Role of cytokines in the modulation of neutrophil chemotaxis in localized juvenile periodontitis

Circulating mitochondrial N-formyl peptides contribute to secondary nosocomial infection in patients with septic shock

Septic shock commonly leads to multiorgan injury both directly via tissue inflammation and secondarily via hypoperfusion, but both can result in mitochondrial N-formyl peptide (mtFP) release into the circulation. However, no studies have evaluated the role of circulating mtFPs during septic shock. We found that a relatively high plasma nicotinamide adenine dinucleotide dehydrogenase subunit-6 (the most potent human mtFP) level was independently associated with the development of secondary infection in patients with septic shock and that the increased susceptibility to secondary infection is partly attributed to the suppression of polymorphonuclear leukocyte (PMN) chemotaxis by mtFP occupancy of formyl peptide receptor-1. Incorporation of these findings into therapeutic strategies may improve clinical outcomes in septic shock patients by preventing PMN chemotactic anergy.

Secondary infections typically worsen outcomes of patients recovering from septic shock. Neutrophil [polymorphonuclear leukocytes (PMNs)] migration to secondarily inoculated sites may play a key role in inhibiting progression from local bacterial inoculation to secondary infection. Mitochondrial N-formyl peptide (mtFP) occupancy of formyl peptide receptor-1 (FPR1) has been shown to suppress PMN chemotaxis. Therefore, we studied the association between circulating mtFPs and the development of secondary infection in patients with septic shock. We collected clinical data and plasma samples from patients with septic shock admitted to the intensive care unit for longer than 72 h. Impacts of circulating nicotinamide adenine dinucleotide dehydrogenase subunit-6 (ND6) upon clinical outcomes were analyzed. Next, the role of ND6 in PMN chemotaxis was investigated using isolated human PMNs. Studying plasma samples from 97 patients with septic shock, we found that circulating ND6 levels at admission were independently and highly associated with the development of secondary infection (odds ratio = 30.317, 95% CI: 2.904 to 316.407, P = 0.004) and increased 90-d mortality (odds ratio = 1.572, 95% CI: 1.002 to 2.465, P = 0.049). In ex vivo experiments, ND6 pretreatment suppressed FPR1-mediated PMN chemotactic responses to bacterial peptides in the presence of multiple cytokines and chemokines, despite increased nondirectional PMN movements. Circulating mtFPs appear to contribute to the development of secondary infection and increased mortality in patients with septic shock who survive their early hyperinflammatory phase. The increased susceptibility to secondary infection is probably partly mediated by the suppression of FPR1-mediated PMN chemotaxis to secondary infected sites.

Mechanical Periodontal Therapy Recovered the Phagocytic Function of Monocytes in Periodontitis

BACKGROUND

Several studies have focused on the association between periodontitis and systemic implications; however, the biological mechanisms of the immune responses before and after periodontal therapy involved in this relationship, such as phagocytic functions, remain unclear.

OBJECTIVES

This study aimed to investigate whether periodontal treatment improves the phagocytic function of blood monocytes in patients with severe periodontitis. Materials and Methods. A nonrandomized sample of 55 participants was enrolled in the study. Two groups were studied: control (n = 27, healthy subjects without periodontal disease) and patients (n = 27, healthy subjects without periodontal disease) and patients (.

RESULTS

Periodontitis induced impaired phagocytosis by monocytes. Phagocytosis at baseline was significantly lower in periodontitis patients [median, 13.2 (range of 7.1 to 20.8) and 60.7 (40.6 to 88.6)] than in controls [27.4 (15.5 to 40.5)] and 98 (68.2 to 122.9)] for nonsensitized or sensitized samples, respectively. After supportive therapy, patients showed a significant enhancement of phagocytic functions [33.7 (14.6 to 53.2) and 108.5 (99.6 to 159.5)] for nonsensitized and sensitized samples, respectively. Periodontal treatment increased the phagocytic capacity to a level similar to that observed in the control group and improved the capacity of phagocytes to produce superoxide anion.

