The interleukin-1 genotype as a severity factor in adult periodontal disease

Interleukin 1 beta gene polymorphism and risk of cervical cancer

OBJECTIVE

To determine whether a polymorphism at position +3953 in exon 5 of the lL-1beta gene (IL-1beta +3953), a condition associated with an increased risk for a number of inflammatory diseases, is also involved in the development of cervical cancer.

METHOD

We isolated DNA from peripheral blood in 150 women with cervical cancer and 200 healthy controls, and IL-1beta +3953 allele polymorphism was determined by polymerase chain reaction.

RESULTS

Genotypes A1/A2 and A2/A2+A1/A2 were associated with increased risk of cervical cancer (odds ratio [OR], 2.88; 95% confidence interval [CI], 1.78-4.67; P<0.001 and OR, 2.85; 95% CI, 1.77-4.6; P<0.001, respectively). The risk in a passive smoker with A2/A2 or A1/A2 genotype was increased more than 5-fold (OR, 5.69; 95% CI, 2.61-12.50; P<0.001) compared with a nonsmoker with the A1/A1 genotype.

CONCLUSION

This study provides evidence of an association between lL-1beta +3953 polymorphism and risk of cervical cancer.

Quantitative messenger RNA expression of Toll-like receptors and interferon-alpha1 in gingivitis and periodontitis

INTRODUCTION

In addition to bacteria, viruses have been reportedly implicated in periodontitis. However, the available data are confined to Toll-like receptor 2 (TLR2) and TLR4, which recognize bacterial products in periodontitis. In the present study, we investigated the expression levels of TLR5, -7, and -9 messenger RNAs (mRNAs) in addition to those of TLR2 and -4, and compared gingivitis and periodontitis. Interferon-alpha1 (IFN-alpha1), which is important for the antiviral response, was also compared.

METHODS

Gene expression was analyzed using quantitative real-time polymerase chain reaction for 59 periodontitis and 27 gingivitis tissue samples together with viral serology in some patients. The presence of plasmacytoid dendritic cells (pDCs), a robust producer of IFN-alpha, was immunohistochemically analyzed in an additional seven periodontitis and two gingivitis specimens.

RESULTS

The expression levels of TLR2, -4, -7, and -9 were significantly higher in periodontitis lesions than gingivitis lesions. The expression level of TLR5 was comparable to levels of TLR2 and -4; however, no significant difference was found between gingivitis and periodontitis. Although the expression of IFN-alpha1 mRNA was higher in periodontitis lesions compared with gingivitis lesions, the level was quite low. Only a few pDCs were found in some periodontitis specimens. No difference was found for antibody-positivity between gingivitis and periodontitis.

CONCLUSION

This is the first study to show that a variety of TLRs are up-regulated in periodontitis lesions compared with gingivitis lesions, suggesting that diverse microbial and possibly viral antigens are involved in the pathogenic mechanisms for periodontal diseases. However, the ligands recognized by the various TLRs in periodontal lesions remain to be determined.

Association of the polymorphisms in promoter and intron regions of the interleukin-4 gene with chronic periodontitis in a Turkish population

OBJECTIVES

The etiology of periodontitis is related to the interaction between micro-organisms and host responses. Host modifying factors, such as genetic predisposition, may increase the severity of periodontitis. Recent works have shown that the levels of cytokine expression are regulated by genetic polymorphisms, and that these variations can interfere with progression of the disease. This study therefore aimed to evaluate whether interleukin (IL) 4 gene polymorphisms are associated with severe generalized chronic periodontitis.

MATERIAL AND METHODS

Seventy-five severe generalized chronic periodontitis patients and 73 healthy subjects were examined. Blood samples were taken and genomic DNA was amplified by polymerase chain reaction (PCR). Identification of 70 base-pair repeat polymorphisms in intron 2 and C-->T polymorphisms at -590 position of the promoter region was performed through PCR-restriction fragment length polymorphism (RFLP).

RESULTS

No significant differences were found in the allele and genotype frequencies between the control and periodontitis group.

CONCLUSION

The IL-4 polymorphisms were not related to severe generalized chronic periodontitis in a Turkish population.

A comprehensive and critical review of dental implant prognosis in periodontally compromised partially edentulous patients

OBJECTIVES

The outcome of implant treatment in periodontally compromised partially edentulous patients has not been completely clarified. Therefore, the aim of the present study was to perform, applying a systematic methodology, a comprehensive and critical review of the prospective studies published in English up to and including August 2006, regarding the short-term (<5 years) and long-term (>or=5 years) prognosis of osseointegrated implants placed in periodontally compromised partially edentulous patients.

MATERIAL AND METHODS

Using The National Library Of Medicine and Cochrane Oral Health Group databases, a literature search for articles published up to and including August 2006 was performed. At the first phase of selection the titles and abstracts and at the second phase full papers were screened independently and in duplicate by the three reviewers (I. K. K., S. K., I. F.).

RESULTS

The search provided 2987 potentially relevant titles and abstracts. At the first phase of evaluation, 2956 publications were rejected based on title and abstract. At the second phase, the full text of the remaining 31 publications was retrieved for more detailed evaluation. Finally, 15 prospective studies were selected, including seven short-term and eight long-term studies. Because of considerable discrepancies among these studies, meta-analysis was not performed.

CONCLUSIONS

No statistically significant differences in both short-term and long-term implant survival exist between patients with a history of chronic periodontitis and periodontally healthy individuals. Patients with a history of chronic periodontitis may exhibit significantly greater long-term probing pocket depth, peri-implant marginal bone loss and incidence of peri-implantitis compared with periodontally healthy subjects. Even though the short-term implant prognosis for patients treated for aggressive periodontitis is acceptable, on a long-term basis the matter is open to question. Alterations in clinical parameters around implants and teeth in aggressive periodontitis patients may not follow the same pattern, in contrast to what has been reported for chronic periodontitis patients. However, as only three studies comprising patients treated for aggressive periodontitis were selected, more studies, specially designed, are required to evaluate implant prognosis in this subtype of periodontitis. As the selected publications exhibited considerable discrepancies, more studies, uniformly designed, preferably longitudinal, prospective and controlled, would be important.

Association of gene polymorphisms for plasminogen activators with alveolar bone loss

BACKGROUND AND OBJECTIVE

The plasminogen activating system is a protease/inhibitor system central to extracellular matrix remodeling with a suggested role in periodontal disease pathology. A few studies have reported polymorphisms in the genes of plasminogen activator inhibitors to be associated with periodontal disease severity. Two gene polymorphisms - a BamHI restriction fragment length polymorphism in the urokinase plasminogen activator gene (uPA) and a HindIII restriction fragment length polymorphism in the plasminogen activator inhibitor type 1 gene (PAI-1) - have been associated with conditions having a vascular component, and our objective was to assess the association of these gene polymorphisms with alveolar bone loss in chronic periodontal disease of adults.

MATERIAL AND METHODS

Genotype was determined by polymerase chain reaction amplification of whole blood, pertinent histories were obtained by interview, and alveolar bone loss was assessed from current radiographs.

