A meta-analysis of Th2 pathway genetic variants and risk for allergic rhinitis

Vitamin D Deficiency and Interleukin Levels in Allergic Rhinitis: A Case-Control Study

Various studies have shown a positive co-relation between Vitamin D deficiency and severity of Allergic Rhinitis (AR) based on subjective symptoms. AR is also associated with serum eosinophilia and raised levels of various interleukins (IL)-particularly IL-4, IL-5 and IL-13. To compare serum Vitamin D levels, IL-4, IL-5, and IL-13 levels, and eosinophilia in AR patients with healthy controls and co-relate disease severity using Sino-nasal Outcome Test-22 (SNOT-22) score in patients with Vitamin D deficiency. 30 patients and 30 healthy controls were recruited. 10 ml blood sample was drawn from each patient and healthy control. It was then processed to evaluate absolute eosinophil count, serum levels of Vitamin D, and IL-4, IL-5, and IL-13. 93.33% of patients with AR and 70% of healthy controls had decreased Vitamin D levels (below 25 ng/ml). The mean Vitamin D levels was 10.50 ± 2.34 ng/ml and 17.54 ± 2.84 ng/ml in the patient and control group, respectively (p = 0.001). But there was no significant co-relation between SNOT-22 score and Vitamin D level, and between interleukin levels in patient and control group. Vitamin D deficiency is associated with Allergic Rhinitis and therefore, checking Vitamin D levels in patients with AR can be considered as routine practice in outpatient clinics. However, co-relation between severity of Allergic Rhinitis and Vitamin D levels and the proven therapeutic role of Vitamin D in Allergic Rhinitis is still debatable and thus, requires large sample size randomised controlled trials.

Vegetable dietary pattern may protect mild and persistent allergic rhinitis phenotype depending on genetic risk in school children

BACKGROUND

The effect of diet on allergic rhinitis (AR), its severity in children, and whether it modifies AR depending on genetic susceptibility are unknown. We investigated the association between dietary patterns and AR in school children and the influence of diet on AR according to a genetic risk score (GRS).

METHODS

Totally, 435 7-year-old school children were recruited from the Panel Study on Korean Children. We used dietary patterns (vegetable, sugar, and meat) and dietary inflammatory index (DII) as dietary parameters. AR and its severity were defined by questionnaires about treatment in the previous 12 months and the Allergic Rhinitis and its Impact on Asthma (ARIA) guideline, respectively. A GRS was calculated using 6 single nucleotide polymorphisms for allergic diseases.

RESULTS

A vegetable diet containing a lot of anti-inflammatory nutrients and higher vitamin D level in blood were negatively correlated, while DII was positively correlated with triglyceride level and triglyceride/HDL cholesterol. Vegetable diet (aOR, 95% CI = 0.73, 0.58-0.94) and DII (1.13, 1.01-1.28) were associated with AR risk. In particular, a high-vegetable diet resulted in a lower risk of mild and persistent AR (aOR, 95% CI = 0.24, 0.10-0.56) while a high DII represented a higher risk (2.33, 1.06-5.10). The protective effect of vegetable diet on AR appeared only among children with a lower GRS (adjusted P = .018).

CONCLUSIONS

A vegetable dietary pattern characterized by high intake of anti-inflammatory nutrients and higher vitamin D level in blood might be associated with a lower risk of mild and persistent AR. This beneficial effect is modified by a genetic factor.

The effect of blocking Notch signaling by γ-secretase inhibitor on allergic rhinitis

OBJECTIVE

This study aimed to investigate the effect of blocking Notch signaling by γ-secretase inhibitor (GSI) on allergic rhinitis.

METHOD

GSI, N-[N-(3,5-difluorophenacetyl-L-alanyl)]-S-phenylglycine t-butylester (DAPT) was administered to ovalbumin-induced AR mice models intranasally. We observed symptoms of sneezing and nose rubbing. To detect the inflammatory state, the serum OVA-specific-IgE, IFN-γ, IL-4, and IL-5 were analyzed by ELISA, and Th cell cytokines in nasal mucosa were analyzed by RT-PCR, including T-bet, IFN-γ, GATA-3, IL-4, and IL-5. In addition, hematoxylin-eosin (HE) and periodic acid-Schiff (PAS) were applied for histopathological examination. As for the evaluation of Notch signaling, we analyzed the Notch-1, Notch signaling target Hes-1, and Hes-5 in mucosa by RT-PCR, besides, used western blotting and immunohistochemistry to assess NICD (Notch intracellular domain).