CONCLUSIONS

The results suggest that periodontal therapy in patients with severe periodontitis provides a state of homeostasis due to the reestablishment of phagocytic function and increased production of NBT (Regional Registry No. RBR-24T799; Universal Registry No. U1111-1133-5512).

Evaluation of peripheral neutrophil functions in aggressive periodontitis patients and their family members in Indian population: An assessment of neutrophil chemotaxis, phagocytosis, and microbicidal activity

Background

Association of neutrophil function abnormalities with localized aggressive periodontitis (LAP) has been reported in Indian population. There are no published studies on the familial aggregation of aggressive periodontitis (AP) and neutrophil function abnormalities associated with it in Indian population. The present study aimed to assess neutrophil chemotaxis, phagocytosis, and microbicidal activity in AP patients and their family members of Indian origin, who may or may not be suffering from AP.

Materials and Methods

Eighteen families with a total of 51 individuals (18 probands, 33 family members) were included. Neutrophil chemotaxis was evaluated against an alkali-soluble casein solution using Wilkinson's method. Phagocytosis and microbicidal activity assay were performed using Candida albicans as an indicator organism.

Statistical Analysis Used

The magnitude of association between the presence of defective neutrophil function and LAP or GAP was calculated using odds ratio and relative risk. Total incidence of AP, and in particular, LAP in the families attributable to the presence of defective neutrophil function was calculated by attributable risk.

Results

The association between depressed neutrophil chemotaxis and presence of AP and LAP or GAP in all the family members (n = 51) was found to be significant (P < 0.05) while that for phagocytic and microbicidal activity were observed to be nonsignificant.

Conclusion

The results of the present study suggest high incidence of AP (LAP and GAP) within families was associated with depressed neutrophil chemotaxis. High prevalence of depressed neutrophil chemotaxis in the family members (61%) of LAP probands exhibiting depressed chemotaxis suggests that the observed abnormalities in neutrophil functions may also be inherited by the family members.

Is there an association between systemic lupus erythematosus and periodontal disease?

Periodontal disease results from the interaction between pathogenic bacteria that colonize supragingival and subgingival biofilms and the host, triggering an inflammatory response, with systemic effects leading to immune-mediated destruction of the attachment apparatus and loss of supporting alveolar bone. Immunological pathways and predisposing genetic factors common to periodontal disease and rheumatic diseases, including systemic lupus erythematosus, have been described. Case reports have suggested greater severity of periodontal disease in patients with systemic lupus erythematosus. However, studies evaluating the influence of the treatment of one disease on the clinical and laboratory manifestations of the other have yielded conflicting results.

Assessment of peripheral neutrophil functions in patients with localized aggressive periodontitis in the Indian population

Background:

Localized aggressive periodontitis (LAP) patients exhibit abnormal neutrophil functions to a variety of environmental and host stimuli. The aim of the present study was to evaluate neutrophils chemotaxis, phagocytosis, microbicidal activity and superoxide generation in LAP patients of Indian origin.

Materials and Methods:

Eleven LAP patients and nine healthy subjects were included in the study. Neutrophil chemotaxis was evaluated against an alkali-soluble casein solution using Wilkinson's method. Phagocytosis and microbicidal activity assay were performed using Candida albicans as an indicator organism. Nitrobluetetrazolium (NBT) test was used to assess superoxide generation by neutrophils using E. coli endotoxin.

Results:

The chemotactic activity and phagocytic and microbicidal activity were observed to be significantly reduced (P < 0.01) in LAP neutrophils. On the contrary, superoxide generation was observed to be significantly increased (P < 0.01) in LAP neutrophils compared with healthy individuals.

Conclusion:

The results of the present study suggest that neutrophil functions, namely chemotaxis, phagocytosis and microbicidal activity, are deficient LAP patients. However, superoxide generation was significantly increased when stimulated by endotoxins, which may explain the tissue damage seen in LAP. These abnormal neutrophil functions may predispose to increased susceptibility for LAP. Further large-scale studies are required in the Indian population to ascertain the cause-and-effect relationship of defective host factors and aggressive periodontitis and to develop treatment strategies for more predictable periodontal treatment outcome.