RESULTS

In 77 elderly patients with a normal distribution of alveolar bone loss, we demonstrated a significant association between levels of alveolar bone loss and these polymorphisms in the uPA and PAI-1 genes. Controlling for the contributions of smoking or diabetes to periodontal bone loss, estimated odds ratios for predicting lower levels of alveolar bone loss, associated with a greater degree of periodontal health, were strongest when defined by the concurrent presence of a homozygous urokinase plasminogen activator genotype and the nuclease-sensitive plasminogen activator inhibitor type 1 (HindIII) allele (odds ratio = 2.6; 95% confidence interval: 5.8-1.3).

CONCLUSION

The urokinase plasminogen activator (BamHI) and plasminogen activator inhibitor type 1 (HindIII) genotypes may serve as useful markers for heritability of bone loss associated with periodontal disease.

Prevalence of OPG and IL-1 gene polymorphisms in chronic periodontitis

AIM

To investigate the association of polymorphisms in the osteoprotegerin (OPG) and interleukin 1 (IL-1) genes with chronic periodontitis (CP).

MATERIAL AND METHODS

One hundred and ninety-four individuals (97 CP patients, 97 controls) were genotyped for the OPG polymorphisms Lys3Asn and Met256Val and for the IL-1 polymorphisms IL-1A (-889C/T) and IL-1B (+3953C/T).

RESULTS

The homozygous variants coding for Lys3 were present at a higher frequency, whereas Asn3 and Met256 were present at a lower frequency in CP patients/controls (Lys3: 31%/25%, Asn3: 23%/32% and Met256: 66%/73%). Heterozygosity for Lys3Asn was observed at a higher frequency in CP patients/controls (46%/43%). Homozygosity for the Val256 genotype was observed in two CP patients (one in controls). Met256Val heterozygosity was more prevalent in CP patients/controls (32%/20%). All differences were statistically not significant between CP patients and controls. In contrast, both IL-1 polymorphisms were statistically significant. The heterozygous variant for IL-1A was present in 32% of the CP patients and in 20% of the controls (homozygosity (patients/controls) CC: 10%/21% and TT: 55%/33%). Heterozygosity for IL-1B was observed in 37% of the CP patients versus 34% in the controls (homozygosity (patients/controls) CC: 26%/57% and TT: 37%/9%).

CONCLUSION

While the association between the IL-1 polymorphisms and CP was confirmed, no association between the OPG polymorphisms and CP could be found.

Destructive periodontitis lesions are determined by the nature of the lymphocytic response

It is now 35 years since Brandtzaeg and Kraus (1965) published their seminal work entitled "Autoimmunity and periodontal disease". Initially, this work led to the concept that destructive periodontitis was a localized hypersensitivity reaction involving immune complex formation within the tissues. In 1970, Ivanyi and Lehner highlighted a possible role for cell-mediated immunity, which stimulated a flurry of activity centered on the role of lymphokines such as osteoclast-activating factor (OAF), macrophage-activating factor (MAF), macrophage migration inhibition factor (MIF), and myriad others. In the late 1970s and early 1980s, attention focused on the role of polymorphonuclear neutrophils, and it was thought that periodontal destruction occurred as a series of acute exacerbations. As well, at this stage doubt was being cast on the concept that there was a neutrophil chemotactic defect in periodontitis patients. Once it was realized that neutrophils were primarily protective and that severe periodontal destruction occurred in the absence of these cells, attention swung back to the role of lymphocytes and in particular the regulatory role of T-cells. By this time in the early 1990s, while the roles of interleukin (IL)-1, prostaglandin (PG) E(2), and metalloproteinases as the destructive mediators in periodontal disease were largely understood, the control and regulation of these cytokines remained controversial. With the widespread acceptance of the Th1/Th2 paradigm, the regulatory role of T-cells became the main focus of attention. Two apparently conflicting theories have emerged. One is based on direct observations of human lesions, while the other is based on animal model experiments and the inability to demonstrate IL-4 mRNA in gingival extracts. As part of the "Controversy" series, this review is intended to stimulate debate and hence may appear in some places provocative. In this context, this review will present the case that destructive periodontitis is due to the nature of the lymphocytic infiltrate and is not due to periodic acute exacerbations, nor is it due to the so-called virulence factors of putative periodontal pathogens.

Effect of cytokine and antigen stimulation on peripheral blood lymphocyte syndecan-1 expression

INTRODUCTION

Cytokines are not only produced by activated lymphocytes but also interact with a number of cell-surface molecules on the same cells. Syndecan-1 is one such cell-surface molecule, which has the capacity to bind a variety of growth factors as well as cytokines. The aim of this study was to examine the effects of transforming growth factor beta (TGF-beta), interleukin-1 (IL-1), IL-2, IL-4, lipopolysaccharide (LPS) from Porphyromonas gingivalis and tetanus toxoid on syndecan-1 expression by B and T lymphocytes.

METHODS

B and T lymphocytes were obtained from the peripheral blood of healthy donors. Following exposure to the above growth factors, cytokines and antigens, syndecan-1 expression was determined by flow cytometry.

RESULTS

Subjects could be categorized as high or low expressors of syndecan-1. In the high-responder group TGF-beta1 alone resulted in a significant increase in syndecan-1 expression by both B and T cells. None of the other cytokines and antigens produced a significant response. When analysed in combination, TGF-beta1 in combination with IL-2, IL-4, P. gingivalis LPS and tetanus toxoid all produced significant increases in syndecan-1 expression by B cells. For T cells, combinations of TGF-beta1 with IL-2 and tetanus toxoid resulted in increased syndecan-1 expression.

CONCLUSIONS

Both B and T lymphocytes synthesize the cell-surface proteoglycan syndecan-1 and its expression can be modulated by TGF-beta1, either alone or in combination with IL-2, IL-4 and LPS from P. gingivalis and tetanus toxoid. While these may reflect general responses under inflammatory conditions their biological significance requires further investigation.

Interleukin 18 and periodontal disease

Cytokines are of major importance in periodontal disease progression. It is generally agreed that control of the Th1/Th2 balance is central to the immunoregulation of periodontal disease. There is increasing evidence in humans that the stable periodontal lesion is mediated by Th1 cells, while the progressive lesion sees a shift toward Th2 cells. Equally, there is conflicting evidence, mainly in animal models, that bone loss is mediated by Th1 responses, and that Th2 responses are protective. In the presence of IL-12, IL-18 induces Th1 responses while, in the absence of IL-12, it promotes Th2 responses. It is clear, therefore, that since IL-18 has the ability to induce either Th1 or Th2 differentiation, it becomes important to consider its role in periodontal disease. This review endeavors to give an overview of this cytokine and its relevance for periodontal disease.

Interleukin- 1 gene polymorphisms as assessed in a 10-year study of patients with early-onset periodontitis

Our 10-year study of early-onset periodontitis (EOP) patients includes repeated clinical observations, microbiological characteristics and analysis of genetic polymorphism of IL-1A and IL-1B genes. Twenty patients (age 15-26 years) were divided according to the clinical status in the 4th year into a group with mean number of teeth with bleeding on probing (BP) 9.8 and mean number of teeth with periodontal pocket (PP) 2.23, and a group with mean number of teeth with BP 5.37 and no PP. Significantly higher values of mean BP and PP were found among the groups during the study but a strong progression of disease was found only in 3 patients. The risk IL-1A allele-2 and IL-1B allele-2 genotype and bacterial presence were analyzed by DNA hybridization methods. No significant differences of bacteria composition (Treponema denticola, Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans) were found between the groups. A higher prevalence of composite IL-1 genotype was detected in the group of EOP patients with progressive disease. Early finding of the disease followed by conservative therapy could positively influence the disease progression. EOP treated in early stages may, but need not, develop into the aggressive form in the presence of risk genotype IL-1.

