Adipokine gene variability and plasma levels in patients with chronic periodontitis -a case-control study

Abstract: Specific variants in genes that encode adipokines and their mRNA and protein expression were previously studied in type 2 diabetes mellitus (T2DM) and obesity, and similar studies have been performed for chronic periodontitis (CP). The aim of this case-control study was to investigate the possible impacts of adiponectin (ADIPOQ), leptin (LEP) and its receptor (LEPR), and resistin (RETN) on the etiopathogenesis of CP. Examinations were performed on 118 non-periodontitis healthy subjects (healthy controls, HC), 205 healthy individuals with CP (H + CP) and 86 type 2 diabetes patients with CP (T2DM + CP). Variants within the ADIPOQ (rs2241766, rs1501299), LEP (rs13228377, rs2167270), LEP receptor (rs1805096), and RETN (rs1862513) genes were determined by qPCR. In addition, the plasma levels of ADIPOQ, LEP, and RETN were analysed by ELISA for 80 individuals. The genotype frequencies of the SNP ADIPOQ +45G/T (rs2241766) differed between the HC and H + CP groups (p=0.03, pcorr>0.05), and carriers of the TT genotype had a lower risk of developing CP compared to carriers of the GG or TG genotypes (p<0.01, pcorr>0.05). However, there were no significant differences in the plasma levels of ADIPOQ, LEP or RETN between the study groups (p > 0.05). Plasma levels of the adipokines were also independent of the gene profiles (p > 0.05). Adipokine plasma levels did not change in patients with H + CP/T2DM + CP compared to HC, but we did identify a specific polymorphism in the ADIPOQ gene that was associated with CP. Although the ADIPOQ +45G/T (rs2241766) gene variant may be a candidate biomarker for CP, further research is required in larger populations with different ethnic backgrounds before any final conclusions can be drawn about the role of this gene in CP.

Asociación del polimorfismo genético de la interleucina -1Beta con periodontitis crónica en adultos peruanos / Connection Between Genetic Polymorphism of Interleukin -1Beta With Chronic Periodontitis in Peruvian Adults

RESUMEN Objetivos. Determinar la asociación del polimorfismo IL-1B C(+3953/4)T con la periodontitis crónica en adultos. Materiales y métodos. Estudio de casos y controles, se incluyeron personas de 18 a 64 años muestreados voluntariamente aplicando el consentimiento informado a través de campañas de salud, realizadas durante el 2012, en diferentes zonas de la ciudad de Lima con características socioeconómicas semejantes. Odontólogos especialistas en periodoncia realizaron el diagnóstico del estado periodontal de los participantes, la genotipificación se realizó a través de la técnica de PCR-RFLP. Los datos fueron analizados mediante regresión logística. Resultados . Los factores asociados con la periodontitis crónica fueron ser mayor de 46 años (OR: 7,58, IC 95 %: 3,32-17,30), tener grado de instrucción superior (OR: 0,43, IC 95 %: 0,27-0,98), la presencia del alelo 2 en el polimorfismo de la IL-1B y el genotipo positivo (2-2) estuvo asociado con la presencia de periodontitis crónica (OR: 2,06, IC 95 %: 1,01-4,21). Conclusiones . La presencia del alelo 2 en el polimorfismo de la IL-1B y el genotipo positivo (2-2) confiere mayor riesgo para el desarrollo de periodontitis crónica en la población de adultos peruanos que fueron estudiados.

ABSTRACT Objectives . To determine the connection between polymorphism IL-1B C(+3953/4)T and chronic periodontitis in adults. Materials and Methods . Case and control study. Individuals between 18 and 64 years of age were included; they were recruited through healthcare campaigns carried out in 2012 in different areas of the city of Lima with similar socio-economic characteristics. Dentists specialized in periodontics performed the diagnosis of the periodontal state of participants; genotyping was made through the PCR-RFLP technique. The data were analyzed by logistic regression. Results . The factors associated with chronic periodontitis were: age over 46 years (OR: 7.50, CI 95%: 1.85-6.37), higher education level achieved (OR: 0.43, CI 95%: 0.27-0.98), the presence of allele 2 in the polymorphism of IL-1B. The positive genotype (2-2) was associated with the presence of chronic periodontitis (OR: 2.06, CI 95%: 1.01-4.21). Conclusions . The presence of allele 2 in the polymorphism of IL-1B and the positive genotype (2-2) confers greater risk for the development of chronic periodontitis in the population of Peruvian adults under study.

