L. Izakovicova Holla

Polymorphism 4G/5G in the plasminogen activator inhibitor‐1 (PAI‐1) gene is associated with IgE‐mediated allergic diseases and asthma in the Czech population

Background: Plasminogen activator inhibitor type 1 (PAI‐1) is a glycoprotein that belongs to the serine protease inhibitor superfamily and has an essential role in tissue remodeling after inflammation. Recently, a single base pair deletion/insertion (4G/5G) polymorphism of the PAI‐1 gene has been associated with an increased risk of asthma in nuclear families from the UK.

TGF-beta1 gene polymorphisms

Transforming growth factor beta (TGF-beta) is a pleiotropic cytokine with significant anti-inflammatory and immunosuppressive properties. The single base pair polymorphism located at -509 (C/T) in the promoter region of the TGF-beta1 gene was previously shown to be associated with elevated total serum IgE levels. We tested the hypothesis that polymorphic alleles of the TGF-beta1 gene are associated with allergies and asthma.

Genotype association of C(-735)T polymorphism in matrix metalloproteinase 2 gene with G(8002)A endothelin 1 gene with plaque psoriasis

Background: Excessive angiogenesis is one of the characteristic features of psoriasis. Objective: To determine the possible genetic background of neo-angiogenesis in plaque psoriasis, frequent polymorphisms in matrix metalloproteinase 2 (MMP-2) and endothelin 1 (ET-1) genes were studied. Methods: The case group (n = 119) included patients with plaque psoriasis, aged 44 ± 15 years. The age of onset of psoriasis was 27 ± 11 years. The control group (n = 184) consisted of healthy subjects without any individual history of psoriasis, aged 37 ± 15 years. C(-735)T MMP-2 and G(8002)A ET-1 polymorphisms were determined by PCR reaction with subsequent restriction analyses. Results: A significant difference in genotype distribution of C(-735)T MMP-2 between psoriatic and control patients was found (pcorr = 0.008). Two associated genotypes (CCGG and CTGG) of the two polymorphisms were significantly less frequent in psoriatic patients (pcorr = 0.03 and pcorr = 0.008, respectively). Conclusion: The results seem to reflect a different susceptibility of MMP-2 as well as of some associated MMP-2 and ET-1 genotypes to psoriasis.

Gene polymorphisms (G82S, 1704G/T, 2184A/G and 2245G/A) of the receptor of advanced glycation end products (RAGE) in plaque psoriasis.

Abstract. Having in mind the relationships among oxidative stress, psoriasis and common disorders, the association between polymorphisms in the gene encoding the receptor for advanced glycation end products (RAGE) and plaque psoriasis, including patients with a personal history of diabetes mellitus, cardiovascular disorders, cancer and allergy, was investigated. The allele frequencies and genotype distribution combinations of the four polymorphisms in the RAGE gene (6p21.3, G82S, 1704G/T, 2184A/G and 2245A/G) were compared in a case-control study of 272 subjects (130 patients with plaque psoriasis and 142 healthy control subjects of comparable age and sex distribution). The polymerase chain reaction with subsequent restriction analysis was used for detection of genotype variants. There was a significantly higher frequency of the 2184G allele of the 2184A/G RAGE polymorphism in psoriatic patients than in the control subjects (odds ratio 2.18, 95% CI 1.32–3.59, P=0.001). The 2184G allele occurred more often in psoriatic patients with a negative history of cardiovascular diseases (odds ratio 2.38, 95% CI 1.35–4.18, P=0.001, Pcorr=0.004), in those with a negative history of diabetes mellitus (odds ratio 2.05, 95% CI 0.1.22–3.45, P=0.004, Pcorr=0.012) and in those with a negative history of cancer (odds ratio 1.97, 95% CI 1.17–3.31, P=0.007, Pcorr=0.014) compared with the corresponding control subjects. We conclude that the 2184G allele of the RAGE gene is a significant risk factor for plaque psoriasis. The risk is associated with the non-presence of some common, especially cardiovascular, diseases in psoriatic patients.