Asymptomatic shedding of HSV-1 in patients undergoing oral surgical procedures and attending for noninvasive treatment

Oral surgery and stress can trigger and/or increase asymptomatic shedding of herpes simplex virus type-1 (HSV-1) into human saliva. In this investigation we examined the frequency of HSV-1 shedding in 32 patients undergoing an oral surgery procedure compared with 40 control patients attending for noninvasive treatment. Control patients comprised 18 migraine patients and 22 patients with temporomandibular (TMD) joint problems. Nested-PCR was carried out on oral rinses collected from each patient prior to treatment and 7 days post-treatment. Fifty-two of sixty-one seropositive patients were positive for HSV-1 DNA in one or both oral rinses. The frequencies of HSV-1 shedding for the oral surgery and control patients were 84.6% and 85.7% respectively. Seropositive patients who started shedding after treatment were significantly higher in oral surgery patients (46.2%) compared to control patients (34.3%). Shedding of HSV-1 in the oral cavity is not only increased by direct surgical trauma, but also appears to be common in migraine and TMD patients attending for general dental treatment. Thus pain or pain-induced stress as well as anxiety associated with dental treatment may also be a risk factor for asymptomatic shedding in specific seropositive patients attending for dental treatment.

Evidence-Based Rationale Supports a National Periodontal Disease Screening Program

INTRODUCTION

The evidence-based decision-making process that led to the inclusion of periodontal diseases (PD) in the newly revised Austrian National Periodic Health Examination (PHE) is described. Although intraoral inspection by physicians had already been a routine part of the PHE, obvious signs of PD, which are highly prevalent in Austria, have been largely ignored.

OBJECTIVE

The objectives of this periodontal screening (PS) program are to direct persons with a series of identifiable risk factors to seek proper care.

METHOD

The PS program development methodology was based on 2 factors: a systematic review of evidence-based publications that establish correlations between individual risk factors or multifactorial risk models with an increased susceptibility to progression of PD, and a selection of brief and cost-effective screening interventions that could be administered by nondental clinicians such as general physicians.

RESULTS

The final screening model is a 3-step intervention:

CONCLUSION

The final PS model within the Austrian PHE is based on a wealth of data justifying an evidence-based intervention. The Austrian population is likely to benefit in many ways from the intervention through increased awareness of PD and through a collaboration of medical and dental clinicians in their prevention.

Oral health risks associated with HLA-types of patients undergoing hematopoietic stem cell transplantation

AIM

Dental caries, gingivitis and periodontitis are frequent long-term complications after hematopoietic stem cell transplantation (HSCT). Not all patients are affected equally. As HLA-genotypes are associated with many functions of the immune system we made use of our long-standing oral health program in HSCT recipients to compare oral health data with recipient HLA-antigens.

PATIENTS AND METHODS

This study includes 267 patients evaluated prior to a planned HSCT at our institution between March 1987 and March 2002. Standardized oral examinations were undertaken at fixed time points: pre-HSCT and at 6 and 12 months post-HSCT. Evaluation included loss of radiologic attachment level, decayed, missing, filled teeth (DMFT) index, and salivary flow rate. For 241 patients (120 males, 121 females) baseline values of these parameters were compared with recipient HLA-A, -B, -C and -DR-antigens.

RESULTS

Significant correlations were found between increased DMFT and HLA-A32 (P = 0.05), -B5 (0.04), and -DR2 (0.05) as well as decreased DMFT with HLA-B35 (0.02) and -C4 (0.04). Significant associations were also found between certain HLA-antigens and loss of radiologic periodontal attachment level [HLA-A1 (<0.01), -C7 (0.04), and -B60 (0.05)], and saliva flow rate [HLA-A30 (0.02)].

CONCLUSIONS

These data suggest that there may be associations between pretransplant caries, other oral parameters and HLA in patients at HSCT. Confirmatory studies concerning the associations of certain HLA-antigens with caries and periodontal diseases will be needed.

Interleukin-6 expression and gene polymorphism are associated with severity of periodontal disease in a sample of Brazilian individuals

Interleukin (IL)-6 is an inflammatory mediator involved in bone resorption. G/C polymorphism at position -174 of the IL-6 gene has been reported to influence IL-6 expression, with the G allele associated with higher expression levels. The aims of this study were to investigate the expression of IL-6 as well as the incidence of IL-6 (-174) gene polymorphism and their correlation to the severity of periodontitis in Brazilians. Peripheral blood mononuclear cells were collected from 12 non-smoker individuals with periodontitis for evaluation of IL-6 expression using flow cytometry. We observed a positive correlation between the mean clinical attachment loss and intensity of expression of IL-6, in which the greater the attachment loss, the higher the expression of IL-6 (P=0 x 007, R2=0 x 52). Also, patients with severe periodontitis displayed a higher intensity of IL-6 expression compared to moderate periodontitis (P=0 x 04). To determine the occurrence of IL-6 gene polymorphism, DNA was obtained from oral swabs of 209 Brazilian individuals with and without periodontitis. Polymerase chain reaction, restriction endonuclease digestion and electrophoresis were performed, allowing for detection of the IL-6 (-174) polymorphism. We observed that non-smokers with moderate periodontitis (P=0 x 05) and control (P=0 x 04) groups displayed a higher incidence of the G genotype when compared to severe periodontitis. This suggests that the G genotype may represent a protective role in severity of periodontitis. Thus, the increased expression of IL-6 and IL-6 (-174) polymorphism are associated with periodontal disease severity in Brazilian individuals.

Citation classics in periodontology: a controlled study

AIM

The aims of this study were to identify the most cited articles in Periodontology published from January 1990 to March 2005; and to analyse the differences between citation Classics and less cited articles.

MATERIAL AND METHODS

The search was carried out in four international periodontal journals: Journal of Periodontology, Journal of Clinical Periodontology, International Journal of Periodontics and Restorative Dentistry and Journal of Periodontal Research. The Classics, that are articles cited at least 100 times, were identified using the Science Citation Index database. From every issue of the journals that contained a Classic, another article was randomly selected and used as a Control.

RESULTS

Fifty-five Classics and 55 Controls were identified. Classic articles were longer, used more images, had more authors, and contained more self-references than Controls. Moreover Classics had on the average a bigger sample size, often dealt with etiopathogenesis and prognosis, but were rarely controlled or randomized studies.

CONCLUSIONS

Classic articles play an instructive role, but are often non-Controlled studies.