Decreased phagocytic function in neutrophils and monocytes from peripheral blood in periodontal disease

Phagocytosis by neutrophils and monocytes constitutes the main defense mechanism against bacterial challenges in periodontitis. Phagocytosis by neutrophils has already been evaluated, whereas phagocytic function of monocytes has hardly been addressed so far.

Polymorphisms within the IL-1 gene cluster: effects on cytokine profiles in peripheral blood and whole blood cell cultures of patients with aggressive periodontitis, juvenile idiopathic arthritis, and rheumatoid arthritis

BACKGROUND

Genetic polymorphisms of cytokines have been associated with the susceptibility, severity, and clinical outcome of inflammatory diseases, such as periodontitis and chronic arthritis. An important question to address is how interleukin (IL)-1 polymorphisms affect the cytokine profiles of patients with such diseases.

METHODS

The study population consisted of Danish white adults, <35 years of age, who were diagnosed with localized aggressive periodontitis (LAgP, n = 18), generalized aggressive periodontitis (GAgP, n = 27), juvenile idiopathic arthritis (JIA, n = 10), and rheumatoid arthritis (RA, n = 23) and healthy individuals with no systemic or oral diseases (n = 25). Genotypes of IL-1A-889, IL-1A+4845, IL-1B-511, and IL-1B+3954 were determined by polymerase chain reaction (PCR)-restriction fragment length polymorphism, and IL-1RN variable number tandem repeat (VNTR) was detected by PCR amplification and fragment size analysis. Analysis of variance was used to evaluate the effects of IL-1 genotypes on the levels of IL-1alpha, -1beta, -1 receptor antagonist, -6, and -10; tumor necrosis factor-alpha (TNF-alpha); and lymphotoxin-alpha in peripheral blood (plasma) and in unstimulated and stimulated whole blood cell cultures from the same blood collection.

RESULTS

The frequencies of IL-1 genotypes investigated did not differ significantly between diseased and control individuals. In LAgP patients, allele 2 of IL-1RN VNTR was associated with significantly higher levels of IL-1alpha, -6, and -10 and TNF-alpha, whereas allele 2 of IL-1B+3954 was associated with significantly lower levels of the same cytokines. In GAgP patients, a general lack of association was found. In JIA and RA patients, IL-1RN VNTR also influenced the cytokine levels.

CONCLUSIONS

IL-1 genotypes were associated with cytokine levels in patients with aggressive periodontitis and chronic arthritis. No associations were observed in control individuals.

Effect of adalimumab on neutrophil function in patients with rheumatoid arthritis

Neutrophils are known to be targets for the biological activity of tumour necrosis factor (TNF)-alpha in the pathogenesis of rheumatoid arthritis (RA). Therefore, these cells may be among the targets of anti-TNF-alpha therapy. In this study we evaluated the effect of therapy with adalimumab (a fully human anti-TNF-alpha mAb; dosage: 40 mg subcutaneously every other week) on certain phenotypic and functional aspects of neutrophils obtained from 10 selected patients with RA and 20 healthy control individuals. Peripheral blood neutrophils were obtained at baseline and during anti-TNF-alpha therapy (2, 6 and 12 weeks after the first administration of adalimumab). All patients had been receiving a stable regimen of hydroxychloroquine, methotrexate and prednisone for at least 3 months before and during the study. Baseline neutrophil chemotaxis was significantly decreased in RA patients when compared with control individuals (P < 0.001). Two weeks after the first administration of adalimumab, chemotactic activity was completely restored, with no differences noted between patients and control individuals; these normal values were confirmed 6 and 12 weeks after the start of anti-TNF-alpha therapy. Phagocytic activity and CD11b membrane expression on neutrophils were similar between RA patients and control individuals; no modifications were observed during TNF-alpha neutralization. The production of reactive oxygen species, both in resting and PMA (phorbol 12-myristate 13-acetate)-stimulated cells, was significantly higher in RA patients at baseline (P < 0.05) and was unmodified by anti-TNF-alpha mAb. Finally, we showed that the activation antigen CD69, which was absent on control neutrophils, was significantly expressed on neutrophils from RA patients at baseline (P < 0.001, versus control individuals); however, the molecule was barely detectable on cells obtained from RA patients during adalimumab therapy. Because CD69 potentially plays a role in the pathogenesis of arthritis, our findings suggest that neutrophils are among the targets of anti-TNF-alpha activity in RA and may provide an insight into a new and interesting mechanism of action of anti-TNF-alpha mAbs in the control of inflammatory arthritis.

