Irena Wojsyk-Banaszak

Mutation analysis of mitochondrial 12S rRNA gene in Polish patients with non-syndromic and aminoglycoside-induced hearing loss.

Mutations in mitochondrial DNA have been reported as associated with non-syndromic and aminoglycoside-induced hearing loss. In the present study, we have performed mutational screening of entire 12S rRNA gene in 250 unrelated patients with non-syndromic and aminoglycoside-induced hearing loss. Twenty-one different homoplasmic sequence variants were identified, including eight common polymorphisms, one deafness-associated mutation m.1555 A>G and three putatively pathogenic variants: m.669 T>C, m.827 A>G, m.961 delT+C(n)ins. The incidence of m.1555 A>G was estimated for 3.6% (9/250); however, where aminoglycoside exposure was taken as a risk factor, the frequency was 5.5% (7/128). Substitution m.669 T>C was identified only in patients with hearing impairment and episode of aminoglycoside exposure, which may suggest that such additional risk factors must appear to induce clinical phenotype. Moreover, two 12S rRNA sequence variants: m.988 G>A and m.1453 A>G, localized at conserved sites and affected RNA secondary structure, may be new candidates for non-syndromic and aminoglycoside-induced hearing loss associated mutations.

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.

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 …

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.

The contribution of the mitochondrial COI/tRNASer(UCN) gene mutations to non-syndromic and aminoglycoside-induced hearing loss in Polish patients

Mutations in mitochondrial DNA have been implicated in both, non-syndromic and aminoglycoside-induced hearing loss. In the present study, we have performed the systematic mutation screening of the COI/tRNA(Ser(UCN)) genes in 250 unrelated Polish subjects with hearing impairment. Three different homoplasmic sequence variants were identified, including one common polymorphism m.7476 C>T in tRNA(Ser(UCN)) and two mutations, m.7444 G>A and m.7445 A>G localized in the COI/precursor of tRNA(Ser(UCN)). The incidence of m.7444 G>A substitution was estimated at 1.6% (4/250), however variable penetrance of hearing loss, age of onset and hearing thresholds among m.7444 G>A carriers was observed. Two subjects had the positive history of aminoglycoside exposure and one of them harbored both m.7444 G>A and 12S rRNA m.1555 A>G mutations. Those suggest that m.7444 G>A itself is not sufficient to produce a clinical phenotype and additional modifier factors are required for pathogenic manifestation of m.7444 G>A substitution. Moreover, we have described the first Polish family with non-syndromic hearing loss, harboring m.7445 A>G mutation. The penetrance of hearing loss in this pedigree was 58% when aminoglycoside-induced hearing impairment was included, and 8% when ototoxic effect was excluded. This finding strongly suggests the possible role of m.7445 A>G in susceptibility to aminoglycoside induced-hearing loss.

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.

Interleukin 1β polymorphism and serum level are associated with pediatric asthma

Interleukin‐1 is a pro‐inflammatory cytokine found in two forms (α and β). The α form is mainly cell‐bound, whereas IL‐1β is primarily secreted by macrophages in response to immune system stimulation. We hypothesized that polymorphic variants of interleukin 1 genes may play a role in childhood asthma risk. The aim of this study was to investigate if IL‐1α and β polymorphism is associated with asthma in a pediatric population and if the genotype affects its serum level.

Leptin gene polymorphism affects leptin level in childhood asthma

BackgroundLeptin may induce inflammation in asthma by activation of Th2 cells. It has also been demonstrated that leptin expression increases upon inflammation and that asthmatic patients show increased serum leptin levels. We hypothesized that the polymorphism in leptin (LEP) and leptin receptor (LEPR) genes is associated with childhood asthma and may affect their serum level. To our knowledge, there are no reports analyzing LEP and LEPR polymorphisms in association with their serum levels in childhood asthma.MethodsWe analyzed 35 subjects: 25 asthmatic pediatric patients and 10 healthy children aged from 6 to 18. The diagnosis of allergic asthma was based on clinical manifestation, lung function, positive skin prick tests and increased immunoglobulin E levels. The polymorphisms were genotyped with use of polymerase chain reaction-restriction fragment length polymorphism method. Serum levels of leptin and leptin receptor were determined using BioVendor enzyme-linked immunosorbent assay kits. Statistical analysis was done with Statistica v.12.ResultsWe observed that leptin levels were increased in asthmatic subjects as compared to healthy controls and were significantly higher during exacerbation than in the asymptomatic period (P = 0.025). We observed that LEP polymorphism (rs13228377) was associated with higher serum leptin levels in asthma and these two variables had high predictive value for asthma risk (P = 0.007, odds ratio 17.5, predictive accuracy 83.9%). LEPR polymorphisms did not show association with its serum level and asthma risk.ConclusionLEP polymorphism may increase asthma risk via influence on its serum level.