RESULTS

The results showed that the DAPT ameliorated the development of AR and suppressed Th2 cytokine levels significantly, alleviating eosinophils infiltration and goblet cells metaplasia, suggesting that the GSI can regulate Th2 response and weaken airway inflammation in AR.

CONCLUSION

Our findings provide evidence that blocking Notch signaling by GSI offers high value in treating AR.

Polymorphisms in host immune response associated genes and risk of nasopharyngeal carcinoma development in Portugal

BACKGROUND

Host genetic susceptibility markers in immune response associated genes may contribute to identify individuals with high risk of developing viral infection and viral-associated cancers. We aimed to characterize different polymorphisms in immune response associated genes and evaluate its association with nasopharyngeal carcinoma (NPC) development.

METHODS

We have developed a hospital-based case-control study selecting 134 patients with NPC (cases) and 732 healthy individuals (controls) from the Northern Region of Portugal. Eight single nucleotide polymorphisms (SNP) were selected: -56C>T IFNGR1 (rs2234711), +4854G>T IL1A (rs17561), +3954C>T IL1B (rs1143634), +1902A>G IL4RA (rs1801275), -1082G>A IL10 (rs1800896), +2018T>C IL1RN (rs419598), HLA-A locus A>T (rs2530388), HCGA9 locus A>T (rs6457110). All polymorphisms were analysed by real-time methodology using TaqMan(®) SNP Genotyping Assays.

RESULTS

The overall analysis revealed no statistical significant differences between genotypes distributions in all of studied polymorphisms (p>0.05). However, the results for HCGA9 rs6457110 polymorphism showed a tendency for an increased risk of NPC development among TT carriers with an almost of 2-fold increased risk (OR=1.86; 95%CI 1.00-3.65).

CONCLUSIONS

This is the first study to characterize these polymorphisms in NPC patients in Portugal. Our study indicates that HCGA9 rs6457110 polymorphism might represent a risk marker for NPC development in our population and that other SNPs should be further studied in larger populations to clarify the evidences. This data reinforces the need for more studies, especially in NPC low-prevalent populations.

Systematic review of immunotherapy for chronic rhinosinusitis

BACKGROUND

Immunotherapy (IT) has been well established as an effective treatment for allergic rhinitis (AR), but little is known about the benefits of IT on clinical outcomes of comorbid chronic rhinosinusitis (CRS). The goal of this publication is to systematically review the literature regarding outcomes of IT in patients with atopic CRS.

METHODS

A systematic review of the literature was conducted including studies that assessed the efficacy of IT on clinical outcome measures in CRS including without polyp, with polyp, and allergic fungal rhinosinusitis subgroups. Excluded articles were those only reporting outcomes specific to asthma or AR.

RESULTS

Seven studies met the inclusion and exclusion criteria for this review, none of which were randomized controlled trials. Generally, symptom scores improved in patients treated with IT when compared with baseline data and control patients. Objective endoscopic exam measures improved with IT treatment in short-term studies. Significant improvements were observed in radiographic assessments, and there was a decreased necessity for revision surgery, interventional office visits, and intranasal and oral steroid use.

CONCLUSION

Conclusions are limited by the paucity of available data on the efficacy of IT for treating CRS-specific outcome measures. There is weak evidence to support the use of IT as an adjunctive treatment in CRS patients, particularly in the postoperative period.

