Paulina Sobkowiak

Are genes associated with energy metabolism important in asthma and BMI

Objective. Increased serum leptin levels have been observed in asthmatic patients. Leptin, via proliferation and activation of Th2 cells, may induce inflammation in asthma. It has also been demonstrated that leptin mRNA expression and protein levels increase in response to inflammatory stimuli. We hypothesized that polymorphisms in the leptin receptor, leptin and ghrelin genes, may affect their expression and, therefore, be responsible for altered response to increased leptin levels observed in asthma. To our knowledge, there were no studies on a potential role of LEPR, LEP, and GHRL polymorphisms in asthma. Subjects and methods. We analyzed 129 pediatric patients with asthma and 114 healthy children from the control group ranging from 6 to 18 years of age. The diagnosis of allergic asthma was based on clinical symptoms, the lung function test, and the positive skin prick test and/or increased immunoglobulin E (IgE) levels. Polymorphisms were genotyped by the polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) method. Statistical analyses were performed with Statistica v.7.1 software (Statistica, StatSoft, Poland; available free at http://www.broad.mit.edu/mpg/haploview/index.php). Linkage disequilibrium analysis was performed with Haploview v.4.0. Results. We observed a statistically significant association of the 3′UTR A/G and the -2549A/G polymorphisms of the leptin gene with asthma. No association with asthma was observed for the K109R and the Q223R polymorphisms of the LEPR gene and the Met72Leu polymorphism of the ghrelin gene. In the analysis of body mass index (BMI) stratified by genotype, we found an association of the -2549A/G LEP, but not of LEPR and GHRL polymorphisms, with higher BMI values in asthmatic patients. We found suggestive evidence for linkage between the two polymorphisms of the LEPR gene (D′ = 0.84 CI: 0.71–0.92; r2 = 0.29) in linkage disequilibrium analysis: The GG haplotype was more frequent in the control healthy group (p = 0.057). No linkage disequilibrium was detected between LEP polymorphisms. Conclusions. Polymorphisms of the leptin gene may be associated with asthma and higher BMI in asthmatic patients. Polymorphisms of the LEPR and GHRL seem unlikely to be associated with asthma or BMI in our sample. The results of haplotype analysis for the LEPR gene may suggest a protective role of the GG haplotype against asthma; however, studies on larger groups are necessary to confirm the observed trend towards association.

Polymorphisms of two histamine-metabolizing enzymes genes and childhood allergic asthma: a case control study

BackgroundHistamine-metabolizing enzymes (N-methyltransferase and amiloride binding protein 1) are responsible for histamine degradation, a biogenic amine involved in allergic inflammation. Genetic variants of HNMT and ABP1 genes were found to be associated with altered enzyme activity. We hypothesized that alleles leading to decreased enzyme activity and, therefore, decreased inactivation of histamine may be responsible for altered susceptibility to asthma.MethodsThe aim of this study was to analyze polymorphisms within the HNMT and ABP1 genes in the group of 149 asthmatic children and in the group of 156 healthy children. The genetic analysis involved four polymorphisms of the HNMT gene: rs2071048 (-1637T/C), rs11569723 (-411C/T), rs1801105 (Thr105Ile = 314C/T) and rs1050891 (1097A/T) and rs1049793 (His645Asp) polymorphism for ABP1 gene. Genotyping was performed with use of PCR-RFLP. Statistical analysis was performed using Statistica software; linkage disequilibrium analysis was done with use of Haploview software.ResultsWe found an association of TT genotype and T allele of Thr105Ile polymorphism of HNMT gene with asthma. For other polymorphisms for HNMT and ABP1 genes, we have not observed relationship with asthma although the statistical power for some SNPs might not have been sufficient to detect an association. In linkage disequilibrium analysis, moderate linkage was found between -1637C/T and -411C/T polymorphisms of HNMT gene. However, no significant differences in haplotype frequencies were found between the group of the patients and the control group.ConclusionsOur results indicate modifying influence of histamine N-methyltransferase functional polymorphism on the risk of asthma. The other HNMT polymorphisms and ABP1 functional polymorphism seem unlikely to affect the risk of asthma.