Interleukin-6 and interleukin-10 gene polymorphisms and the risk of further periodontal disease progression

Abstract: Susceptible genotypes to periodontal disease are associated with disease onset and progression. The aim of this study was to examine the effect of gene polymorphisms on the risk of further disease progression and the need for further treatment among adults with chronic periodontal disease. Sixty-seven patients diagnosed with chronic periodontitis were grouped according to genotype status and risk of further progression of disease and tooth loss. All individuals were clinically evaluated for probing pocket depth, clinical attachment loss and bleeding on probing at baseline and 45 days after treatment. Blood samples were collected at baseline and genotyping of the polymorphisms in IL-6 (rs1800796) and IL-10 (rs1800872) genes were performed by PCR. Following DNA separation and genotyping, 65.7% of the patients were homozygous carriers of the IL-6 −572G and 49.3% were carriers of the IL-10 −592A allele. Individuals at risk of disease progression ranged from 7.5% to 62.7% based on the criteria used. Carriers of the IL-10 −592A allele were significantly associated with BOP ≥ 30% and therefore exhibited a higher risk of further periodontal breakdown (p = 0.018) with an odds ratio of 1.18. None of the other definitions of disease progression were significantly associated with the examined IL-6 and IL-10 genotypes (p > 0.05). IL-10 polymorphism was associated with an increased risk of further disease progression and the potential need for further treatment following non-surgical periodontal treatment. Susceptible IL-6 genotypes were not associated with the risk of persisting or recurrent disease activity.

The effects of IL-10 gene polymorphism on serum, and gingival crevicular fluid levels of IL-6 and IL-10 in chronic periodontitis

Abstract Objective Anti-inflammatory cytokines play a crucial role in periodontitis by inhibiting synthesis of pro-inflammatory cytokines. The purpose of this study was to evaluate the effect of interleukin-10 (-597) gene polymorphism and genotype distributions on chronic periodontitis (CP) development and IL-6 and IL-10 levels in gingival crevicular fluid (GCF) and serum before and after non-surgical periodontal treatment. Material and Methods The study population consisted of 55 severe generalized CP patients as CP group and 50 healthy individuals as control group. Plaque index, gingival index, probing depth and clinical attachment level were recorded and GCF and blood samples were taken at both the baseline and the sixth week after non-surgical periodontal treatment. PCR-RFLP procedure was used for gene analyses and cytokine levels were measured via ELISA. Results IL-10 genotype distribution was significantly different between CP and control groups (p=0.000, OR:7, 95%CI, 2.83-60.25). Clinical measurements significantly improved in the CP group after periodontal treatment (p<0.05). Periodontal treatment significantly decreased GCF IL-6 and IL-10 levels. No significant difference was found in clinical parameters between IL-10 AA and AC+CC genotypes at both the baseline and the sixth week (p>0.05). Sixth week GCF IL-10 levels were significantly lower in patients carrying IL-10 AC+CC genotype compared to the patients carrying IL-10 AA genotype (p<0.05). Serum IL-6 and IL-10 levels were lower in patients carrying the IL-10 AA genotype compared to patients with IL-10 AC+CC genotype, but the difference was not significant (p>0.05). Conclusion IL-10 AA genotype carriers had lower IL-6 and IL-6/10 levels in serum; however, GCF IL-6/10 levels were similar in both genotypes. Within the limitations of our study, a possible association between IL-10(-597) gene polymorphism and CP might be considered.