Polymorphisms of tumor necrosis factor-α, transforming growth factor-β, and interleukin-10 in asthma associated with olive pollen sensitization

Sensitization to specific olive pollen-allergens (Ole e 2 and 10) has been correlated with a clinical pattern of asthma. This study analyzes the association between several polymorphims of TNFA (G-308A, C-857T, and C-1031T), IL10 (C-571A and A-1117G), and TGFB (C-509-T) and these sensitizations. These polymorphisms were genotyped by allelic discrimination, in olive pollen-allergic patients (phenotyped for specific Ole e 2 and 10 sensitizations) and healthy controls. Levels of serum-soluble cytokines were correlated with specific genotypes and clinical phenotypes. The results showed that heterozygous TGFB C-509T genotype, besides having the lowest sera TGF- levels, was significantly increased in olive pollen-allergic patients compared with controls. According specific sensitizations, CC genotype of IL10 C-571A could be a protective factor for Ole e 2 sensitization and mainly for asthmatic Ole e 2 sensitized patients compared with asthmatic non-Ole e 2 sensitized patients (OR: 0.26, P = 0.008). In contrast, heterozygous CA genotype was increased in Ole e 2 asthmatic subjects compared to asthmatic non-Ole e 2 sensitized patients. Lastly, heterozygous TNFA G-308A genotype was associated with Ole e 10 sensitization (OR: 2.5, P = 0.04). In conclusion, these results suggest a role of TGF-β1 in olive-pollen sensitization and TNF-α and IL-10 genotypes in the asthma induced by specific olive-pollen allergens.

Integrated genome-wide association, coexpression network, and expression single nucleotide polymorphism analysis identifies novel pathway in allergic rhinitis

BACKGROUND

Allergic rhinitis is a common disease whose genetic basis is incompletely explained. We report an integrated genomic analysis of allergic rhinitis.

METHODS

We performed genome wide association studies (GWAS) of allergic rhinitis in 5633 ethnically diverse North American subjects. Next, we profiled gene expression in disease-relevant tissue (peripheral blood CD4+ lymphocytes) collected from subjects who had been genotyped. We then integrated the GWAS and gene expression data using expression single nucleotide (eSNP), coexpression network, and pathway approaches to identify the biologic relevance of our GWAS.

RESULTS

GWAS revealed ethnicity-specific findings, with 4 genome-wide significant loci among Latinos and 1 genome-wide significant locus in the GWAS meta-analysis across ethnic groups. To identify biologic context for these results, we constructed a coexpression network to define modules of genes with similar patterns of CD4+ gene expression (coexpression modules) that could serve as constructs of broader gene expression. 6 of the 22 GWAS loci with P-value ≤ 1x10-6 tagged one particular coexpression module (4.0-fold enrichment, P-value 0.0029), and this module also had the greatest enrichment (3.4-fold enrichment, P-value 2.6 × 10-24) for allergic rhinitis-associated eSNPs (genetic variants associated with both gene expression and allergic rhinitis). The integrated GWAS, coexpression network, and eSNP results therefore supported this coexpression module as an allergic rhinitis module. Pathway analysis revealed that the module was enriched for mitochondrial pathways (8.6-fold enrichment, P-value 4.5 × 10-72).

CONCLUSIONS

Our results highlight mitochondrial pathways as a target for further investigation of allergic rhinitis mechanism and treatment. Our integrated approach can be applied to provide biologic context for GWAS of other diseases.

Effect of antibiotic use and mold exposure in infancy on allergic rhinitis in susceptible adolescents

BACKGROUND

Antibiotic use in infancy induces alteration in intestinal microbiota and is associated with the development of allergic diseases. Mold exposure is also associated with allergic diseases. Genetic susceptibility may interact with specific environmental factors in allergic disease development.

OBJECTIVE

To investigate independent and combined effects of antibiotic use and mold exposure in infancy on the risk of allergic rhinitis (AR) in adolescents.

METHODS

Data on AR and environmental factors were collected using the International Study of Asthma and Allergies in Childhood questionnaire from 7,389 adolescents from Seoul, Korea. TaqMan genotyping was performed for interleukin 13 (IL-13) (rs20541) and Toll-like receptor 4 (rs1927911) polymorphisms in 1,395 adolescents.

RESULTS

Age, parental history of AR, antibiotic use in infancy, and pet ownership during pregnancy or infancy were associated with an increased risk of current AR (diagnosis of AR and symptoms of AR within the preceding 12 months). Having older siblings was a protective effect. The adjusted odds ratio (aOR) for current AR for combined antibiotic use and mold exposure in infancy was 1.45 (95% confidence interval [CI], 1.01-2.09). For each factor separately, aORs were 1.25 (95% CI, 1.04-1.50) and 0.99 (95% CI, 0.75-1.31), respectively. Antibiotic and mold exposure in infancy, GA or AA genotypes of IL-13 (rs20541) (aOR 4.53; 95% CI, 1.66-12.38; P for interaction = .05), and CT+TT genotype of Toll-like receptor 4 (rs1927911) (aOR, 3.20; 95% CI, 1.24-8.26; P for interaction = .18) increased the risk of current AR.