A combination of alleles 2 of interleukin (IL)-1A(-889) and IL-1B(+3954) is associated with lower gingival bleeding tendency in plaque-induced gingivitis in young adults of Arabic heritage

The aim of this study was to investigate the possible association of a distinct combination of polymorphisms in the interleukin (IL)-1 gene cluster on gingival bleeding tendency in young adult Arabs with plaque-induced gingivitis. Fifty otherwise healthy, nonsmoking volunteers, 19-28 years of age, participated. Clinical examinations included periodontal probing depth, bleeding on probing, and plaque index. Probing was done with a pressure-controlled probe at about 1.27 MPa. Examinations were repeated after 2 and 4 weeks. Polymorphisms in the IL-1 gene cluster were assessed using a reverse hybridization assay. A subject carrying alleles 2 at IL-1A ( -889 ) and IL-1B ( +3954 ) was designated genotype-positive. Twenty-six subjects were genotype-positive (52%). A repeated measures two-level (occasion, subject) model of the proportion of sites bleeding on probing, which was adjusted for gender, average plaque index, probing depth, and calculus, revealed a significantly lower proportion of bleeding sites in genotype-positive subjects (estimate -0.050, standard error 0.025, p < 0.05). Biserial correlations of bleeding proportions were high (0.71-0.78), confirming the steady-state plaque environment. It was concluded that inflammatory responses to dental plaque were considerably dampened in genotype-positive, nonsmoking young adults of Arabic heritage.

MMP-2, MMP-9 and TIMP-2 gene polymorphisms in Chinese patients with generalized aggressive periodontitis

BACKGROUND

Aggressive periodontitis (AgP) has a genetic basis. It has been reported that the functional gene polymorphisms of matrix metalloproteinase (MMP)-2, MMP-9 and tissue inhibitor of metalloproteinase-2 (TIMP-2) alter their expressions in transcriptional level and they are involved in the tissue destruction of periodontitis. The study was carried out to analyse the association of functional polymorphisms in MMP-2, MMP-9 and TIMP-2 with generalized AgP (G-AgP) in a Chinese population.

MATERIAL AND METHODS

The study population consisted of 79 Chinese patients with G-AgP and 128 healthy controls. DNA was obtained from oral mucosa swab samples. MMP-2 genotypes were determined by PCR-based denaturing high-performance liquid chromatography analysis while MMP-9 and TIMP-2 genotypes were identified by a PCR-based restriction fragment length polymorphism. Chi2 test after Yates' correction was used to investigate the possible association of the genotypes with the G-AgP.

RESULTS

Although gene polymorphisms for MMP-2 and MMP-9 did not show any association with the G-AgP, the analysis of the TIMP-2 -418G to C gene polymorphism revealed significant differences between the patients and controls. Compared with controls, a significant increasing trend of TIMP-2 -418C carrier in the G-AgP patients occurred (p=0.013).

CONCLUSION

It is suggested that the TIMP2 -418G to C gene polymorphism is associated with G-AgP in the Chinese subjects.

Polymorphisms in the CD14 and IL-6 genes associated with periodontal disease

AIM

To compare the frequencies of cytokine and receptor molecule genotypes in patients with chronic periodontitis with the corresponding frequencies in a reference population and to study the relationship between periodontal disease severity and polymorphisms in the studied genes.

SUBJECTS AND METHODS

CD14, IL-6, TNF-alpha, IL-10, IL-1alpha, IL-1beta, and TLR-4 polymorphisms of 51 periodontitis patients were studied using polymerase chain reaction. The genotype frequencies in the periodontitis patients and a reference population (n=178) were compared. Probing pocket depth (PD), periodontal attachment level (AL), and alveolar bone level (BL) were related to the genotypes.

RESULTS

No statistically significant differences could be found between the frequencies of the cytokine genotypes in the periodontitis patients and in the reference group. The extent of periodontal disease was higher in subjects with the T-containing genotype of CD14(-260) and the GG genotype of IL-6(-174) when compared with the extent in the rest of the group. Subjects carrying the composite genotype of the above two were most severely affected by periodontal disease.

CONCLUSION

According to the present results, an evident association exists between the carriage of the T-containing genotype of CD14(-260) and the GG genotype of IL-6(-174) and the extent periodontal disease.

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.

Association of interleukin-10 gene polymorphisms with severe generalized chronic periodontitis

BACKGROUND

Interleukin-10 (IL-10), an anti-inflammatory cytokine, plays a role in periodontal disease by inhibiting synthesis of proinflammatory cytokines and stimulating protective antibody production. Genetic polymorphisms in the IL-10 gene might be useful as a marker to diagnose susceptibility to periodontitis. Therefore, the aim of this study was to investigate the association between IL-10 gene polymorphisms and severe generalized chronic periodontitis (CP) in a Turkish population.

METHODS

Samples of venous blood and DNA were obtained from 75 patients with severe generalized CP and 73 healthy subjects. The IL-10 promoter sequences at positions -597 and -824 were amplified by polymerase chain reaction, and polymorphisms were detected by restriction enzyme cleavage. Genotype and allele frequencies were calculated, and data were analyzed using the chi(2) test.

RESULTS

There was a statistically significant difference in frequencies of genotypes (AA/CC + CA: P = 0.00007, odds ratio = 12.37, 95% confidence intervals = 2.74 to 7.77; CC/CA + AA: P = 0.001, odds ratio = 3.05, 95% confidence intervals = 1.47 to 6.33) and alleles (P = 0.0002, odds ratio = 2.61, 95% confidence intervals = 1.52 to 4.51) at position -597 C to A between patients with severe generalized CP and healthy controls, whereas there was no significant difference in genotypes and allele frequencies at position -824 C to T between patients with CP and healthy subjects.

CONCLUSION

Within the limitations of sample selection and number, the IL-10 gene polymorphism at position -597 seems to be associated with severe generalized CP.

Subgingival chlorhexidine varnish administration as an adjunct to same-day full-mouth root planing. II. Microbiological observations

BACKGROUND

Recently, the clinical additive value of a highly concentrated chlorhexidine (CHX) varnish, when applied subgingivally as an adjunct to scaling and root planing, was described. The objective of the present study was to investigate the microbiological impact of a treatment strategy for chronic periodontitis based on a combination of same-day full-mouth root planing and subgingival CHX varnish administration.

METHODS

A randomized, controlled, single-blind, parallel trial was conducted on 33 non-smoking chronic periodontitis patients. The control group received oral hygiene instructions and same-day full-mouth root planing. The test group received the same instructions and treatment; however, all pockets also were disinfected using a supersaturated CHX varnish. Subgingival plaque samples were collected from the deepest site per quadrant in each patient at baseline and after 1, 3, and 6 months. Pooled sample analysis was performed using a multiplex polymerase chain reaction-based method for the identification of Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythensis (Tf), Treponema denticola (Td), and Prevotella intermedia (Pi).

RESULTS

In terms of detection frequency and bacterial levels, significant, mainly temporary, reductions from baseline were found in both groups. When a comparison was made between the control and the test group, significant differences in the detection frequency of Tf (P = 0.024) and Td (P = 0.024), which favored the test group, were found at 1 month. A similar phenomenon was seen for Td (P = 0.031) based on bacterial levels. An important trend toward lower Tf levels in the test group also was found at 1 month (P = 0.052). Compared to baseline levels, microbiological benefits in the test group seemed to be maintained, at least in part, over a 6-month period. In contrast, all microbial levels had relapsed in the control group at study termination.

CONCLUSION

The microbiological results of the present study promote the subgingival administration of a highly concentrated CHX varnish as an adjunct to same-day full-mouth root planing.