Effect of Alox-15 Polymorphism on GCF Levels of Lipoxin-A4 in Chronic Periodontitis: A Preliminary Study

Lipoxins play an important role in periodontal resolution, hence, investigation of genetic polymorphism of lipoxin gene may provide important information on the role of lipoxins in periodontal disease pathogenesis. The aim of this study was to investigate a polymorphism of C-to-T substitution at position c.-292 in ALOX15 (reticulocyte-type 15 lipoxygenase 1) gene in patients with chronic periodontitis and to associate the polymorphism with gingival crevicular fluid (GCF) lipoxin A4 (LXA4) levels. Forty-five chronic periodontitis and 45 periodontally healthy patients were included in this case-control study. Plaque index, calculus index, sulcus bleeding index, full mouth probing depth (PD) and clinical attachment loss (CAL) were recorded. GCF and blood samples were collected. GCF was analyzed for LXA4 levels by enzyme linked immunosorbant assay. Genotyping of ALOX15 polymorphism was studied using PCR. Mean LXA4 was lower in periodontitis group compared to the periodontally healthy group. There was a negative correlation between CAL and LXA4. The CC genotype was higher in the study group than in the control group. In the study group, mean CAL was significantly lower among individuals with the CT genotype. Mean LXA4 was significantly lower in CC genotype (45.0±7.11 ng/mL) compared to CT genotype (50.81±5.81 ng/mL) among the patients with periodontitis. The results suggest that LXA4 and c.-292T allele are associated with periodontal health. Polymorphisms in the ALOX15 gene may influence periodontal disease pathogenesis. Hence, investigation of such polymorphisms could benefit the evaluation of lipoxins role in periodontal disease.

Resumo Lipoxinas desempenham um papel importante na recuperação periodonta, portanto, a investigação do polimorfismo genético do gene da lipoxina pode fornecer informações importantes sobre o papel das lipoxinas na patogênese da doença periodontal. O objetivo deste estudo foi investigar um polimorfismo de substituição C-to-T na posição c-292 no gene ALOX15 (reticulócito-tipo 15 lipoxigenase 1) em pacientes com periodontite crônica e associar o polimorfismo com a lipoxina A4 (LXA4) do fluido gengival crevicular (FGC). Quarenta e cinco pacientes com periodontite crônica e 45 pacientes periodonalmente saudáveis foram incluídos neste estudo caso-controle. Índice de placa, índice de cálculo, índice de sangramento do sulco, profundidade de sondagem (PS) da boca toda e perda de inserção clínica (PIC) foram registrados. Amostras do FGC e de sangue foram coletadas. O FGC foi analisado quanto aos níveis de LXA4 por ensaio imunoadsorvente ligado à enzima (ELISA). A genotipagem do polimorfismo ALOX15 foi estudada por PCR. A média de LXA4 foi menor no grupo de periodontite em comparação com o grupo periodontalmente saudável. Houve uma correlação negativa entre PIC e LXA4. O genótipo CC foi maior no grupo de estudo do que no grupo controle. No grupo de estudo, a média de PIC foi significativamente menor entre os indivíduos com o genótipo CT. A média de LXA4 foi significativamente menor no genótipo CC (45,0 ± 7,11 ng / mL) em comparação com o genótipo CT (50,81 ± 5,81 ng / mL) entre os pacientes com periodontite. Os resultados sugerem que o alelo LXA4 e o alelo c-292T estão associados à saúde periodontal. Polimorfismos no gene ALOX15 podem influenciar a patogênese da doença periodontal. Assim, a investigação de tais polimorfismos pode beneficiar a avaliação do papel das lipoxinas na doença periodontal.