Pulmonary manifestation of immunoglobulin G4-related disease in a 7-year-old immunodeficient boy with Epstein-Barr virus infection: a case report.

BackgroundImmunoglobulin G4-related disease (IgG4-RD) is a multiorgan fibroinflammatory condition with lymphoplasmacytic infiltrates containing abundant IgG4-positive plasma cells. The immunopathogenesis of the disease and the potential role of triggering autoantigens or infectious factors have not been clearly defined. Immunoglobulin G4-related lung disease is a new and emerging condition in pediatric patients and to date, there have been only two reports regarding pulmonary manifestation of IgG4-RD in children recently published. This is the first report of IgG4-related lung disease in an immunodeficient child with Epstein-Barr virus infection.Case presentationWe report on the case of a 7-year old atopic boy who was hospitalized with an initial clinical and radiological diagnosis of pneumonia, positive Epstein-Barr virus (EBV)-DNA in the blood and defective adaptive immunity. The lung CT showed a consolidated mass lesion adjacent to the posterior wall of the chest and the diaphragm. The child underwent surgical resection of the tumor, and the histologic examination of the lung specimens revealed lymphoplasmacytic infiltrates with fibrosis and vasculitis correlating with IgG4-related lung disease. Subsequent monitoring of the patient with lung CT, pulmonary function tests and IgG4 levels did not show signs of active disease.ConclusionsThe diagnosis of IgG4-related lung disease in children is challenging because of its rarity, nonspecific symptomatology and heterogeneous morphological manifestations. Further studies are required in children with pulmonary presentation of IgG4-RD to better understand pathogenesis of this condition, possible immunological or infectious triggering factors, and finally, to determine pediatric patient-targeted therapeutic interventions.

521 Serum NT-3 and NT-4 Levels are Associated with Clinical Severity in Asthmatic Children

Background Neuronal modulation of inflammation and airway hyperresponsiveness has been well described in asthma and neurotrophins provide the link between inflammation and neuronal dysfunction. In humans, elevated BDNF, NGF and NT-3 levels have been found in bronchoalveolar lavage fluid (BALF) following allergen provocation. Moreover, BDNF levels are significantly higher in untreated asthmatic patients in comparison to those treated with inhaled glucocorticoids and non asthmatic controls. It has also been shown that allergic inflammation increases local all 4 neurotrophins production that are important mediators of eosinophil survival in BALF. The aim of this study was to analyze if levels of neurotrophins in serum of asthmatic pediatric patients are altered in the course of disease (exacerbation and asymptomatic period) and therefore may serve as potential biomarkers for disease activity or symptoms severity. Methods In the study we included 98 children diagnosed with asthma. The blood was collected twice: during exacerbation and in the asymptomatic period. The serum levels of 4 neurotrophins (BDNF, NGF, NT-3, NT-4) were analyzed with use of DuoSet ELISA Development Kit (R&D). Statistical analysis was performed with Statistica v. 9.0. Results Analysis revealed no significant differences in neurotrophins levels in serum between asthmatic patients during asthma exacerbation and asymptomatic period. However, we found that serum levels of NT-3 and NT4 correlate with disease severity, being significantly lower in mild asthmatics as compared to patients with moderate and severe asthma (P < 0.01). Conclusions Our results suggest that neurotrophins levels do not seem to correlate with the clinical symptoms activity in the course of asthma, however 2 of them (NT-3 and NT-4) correlate with disease severity.