Barbara Hrdličková

Association of Toll-like receptor 9 haplotypes with chronic periodontitis in Czech population.

AIM Toll-like receptors (TLRs) belong to the pattern recognition receptors family of signal molecules that recognize conserved microbial structures. The aim of this study was to analyse polymorphisms in the TLR genes and their association with chronic periodontitis (CP). MATERIAL AND METHODS Two polymorphisms (2408G/A, i.e. Arg753Gln and -16934A/T) in TLR-2 and three variants (-1486C/T, -1237C/T and+2848A/G) in the TLR-9 genes were studied in 222 patients with CP and 259 unrelated controls. All polymorphisms were detected using the polymerase chain reaction-restriction fragment length polymorphism methods. Subgingival bacterial colonization was investigated by the VariOr Dento test. RESULTS No significant differences were found in allele and genotype frequencies of all polymorphisms between patients and controls. Nevertheless, complex analysis revealed differences in TLR9 haplotype frequencies between both groups (p=0.001). Specifically, the haplotype T(-1486)/T(-1237)/A(2848) was significantly more frequent (9.6%versus 2.8%, p<0.000001) and the haplotype T(-1486)/T(-1237)/G (2848) of the TLR9 gene was less frequent (35.9%versus 43.3%, p=0.01) in patients than in controls. However, no significant relationships between periodontal pathogens, TLR polymorphisms and CP were found. CONCLUSIONS In conclusion, although no significant role of the TLR2 gene in periodontitis was found, our results indicate that TLR9 haplotypes may be associated with susceptibility to CP.

Matrix metalloproteinase 8 (MMP8) gene polymorphisms in chronic periodontitis

OBJECTIVE Previous studies have suggested that some functional polymorphisms in the matrix metalloproteinase (MMPs) genes are associated with the risk of periodontal disease. However, to date no study has investigated MMP8 gene variants in relation to chronic periodontitis (CP). The aim of this study was to analyse polymorphisms in the MMP8 gene and their associations with microbial composition and clinical manifestation of CP. DESIGN A total of 619 unrelated Czech subjects were included in the present study. Two polymorphisms [-799C/T (rs11225395) and +17C/G (rs2155052)] in the MMP8 gene were studied in 341 patients with CP and 278 unrelated non-periodontitis controls. Both polymorphisms were detected using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods. Subgingival bacterial colonisation (occurrence of bacteria in subgingival pockets and gingival sulci) was investigated by a commercial semiquantitative kit in selected subjects (N=169). RESULTS Our results showed no differences in the allele and genotype frequencies of the MMP8 -799C/T and +17C/G polymorphisms between patients with CP and controls (p>0.05). Nevertheless, the haplotype T(-799)/C(+17) was significantly more frequent in patients with CP than in controls [43.7% vs. 37.6%, p<0.05, OR=1.273 (95% CI: 1.013-1.601)]. Despite significant differences determined in the occurrence of periodontal bacteria between patients with CP and non-periodontitis controls (from p<0.000001 to p<0.05), no significant relationships between periodontal pathogens, MMP8 polymorphisms and CP were found (p>0.05). CONCLUSIONS Although none of the investigated SNPs in the MMP8 gene was individually associated with periodontitis, specific haplotype showed association with clinical manifestation of chronic periodontitis in a Czech population.

Relationship between the 17q21 locus and adult asthma in a Czech population.

Several whole-genome association studies have shown a significant link between childhood asthma and the 17q12 chromosome region. We selected tagging single nucleotide polymorphisms (SNPs) in the ORMDL3 gene (17q12) to investigate gene variability in relation to adult allergic asthma and asthma/atopy traits in a Czech Caucasian population of adults. We conducted a case-control association study comprising 668 unrelated subjects (337 asthmatic and 331 control subjects). Four selected SNPs (rs17608925, rs12603332, rs8076131, and rs3169572) were genotyped using the TaqMan SNP Genotyping Assays. The single locus analysis showed only a borderline association between rs3169572 variant and asthma (p = 0.030, p(corr) > 0.05). However, seven different haplotypes were identified; among them, the TTAA haplotype was marginally associated with asthma (p = 0.045, p(corr) > 0.05) and TCAG haplotype was significantly associated with asthma in males (p = 0.009, p(corr) < 0.05, odds ratio = 1.48, 95% confidence interval = 1.10-2.00). In addition, associations between the ORMDL3 genotypes and the total IgE level (p = 0.05, p(corr) > 0.05) and hypersensitivity to the pollen (p = 0.007, p(corr) < 0.05) were established. However, no relationship between ORMDL3 SNPs and the pulmonary functions was found (p > 0.05). These findings suggest that the genetic variability in the 17q21 region may be one of the risk factors also for adult asthma, especially in male individuals.