Analysis of polymorphisms in Interleukin 10, NOS2A, and ESR2 genes in chronic and aggressive periodontitis

Abstract The objective of this study was to investigate the association between single nucleotide polymorphisms (SNPs) in the IL10, NOS2A, and ESR2 genes and chronic periodontitis (CP) and aggressive periodontitis (AgP). Three groups of patients underwent periodontal and radiographic evaluations: CP (n = 61), AgP (n = 50), and periodontally healthy (control group=61). Genomic DNA was extracted from oral epithelial cells and used for genotyping by real-time polymerase chain reaction using TaqMan® probes. The investigated SNPs were: -1087G > A, -819C > T and -592C > A in the IL10; +2087G > A in the NOS2A, and +1730G > A in the ESR2 gene. Differences in genotype and allele frequencies of each polymorphism and some individual characteristics were analyzed using the chi-square test and multivariate logistic regression analysis. Analysis of SNPs and haplotypes in the IL10 and SNP in the ESR2 gene did not present any significant association with AgP or CP. The +2087G allele of the NOS2A gene tended to be significantly associated with periodontal disease. Patients carrying the genotype +2087GG in the NOS2A gene were genetically protected against the development of CP (p = 0.05; OR = 0.44; 95%CI = 0.20-0.95). This result showed greater significance when patients with AgP and CP were combined (total PD) (p = 0.03; OR = 0.46; 95%CI = 0.23-0.92). In conclusion, the studied Brazilian population had a significantly higher frequency of the GG genotype for the +2087 SNP in the NOS2A gene in individuals without periodontitis, although statistical significance was not maintained after multiple logistic regression.

Association of Interleukin-17 polymorphism (-197G/A) in chronic and localized aggressive periodontitis

Abstract Interleukin 17(IL-17) is a pro-inflammatory cytokine produced mainly by Th17 cells. The present study was undertaken to investigate a possible association between IL-17 A genetic polymorphism at (-197A/G) and susceptibility to chronic and localized aggressive periodontitis (LAgP) in an Indian population. The study was carried out on 105 subjects, which included 35 LAgP patients, 35 chronic periodontitis patients and 35 healthy controls. Blood samples were drawn from the subjects and analyzed for IL-17 genetic polymorphism at (-197A/G), by using the polymerase chain reaction-restriction fragment length polymorphism method. A statistically significant difference was seen in the genotype distribution among chronic periodontitis patients, LAgP patients and healthy subjects. There was a significant difference in the distribution of alleles among chronic periodontitis patients, LAgP patients and healthy subjects. The odds ratio for A allele versus G allele was 5.1 between chronic periodontitis patients and healthy controls, and 5.1 between LAgp patients and healthy controls. Our study concluded that IL-17 A gene polymorphism at (-197A/G) is linked to chronic periodontitis and LAgP in Indian population. The presence of allele A in the IL-17 gene polymorphism (-197A/G) can be considered a risk factor for chronic periodontitis and LAgP.

Analysis of association of TaqI VDR gene polymorphism with the chronic periodontitis in Dravidian ethnicity.

AIM: The aim of this study is to analyze the association of TaqI vitamin D receptor (VDR) gene polymorphism with the chronic periodontitis (CP) in Dravidian ethnicity. MATERIALS AND METHODS: A total of 120 subjects were recruited for this study, which included 60 CP and 60 healthy controls. TaqI VDR gene polymorphism was analyzed using specific primers and amplified by polymerase chain reaction (PCR) and visualized under 2% agarose gel. RESULTS: Our study results showed that Tt and tt genotype had a higher frequency of occurrence in CP compared with controls. Similarly, t allele was found to be associated with CP. CONCLUSION: Our study concludes that TaqI VDR gene polymorphism is associated with CP in Dravidian ethnicity.

