Analysis of the Association of IL-1A, IL-1B and IL-1RN Polymorphisms with Peri-implantitis in a Portuguese Population.

PURPOSE: The aim of this study was to investigate whether genetic variations in cytokine genes involved in the pathogenesis of peri-implantitis, could be associated with its occurrence, an issue that remains controversial and may vary according to the population evaluated. MATERIAL AND METHODS: A cross-sectional analytical study was carried out on 102 Portuguese Caucasian individuals divided into two groups: 43 individuals with peri-implantitis and 59 individuals with peri-implant health. Samples from the buccal mucosa were obtained and genetic analysis was performed using the real-time polymerase chain reaction (PCR) technique for IL-1A and IL-1B and using PCR and restriction fragment length polymorphism analysis for IL-1RN. RESULTS: The IL-1A -889 C/T polymorphism showed a higher prevalence of the less common allele (T allele) in cases of peri-implantitis than in healthy cases (27.9% vs 16.9%, respectively), but without statistical significance (p = 0.060). For the IL-1B +3954 C/T and IL-1RN (variable number of tandem repeats) polymorphisms, the analysis revealed that the allele and genotype frequencies did not differ significantly between groups. There was a significant association between a history of periodontitis and peri-implantitis (p = 0.020). CONCLUSIONS: The genetic polymorphisms evaluated had no influence on the occurrence of periimplantitis in the population studied. Further research into genetic variations in different populations is needed to elucidate the role of genetic factors in the onset and progression of periimplant disease.

The Influence of Genetic Polymorphisms on the Expression of Interleukin-1beta, Prostaglandin E2 and Tumor Necrosis Factor Alpha in Peri-Implant Crevicular Fluid: A Cross-Sectional Study.

The aim of this study was to evaluate the possible relationships between polymorphisms in the interleukin-1 (IL-1) A, IL-1B, and IL-1RN genes and concentrations of the inflammatory mediators IL-1ß, tumor necrosis factor-alpha (TNF-α), and prostaglandin E2 (PGE2) in peri-implant crevicular fluid (PICF). A cross-sectional analytical study was conducted on 51 patients with dental implants. Samples from the buccal mucosa were obtained, and genetic analysis was performed using the real-time polymerase chain reaction (PCR) technique for IL-1A and IL-1B and PCR and restriction fragment length polymorphism analysis for IL-1RN. For the biochemical analysis, the concentrations of IL-1ß and TNF-α were analyzed using multiplexed fluorescent sphere immunoassays, and PGE2 by enzyme-linked immunosorbent assay. In patients with detected IL-1RN polymorphism, there was an increase in the concentration of the three mediators with statistically significant differences in the mean values of TNF-α and PGE2, regardless of peri-implant health status (p = 0.002 and p = 0.049, respectively). The concentrations of all three mediators were positively and significantly correlated (IL-1ß vs. TNF-α Rho = 0.480, p < 0.001; IL-1ß vs. PGE2 Rho = 0.382, p = 0.006; and TNF-α vs. PGE2 Rho = 0.528, p < 0.001). We can conclude that the IL-1RN polymorphism exerts an influence on the PICF immune response, which may explain the influence of this genetic polymorphism on the occurrence of peri-implantitis.

Association between IL-1A and IL-1B gene polymorphisms with peri-implantitis in a Portuguese population-a pilot study.

Background: Scientific evidence indicates that biological complications in dental implants tend to be concentrated in a subset of individuals, which seems to imply that the host response may play a determining role in implant success. Over the last few decades, several polymorphisms have been studied. Polymorphisms in the interleukin (IL) 1 gene cluster have been associated with periodontitis. There are some similar features in the sequence of immunopathological events in peri-implant and periodontal infections. We aimed to investigate if individuals carrying the genetic single nucleotide polymorphism (SNP) in the IL-1A (rs1800587) and IL-1B (rs1143634) genes are more susceptible to develop peri-implantitis. Methods: A cross-sectional analytic pilot study was conducted in 20 Caucasian Portuguese subjects divided into two groups: 10 subjects with peri-implantitis and 10 subjects with peri-implant health (control group). Samples containing cells from the buccal mucosa were stored at -20 °C and later submitted to the DNA extraction process. Genetic analysis was performed using the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. Data were analyzed by using descriptive and inferential statistical methodologies. Results: For the IL-1A (-889) gene polymorphism, it was observed that the mutated allele was present in a higher percentage in the peri-implantitis group compared to the control group (30% vs 15% respectively, Fisher's exact test, p = 0.45). For the IL-1B (+3954) gene polymorphism, it was also observed that the altered allele was present in a higher percentage in the disease group compared to the control group (35% vs 10% respectively, Fisher's exact test, p = 0.13). The positive genotype (at least one allele with nucleotide sequence changed in both genes) was detected in six patients, five belonging to the disease group and one to the health group. Conclusions: Regarding IL-1 gene polymorphisms, there was no statistically significant difference between the health and disease group, however a trend should be highlighted, showing a potential link between the IL-1 genotype and peri-implantitis. More studies are needed to clarify the role of genetic polymorphisms in the development of peri-implantitis.

The role of 5-HTTLPR polymorphism in alcohol craving experience.

The way in which genetic risk mediates the development of craving in alcohol dependence is still relatively unknown. The authors sought to clarify the extent to which alcohol craving could be predicted by a relevant polymorphism in the promoter region of the gene encoding the 5-HT transporter (5-HTTLPR). A sample of 101 alcohol-dependent patients admitted for alcohol treatment was recruited for the study. At admission, blood samples were taken for DNA extraction and alcohol craving information was collected with a composite measure. The 5-HTT polymorphism was genotyped. Alcohol dependent patients who were homozygous for the long allele (LL) self-reported higher scores of craving when compared to patients that were homozygous for the short allele (SS). However, the results were not statistically significant. Also, no significant associations were observed between the 5-HTTLPR genotype and other drinking variables. No 5-HTTLPR genotype effects were observed on alcohol craving experience in a sample of alcohol-dependent outpatients.