Prevalence of Human Herpesviruses in Patients with Aggressive Periodontitis

BACKGROUND

Recent studies have demonstrated that various human viruses, especially cytomegalovirus (HCMV) and Epstein-Barr virus type-1 (EBV-1), seem to play a part in the pathogenesis of human periodontitis. The aim of this investigation was to evaluate the subgingival presence of HCMV and EBV in patients with aggressive periodontitis (AgP) and healthy subjects and to examine the effect of treatment on the incidence of these viruses 3 months following surgery.

METHODS

A polymerase chain reaction (PCR) method determined the presence of HCMV and EBV-1. Subgingival plaque samples from 17 consecutive AgP patients and 16 healthy controls were collected. The following indices were measured: plaque index (PI), gingival index (GI), probing depths (PD), and clinical attachment loss (CAL). Clinical parameters were assessed pretherapy and at 3 months following surgical and antimicrobial therapy.

RESULTS

HCMV was detected in 64.7% of AgP patients but not detected in healthy subjects (P < 0.001) and EBV-1 in 70.6% of AgP patients and 6.3% of the healthy controls (P < 0.001). HCMV and EBV-1 coinfection was detected in 41.7% of AgP patients. A statistically significant decrease was found in all clinical parameters 3 months after treatment. There was a statistically significant decrease in HCMV and EBV-1 following therapy (P < 0.001; no HCMV; 1 patient with EBV-1).

CONCLUSIONS

These findings indicate that subgingival presence of EBV-1 HCMV is strongly associated with aggressive periodontitis, and coinfection with HCMV and EBV-1 appears to be particularly deleterious to periodontal health.

Evaluation of human leukocyte N-formylpeptide receptor (FPR1) SNPs in aggressive periodontitis patients

Polymorphonuclear neutrophils (PMNs) are attracted to sites of infection by N-formylpeptide (fMLP) chemoattractants. The high-affinity fMLP receptor (FPR1) of phagocytic cells interacts with bacterial fMLP and mediates chemotaxis, degranulation, and superoxide production. These cellular functions are disrupted in PMN from aggressive periodontitis (AP) patients. Two FPR1 gene single nucleotide polymorphisms (SNPs), c.329T>C and c.378C>G, have been associated with a localized form of AP in African-American patients. To evaluate the generality of these SNPs in AP patients, we sequenced a 363 bp interval of the FPR1 gene in an ethnically diverse group of patients (n=111) and controls (n=115). Neither c.329T>C nor c.378C>G were detected in the 452 alleles sequenced. Six SNPs were identified including two located in the FPR1 second extracellular loop that were significantly associated with the AP phenotype in African-American patients (p.R190W, P=0.0033; and p.N192K, P=0.0018). These two SNPs show three predominant haplotypes, each associated with a different disease risk in African-Americans. These data do not support the hypothesis that the FPR1 SNPs c.329T>C and c.378C>G play an etiologic role in aggressive periodontitis, but do suggest that SNPs in the second extracellular loop may be etiologically important.

Periodontal diseases in the child and adolescent

BACKGROUND

Periodontal diseases are among the most frequent diseases affecting children and adolescents. These include gingivitis, localized or generalized aggressive periodontitis (a.k.a., early onset periodontitis which includes generalized or localized prepubertal periodontitis and juvenile periodontitis) and periodontal diseases associated with systemic disorders. The best approach to managing periodontal diseases is prevention, followed by early detection and treatment.