Participación de los mediadores de la respuesta inmune inflamatoria en la resorción del hueso alveolar durante la periodontitis crónica: revisión de la literatura / Participation of the immune response mediators in inflamatory alveolar bone resortion during chronic periodontitis: a literature review

La enfermedad pulmonar obstructiva crónica (EPOC) abarca todas aquellas enfermedades respiratorias que cursan con obstrucción no totalmente reversible del flujo aéreo. La limitación es progresiva y está asociada a una respuesta inflamatoria. La denominación de fenotipo se utiliza para referirse a formas clínicas de los pacientes con EPOC, describiéndose: 1. No agudizador, con enfisema o bronquitis crónica, 2. Mixto EPOC-asma, 3. Agudizador con enfisema y 4. Agudizador con bronquitis crónica. La superposición de los síntomas hace difícil el diagnóstico, y para la mayoría de los pacientes, el tabaquismo es el factor etiológico más importante. La obstrucción de las vías bronquiales en el asma es esencialmente reversible, pero muchos años de exacerbaciones recurrentes puede producir una obstrucción permanente debido al remodelado de las vías respiratorias. La inflamación crónica esta asociada a un aumento en la hiperreactividad de la vía aérea que conduce a episodios recurrentes de sibilancias, disnea, opresión torácica y tos, particularmente en la noche o temprano en la mañana. Estos episodios se asocian generalmente a la obstrucción generalizada pero variable en el flujo aéreo pulmonar que es frecuentemente reversible espontáneamente o con tratamiento

Chronic obstructive pulmonary disease (COPD) includes all those respiratory diseases that curse with not fully reversible obstruction of the airflow. The limitation is progressive and its associated with a inflammatory response. The denomination of phenotype is used to refer to clinical forms of COPD patients, describing: 1. No peaking, emphysema or chronic bronchitis, 2. Mixed COPD-asthma, 3. Peaking with emphysema and 4. Peaking with chronic bronchitis. The superposition of the symptoms makes the diagnosis difficult, and for most patients, smoking is the most important etiologic factor. The bronchial airway obstruction in asthma is essentially reversible, but many years of recurrent exacerbations can produce a permanent obstruction due to airway remodelling. Chronic inflammation is associated with increased airway hyper responsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness and coughing, particularly at night or early in the morning. These episodes are usually associated with widespread but variable obstruction in lung airflow that is often reversible either spontaneously or with treatment

Comparison of inflammatory microRNA expression in healthy and periodontitis tissues

MicroRNAs (miRNAs) are short RNA molecules that negatively regulate gene expression primarily by degrading target mRNA or inhibit the translation of protein product. Recently, many reports have shown the altered miRNA expression in various diseases. However, there are no reports on miRNA expression related to periodontitis. Thus, this study aimed to compare the miRNAs differentially expressed in healthy and chronic periodontitis tissues and to determine the miRNAs closely associated with chronic periodontitis. To find out the miRNAs differentially induced in healthy and chronic periodontitis tissues, miRNA microarray was carried out and the expression of miRNAs was confirmed by real-time PCR. According to miRNA microarray analyses, six miRNA genes, let-7a, let-7c, miR-130a, miR301a, miR-520d, and miR-548a, were up-regulated more than 8 fold compared to the healthy gingiva. The expression of twenty-two miRNAs was increased more than 4 fold. Among these miRNAs, eight miRNAs which are known to be closely related to inflammation were selected. Six of these miRNA genes, miR-181b, miR-19b, miR-23a, miR-30a, miR-let7a, and miR-301a, were amplified successfully and increased much more in periodontitis gingivae than in healthy ones. In summary, this study indicate that six miRNAs up-regulated in periodontitis gingiva may play a key role in chronic periodontitis.

Allele, genotype, and composite genotype effects of IL-1A +4845 and IL-1B +3954 polymorphisms for chronic periodontitis in an Indian population.