Salivary enzyme levels after scaling and interleukin-1 genotypes in Japanese patients with chronic periodontitis

BACKGROUND

Saliva has been used as a diagnostic fluid in medicine and dentistry. It is easy to collect using non-invasive methods. The intracellular enzymes present in saliva have been studied as markers of periodontal disease. The purpose of this study was to determine the salivary enzyme levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) after scaling and to clarify the influence of interleukin (IL)-1 genotypes on these enzyme levels.

METHODS

Forty-nine Japanese patients with chronic periodontitis (24 men and 25 women; mean age: 55.1 years) were enrolled in this study. Measurements of clinical parameters including probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP) and collections of stimulated whole mixed saliva were performed at baseline and 4 weeks after scaling. After evaluation of salivary AST, ALT, and LDH levels, DNA was extracted from various cells in whole saliva. IL-1A+4845 G/T genotype was determined by polymerase chain reaction amplification, followed by enzyme digestion and electrophoresis. Statistical analysis was performed by the Wilcoxon signed-rank and Mann-Whitney U tests. A significant difference was set at P <0.05.

RESULTS

Mean PD, CAL, and BOP values significantly decreased after scaling (mean +/- SE: 3.2 +/- 0.1 mm to 2.6 +/- 0.1 mm in PD; 3.9 +/- 0.2 mm to 3.3 +/- 0.2 mm in CAL; and 41% +/- 4% to 18% +/- 3% in BOP) (P <0.001). The values of AST, ALT, and LDH were 77.0 +/- 7.5, 43.9 +/- 5.5, and 753.4 +/- 96.5 (units per liter [U/l]) at baseline, and significantly decreased to 55.5 +/- 6.5, 30.0 +/- 5.5, and 394.7 +/- 34.0 (U/l) after scaling, respectively (P = 0.01, P = 0.006, and P <0.001). The carriage rate of the IL-1A+4845 allele 2 was 24.5%. No difference was noted in the decrease in PD, CAL, and BOP after scaling between the carriers (N = 12) and non-carriers (N = 37) of IL-1A+4845 allele 2. However, the IL-1A allele 2 non-carriers displayed a significant decrease in salivary AST and ALT levels (P <0.001), in contrast to the carriers who did not show any changes in the salivary levels of the enzymes after scaling.

CONCLUSIONS

These results documented that salivary AST, ALT, and LDH levels reflect inflammation and destruction of periodontal tissue, suggesting clinically useful markers following periodontal therapy. In addition, although IL-1A+4845 alleles may not influence clinical parameters, they may influence post-scaling values of salivary AST and ALT.

The combined genotypes of stimulatory and inhibitory Fc gamma receptors associated with systemic lupus erythematosus and periodontitis in Japanese adults

BACKGROUND

The pathobiology of systemic lupus erythematosus (SLE) is similar to that of periodontitis in that the immunoglobulin G Fc receptor (FcgammaR) and proinflammatory cytokines play an important role. Genetic variations of FcgammaR and interleukin (IL)-1 are associated with susceptibility to both diseases. Therefore, we evaluated whether the combination of FcgammaR or IL-1 polymorphic genes represents a common risk factor for SLE and periodontitis.

METHODS

The study population consisted of Japanese adults with SLE and periodontitis (SLE+P group; n = 46), SLE only (SLE group; n = 25), periodontitis only (P group; n = 58), and healthy individuals with no systemic or oral disease (H group; n = 44). Clinical periodontal condition was evaluated by measurement of probing depth, clinical attachment level, and alveolar bone loss. Genomic DNA was isolated from peripheral blood and analyzed for determination of FcgammaR genotypes (FcgammaRIIA, FcgammaRIIB, FcgammaRIIIA, and FcgammaRIIIB) and IL-1 genotypes (IL-1A +4845 and IL-1B +3954) by allele-specific polymerase chain reactions or DNA sequencing.

RESULTS

A significant overrepresentation of the R131 allele of stimulatory FcgammaRIIA and the 232T allele of inhibitory FcgammaRIIB was found in the SLE+P group compared to the H group (P = 0.01 and P = 0.0009, respectively). The combination of FcgammaRIIA-R131 and FcgammaRIIB-232T alleles yielded a strong association with SLE and periodontitis (SLE+P group versus P group: P = 0.01, odds ratio: 3.3; SLE+P group versus H group: P = 0.0009, odds ratio: 11.2). Furthermore, SLE patients with the combined FcgammaR risk alleles exhibited more severe periodontal tissue destruction compared to other SLE patients. The frequencies of IL-1 polymorphic alleles were too low to assess the association with SLE or periodontitis.

CONCLUSION

The combination of stimulatory FcgammaRIIA and inhibitory FcgammaRIIB genotypes may increase susceptibility to SLE and periodontitis in the Japanese population.

Effect of a cyclooxygenase-2 inhibitor on interleukin-1beta-stimulated activation of the transcription factor nuclear factor-kappa B in human gingival fibroblasts

BACKGROUND

In previous work, the cyclooxygenase-2 inhibitor NS-398 inhibited interleukin (IL)-1beta-stimulated prostaglandin E(2) (PGE(2)) production almost completely while partially inhibiting IL-6 production in aggressive periodontitis (AgP) human gingival fibroblasts. PGE(2) and the transcription factor nuclear factor-kappa B (NF-kappaB) regulate IL-1beta-stimulated IL-6 production. Cytoplasmic NF-kappaB is bound to inhibitors (IkappaB proteins). IL-1beta initiates a cascade resulting in phosphorylation and degradation of IkappaB, allowing nuclear translocation of NF-kappaB and target gene activation. The purpose of this study was to determine whether NS-398 inhibited phosphorylation of IkappaB and NF-kappaB activation.

METHODS

AgP fibroblasts (1 to 2 x 10(6)) were exposed to IL-1beta (1 x 10(11)M) with or without NS-398 (10 nM) in serum-free medium. The NF-kappaB subunit p65 and phospho-IkappaBalpha were measured in whole cell, cytoplasmic, or nuclear extracts, using colorimetric assays. Enzyme-linked immunosorbent assays were used to measure PGE(2) and IL-6 production by 2.5 x 10(4) cells after exposure to IL-1beta with or without NS-398 in serum-free medium.

RESULTS

Consistent with previous results, NS-398 reduced IL-1beta-stimulated PGE(2) by approximately 98% (P <0.001) and IL-6 by approximately 65% (P <0.001). IL-1beta increased nuclear and cytoplasmic p65 ( approximately 8-fold [P <0.001] and approximately 2.5-fold [P <0.03], respectively) over control levels. NS-398 reduced IL-1beta-stimulated nuclear and cytoplasmic p65 to control levels. IL-1beta increased phospho-IkappaBalpha in whole cell extracts by a maximum of approximately 9.5 times (P = 0.0001), and this was inhibited significantly by NS-398 (P <or=0.008).

CONCLUSIONS

NS-398 inhibited NF-kappaB activation and nuclear p65 levels in human gingival fibroblasts. This seemed to be due to inhibition of the phosphorylation cascade resulting in formation of phospho-IkappaBalpha and free p65. NF-kappaB inhibition may be useful in treating inflammatory diseases such as AgP.

