is intended to verify the correlation among clinical indices of the peri-implant soft tissues, the histological condition and the presence of 3 pathogens commonly associated with peri-implant diseases (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Tannerella forsythia). Materials: Four clinical indices, Gingival Index (GI), Sulcus Bleeding Index, GI modified by Mombelli, and Plaque Index modified by Mombelli (mPI) were evaluated around I dental implant of each subject (n = 10). Subgingival plaque was collected for bacterial analysis (polymerase chain reaction) and a biopsy of peri-implant soft tissues for histological analysis was harvested. The clinical indices and detected pathogens correlated with a developed histological index (HI). Results: There was no statistically significant relationship between the clinical indices (GI, Sulcus Bleeding Index, and GI modified by Mombelli) and the HI, except for the mPI on the central area of lingual aspects (r = 0.85, P = 0.0029). There was a tendency for a positive correlation between the mPI on the central area of buccal aspects and the HI (r = 0.63, P = 0.0544). The counting of lymphocytes and plasmocytes correlated positively with 111, thus suggesting the index reliability. The prevalence of A. actinomycetemcomitans, P. gingivalis, and T. forsythia did not present a significant relationship with the HI. Conclusion: Despite the small number of samples and the poor statistical significance, the mPI seems to be useful for evaluation of inflammatory severity on soft tissue around dental implants as demonstrated by its relationship with the HI. Further studies are necessary to elucidate this subject. (Implant Dent 2009;18:334-344)

Inducible nitric oxide synthase-deficient mice show exacerbated inflammatory process and high production of both Th1 and Th2 cytokines during paracoccidioidomycosis

Paracoccidioidomycosis, the major systemic mycosis in Latin America, is caused by fungus Paracoccidioides brasiliensis. To analyze the influence of inducible nitric oxide synthase (iNOS) in this disease, iNOS-deficient (iNOS(-/-)) and wild-type (WT) mice were infected intravenously with P. brasiliensis 18 isolate. We found that, unlike WT mice, iNOS(-/-) mice did not control fungal proliferation, and began to succumb to infection by day 50 after inoculation of yeast cells. Typical inflammatory granulomas were found in WT mice, while, iNOS(-/-) mice presented incipient granulomas with intense inflammatory process and necrosis. Additionally, splenocytes from iNOS(-/-) mice did not produce nitric oxide, however, their proliferative response to Con-A was impaired, just like infected WT mice. Moreover, infected iNOS(-/-) mice presented a mixed pattern of immune response, releasing high levels of both Th1 (IL-12, IFN-gamma and TNF-alpha) and Th2 (IL-4 and IL-10) cytokines. These data suggest that the enzyme iNOS is a resistance factor during paracoccidioidomycosis by controlling fungal proliferation, by influencing cytokines production, and by appeasing the development of a high inflammatory response and consequently formation of necrosis. However, iNOS-derived nitric oxide seems not being the unique factor responsible for immunosuppression observed in infections caused by P. brasiliensis. (c) 2008 Elsevier Masson SAS. All rights reserved.

The broad effects of the functional IL-10 promoter-592 polymorphism: modulation of IL-10, TIMP-3, and OPG expression and their association with periodontal disease outcome

Periodontal diseases are infectious diseases, in which periodontopathogens trigger chronic inflammatory and immune responses that lead to tissue destruction. It occurs through the generation of metalloproteinases and the activation of bone resorption mechanisms. Anti-inflammatory cytokines such as IL-10 seem to attenuate periodontal tissue destruction through the induction of tissue inhibitors of metalloproteinases (TIMPs) and the inhibitor of osteoclastogenesis osteoprotegerin (OPG). A high individual variation in levels of IL-10 mRNA is verified in periodontitis patients, which is possibly determined by genetic polymorphisms. In this study, the IL-10 promoter -592C/A single nucleotide polymorphism ( SNP), which is associated with a decrease in IL-10 production, was analyzed by RFLP in 116 chronic periodontitis (CP) patients and 173 control (C) subjects, and the IL-10, TIMPs, and OPG mRNA expression levels in diseased gingival tissues were determined by real-time-PCR. The IL-10-592 SNP CA (P=0.0012/OR=2.4/CI:1.4-4.1), AA (P=0.0458/OR=2.3/CI:1.1-4.9), and CA+AA (P=0.0006/OR=2.4/CI: 1.4-3.4) genotypes and the allele A (P=0.0036/OR=1.7/CI:1.2-2.4) were found to be significantly more prevalent in the CP group when compared with control subjects. Both CA and AA genotypes were associated with lower levels of IL-10, TIMP-3, and OPG mRNA expression in diseased periodontal tissues and were also associated with disease severity as mean pocket depth. Taken together, the results presented here demonstrate that IL10-592 SNP is functional in CP, being associated with lower levels of IL-10 mRNA expression, which is supposed to consequently decrease the expression of the downstream genes TIMP-3 and OPG, and influence periodontal disease outcome. J. Leukoc. Biol. 84: 1565-1573; 2008.