METHODS

This paper reviews the current literature concerning the most common periodontal diseases affecting children: chronic gingivitis (or dental plaque-induced gingival diseases) and early onset periodontitis (or aggressive periodontitis), including prepubertal and juvenile periodontitis. In addition, systemic diseases that affect the periodontium and oral lesions commonly found in young children are addressed. The prevalence, diagnostic characteristics, microbiology, host-related factors, and therapeutic management of each of these disease entities are thoroughly discussed.

Associations of serum concentrations of IgG, IgA, IgM and interleukin-1beta with early-onset periodontitis classification and race

BACKGROUND

The significance of serum concentrations of various antibodies and cytokines in the pathogenesis of early-onset periodontitis (EOP) is not well understood. Recent reports suggest differences between young blacks and whites in certain humoral responses, regardless of periodontal status. This study was undertaken to compare the serum concentrations of IgG, IgA, IgM, and IL-1beta in EOP subjects with that of healthy controls, and to study the effect of race on these levels.

MATERIAL AND METHODS

This case-control study included 228 individuals, 19-25 years old who were selected from a larger population examined in the National Survey of Oral Health of United States Children in 1986/1987. The subjects were classified by their EOP status and they included 166 subjects with EOP and 62 healthy controls. Blood samples were used to assess the serum concentrations of IgG, IgM, IgA, IgG subclass, and IL-1beta.

RESULTS

The serum concentrations of IgG, IgG subclasses, IgA, and IgM in blacks were not significantly different in the generalized, localized and incidental EOP groups as compared to the healthy controls. The serum IL-1beta concentration was slightly and uniformly lower in the EOP groups than in the control group, although not statistically significant. Blacks had significantly higher serum concentrations of total IgG, and of IgG1, IgG2 and IgG3 than whites and Hispanics. Hispanics had significantly higher serum concentrations of IgM and IgG4 than whites and blacks. Hispanics also had a significantly higher serum concentration of IL-1beta than blacks.

CONCLUSIONS

Total antibody response in blacks is not associated with EOP classification. Race has a significant effect on serum antibody concentrations irrespective of disease classification, with blacks having significantly higher serum concentrations of IgG1, IgG2 and IgG3 than whites and Hispanics.

Altered chemotactic behavior of crevicular PMNs in different forms of periodontitis

BACKGROUND, AIMS

Polymorphonuclear neutrophils (PMN) are the predominant host defence cells in the gingival sulcus. Previous work demonstrates that the in vitro phagocytosis of crevicular cells in localised early onset periodontitis (LEOP) and generalised early onset periodontitis (GEOP) lesions is diminished. The present study extends this work by characterizing the chemotaxis function of crevicular fluid (CF) PMNs in various forms of periodontitis.

METHODS

We investigated 7 patients with LEOP, 11 patients with GEOP, 12 patients with adult periodontitis (AP) and 2 age- and sex-matched healthy control groups. The two deepest sites of each quadrant in test and control subjects were selected for crevicular sampling. Chemotaxis was performed in a micro chamber (moist atmosphere, 5% CO2, 37 degrees C, 30 min) using N-formyl-methionyl-leucyl-phenylalanine (FMLP, 1 x 10(-7) mol FMLP/l) as a chemoattractant. The total chemotaxis was defined as the difference between the number of cells migrating towards FMLP minus the number of cells migrating towards PBS, counted in 20 randomly selected fields. Membranes were examined microscopically at 400 x magnification.

RESULTS

The chemotactic activity in the adult periodontitis group was significantly higher compared to the age-related control group. However, we found a statistically significant reduction of chemotactic activity in LEOP and GEOP patients compared to the controls.

CONCLUSIONS

These results indicate an increase of chemotactic activity from CF-PMN in patients with adult periodontitis, but on the other hand, a significant reduction of chemotactic responsiveness of these cells in LEOP and GEOP lesions.