Neurotrophin serum concentrations and polymorphisms of neurotrophins and their receptors in children with asthma

BACKGROUND In the recent years numerous studies have analysed the effects of neurotrophins on allergic inflammation in airway diseases reporting increased neurotrophin levels locally in the airways as well as in serum of asthmatic patients. We aimed to investigate if levels of neurotrophins in serum of asthmatic children are influenced by the genotype of functional variants within genes encoding analysed neurotrophins and their specific receptors. METHODS In the study we included 98 children diagnosed with asthma. Genotyping of 9 polymorphisms located in neurotrophins genes and their receptors genes was done with use of TaqMan SNP genotyping assays or PCR-RFLP. The serum levels of four neurotrophins (BDNF, NGF, NTF3, NTF4) were analysed during exacerbation of asthma symptoms with use of DuoSet ELISA Development Kit (R&D). RESULTS The two patients with the genetic variant A/A of NTRK1 (rs6334) showed significantly higher NGF serum concentrations (113.4 and 218.1 pg/mL) as compared to the mean NGF serum concentrations in the total group of patients (34.8 pg/mL). We also observed a significant epistatic interactions between variants of NGF rs6330 and NTRK1 rs6334 that influenced NGF serum level (P = 0.0004). Analysis of four neurotrophins serum levels in relation to different genotypes of analysed neurotrophins genes showed no significant differences among analysed asthmatic children. CONCLUSIONS Our results suggest that, among analysed neurotrophins, NGF serum levels may be influenced by the genotype of NTRK1 gene individually as well as in the interaction with NGF functional genetic variant suggesting their involvement in allergic inflammation in asthma. Serum levels of the other neurotrophins do not seem to be affected by the variants in the analysed genes.

Association of BDNF Gene Polymorphism With Asthma in Polish Children

Allergic asthma is associated with changes in neuronal control in the airways that modulate inflammation and airway hyperresponsiveness. The link between inflammation and neuronal dysfunction is provided mainly by neurotrophins, in particular Brain Derived Neurotrophic Factor (BDNF). In humans, significantly higher serum BDNF levels have been observed in asthmatic patients when compared with healthy subjects. BDNF levels are also significantly higher in untreated asthmatic patients in comparison to those treated with inhaled glucocorticoids and nonasthmatic controls. Allergic inflammation increases local BDNF production and its concentration correlates with clinical parameters of allergic airway dysfunction. The aim of this study was to analyze the possible association of BDNF gene polymorphism with susceptibility to asthma and disease severity. We analyzed 146 children diagnosed with asthma and 227 children from the control group. Genotyping of 4 BDNF polymorphisms (rs12273363, rs7124442, rs6265, and rs2030324) was done with use of PCR-RFLP and TaqMan SNP genotyping assay. Genetic association analysis was performed in Statistica. Linkage disequilibrium was determined with Haploview. Single marker analysis revealed a significant association of C allele of rs2030324 polymorphism with asthma susceptibility (P = 0.048). However, BDNF polymorphism was not associated with severe asthma. Strong linkage disequilibrium was observed between all of the BDNF polymorphisms analyzed grouped in one haplotype block. We found a significant association of TTGC haplotype with asthma (P = 0.025). Our results suggest that genetic variation in the BDNF gene may contribute to asthma susceptibility in case of rs2030324 polymorphism and TTGC haplotype, however it does not influence asthma severity.

Serum neurotrophin-3 and neurotrophin-4 levels are associated with asthma severity in children

To the Editors: Asthma is the most common chronic disease in childhood and is characterised by chronic airway inflammation, reversible airflow obstruction and hyperresponsiveness of the airways. Among the substantial pathophysiological aspects of asthma are neuroimmune interaction mechanisms; neurotrophins are mediators of the interactions providing links between immune, structural and neuronal cells. In recent years, several studies have analysed the effects of neurotrophins on allergic inflammation and airway diseases. Elevated brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF) and neurotrophin-3 (NT-3) levels have been found in bronchoalveolar lavage fluid (BALF) after allergen challenge in allergic asthmatic patients [1,2]. It has also been shown that asthmatic patients demonstrate elevated levels of neurotrophins (NGF and BDNF) in serum and locally in the airways [3,4], and that allergen provocation significantly increases neurotrophin levels in the airways [2]. Increased neurotrophin (BDNF) concentration also correlated with clinical parameters of allergic airway dysfunction, such as airflow limitation and airway hyperresponsiveness, in asthmatic patients [5], whereas its level is normalised after treatment with inhaled corticosteroids [4]. However, to our knowledge, only one study has investigated neurotrophin (BDNF) levels in a paediatric population of asthmatic patients [6]. We hypothesise that given the relationship between neuronal cells and the immune system in asthma, altered peripheral expression of neurotrophins associated with neuronal dysregulation may affect the course of asthma and disease severity in children. The present study was performed on a Polish sample of 98 …