Characterization of CD4(+)CD25(+) natural regulatory T cells in the inflammatory infiltrate of human chronic periodontitis

Periodontitis is an infectious disease, where putative periodontopathogens trigger chronic inflammatory and immune responses against periodontal structures, in which an unbalanced host response is also determinant to the disease outcome. It is reasonable to assume that patient susceptibility to periodontal tissue destruction could be determined by the balance between the response against periodontopathogens and regulatory mechanisms of these events mediated by suppressive T cells. In the present study, we identified and characterized natural regulatory T cells ( Tregs) in the inflammatory infiltrate of human chronic periodontitis ( CP) with emphasis on phenotypic analyses that were carried out to address the participation of Tregs in CP. Results showed that patients with CP presented increased frequency of T lymphocytes and CD4(+)CD25(+) T cells in the inflammatory infiltrate of gingival tissues. These cells exhibited the phenotypic markers of Tregs such as forkhead box p3 ( Foxp3), CTLA- 4, glucocorticoidinducible TNFR, CD103, and CD45RO and seemed to be attracted to the inflammation site by the chemokines CCL17 and CCL22, as their expression and its receptor CCR4 were increased in CP patients. Moreover, besides the increased detection of Foxp3 mRNA, diseased tissues presented high expression of the regulatory cytokines IL-10 and TGF-beta. In addition, the inflammatory infiltrate in CP biopsies was composed of CD25(+)Foxp3(+) and CD25(+)TGF-beta(+) cells, thus corroborating the hypothesis of the involvement of Tregs in the pathogenesis of CP. Finally, these results indicate that Tregs are found in the chronic lesions and must be involved in the modulation of local immune response in CP patients.

Quantitative analysis of Langerhans` cells in oral chronic graft-vs.-host disease

The Langerhans cells (LCs) are scattered throughout the epithelium of skin and mucosa and have been associated with the graft-vs.-host disease (GVHD), which is the highest cause of morbidity and mortality in patients who underwent bone marrow transplant (BMT). This study aims at quantifying the LCs in the oral chronic GVHD (cGVHD). Microscopic sections from biopsies carried out in the buccal mucosa of 40 patients who underwent allogenic BMT and developed (20) or not (20) oral cGVHD (Groups 1 and 2, respectively) were utilised. For the control group, free surgical margins of 20 biopsies of non-inflammatory lesions in the buccal mucosa (Group 3) were used. The sections were studied in routine colouration and immunostained for CD1a. Group 1 (with cGVHD) presented a greater number of Langerhans` cells/mm(2) (50.6 +/- 37.2) when compared with the other groups (Group 2, 23.11 +/- 19.7; Group 3, 16.6 +/- 17.3). Our results suggest a greater recruitment of LCs in patients transplanted with cGVHD, probably as a result of cytokines secreted by the inflammatory cells.

Detection of cytokines and nitric oxide synthase in skin lesions of Jorge Lobo`s disease patients

Studies investigating the immunopathological aspects of Jorge Lobo`s disease have shown that the inflammatory infiltrate consists mainly of histiocytes and multinucleated giant cells involving numerous yeast-like cells of Lacazia loboi, with the T lymphocytes more common than B lymphocytes and plasma cells. The quantification of cytokines in peripheral blood mononuclear cells culture supernatant has revealed alterations in the cytokines profile, characterized by predominance of a Th2 profile. In view of these findings and of the role of cytokines in cell interactions, the objective of the present study was to investigate the presence of the cytokines IL-10, TGF-ss 1 and TNF-alpha, as well as iNOS enzyme in granulomas induced by L. loboi. Histological sections obtained from skin lesions of 16 patients were analyzed by immunohistochemistry for the presence of these cytokines and iNOS. The results showed that TGF-ss 1 was the cytokine most frequently expressed by cells present in the inflammatory infiltrate, followed by IL-10. There was a minimum to discrete positivity of cells expressing TNF-alpha and iNOS. The results suggest that the presence of immunosuppressive cytokines in skin lesions of patients with the mycosis might be responsible for the lack of containment of the pathogen as demonstrated by the presence of numerous fungi in the granuloma.