Introduction: The pro-inflammatory cytokine interleukin-1 (IL-1) is a key modulator of host responses to microbial infection and a major modulator of extracellular matrix catabolism and bone resorption, and polymorphisms in the IL-1 gene cluster have been associated with an increased risk of developing severe adult periodontitis. A case control study was performed to determine the role of IL-1A+4845 and IL-1B+3954 polymorphisms in the predisposition to chronic periodontitis. Materials and Methods: The study was conducted with 103 unrelated participants recruited from Manipal College of Dental Sciences, Manipal, which included 51 chronic periodontitis patients and 52 normal periodontally healthy individuals. Extensive clinical data were collected, bone loss was the major outcome variable and smokers and diabetics were excluded from the study to eliminate the influence of these risk factors. Genomic DNA was isolated from the blood samples of participants for genotyping IL-1A+4845 and IL-1B+3954 polymorphisms by polymerase chain reaction-restriction fragment length polymorphism and the data statistically analyzed. Results: Allele 2 of the IL-1A+4845 polymorphism was carried by 38% of all participants; of these only 6 were homozygous for the allele. Allele 2 of the IL-1B+3954 was carried by 21% of the subjects; only 1 was homozygous for allele 2. The composite genotype was carried by 31% of the cases and by 38% of the controls. Overall, 35% participants carried the composite IL-1 genotype. No statistically significant association was found for the distributions. Conclusions: The distribution of the IL-1 positive composite genotype is in concordance with the frequencies reported in the Caucasians. Association was not found for the effect of allele, genotype, composite genotype, and haplotypes of IL-1A+4845 and IL-1B+3954 polymorphisms with periodontitis. Its utility as a risk marker in this population was not borne out by the study.

Evaluation of telomerase expression in chronic periodontitis.

Background : Human telomerase is a multi subunit ribonucleoprotein enzyme concerned with telomeric lengthening and homeostasis in man. This enzyme has been found to be elevated in inflammatory conditions like rheumatoid arthritis and silica injury lung. Since chronic periodontitis is also an inflammatory condition where immune cells and cytokines mediate tissue destruction, we set out to evaluate telomerase in gingival tissue samples from healthy subjects and chronic periodontitis patients by reverse transcriptase polymerase chain reaction. Materials and Methods : Gingival biopsies were obtained from eight healthy subjects and eight chronic periodontitis patients. Reverse transcriptase polymerase chain reaction (RTPCR) was carried out to evaluate telomerase gene expression in the samples. Results : None of the healthy gingival tissue samples expressed the telomerase gene while all the chronic periodontitis samples expressed it. The severe chronic periodontitis samples expressed the gene more intensely than the moderate chronic periodontitis samples. Conclusion : Various mechanisms have been explained to account for telomerase elevation in chronic periodontitis .This study helps us understand the role of telomerase in the pathogenesis of periodontal disease. It could be concluded that telomerase could be used as a marker to assess the severity of inflammation in chronic periodontitis.

Efectos del tratamiento periodontal sobre los marcadores de inflamación sistémica en pacientes con riesgo de enfermedad cardiaca coronaria: Estudio piloto / Effects of periodontal therapy on markers of systemic inflammation in patients with coronary heart disease risk

Background- Studies investigating effects of periodontal treatment (PT) on markers of inflammation in healthy subjects show conflicting results. Few studies have investigated the effects ofPT among subjects with coronary heart disease (CHD) risk factors. Aim: To report the results of a pilot prospective study on the effects of periodontal treatment on markers of inflammation among subjects with CHD risk factors. Material and methods: Seventy three patients aged 53±6 years (25 percent males) with chronic periodontitis, dyslipidemia and other CHD risk factors were subjected to PT consisting on root planning and oral metronidazol and amoxicillin for 7 days. Periodontal clinical parameters, serum C-reactive protein (CRP), fibrinogen levels and erythrocyte sedimentation rate (ESR) were assessed before and at 6 weeks añerPT. Polymorphisms at the ILlA-889 andIL1B+3954genes were also genotyped. Results: After the treatment period, CRP levels significantly increased from 3.6±3.7 mg/ L to 5.4±5.7 mg/L (p =0.001). No significant changes were observed in fibrinogen levels and ESR. Higher post-treatment CRP levels were significantly associated with the composite polymorphic genotype at the ILlA-889 and IL1B+3954 genes (p =0.0001), and extensive periodontitis (p =0.005). Moderate alcohol consumption appeared as a protective factor for CRP elevation (p =0.029). Conclusions: The increase of the CRP levels after PT in patients with CVD risk factors appeared associated with IL-1 gene polymorphisms and extensive periodontitis.