Role ofADRB2 gene polymorphism in asthma and response to β2-agonists in Polish children

The aims of this study were: (1) to find associations of asthma with single-nucleotide polymorphisms (SNPs) within theADRB2 gene: Arg16Gly, Gln27Glu, −1023 G/A, −367 T/C, −47 C/T ; (2) to define linkage disequilibrium in the gene region, basing on the analyzed SNPs; and (3) to analyze the importance ofADRB2 polymorphism for response to bronchodilator drugs in children diagnosed with bronchial asthma. We compared 113 asthmatic children and 123 healthy subjects from the Polish population. Genotyping was performed by PCR-RFLP. We found an association of the A allele of −1023A/GADRB2 polymorphism with asthma (P = 0.024). No significant associations with other SNPs were detected. Moderate linkage was found between Gln27Glu and −47C/T polymorphisms in linkage disequilibrium analysis (D’ = 0.85,r2 = 0.429, LOD = 31.97). No significant differences were found in haplotype frequencies in comparison to the control group, implicating that they are not associated with susceptibility to asthma in the analyzed population. There was no significant correlation between the analyzed SNPs of theADRB2 gene and the response to β2-agonists. This is the first report providing suggestive evidence for association of —1023A/GADRB2 polymorphism with an increased risk of asthma. The analyzed SNPs may not play a major role in response to β2-agonists in asthmatic children.

Polymorphisms in the interleukin 4, interleukin 4 receptor and interleukin 13 genes and allergic phenotype: A case control study.

PURPOSE Interleukin 4 (IL4), interleukin 4 receptor (IL4R) and interleukin 13 (IL13) play a key role in the pathogenesis of allergy and asthma development. IL4 and IL13 strongly influence bronchial hyperreactivity in response to allergen, airway remodeling, airway inflammation and airway smooth muscle proliferation. Both IL4 and IL13 exert biologic effect via interleukin 4 receptor. The aim of this study was to evaluate the impact of the polymorphisms within interleukin 4 (rs2243250, rs2227284), interleukin 4 receptor α chain (rs1805010, rs1805011) and interleukin 13 (rs20541) genes on the incidence of allergic phenotype in Polish pediatric population. MATERIAL/METHODS We compared 177 asthmatic pediatric patients with 194 healthy children. Five polymorphisms within IL4, IL13 and IL4Rα genes were analyzed. Genotypes of four polymorphisms (rs2243250, rs2227284, rs1805011, rs20541) were assigned by TaqMan SNP Genotyping Assays (Applied Biosystems), whereas rs18050100 polymorphism was established using PCR-RFLP method. RESULTS We observed an association of rs1805011 polymorphism of IL4Rα gene with allergy (p=0.021), mild asthma (p=0.00005) and atopic dermatitis (p=0.0056). Significant correlation was found between rs20541 in IL-13 gene and the positive skin prick test results (p=0.029), along with rs2243250 polymorphism with clinical atopy (p=0.033) and rs2227284 with total IgE levels (p=0.00047). No associations were found for rs1805010. CONCLUSIONS Our results indicate that rs1805011 polymorphism of IL4Rα gene seems to influence allergy risk, especially mild asthma and atopic dermatitis predisposition in Polish children. Subgroup analysis of three other SNPs revealed possible influence on allergy development.

Multilocus Analysis of Candidate Genes Involved in Neurogenic Inflammation in Pediatric Asthma and Related Phenotypes: A Case–Control Study