Inflammatory Papillary Hyperplasia of the Palate: Quantitative Analysis of Candida albicans and its Negative Correlation with Microscopic and Demographic Aspects

Inflammatory papillary hyperplasia of the palate (IPHP) is a tissue-reactive overgrowth characterized by hyperemic mucosa with nodular or papillary appearance in the palate. The exact pathogenesis is still unclear. In this study, the presence of Candida albicans in the epithelial lining was evaluated using the indirect immunofluorescence staining technique. Strongly stained C albicans was observed only in the lesions of the IPHP group. Therefore, the detection of C albicans in almost all samples from IPHP tissue enabled a suggestion as to the microbial etiology of the disease, since the use of dental prostheses was reported. Int J Prosthodont 2011;24:235-237

Chemokines in human periodontal disease tissues

An immunoperoxidase technique was used to examine IP-10 (interferon-gamma inducible protein 10), RANTES (regulated on activation normal T cell expressed and secreted), MCP-1 (monocyte chemoattractant protein-1), and MIP-1alpha (macrophage inflammatory protein-1alpha) in gingival biopsies from 21 healthy/gingivitis and 26 periodontitis subjects. The samples were placed into 3 groups according to the size of infiltrate. MIP-1alpha+ cells were more abundant than the other chemokines with few MCP-1+ cells. The mean percent MIP-1alpha+ cells was higher than the percent MCP-1+ cells (P = 0.02) in group 2 (intermediate size infiltrates) lesions from periodontitis subjects, other differences not being significant due to the large variations between tissue samples. Analysis of positive cells in relation to CD4/CD8 ratios showed that with an increased proportion of CD8+ cells, the mean percent MIP-1alpha+ cells was significantly higher in comparison with the mean percent RANTES+ and MCP-1+ cells (P < 0.015). Endothelial cells were MCP-1+ although positive capillaries were found on the periphery of infiltrates only. Keratinocyte expression of chemokines was weak and while the numbers of healthy/gingivitis and periodontitis tissue sections positive for IP-10, RANTES and MCP-1 reduced with increasing inflammation, those positive for MIP-1alpha remained constant for all groups. In conclusion, fewer leucocytes expressed MCP-1 in gingival tissue sections, however, the percent MIP-1alpha+ cells was increased particularly in tissues with increased proportions of CD8 cells and B cells with increasing inflammation and also in tissues with higher numbers of macrophages with little inflammation. Further studies are required to determine the significance of MIP-1alpha in periodontal disease.

Cytokines in periodontal disease: where to from here?

Numerous studies have attempted to elucidate the cytokine networks involved in chronic periodontitis, often with conflicting results. A variety of techniques were used to study cells in situ, cells extracted from gingival tissues, peripheral blood mononuclear cells, purified cell populations, and T cell lines and clones. Bacterial components, including sonicates, killed cells, outer membrane components, and purified antigens, have all been used to stimulate cells in vitro, making comparisons of cytokine profiles difficult. As it is likely that different cells are present at different disease stages, the inability to determine disease activity clinically is a major limitation of all these studies. In the context of tissue destruction, cytokines such as IL-1, IL-6 and IL-18 are likely to be important, as are their regulating cytokines IL-10 and IL-11. In terms of the nature of the inflammatory infiltrate, two apparently conflicting hypotheses have emerged: one based on direct observations of human lesions, the other based on animal experimentation and the inability to demonstrate IL-4 mRNA in gingival extracts. In the first of these, Th1 responses are responsible for the stable lesion, while in the second Th2 responses are considered protective. Using Porphyromonas gingivalis specific T cell lines we have shown a tendency for IFN-gamma production rather than LL-I or IL-10 when antigen is presented with peripheral blood mononuclear cells which may contain dendritic cells. It is likely that the nature of the antigen-presenting cell is fundamental in determining the nature of the cytokine profile, which may in turn open up possibilities for new therapeutic modalities.

