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.

Awareness of the association between periodontal disease and pre-term births among general dentists, general medical practitioners and gynecologists.

In the recent decades, periodontal disease has been identified as a risk factor for pre-term deliveries. Hence, it is important to evaluate the awareness of health-care providers of the association between periodontal diseases and pre-term birth. A self-administered questionnaire was distributed to random samples representing general medical practitioners (GMPs), general dental practitioners (GDPs) and Gynecologists for this study. A knowledge score was calculated for correct answers to 11 survey questions related to oral health effects during pregnancy and compared among the three groups. In this study, 133 physicians, 135 dentists and 100 Gynecologists completed the questionnaire. More GDPs (67.4%) than GMPs (56.4%) and Gynecologists (63%) reported there was an association between periodontal disease and pre-term low birth weight. Efforts to increase this awareness may prove valuable in improving preventive care during pregnancy.

Effect of smoking on neutrophil apoptosis in chronic periodontitis: An immunohistochemical study.

Context: Periodontal disease is caused by chronic infection inducing an inflammatory reaction leading to breakdown of tooth-supporting tissues. There are various risk factors for the disease, and smoking is one of them. Apoptosis plays a critical role in the regulation of inflammation and host immune response which helps in tissue homeostasis, and a disturbance in this is often associated with disease. The imbalance between the apoptosis and proliferation in the periodontal tissue results in periodontal disease. Neutrophils play an important role in the defense mechanism and are the most abundant immune cells in gingival inflammatory infiltrate in patients suffering from periodontal disease. Neutrophil disorders are associated with rapid destruction of periodontal tissues. Aim: To study the influence of smoking on apoptosis of neutrophils by quantifying them in the gingival connective tissue of smoking and nonsmoking subjects suffering from chronic periodontitis. Materials and Methods: Thirty gingival biopsies were harvested from 15 smoking and 15 nonsmoking subjects who suffered from chronic periodontitis. The apoptosis of neutrophils was assessed and quantified using p53 monoclonal mouse antihuman antibody. Statistical Analysis Used: Chi-square/Fisher'sexact test was used to find the significance of study parameters on a categorical scale between the two groups. Results: Neutrophil apoptosis was significantly more in the group of nonsmokers. There was no statistical difference between plaque and bleeding index, but there was a significant increase in clinical attachment loss among smokers. Conclusions: The study reveals that smoking plays a significant role in the inhibition of neutrophil apoptosis, thereby contributing to the destruction of periodontal tissues in periodontitis.

Association between gingival crevicular fluid prostaglandin E 2 level and preterm low birth weight.

Background: Periodontal infections, which serve as a reservoir of inflammatory mediators such prostaglandin E 2 (PGE 2 ), may pose a threat to the fetal-placental unit and cause preterm delivery. Aim: This study was conducted to estimate the PGE 2 levels in gingival crevicular fluid (GCF) and to explore the association between GCF-PGE 2 levels and preterm low birth weight (PLBW). Materials and Methods: Twenty-two pregnant patients were selected for the study. GCF samples were collected from these patients before delivery and again at 1 month after delivery. PGE 2 level was estimated using a commercially available ELISA kit (Neogen™). Results: The mean GCF-PGE 2 level was 5.8 ng/ml before parturition and 5.5 ng/ml after parturition, but the difference was not statistically significant. There was negative correlation between PGE 2 levels and gestational age at birth. Conclusion: The study provides weak evidence that there is correlation between GCF-PGE 2 levels and birth outcome. Further clinical trials with large samples are required to confirm the association between GCF-PGE 2 levels and PLBW.

Effect of gene polymorphisms on periodontal diseases.

Periodontal diseases are inflammatory diseases of supporting structures of the tooth. It results in the destruction of the supporting structures and most of the destructive processes involved are host derived. The processes leading to destruction and regeneration of the destroyed tissues are of great interest to both researchers and clinicians. The selective susceptibility of subjects for periodontitis has remained an enigma and wide varieties of risk factors have been implicated for the manifestation and progression of periodontitis. Genetic factors have been a new addition to the list of risk factors for periodontal diseases. With the availability of human genome sequence and the knowledge of the complement of the genes, it should be possible to identify the metabolic pathways involved in periodontal destruction and regeneration. Most forms of periodontitis represent a life-long account of interactions between the genome, behaviour, and environment. The current practical utility of genetic knowledge in periodontitis is limited. The information contained within the human genome can potentially lead to a better understanding of the control mechanisms modulating the production of inflammatory mediators as well as provides potential therapeutic targets for periodontal disease. Allelic variants at multiple gene loci probably influence periodontitis susceptibility.