Objectives. Asthma is a heterogenous complex disorder caused by chronic inflammation of the airways. The key issue in genetic association studies of complex disorders is the identification of multiple low-risk genes that individually have little impact on the phenotype, but in combination account for the clinical manifestation of asthma. Since neurogenic inflammation is emerging as a candidate factor in the pathogenesis of asthma, the aim of the study was to investigate whether genetic variants of neurotrophin genes are associated with asthma disease severity or asthma-related phenotypes in a pediatric population. Methods. We genotyped 27 polymorphisms located in neurotrophin genes, using TaqMan SNP genotyping assays or Polymerase Chain Reaction - Restriction Fragments Lengths Polymorphism (PCR-RFLP) in 200 children diagnosed with asthma and 226 controls. Interactions between 27 polymorphic loci and asthma-related phenotypes were determined using the Multifactor Dimensionality Reduction (MDR) method. Results. In single marker analysis, we observed an association of MAP3K1 gene polymorphisms (rs702689 and rs889312) with asthma. We also observed that four Single Nucleotide Polymorphisms (SNPs) were associated with severe asthma. Analysis stratified by asthma-related phenotype revealed an association between atopy and NGFR (rs3785931), while BDNF (rs7124442), NTRK2 (rs1212171), NGFR (rs2072446), and FYN (rs3730353) variants were associated with increased exhaled nitric oxide (exNO). In addition, gene–gene interaction analysis revealed a significant epistatic interaction between MAPK (rs889312) and NGF (rs11102930) variants in asthma susceptibility. Conclusions. Our results suggest that genetic variants of MAP3K1 and NGF genes involved in the regulation of neurogenic inflammation may contribute to asthma, possibly via enhanced NGF expression and MAPK signaling pathway activation.

Evaluation of exhaled breath temperature (EBT) as a marker and predictor of asthma exacerbation in children and adolescents

ABSTRACT Introduction: Noninvasive and easy-to-use tools to monitor airway inflammation in asthma are needed to maintain disease control, particularly in pediatric population. The aim of the study was to evaluate exhaled breath temperature (EBT) in pediatric respiratory clinic setting. Methods: We evaluated 37 children and adolescents with asthma (5–17 years; median: 11 years). The patients were followed up in stable condition and during exacerbations (paired observations in n = 19 subjects). We evaluated medication use, EBT, fractional exhaled nitric oxide (FeNO), spirometry and atopic status of patients. Results: EBT was significantly higher in children with asthma exacerbation {entire group: median [interquartile range (IQR)]: 32.3 [1.1]°C vs. 33.8 [1.7]°C; p < 0.001 and mean ± SD: 33.1 ± 1.0°C vs. 33.6 ± 1.1°C; p = 0.038 for paired observations}. Significant correlation was observed between EBT and FeNO in the entire group (r = 0.22; p = 0.03). No difference was observed in EBT median values in atopic and non-atopic subjects in the entire group (median [IQR]: 32.6 [1.6] vs. 32.7 [2.0]; p = 0.88) and in subgroups. There was no difference in EBT values in patients receiving systemic or inhaled glucocorticosteroids (p = 0.45 and 0.83). There was no significant correlation between EBT and body or room temperature. The only significant predictor of exacerbation in logistic regression model was EBT {aOR = 2.4; 95% [confidence interval (CI)]: 1.4–4.1}. ROC analysis demonstrated applicability of EBT as a marker of asthma exacerbation in children (AUC = 0.748; p < 0.001; cut-off = 33.3°C; sensitivity: 64.3%; specificity: 82.1%). Conclusions: We suggest that EBT may serve as marker and predictor of asthma exacerbation in children. EBT follow-up may be useful in asthma monitoring in children and adolescents.

Pancreatic Elastase-1 Quick Test for rapid assessment of pancreatic status in cystic fibrosis patients

BACKGROUND At present, fecal elastase-1 ELISA determination is the most sensitive and specific tubeless pancreatic function test available. However, the results are not available the same day in routine clinical practice. This prospective study aims at evaluating the sensitivity and specificity of the Elastase-1 Quick™ Test by comparing the results with the ELISA test. METHODS The study was composed of three groups: the screening-diagnosed cystic fibrosis (CF) patients (n=28), the screened, but non-CF subjects (n=36) and non-screened CF patients (n=62). Pancreatic status (normal vs abnormal) was evaluated using the Pancreas Elastase-1 Quick™ Test. Fecal elastase-1 concentration was determined with a commercially available ELISA kit, used as reference. The cut-off for abnormal results was set at <200μg/g of stool. RESULTS The Pancreatic Elastase-1 Quick Test™ showed the following sensitivities and specificities in the studied groups: 92.8% and 96.6% in all subjects, 90.5% and 100% in screening samples, and 92.8 and 90.5% in CF patients. CONCLUSION Pancreatic Elastase-1 Quick Test™ proves to be a rapid and reliable option to qualitatively evaluate pancreatic function for diagnostic purposes in a clinical setting of CF care.