Differential Production of Macrophage Inflammatory Protein-1 alpha, Stromal-Derived Factor-1, and IL-6 by Human Cultured Periodontal Ligament and Gingival Fibroblasts Challenged With Lipopolysaccharide From P. gingivalis

Background: Fibroblasts are considered important cells in periodontitis. When challenged by different agents, they respond through the release of cytokines that participate in the inflammatory process. The aim of this study is to evaluate and compare the expression and production of macrophage inflammatory protein (MIP)-1 alpha, stromal-derived factor (SDF)-1, and interleukin (IL)-6 by human cultured periodontal ligament and gingival fibroblasts challenged with lipopolysaccharide (LPS) from Porphyromonas gingivalis. Methods: Fibroblasts were cultured from biopsies of gingival tissue and periodontal ligament of the same donors and used on the fourth passage. After confluence in 24-well plates, the culture medium alone (control) or with 0.1 to 10 mu g/ml of LPS from P. gingivalis was added to the wells, and after 1, 6, and 24 hours, the supernatant and the cells were collected and analyzed by enzyme-linked immunosorbent assay and real-time polymerase chain reaction, respectively. Results: MIP-1 alpha, SDF-1, and IL-6 protein production was significantly greater in gingival fibroblasts compared to periodontal ligament fibroblasts. IL-6 was upregulated in a time-dependent manner, mainly in gingival fibroblasts (P<0.05), which secreted more MIP-1 alpha in the lowest concentration of LPS used (0.1 mu g/ml). In contrast, a basal production of SDF-1 that was inhibited with the increase of LPS concentration was detected, especially after 24 hours (P<0.05). Conclusion: The distinct ability of the gingival and periodontal ligament fibroblasts to secrete MIP-1 alpha, SDF-1, and IL-6 emphasizes that these cells may differently contribute to the balance of cytokines in the LPS-challenged periodontium. J Periodontol 2010;81:310-317.

Ross River virus transmission, infection, and disease: a cross-disciplinary review

Ross River virus (RRV) is a fascinating, important arbovirus that is endemic and enzootic in Australia and Papua New Guinea and was epidemic in the South Pacific in 1979 and 1980. Infection with RRV may cause disease in humans, typically presenting as peripheral polyarthralgia or arthritis, sometimes with fever and rash. RRV disease notificatïons in Australia average 5,000 per year. The first well-described outbreak occurred in 1928. During World War II there were more outbreaks, and the name epidemic polyarthritis was applied. During a 1956 outbreak, epidemic polyarthritis was linked serologically to a group A arbovirus (Alphavirus). The virus was subsequently isolated from Aedes vigilax mosquitoes in 1963 and then from epidemic polyarthritis patients. We review the literature on the evolutionary biology of RRV, immune response to infection, pathogenesis, serologic diagnosis, disease manifestations, the extraordinary variety of vertebrate hosts, mosquito vectors, and transmission cycles, antibody prevalence, epidemiology of asymptomatic and symptomatic human infection, infection risks, and public health impact. RRV arthritis is due to joint infection, and treatment is currently based on empirical anti-inflammatory regimens. Further research on pathogenesis may improve understanding of the natural history of this disease and lead to new treatment strategies. The burden of morbidity is considerable, and the virus could spread to other countries. To justify and design preventive programs, we need accurate data on economic costs and better understanding of transmission and behavioral and environmental risks.

Increased circulating levels of matrix metalloproteinase (MMP)-8, MMP-9, and pro-inflammatory markers in patients with metabolic syndrome

Background: Metabolic syndrome (MetS) predisposes to cardiovascular complications. Increased concentrations of pro-inflammatory mediators and imbalanced concentrations of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) may reflect the pathophysiology of MetS. We compared the circulating levels of MMPs, TIMPs, and inflammatory mediators in MetS patients with those found in healthy controls. Methods: We studied 25 healthy subjects and 25 MetS patients. The plasma levels of pro-MMP-2 and pro-MMP-9 were determined by gelatin zymography. The plasma concentrations of MMP-8, MMP-3, TIMP-1, TIMP-2, monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6), intercellular adhesion molecule (sICAM-1), and sP-selectin were measured by ELISA kits. Results: We found higher sP-selectin, sICAM-1, MCP-1, and IL-6 (all P<0.05) concentrations in MetS patients compared with healthy controls. No differences in pro-MMP-2, MMP-3, and TIMP-2 levels were found (all P>0.05). However, we found higher pro-MMP-9, MMP-8. and TIMP-1 levels in MetS patients compared with healthy controls (all P<0.05). Conclusions: Patients with MetS have increased circulating concentrations of pro-MMP-9, MMP-8, and TIMP-1 that are associated with increased concentrations of pro-inflammatory mediators and adhesion molecules. These findings suggest that MMPs may have a role in the increased cardiovascular risk of MetS patients. Pharmacological interventions targeting MMPs, especially MMP-9 and MMP-8 deserve further investigation in MetS patients. (C) 2009 Elsevier B.V. All rights reserved.