Haplotypes of the IL-1 gene cluster are associated with gastroesophageal reflux disease and Barrett’s esophagus

OBJECTIVES Gastroesophageal reflux (GERD) is a one of the major public health problem that can lead to reflux esophagitis (RE), Barretts esophagus (BE), and esophageal adenocarcinoma (EAC). The aim of our study was to determine the impact of IL-1 gene polymorphisms on the development of GERD, RE and BE. METHODS Three hundred and thirty-three Czech patients with gastroesophageal reflux and 165 healthy controls were included in this case-control study. Four polymorphisms in the genes of the IL-1 cluster [IL-1A(-889C/T), IL-1B(-511C/T), IL-1B(+3953C/T), and IL-1RN(VNTR)] were analyzed. RESULTS Significant differences were found in IL-1RN 1/2 genotype between patients with GERD/RE and controls and in IL-1B+3953 T allele between patients with BE and healthy subjects. In addition, complex analysis revealed differences in IL-1 haplotype frequencies between the groups. Specifically, the haplotype TCCL was significantly more frequent (p = 0.016) in GERD patients than in controls and the haplotype CCCL more frequent (p = 0.008) in RE patients than in controls. However, in patients with BE, frequency of haplotype TCTL was lower (p = 0.05) and haplotypes CTCL and TCCL were higher (p = 0.03 and p = 0.02) in comparison with the controls. CONCLUSIONS Our results suggest that IL-1 haplotypes may be associated with susceptibility to GERD, RE and BE.

Interferon-γ +874A/T polymorphism in relation to generalized chronic periodontitis and the presence of periodontopathic bacteria

BACKGROUND Interferon gamma (IFN-γ) is one of the key regulatory cytokines that has a significant effect on immune responses. It may be important in the chronic inflammatory diseases such as periodontitis in which increased IFN-γ levels were found. The aim of this study was to analyze +874A/T polymorphism in the IFN-γ gene and its associations with the presence of periodontopathic bacteria and susceptibility to generalized chronic periodontitis (CP). METHODS A total of 498 unrelated Czech white subjects were included in the present study. Genomic DNA was obtained from the peripheral blood of 244 patients with CP and 254 healthy subjects. The IFN-γ +874A/T polymorphism was determined by amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). Subgingival bacterial colonization (A. actinomycetemcomitans, P. gingivalis, P. intermedia, T. forsythia, T. denticola, P. micros, F. nucleatum in subgingival pockets) was investigated by the DNA-microarray based periodontal pathogen detection kit in a subgroup of subjects (N=110). RESULTS Our results showed no differences in the allele and genotype frequencies of the IFN-γ +874A/T polymorphism between patients with CP and controls (P>0.05). Although we found significant differences in the occurrence of periodontal bacteria between patients with CP and healthy controls (from P<0.00001 to P<0.05), no significant association between IFN-γ +874A/T polymorphism and periodontal pathogens was observed in any group. CONCLUSIONS In conclusion, these findings indicate that putative functional variant in the IFN-γ is not associated with susceptibility to chronic periodontitis or microbial composition in the Czech population.

Association of Single Nucleotide Polymorphisms in the Eosinophil Peroxidase Gene with Allergic Rhinitis in the Czech Population

Background: Eosinophil peroxidase (EPO) gene codes a cationic protein released from the specific granules of activated eosinophils. Eosinophil granulocytes play a central role in the protection of organisms against parasites. They are also regarded as key effector cells in allergic inflammation. We attempted to determine the polymorphisms in the EPO gene typical for the Czech population and to analyze their associations with allergic rhinitis and its intermediary phenotypes. Methods: We sequenced all 12 exons of the EPO gene, and selected variants were subsequently analyzed by polymerase chain reaction and restriction fragment length polymorphism methods in a case-control study comprising a total of 613 subjects (319 controls and 294 patients with rhinitis). Results: In total, 5 polymorphisms (–1710T/C and –1710T/CTCC, 2649T/C, 3097A/G and 3979A/G) were found in the EPO gene. Polymorphisms 2649T/C and 3097A/G were in complete linkage disequilibrium (D′ = 1 for both groups), and both of them were in a strong disequilibrium with the 3979A/G variant (D′ = 0.801 for controls, D′ = 0.848 for rhinitics). Consequently, these 3 polymorphisms were studied in association with the allergic phenotype. In a single locus analysis, only 3979A/G single nucleotide polymorphism was marginally significantly associated with rhinitis (p = 0.030, pcorr > 0.05). This polymorphism also showed a marginal association with total serum IgE levels (loge IgE, mean ± SD: genotypes GG = 2.60 ± 1.20; GA = 2.47 ± 1.88; AA = 2.38 ± 1.49; p < 0.05). Furthermore, significant differences in haplotype frequencies between patients and healthy subjects were observed (p < 0.05). Conclusions: Our study supports the hypothesis that genetic variability in the EPO gene may contribute to the susceptibility to allergic rhinitis (or related phenotypes) in the Czech population.