The association of the composite IL-1 genotype with periodontitis progression and/or treatment outcomes: a systematic review

BACKGROUND

Genetically transmitted traits such as cytokine gene polymorphisms may accentuate the host inflammatory response to the bacterial challenge and influence susceptibility to periodontitis.

OBJECTIVE

To systematically review the evidence of an association between the interleukin-1 (IL-1) composite genotype, i.e. presence of the allele 2 in the gene clusters IL-1A-889 and in IL-1B +3953, and periodontitis progression and/or treatment outcomes.

MATERIAL AND METHODS

Based on the focused question, a search was conducted for longitudinal clinical trials comparing progression of periodontitis and/or treatment outcomes in IL-1 genotype-positive (carrying allele 2) and IL-1 genotype-negative (not carrying allele 2) subjects. A search in the National Library of Medicine computerized bibliographic database MEDLINE and a manual search were performed. Selection of publications, extraction of data and validity assessment were made independently by two reviewers.

RESULTS

The search provided 122 titles of which 11 longitudinal publications were included. The heterogeneity of the data prevented the performance of a meta-analysis. While findings from some publications rejected a possible role of IL-1 composite genotype on progression of periodontitis after various therapies, other reported a prognostic value for disease progression of the positive IL-1 genotype status. When assessed on a multivariate risk assessment model, several publications concluded that the assessment of the IL-1 composite genotype in conjunction with other covariates (e.g. smoking and presence of specific bacteria) may provide additional information on disease progression. The small sample size of the available publications, however, requires caution in the interpretation of the results.

CONCLUSION

Based on these findings, (i) there is insufficient evidence to establish if a positive IL-1 genotype status contributes to progression of periodontitis and/or treatment outcomes. Therefore, (ii) results obtained with commercially available tests should be interpreted with caution.

Associations between peri-implant crevicular fluid volume, concentrations of crevicular inflammatory mediators, and composite IL-1A ?889 and IL-1B +3954 genotype: A cross-sectional study on implant recall patients with and without clinical signs of peri-implantitis

OBJECTIVES

To assess possible relationships between peri-implant crevicular fluid (PICF) volumes, biochemical markers of the peri-implant immune response, and periodontitis-associated genotype.

MATERIAL AND METHODS

PICF samples from 29 implant maintenance patients, 24 wearing overdentures, five having single crowns and bridgework (11 patients with peri-implantitis and 18 individuals with healthy peri-implant conditions), were analyzed for per site and per crevicular-fluid-volume concentrations of interleukin-1beta, plasminogen activator inhibitor type 2, and prostaglandin E2 by ELISA. Associations between the three substance concentrations and to crevicular fluid flow rate were analyzed by linear regression analysis. The possible differentiating influence of the composite interleukin-1A and -1B genotype on the patients' peri-implant health and biochemical inflammatory status was checked formally with t-test statistics and the Wilcoxon' test. One implant per patient was chosen for analysis.

RESULTS

In patients with healthy peri-implant conditions, genotype-positive individuals showed elevated crevicular fluid flow rates and at the same time reduced mediator concentrations. In patients with an implant affected from peri-implantitis, no statistically significant influence of the periodontitis-associated genotype around the fixture can be stated. There was no statistical difference between per site and per crevicular-fluid-volume concentration analyses. All three mediator concentrations were positively related to each other, while there was a strong negative correlation between crevicular fluid volume and plasminogen activator inhibitor 2 or prostaglandin E2.

CONCLUSIONS

The Interleukin-1 polymorphism investigated exerted only little influence on the peri-implant crevicular immune response, and this influence appeared to be of limited impact in sites with established peri-implantitis lesions.

The potential prognostic value of some periodontal factors for tooth loss: a retrospective multilevel analysis on periodontal patients treated and maintained over 10 years

BACKGROUND

The great challenge in clinical periodontology is assigning a prognosis to a periodontally affected patient. Many different factors can affect the long-term maintenance of periodontally compromised teeth. The main questions usually considered by the periodontist are: 1) Will a tooth lose more bone in the future? 2) Will the tooth itself be lost in the future? The purpose of this retrospective study was to evaluate the value of some clinical, genetic, and radiographic variables in predicting tooth loss in periodontal patients (aged 40 to 60 years) treated and maintained for 10 years.

METHODS

Sixty consecutive non-smoking patients (aged 46.77 +/- 4.96 years) with moderate to severe chronic periodontitis (CP) were treated with scaling and root planing (SRP). Some patients also underwent additional surgical treatments. All patients were maintained in the same private practice for 10 years. The frequency of recall appointments was 3.4 +/- 1.0 months. At baseline (T(0)) and 10 years later (T(2)) the following clinical variables were evaluated: the number of teeth, probing depths (PD), tooth mobility (TM), and presence of prosthetic restorations (PR). In addition, radiographic measurements were taken of the mesial and distal distances from the cemento-enamel junction (CEJ) to the bottom of the defect (BD), to the bone crest (BC), and to the root apex (RA). At T(2), a genetic test to determine the IL-1 genotype and genetic susceptibility for severe periodontal disease was performed for all 60 patients, and they were classified as IL-1 genotype positive (G+) or negative (G-) according to the test results. Tooth loss was used as the outcome variable. Different predictor variables were then tested using a two-level statistical model (patient and tooth levels). At the patient level, these were: age, gender, mean bone loss (mean CEJ-BD)(T0), the interleukin-1 (IL-1) genotype, the interaction between mean bone loss, and IL-1 genotype (mean CEJ-BD(T0) x IL-1 genotype). At the tooth level, the variables were: TM(T0), prosthetic restorations (PR)(T0), molar teeth (MT)(T0), the infrabony component of the defect (BC-BD)(T0), PD(T0), bone level (CEJ-BD)(T0), and residual supporting bone (BD-RA)(T0).

RESULTS

Among the considered predictor variables, the following were significantly associated with the outcome variable: 1) MT(T0) (P <0.0001); 2) BC-BD(T0) (P = 0.0377); and 3) BD-RA(T0) (P <0.0001). MT(T0) were found to be more prone to loss and the amount of BD-RA(T0) prognostic for tooth loss: the lower the residual amount of supporting bone, the higher the probability of tooth loss. Conversely, the BC-BD(T0)was associated with a reduced probability of future tooth loss: the greater the infrabony component, the lower the probability of tooth loss. None of the other considered predictors proved predictive for tooth loss.

CONCLUSIONS

Within the scope of this study, many traditional prognostic factors were ineffective in predicting future tooth loss and, therefore, were of no prognostic value. Conversely, a few specific factors at the tooth level emerged as viable prognostic factors. The use of these factors may be of great value to practitioners as predictors of tooth loss when assigning a prognosis.

Effect of Tumor Necrosis Factor-α Gene Polymorphism on Peri-Implant Bone Loss Following Prosthetic Reconstruction

PURPOSE

The present study investigates the association between a specific polymorphism in the tumor necrosis factor (TNF)-alpha gene, consisting of allele 2 of TNF-alpha-308, and peri-implant bone loss following prosthetic reconstruction.

MATERIALS AND METHODS

This case-control study included 36 patients (20 women, 16 men; mean age 46 years) who had used implant-supported prostheses for a minimum of 6 months and a maximum of 31 months. The patients were nonsmoking, white Caucasian Brazilians, in good general health, and were not receiving medication. In the case group, patients exhibited 1 or more implants with a diagnosis of peri-implant bone loss following prosthetic reconstruction; control patients had 1 or more healthy implants.