IL1 gene polymorphisms in relation to external apical root resorption concurrent with orthodontia

OBJECTIVE External apical root resorption (EARR) is permanent shortening of the end of the tooth root. It is a common clinical complication of orthodontic treatment. Polymorphisms in the interleukin 1 (IL1) gene cluster have been related to an increased EARR risk. The aim of this study was to analyze possible associations of IL1 gene variants with EARR in Czech population. SUBJECTS AND METHODS In this case-control study, 32 patients with EARR (age 15.0 ± 4.1 years) and 74 controls (age 15.2 ± 5.3 years) were genotyped using PCR-based methods for IL1A (-889C/T), IL1B (+3953C/T), and IL1RN [IL1 receptor antagonist, variable number tandem repeat (VNTR)] gene polymorphisms. RESULTS While no statistical significant differences in the IL1A and IL1B genotype, allele and reconstructed IL1 haplotype frequencies between patients with EARR and controls were found, marginally significant differences were observed in the frequencies of IL1RN variant (P = 0.05 for *22 genotype and P = 0.06 for a short (2) allele). In addition, significant associations between IL1RN*12, *22 genotypes and the short (2) allele and EARR were identified in the subgroup of girls (P = 0.04 and P = 0.02, P = 0.02). CONCLUSIONS Although no significant role of IL1A (-889C/T) and IL1B (+3953C/T) variants in EARR was confirmed, IL1RN VNTR may be associated with EARR, especially in girls.

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.

Interleukin-18 in asthma and other allergies

The prevalence of atopic diseases such as bronchial asthma has increased over the last decades, making allergies a very serious public health problem. Allergic predisposition is regarded as a multifactorial condition whose onset and severity are influenced by both genetic and environmental factors [1]. The search for genes that contribute to the aetiology of allergic asthma has included several complete screens of the human genome and a number of association and linkage studies. One of the regions most consistently linked to asthma and/or its intermediary phenotypes, such as high total serum IgE levels and eosinophilia, is a region on chromosome 11q, which contains many loci that, on the basis of their functions, are candidate asthma-susceptibility genes [2, 3]. The study by Higa et al. [4] in this issue of Clinical and Experimental Allergy is a further example of such association and extends our present knowledge by investigating IL-18 gene polymorphisms in atopic asthma. Our understanding of the immunological processes leading to allergic asthma has improved greatly in recent years. The paradigm of antagonism between T helper (Th) lymphocyte subset and their cytokines, first described in the early 1990s [5], has resulted in the widely accepted hypothesis that atopy and asthma are ‘Th2 diseases’. In its simplest terms this hypothesis argues that a relative increase in Th2 responses in combination with a decrease in Th2 responses drives the allergic phenotype [6]. IL-18 belongs among those several factors, which are known to influence the balance of Th1/Th2 immune response. Interleukin-18, a member of the IL-1 family, was originally described as IFN-g-inducing factor (IGIF) and it is generally considered a Th1-type response [7]. IL-18, in collaboration with IL-12, strongly induces type I cytokines such as INF-g leading to the production of molecules destructive to tissues, including nitric oxide, reactive oxygen species and TNF-a. Interestingly, IL-18 is also capable of generating a Th2 cell response under certain conditions, as measured by the production of Th2 cytokines and initiation of allergic manifestation [8]. However, recent reports indicate that IL-18 can directly stimulate IL-4 production and histamine release from basophiles [9], enhance IL-4 and IL-13 production from both NK and T cells in synergy with IL-2 [10, 11], and induce IgE expression by B cells [12]. In addition, IL-18 has also been shown to indirectly induce B cell isotype switching to IgE and, together with its effects on Th2 cytokine production, has been demonstrated to play a role in allergic inflammation [13]. However, these reports demonstrated a pleiotropic role for IL-18 in Th1 and Th2 responses dependent on the cytokine milieu [14]. The possible functions of IL-18 at different levels of the allergic mechanisms were mainly analysed by in vitro and mice studies. Wild et al. [13] found that the intranasal application of IL-18 together with ragweed increased the production of ragweed-specific IgE and IgG1 in serum and production of BAL eosinophilia in a mouse model of allergic asthma, effects consistent with the support of a Th2 phenotype. Furthermore, intrapulmonary administration of IL-18 in mice was associated with increased eotaxin levels and eosinophilic recruitment in the airways [15]. Thus, IL-18 seems to drive the allergic inflammation by its ability to stimulate eosinophilia and IgE production in mice models. The IL-18-induced IgE accumulation in vivo was completely dependent on the IL-4/IL-4R system but not on IL-13 [12, 13]. IL-18 is synthesized as an inactive precursor (pro-IL-18), a 24-kDa polypeptide, and like IL-1b it is cleaved by the IL-1bconverting enzyme (ICE, also known as cysteine proteinase caspase-1) in a biologically active 18-kDa monomer [16]. A recent report suggests proteinase 3 as a possible alternative enzyme necessary for IL-18 processing [17]. Pro-IL-18 expression is widespread, including monocyte/macrophages, dendritic cells, Kupffer cells, keratinocytes, Langerhans cells, B cells and airway epithelial cells. IL-18 acts through the membrane receptors IL-18Ra and IL-184Rb to transduce the signal into the nucleus. The genes for IL-18 and its receptor map to different chromosomes. The human IL-18 gene is located on chromosome 11q22.2-22.3 [18], and it is composed of six exons and five introns spanning about 19.5 kb. Several studies have demonstrated that increased IL-18 expression and serum levels are associated with allergic diseases. Tanaka et al. [19] recently described that serum IL18 levels were elevated in patients with acute asthma and that these levels quickly decreased after treatment. Also Wong et al. [20] demonstrated increased IL-18 levels in patients with allergic asthma. Furthermore, Yoshizawa et al. [21] reported that significantly higher serum IL-18 levels were found in patients with atopic dermatitis than in control subjects, and that serum IL-18 levels were correlated with disease severity and with the number of eosinophils in peripheral blood. However, a recent report has demonstrated significantly higher concentrations of IL-18 in nasal secretion of persistent allergic rhinitis patients compared to healthy controls, with a slow increase during the course of the pollen season [22]. In addition, Tanaka et al. [23] indicated that NC/Nga mice that Clin Exp Allergy 2003; 33:1023–1025