Analysis of the association between interleukin-1beta (+3954) gene polymorphism and chronic periodontitis in a sample of the south Indian population.

AIM: The aim of this study was to determine the association between IL-1B (+3954) gene polymorphism and chronic periodontitis in a sample of the south Indian population. SETTINGS AND DESIGN: This study employed a cross-sectional design involving individuals from the state of Tamil Nadu in the southern part of India. MATERIALS AND METHODS: Genomic DNA was obtained from the white blood cells of 30 patients with chronic periodontitis (18 males and 12 females) and 31 healthy controls (20 males and 11 females). The age of the subjects ranged from 30 to 55 years old and all were non smokers. DNA was amplified using the polymerase chain reaction (PCR) with specific primers flanking the locus +3954 of IL-1beta gene and analyzed by 3% agarose gel electrophoresis. STATISTICAL ANALYSIS: A Chi-square test was used to determine the genotype distribution between the groups and the relative risk was estimated with a 95% confidence interval. RESULTS AND CONCLUSION: The chronic periodontitis group displayed a higher percentage of T allele, even though it was not statistically significant. The relative risk analysis between genotypes showed that the risk was higher for the CT genotype compared with the CC genotype and the risk was significant. In conclusion, our data suggested that there was no significant association between IL-1beta (+3954) gene polymorphism and chronic periodontitis in the south Indian population.

Microbiological composition associated with vitamin D receptor gene polymorphism in chronic periodontitis

The aim of this cross-sectional study was to examine the relationship between the composition of the subgingival microbiota and the vitamin D receptor (VDR) gene polymorphism in Brazilian adults with chronic periodontitis. The clinical parameters of probing depth, clinical attachment level, bleeding on probing, plaque accumulation and suppuration were measured in 60 Caucasian adults who were divided into two groups: 30 healthy individuals (control) and 30 with chronic periodontitis (ChP). Subgingival plaque samples were collected from 6 sites per subject and analyzed for 38 bacterial species using the Checkerboard DNA-DNA Hybridization. DNA was obtained from the subjects' epithelial cells by scraping the buccal mucosa and using a mouthwash containing 3 percent of glucose. Polymorphism in the VDR gene was analyzed by the polymerase chain reaction (PCR), followed by Taql digestion (RFLP). The healthy subjects presented significantly lower levels (0.3 × 10(7) ± 0.7 × 10(7)) of total microbial counts in comparison with subjects with chronic periodontitis (4.5 × 10(7) ± 2.9 × 10(7)). Regarding the occurrence of VDR polymorphism, it was observed that the Tt genotype was more prevalent in the Periodontitis group (60 percent) than in the Healthy group (30 percent), while the prevalences of the TT genotype were 23.3 percent and 53.3 percent, respectively (Chi-square test, p < 0.05). No difference was found in the composition of subgingival microbiota among the VDR genotypes evaluated for the Healthy and Periodontitis groups. In conclusion, the Tt genotype was associated with periodontal disease; however, no association with the subgingival microbiota was observed.

Lack of association between the TNF-α -308 (G/A) genetic polymorphism and periodontal disease in Brazilians

This study evaluated the frequency of the tumor necrosis factor-alpha (TNF-α) -308 G/A polymorphism in Brazilians with periodontal health (PH = 51), chronic periodontitis (CP = 74) and generalized aggressive periodontitis (GAgP = 38). Human DNA was obtained from mouthwash samples and TNF-α genotyping was performed by PCR and RFLP analyses. Differences in clinical and genetic parameters among groups were sought by Kruskal-Wallis, χ² and Fisher's exact tests. The allele -308G was detected in 91.7 percent, whereas the allele -308A was found in 35.4 percent of all subjects. No significant differences were observed in the frequency of these alleles (χ² = 2.610, p > 0.05) and the genotypes G/G, G/A, and A/A (χ² = 2.547, p = 0.636) among groups. The data suggest that the TNF-α -308 G/A polymorphism is not associated with periodontitis in this Brazilian population.