RESULTS

Polymorphism in the TNF-alpha gene, allele 2 of TNF-alpha, was not associated with an increased risk for peri-implant bone loss following prosthetic reconstruction (P=0.19; chi2=1.71; df=1), although 21.1% of the subjects carried allele in the control group 2, and 41.2% carried allele 2 in the case group.

CONCLUSIONS

Polymorphism in allele 2 of the TNF-alpha-308 gene is not associated with an increased risk for peri-implant bone loss following prosthetic reconstruction. However, further studies based on a greater number of patients are necessary.

Subgingival Chlorhexidine Varnish Administration as an Adjunct to Same-Day Full-Mouth Root Planing. I. Clinical Observations

BACKGROUND

Chemo-mechanical treatment concepts have been developed to improve the outcome of non-surgical periodontal therapy. Recently, the clinical additive value of a supersaturated chlorhexidine varnish was shown when used as an adjunct to staged scaling and root planing. The aim of this study was to investigate the clinical effects of a treatment strategy for chronic periodontitis based on a combination of same-day full-mouth root planing and subgingival chlorhexidine varnish administration.

METHODS

A randomized, controlled, single-blind, parallel trial was conducted on 33 non-smoking chronic periodontitis patients. The control group received oral hygiene instructions and same-day full-mouth root planing. The test group received the same instructions and treatment; however, all pockets were disinfected using a chlorhexidine varnish. Clinical response parameters were recorded at baseline and after 1, 3, and 6 months.

RESULTS

Both groups showed significant reductions in probing depth following therapy (P <0.001). There was no significant difference in full-mouth probing depth between the groups at any examination point. However, when a site-specific comparison was made, additive effects were found in the test group; an extra pocket reduction of 0.93 mm (P = 0.044) for initially deep pockets (>or=7 mm) was found at study termination. Additive clinical attachment gains seemed to be temporary. Impermanent extra pocket reductions and clinical attachment gains were found for initially medium-deep pockets (4 to 6 mm).

CONCLUSION

The outcome of same-day full-mouth root planing may benefit from the subgingival administration of a highly concentrated chlorhexidine varnish, at least in terms of pocket reduction in initially deep sites (>or=7 mm).

Medical Contraindications to Implant Therapy: Part II: Relative Contraindications

Systemic conditions and habits influence dental implant survival to varying degrees. Illnesses that impair the normal healing cascade worsen surgical success. The mere presence of a disease, however, does not necessarily preclude implant therapy or affect significantly long-term outcomes. Certain disorders, when controlled, or other situations allow implant survival rates that match those in health. This paper reviews these relative contraindications, which include adolescence, aging, osteoporosis, smoking, diabetes, positive interleukin-1 genotype, human immunodeficiency virus positivity, cardiovascular disease, and hypothyroidism.

Gingivitis susceptibility and its relation to periodontitis in men

The objective of this cross-sectional study was to evaluate whether gingivitis susceptibility is associated with periodontitis. We analyzed data of 462 men in the VA Dental Longitudinal Study aged 47 to 92 years who had never smoked or had quit smoking 5+ years previously. Multiple logistic regression models, with tooth-level bleeding on probing at sites with attachment loss<or=2 mm as the dependent variable, were derived with adjustment for plaque, calculus, crown coverage, age, income, education, marital status, body mass index, diabetes, and vitamin C intake, and stratification by age (<65, 65+ years). Periodontitis and mean attachment loss were positively associated with bleeding on probing, with stronger associations among men<65 years old (for periodontitis, OR 2.1; 95% CI 1.5, 3.1) than men 65+ years of age (OR 1.2; 95% CI 0.9, 1.6). Our results suggest that among never and former smokers, gingivitis susceptibility is higher among men with periodontitis compared with that in men without periodontitis.

The IL1A (?889) gene polymorphism is associated with chronic periodontal disease in a sample of Brazilian individuals

BACKGROUND AND OBJECTIVE

It has been proposed that genotypes reflective of polymorphisms in cytokine genes can predispose individuals to disease by enhancing inflammatory processes. The C/T polymorphism at position -889 of the IL1A gene influences interleukin-1alpha expression, with the T allele inducing higher expression. The aim of this study was to evaluate the association of the IL1A (-889) gene polymorphism in Brazilian individuals with different clinical forms of periodontitis and severity of disease.

MATERIAL AND METHODS

DNA was obtained from oral swabs of 163 Brazilian individuals and was amplified using the polymerase chain reaction (PCR). Products were submitted to digestion and were analyzed by electrophoresis to distinguish the C and T alleles.

RESULTS

A significant difference in the genotype distribution was observed when comparing the chronic periodontitis group with the control group, evaluating only nonsmokers (chi-squared analysis = 9.91; p = 0.007), as well as when smokers were included (chi-squared analysis = 6.36; p = 0.04). Moreover, we observed a higher incidence of the T allele in the chronic periodontitis group (37.8%) when compared with the control group (18.4%) in nonsmokers (p = 0.006, odds ratio = 2.69, confidence interval = 1.27-5.68) and also when smokers were included (p = 0.03, odds ratio = 1.87, confidence interval = 0.98-3.56). No statistical difference was observed when the aggressive periodontitis group was compared with the control group. With regard to severity of disease, no statistical difference was observed.

CONCLUSION

These data show an association of the IL1A (-889) polymorphism with chronic periodontitis in Brazilian individuals.

Evaluation of the Incidence of Periodontitis-Associated Bacteria in the Atherosclerotic Plaque of Coronary Blood Vessels

BACKGROUND

Unstable atherosclerotic plaque is a dangerous clinical condition, possibly leading to acute coronary deficiency resulting in cardiac infarction. Questions about the role of inflammatory factors in the formation of pathological lesions in the endothelium of coronary vessels have often been raised. This condition may be caused by bacteria that are able to initiate clot formation in a blood vessel, destabilizing an atherosclerotic plaque that is already present. The sources of these pathogens are chronic inflammatory processes occurring in the host, including periodontal disease, which is one of the most frequent conditions. The aim of this study was to evaluate the incidence of selected anaerobic bacteria in subgingival and atherosclerotic plaque in patients treated surgically because of coronary vessel obliteration.

METHODS

The study was performed on 20 individuals with chronic periodontitis. Subgingival plaque was collected from periodontal pockets >5 mm. DNA testing was used to identify eight pathogens responsible for periodontal tissue destruction. Material from atherosclerotic plaques was collected from the same patients during bypass surgery, and DNA testing by the same method was performed.

RESULTS

In 13 of 20 patients, the pathogens most frequently found in severe chronic periodontitis were also found in coronary vessels. In 10 cases, those species of bacteria were also present in atherosclerotic plaque. The most frequently identified bacteria were Porphyromonas gingivalis and Treponema denticola.

CONCLUSIONS

In patients with the severe form of chronic periodontitis, it seems that clinical attachment loss is not associated with bacterial permeability into coronary vessels. What is important is the presence of an active inflammatory process expressed by a significantly higher bleeding index in those patients in whom the examined bacterial species were found in atherosclerotic plaque.