G551D CF mice display an abnormal host response and have impaired clearance of Pseudomonas lung disease

Several cystic fibrosis (CF) mouse models demonstrate an increased susceptibility to Pseudomonas aeruginosa lung infection, characterized by excessive inflammation and high rates of mortality. Here we developed a model of chronic P. aeruginosa lung disease in mice homozygous for the murine CF transmembrane conductance regulator G551D mutation that provides an excellent model for CF lung disease. After 3 days of infection with mucoid P. aeruginosa entrapped in agar beads, the G551D animals lost substantially more body weight than non-CF control animals and were less able to control the infection, harboring over 40-fold more bacteria in the lung. The airways of infected G551D animals contained altered concentrations of the inflammatory mediators tumor necrosis factor-alpha, KC/N51, and macrophage inflammatory protein-2 during the first 2 days of infection, suggesting that an ineffective inflammatory response is partly responsible for the clearance defect.

Antigen-presenting cells in human periodontal disease tissues

T cells are present in the inflammatory infiltrates of periodontal disease lesions and require antigen presentation by antigen-presenting cells (APCs). While it is still not known whether Th1 or Th2 cells predominate in these lesions, it has been reported that different APCs may induce activation of different T-cell subsets. An immunoperoxidase technique was used to investigate the presence of CD1a+, CMRF-44+, CMRF-58+ and CD83+ dendritic cells, CD14+ macrophages or dendritic cell precursors and CD19+ B cells in gingival biopsies from 21 healthy or gingivitis and 25 periodontitis subjects. The samples were divided into three groups according to the size of infiltrate (group 1, small infiltrates; group 2, medium infiltrates; group 3, extensive infiltrates). The presence of numerous CD1a+ Langerhans cells was noted in the epithelium with no differences between the healthy/gingivitis and periodontitis groups. The percentage of CD83+ dendritic cells in the infiltrates was higher than the percentage of CD1a+, CMRF-44+ or CMRF-58+ dendritic cells. Endothelial cells positive for CD83 were found predominantly in areas adjacent to infiltrating cells, CD83+ dendritic cells being noted in the region of CD83+ endothelium. The percentage of CD14+ cells in the inflammatory infiltrates was similar to that of CD83+ dendritic cells. B cells were the predominant APC in group 2 and 3 tissues. The percentage of B cells in group 3 periodontitis lesions was increased in comparison with group 1 periodontitis tissues and also in comparison with group 3 healthy/gingivitis sections. Functional studies are required to determine the roles of different APC subpopulations in periodontal disease.

Apoptosis in the pathogenesis of renal disease with a focus on tubulointerstitial injury

Renal cell apoptosis is important not only in normal physiological conditions of the kidney but also in pathological processes. In normal renal development, it removes unwanted, damaged or harmful cells, and in the healthy adult kidney, it maintains cellular homeostasis by regulating the balance between cell proliferation and cell loss. The apoptotic process has now been described in the pathogenesis and prognosis of certain renal diseases with both beneficial and detrimental roles. It causes deletion of cells intrinsic to the kidney after, for example, toxic, ischaemic, immune or radiation damage, and this loss can be destructive and can cause significant reduction of renal function. In contrast, it can control and limit inflammatory processes in both the acute and chronic phases of renal disease. Information on the positive and negative outcomes of renal cell apoptosis, plus the thousands of publications on more general aspects of apoptosis mechanisms, have now presented real opportunities for the development of therapies that selectively delete or protect certain renal cell populations. This review will discuss some of the more general aspects of renal cell apoptosis and then concentrate on the detrimental or beneficial roles of apoptosis in the initiation, progression or resolution of selected, mainly tubulointerstitial, renal diseases.