MCP-1 and CCR2 gene polymorphisms in Czech patients with allergic disorders

Several lines of evidence suggest that chemokines play an important role in asthma and allergy. We analysed polymorphisms at –2518A/G and –2076A/T of MCP‐1 and V64I of CCR2 gene in healthy subjects (n = 306) and allergic patients (n = 332). Allele and genotype frequencies did not differ significantly between groups. Nevertheless, MCP‐1 variants were associated with allergen sensitization. The results suggest that MCP‐1, but not CCR2 gene variants, may participate in the pathogenesis of allergic phenotypes at least in the Caucasian population.

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.

Lack of Association between Lactotransferrin Polymorphism and Dental Caries

Objective: Dental caries is a complex, multifactorial disease and one of the most common illnesses worldwide. Its etiology is related to microbial, dietary and host factors. Recent evidence suggests a role of lactotransferrin (LTF) in caries. The purpose of this study was to determine the association between LTF gene polymorphism and dental caries. Methods: In this case-control study, 637 unrelated children, aged 11-13 years, were enrolled. The subjects were divided into two groups, i.e. caries-free (decayed/missing/filled teeth = 0) and caries-affected children (decayed/missing/filled teeth ≥ 1). The LTF rs1126478 (140A/G in exon 2, Lys/Arg) genotypes were determined by PCR with restriction analysis using the EarI enzyme. Results: Of 637 children, 155 (24.3%) were caries free. There were no statistically significant differences between caries levels and allele or genotype distributions in the total cohort. When the caries-affected group (n = 482) was stratified into low (decayed/missing/filled teeth = 1), moderate (2 ≤ decayed/missing/filled teeth ≤ 3) and high (decayed/missing/filled teeth ≥ 4) caries experience, allele and genotype frequencies were similar among all subgroups. Conclusions: The LTF 140A/G (exon 2, Lys/Arg) polymorphism was not associated with the susceptibility to or severity of dental caries in the Czech population.