No correlation of five gene polymorphisms with periodontal conditions in a Greek population

BACKGROUND

Various studies have examined possible correlations between a number of cytokine gene polymorphisms and periodontal disease in populations of different origins. The present study sought the correlation between four single-nucleotide polymorphisms (IL1A+3954, IL1B+4845, TNFA-308, COL1A1 Sp1), a variable number of tandem repeats polymorphism (IL1RN intron 2) and periodontal conditions in subjects of Greek origin.

METHODS

One hundred and ninety-two healthy subjects, stratified as non-periodontitis and periodontitis (chronic and aggressive) cases, participated in the present study. Genotyping was performed by polymerase chain reaction-based techniques using the primers and conditions described in the literature. The frequencies of genotypes between study groups were compared using Genepop v3.3 genetic software and Instat statistical package.

RESULTS

No differences were observed among the groups concerning the distributions of genotypes under investigation.

CONCLUSIONS

Carriage rates of the polymorphisms under investigation in systemically healthy subjects of Greek origin are well within the range reported for Caucasians but these polymorphisms cannot discriminate between non-periodontitis and periodontitis (chronic or aggressive) cases.

Relationship between IL-1A polymorphisms and gingival overgrowth in renal transplant recipients receiving Cyclosporin A

AIM

Levels of interleukin-1alpha (IL-1alpha) are elevated in periodontal inflammation. IL-1A gene polymorphisms are associated with inflammatory diseases. This study aimed to investigate IL-1A gene polymorphism in Cyclosporin A (CsA)-treated renal transplant patients and investigate the association between this polymorphism and gingival crevicular fluid (GCF) levels of several cytokines.

MATERIALS AND METHODS

Fifty-one renal transplant patients on CsA treatment (25 with and 26 without gingival overgrowth) and 29 healthy controls were recruited for the study. Demographic, pharmacological and periodontal parameters were recorded and gingival overgrowth was assessed.

RESULTS

Multiple regression analysis showed that genotype was significantly associated with gingival overgrowth (p=0.02). Carriage of the IL-1A (-889) T allele was strongly protective [95% confidence interval (CI): 0.046-0.77], although not significantly associated with IL-1alpha protein levels in GCF. IL-1alpha, IL-1beta and IL-8, but not IL-6, were detected in GCF of CsA-treated patients, but none of them was significantly associated with gingival overgrowth.

CONCLUSIONS

This study is the first to associate a gene polymorphism as a risk factor for CsA-induced gingival overgrowth in renal transplant patients, demonstrating that IL-1A polymorphism might alter individual susceptibility to CsA. However, there was no association between GCF cytokine levels and the presence of gingival overgrowth or patient IL-1A genotype.

Correlation between single nucleotide polymorphisms in a calprotectin subunit gene and risk of periodontitis in a Chinese population

S100A8, the light subunit of calprotectin, has been known to be associated with periodontal inflammation. The present study looked to detect whether three polymorphisms in the upstream region of the S100A8 gene are correlated with periodontitis. Three hundred and twenty one subjects, including chronic periodontitis (CP) patients, aggressive periodontitis (AgP) patients and periodontally healthy controls, were recruited. The SNPs rs3795391, rs3806232 and rs3885688 were analyzed by PCR-RFLP analysis. No person carried the rs3885688 polymorphism in this cohort. For the other two polymorphisms, the combined effects of genotype/allele and gender were shown to be associated with the risk of periodontitis using multivariate logistic regression analysis. The G+ genotype/G allele may be considered to exert a significant protective effect in males against AgP (Genotype: rs3795391: P= 0.032, rs3806232: P= 0.017; Allele: rs3795391: P= 0.024, rs3806232: P= 0.013). Although the combined effects of genotype and gender on CP susceptibility were not observed for these two polymorphisms, there does seem to be increased risk of CP in males with allele A compared to females with allele A (rs3795391: P= 0.008; rs3806232: P= 0.009). Hence we found an important association between polymorphisms in the S100A8 gene and periodontitis in a Chinese population.

Genetic polymorphisms in the MMP-1 and MMP-3 gene may contribute to chronic periodontitis in a Brazilian population

OBJECTIVES

Matrix metalloproteinase-1 and -3 (MMP-1, MMP-3) represent proteinases that degrade macromolecules of the extracellular matrix. These enzymes play a fundamental role during destruction of periodontal tissues. Genetic polymorphisms were characterized in the promoter region of the MMP-1 and MMP-3 genes. The aim of this study was to investigate the relationship between these genetic variations with chronic periodontitis in a Brazilian population.

MATERIAL AND METHODS

Non-smoking subjects (n = 114) exhibiting sites > or = 5 mm clinical attachment loss were recruited for study. Control subjects (n = 109) should not exhibit clinical signals of periodontitis. MMP-1 (-1607 1G/2G, -519 A/G) and MMP-3 (-1612 5A/6A) gene promoter polymorphisms were genotyped using PCR-RFLP methods.

RESULTS

Analysis of polymorphisms showed no differences in distribution of the -1607 1G/2G and -519 A/G variants in the MMP-1 gene between the healthy and periodontitis group (p > 0.05). However, the distribution of genotype frequencies of the -1612 5A/6A polymorphism in the MMP-3 gene showed that the 5A/5A genotype was significantly more frequent in the periodontitis group (p = 0.008). The same was not observed in the 5A/6A genotype once only one 5A allele is carried. We also observed a trend to increase the frequency of the MMP-1/MMP-3 haplotype (2G/5A) in the periodontitis group (p = 0.08).

CONCLUSION

On the basis of the results, no significant association is found for the MMP-1 polymorphisms with susceptibility of periodontitis, while the MMP-3 gene polymorphism may contribute to periodontal tissue destruction during periodontitis in Brazilian subjects.

Evaluation of RANK/RANKL/OPG gene polymorphisms in aggressive periodontitis

BACKGROUND AND OBJECTIVE

Aggressive periodontitis (AgP) is a specific type of periodontal disease that is characterized by rapid attachment loss and bone destruction. While attempting to identify genetic polymorphisms associated with AgP, previous research has focused on candidate genes that may be involved in immune responses to microbial infections. In this study, the focus was on single nucleotide polymorphisms (SNPs) in the key mediators of osteoclast differentiation and activation, which involve receptor activator of nuclear factor-kappaB (RANK), RANK ligand (RANKL) and osteoprotegrin (OPG), in the Japanese population. The aim of this study was to evaluate the association of RANK/RANKL/OPG gene polymorphisms with AgP in the Japanese population.

MATERIAL AND METHODS

We examined 99 patients with AgP and 89 controls from the Japanese population to explore the possibility of RANK/RANKL/OPG loci as candidate regions associated with the disease. All exons and relevant exon-intron boundaries of these three candidate genes were amplified by polymerase chain reaction (PCR) using 19 primers, followed by direct sequencing. The polymorphisms were identified by comparing the sequences obtained from 48 subjects.

RESULTS

We identified 27 SNPs in RANK, including 10 novel SNPs and seven SNPs each in both RANKL and OPG. A pairwise linkage disequilibrium analysis using the r2 statistic showed that some SNP pairs from the three loci are in tight linkage disequilibrium.

CONCLUSION

An association analysis with allelotypes showed that SNPs identified in the RANK/RANKL/OPG genes have no significant association with AgP in the Japanese population.