Anna Bręborowicz

Mutations in STAT3 and diagnostic guidelines for hyper-IgE syndrome

BACKGROUND The hyper-IgE syndrome (HIES) is a primary immunodeficiency characterized by infections of the lung and skin, elevated serum IgE, and involvement of the soft and bony tissues. Recently, HIES has been associated with heterozygous dominant-negative mutations in the signal transducer and activator of transcription 3 (STAT3) and severe reductions of T(H)17 cells. OBJECTIVE To determine whether there is a correlation between the genotype and the phenotype of patients with HIES and to establish diagnostic criteria to distinguish between STAT3 mutated and STAT3 wild-type patients. METHODS We collected clinical data, determined T(H)17 cell numbers, and sequenced STAT3 in 100 patients with a strong clinical suspicion of HIES and serum IgE >1000 IU/mL. We explored diagnostic criteria by using a machine-learning approach to identify which features best predict a STAT3 mutation. RESULTS In 64 patients, we identified 31 different STAT3 mutations, 18 of which were novel. These included mutations at splice sites and outside the previously implicated DNA-binding and Src homology 2 domains. A combination of 5 clinical features predicted STAT3 mutations with 85% accuracy. T(H)17 cells were profoundly reduced in patients harboring STAT3 mutations, whereas 10 of 13 patients without mutations had low (<1%) T(H)17 cells but were distinct by markedly reduced IFN-gamma-producing CD4(+)T cells. CONCLUSION We propose the following diagnostic guidelines for STAT3-deficient HIES. Possible: IgE >1000IU/mL plus a weighted score of clinical features >30 based on recurrent pneumonia, newborn rash, pathologic bone fractures, characteristic face, and high palate. Probable: These characteristics plus lack of T(H)17 cells or a family history for definitive HIES. Definitive: These characteristics plus a dominant-negative heterozygous mutation in STAT3.

The hyperimmunoglobulin E syndrome - clinical manifestation diversity in primary immune deficiency

The hyper-IgE syndromes are rare, complex primary immunodeficiencies characterized by clinical manifestation diversity, by particular susceptibility to staphylococcal and mycotic infections as well as by a heterogeneous genetic origin. Two distinct entities - the classical hyper-IgE syndrome which is inherited in an autosomal dominant pattern and the autosomal recessive hyper-IgE syndrome have been recognized. The autosomal dominant hyper-IgE syndrome is associated with a cluster of facial, dental, skeletal, and connective tissue abnormalities which are not observable in the recessive type. In the majority of affected patients with autosomal dominant hyper-IgE syndrome a mutation in the signal transducer and the activator of the transcription 3 gene has been identified, leading to an impaired Th17 cells differentiation and to a downregulation of an antimicrobial response. A mutation in the dedicator of the cytokinesis 8 gene has been identified as the cause of many cases with autosomal recessive hyper-IgE syndrome and, in one patient, a mutation in tyrosine kinase 2 gene has been demonstrated. In this paper, the authors provide a review of the clinical manifestations in the hyper-IgE syndromes with particular emphasis on the diversity of their phenotypic expression and present current diagnostic guidelines for these diseases.

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.

Association analysis of brain-derived neurotrophic factor gene polymorphisms in asthmatic children.

Brain‐derived neurotrophic factor (BDNF) has been described to modulate airway hyper‐responsiveness and inflammation and was involved in late allergic reaction in asthma and higher levels of circulating BDNF were present in allergic asthmatics. In BDNF gene, Val66Met and C‐270T polymorphisms were described. There were, however, very few studies analyzing BDNF gene polymorphisms in asthma. The aim of this study was to analyze the possible relationship between these two polymorphisms in the BDNF gene and asthma. Fifty‐six pediatric asthmatic patients were analyzed, aged from 6 to 18. The diagnosis of atopic asthma was based on clinical manifestation, lung function test and increased immunoglobulin E level, and/or positive skin prick tests. The control group consisted of 109 healthy subjects. The polymorphisms were genotyped with the use of polymerase chain reaction–restriction fragment length polymorphism method. We did not observe an association of Val/Met polymorphism and the presence of asthma. However, we observed that Val allele is much more frequent in the male group of asthmatic patients (p = 0.06). For −270C/T polymorphism, we found significant differences between asthmatic patients and the control group (p = 0.041 for genotypes and p = 0.005 for alleles). The results may suggest a relationship between the BDNF gene and asthma and male gender of asthmatic children.

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.

Health-related quality of life in Polish adolescents with Hymenoptera venom allergy treated with venom immunotherapy

Introduction Venom allergy, though rare, may seriously influence health-related quality of life (HRQoL). There is a paucity of research on HRQoL of adolescents and young adults with Hymenoptera venom allergy. The aim was to assess the level of HRQoL and to evaluate its independent predictors in Polish adolescents and young adults treated with venom immunotherapy. Material and methods A multicenter cross-sectional study based on the Vespid Allergy Quality of Life Questionnaire (VQLQ) adapted for Polish adolescents was used. The study sample included 87 patients (14-21 years) studied at different stages of venom immunotherapy (VIT). Statistical analysis was done with multivariate linear regression. Results Anxiety level was higher in patients with 4th grade of Muellers classification (anaphylactic shock) than in those with 3rd grade (B = 0.84, 95% CI = 0.07-1.61, p = 0.03). Caution increased along with an increase of anxiety of adolescents treated with VIT (B = 0.54, 95% CI = 0.39-0.68, p < 0.01). Level of limitations increased with increasing caution of adolescents (B = 0.63, 95% CI = 0.35-0.91, p < 0.01). Discomfort increased along with a rise of caution of patients (B = 0.38, 95% CI = 0.22-0.55, p < 0.01). Similarly, it increased with an increase of their feeling of limitations (B = 0.37, 95% CI = 0.23-0.51, p < 0.01). The level of discomfort in adolescents treated with VIT was lower in those who were treated with conventional protocol in comparison to those treated with rush or ultra-rush ones (B = –0.47, 95% CI = –0.90 - –0.03, p = 0.04). Conclusions Severity of anaphylactic reaction is an independent determinant of anxiety level in adolescents treated with VIT. The VIT protocol affects HRQoL of treated patients.

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.

Toll-Like Receptor Stimulation Induces Higher TNF-α Secretion in Peripheral Blood Mononuclear Cells from Patients with Hyper IgE Syndrome

Hyper IgE syndromes (HIES) are primary immunodeficiency disorders of unknown pathogenesis. Patients are typically affected with ‘cold’ abscesses of the skin, recurrent cyst-forming pneumonia, chronic mucocutaneous candidiasis and other less frequent features such as progressive skeletal abnormalities. Defective signaling in the Toll-like receptor (TLR) pathways has been suggested as a responsible pathologic mechanism, however, in previous reports, 10 patients revealed no defect in inflammatory cytokine responses to different TLR ligands. Here, we report the increase in pro-inflammatory cytokines TNF-α and IL-8, following TLR2 and TLR4 stimulation in a larger cohort of 25 additional patients with HIES, and provide a meta-analysis of the TLR data in HIES.

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 …