Regression coefficient analysis of neutrophil chemotaxis in periodontitis

Micropore-filter techniques have been widely used to assess motility and chemotaxis of neutrophils. In some cases the results were impaired by inadequate methods of evaluation and failures of the test system. For clinical purposes the mode of test evaluation should be able to differentiate between failures of the test system (false-negative) and real functional defects (true-negative). A new method has been developed to check parallel assays for homogeneity. Based on earlier procedures this type of evaluation uses the comparison of regression coefficients to identify false-negative test results within the cell population of an individual. The newly developed method was used to study the chemotactic response in a group of 49 patients and 22 healthy volunteers. Intraclass correlation coefficients of the regression coefficient analysis and the leukotactic index were calculated and compared. It could be demonstrated that the regression coefficient analysis had the same sensitivity as the leukotactic index. Slight variations in the cell counts at a single plane of the chemotactic filter affecting the leukotactic index by 18% had no measurable influence on the calculated regression coefficient.

Cytoskeletal actin reorganization in neutrophils from patients with localized juvenile periodontitis

Localized juvenile periodontitis (LJP) is an early-onset periodontal disease associated with a polymorphonuclear neutrophil (PMN) defective migratory response. Kinetics of actin polymerization-depolymerization determine the shape changes occurring in the plasma membrane-associated cytoskeleton and provide the driving force for directed cell migration (chemotaxis). Therefore, we investigated the relation between an abnormality in LJP PMN chemotaxis and an altered reorganization of the actin filament network. PMNs isolated from peripheral blood of LJP patients (n=14) and matching control subjects (n=12) were evaluated for random and directed migration in a Boyden chamber assay, and the kinetics of actin polymerization were studied by flow cytometry. Three groups of LJP patients could be distinguished on the basis of their PMN-chemotactic response compared to their matched control: depressed (n=6), normal (n=4), and elevated (n=4). The abnormal (depressed or elevated) chemotaxis was generally not related to abnormal random migratory response, except for two patients. Since the kinetics of formyl-methionyl-leucyl-phenylalanine-induced F-actin response were highly variable from one subject to another, means were calculated at each timepoint with the values obtained from each group of subjects and compared by a general factorial design analysis. No statistically significant differences were detected between the control group and the LJP patient group. Furthermore, the data did not show a correlation between the kinetics of actin polymerization-depolymerization and the abnormal chemotactic response observed in LJP PMNs. Hence, the chemotaxis defect in LJP PMN appears to be mediated by signaling events that carry their effect independently of an intact cytoskeleton.

The role of Actinobacillus actinomycetemcomitans in the pathogenesis of periodontal disease

Periodontal disease consists of a constellation of complex bacterium-host cell interactions. One example of these oral pathogens, Actinobacillus actinomycetemcomitans, has an arsenal of putative virulence determinants that account for its potent periodontopathogenicity. Of these determinants, invasion of host cells and leukocytotoxicity have been studied extensively.

Effects of Porphyromonas gingivalis culture products on the morphology of peripheral blood polymorphonuclear leucocytes from periodontitis patients and healthy subjects

The effects of Porphyromonas gingivalis culture supernatant from strain W50, its avirulent variant (W50/BE1) and sterile BM culture medium on the morphological changes in polymorphonuclear leucocytes (PMN) from 10 patients with periodontitis (3 juvenile periodontitis, 7 rapidly progressive periodontitis) were compared with those from 10 healthy controls. Large non-polar cells ( > 160 microns2) were increased in patients to 182.8% (p = 0.0076) and 245.5% (p = 0.0002) of control values with W50 and W50/BE1 supernatant respectively. In contrast, numbers of small non-polar cells ( < 80 microns2) and polarised cells were decreased in the patient group. Patient/control ratios for small non-polar cells were 30.3% (p = 0.0007) and 33.6% (p = 0.0005) with W50 and W50/BE1, respectively, and 38.2% (p = 0.0147) for polarised cells exposed to W50 supernatant. The data indicate that PMN from patients with periodontitis differ significantly from those of healthy controls in the shape changes which occur after exposure to P. gingivalis culture supernatant.