CONCLUSION

Antibiotic use and mold exposure in infancy have additive effects on the risk of current AR in genetically susceptible adolescents. Gene-environment interactions between IL-13 (rs20541) and antibiotics or mold may play a role in AR.

Gene polymorphisms of Interleukin-4 in allergic rhinitis and its association with clinical phenotypes

BACKGROUND

Allergic rhinitis (AR) is an inflammatory disorder of the upper airway. T-helper (Th)2 cytokines seems to have major roles behind the scene of unpleasant symptoms resulted from AR. Expression of interleukin (IL)-4 and its receptor could be affected by single nucleotide polymorphisms (SNPs). This study assessed the effect of 4 genetic variants within genes of IL-4 and IL-4R in AR.

METHODS

Allele frequencies of one IL-4R variant (rs1801275) and three SNPs of IL-4 (rs2243248, rs2243250, and rs2070874) were investigated in 98 patients with AR, compared to a group of controls, using PCR sequence-specific-primers (PCR-SSP) method.

RESULTS

Homozygosity for the C allele of rs2243250 in IL-4 was significantly overrepresented in the patient group. CC genotype in rs2070874 significantly was correlated with AR. GG/CC/CC and TT/TT/TT (rs2243248, rs2243250, and rs2070874) haplotypes in the IL-4 gene had a significant negative correlation with AR.

CONCLUSION

SNPs in IL-4 are associated with AR and could change the clinical picture of the disease in patients.

Association of interleukin-13 SNP rs20541 (Arg>Gln) to allergic rhinitis in an Asian population of ethnic Chinese in Singapore

In this study, we report our findings as we evaluated the association of IL-13 SNP rs20541 to AR as reported in the meta-analysis (Ying, X-J et al., April, Gene 2013) in an Asian population of 1322 ethnic Chinese recruited in Singapore well defined and characterized for allergic rhinitis. The SNP was significantly associated with AR at an odds ratio of 1.57 for the homozygous genotype comparisons indicating a strong risk for AR. This highlights the importance of this mutation in Asian populations for risk towards allergic phenotypes and also warrants further functional work to characterize the mechanism behind this genetic predisposition.

Association of interleukin-13 SNP rs20541 with allergic rhinitis risk: a meta-analysis

Studies investigating the association between interleukin-13 (IL-13) single nucleotide polymorphism (SNP) rs20541 and allergic rhinitis (AR) risk have reported conflicting results. The aim of the present study was to conduct a meta-analysis assessing the possible association of IL-13 SNP rs20541 with AR risk. Eight studies were included in the present meta-analysis (2153 cases and 3931 controls). The combined results based on all studies showed that IL-13 SNP rs20541 was associated with increased AR risk (Gln versus Arg: odds ratio (OR)=1.18, 95% confidence interval (CI)=1.08-1.30; Gln/Gln versus Arg/Arg: OR=1.52, 95% CI=1.20-1.92; Arg/Gln+Gln/Gln versus Arg/Arg: OR=1.19, 95% CI=1.06-1.33; Gln/Gln versus Arg/Gln+Arg/Arg: OR=1.42, 95% CI=1.13-1.79). When stratifying for race, IL-13 SNP rs20541 exhibited increased AR risk in Asians (Gln versus Arg: OR=1.20, 95% CI=1.06-1.36; Gln/Gln versus Arg/Arg: OR=1.57, 95% CI=1.17-2.12; Arg/Gln+Gln/Gln versus Arg/Arg: OR=1.22, 95% CI=1.04-1.44; Gln/Gln versus Arg/Gln+Arg/Arg: OR=1.45, 95% CI=1.09-1.93), while no significant association was detected in Caucasians (Gln versus Arg: OR=1.28, 95% CI=0.93~1.78; Gln/Gln versus Arg/Arg: OR=1.42, 95% CI=0.96-2.11; Arg/Gln+Gln/Gln versus Arg/Arg: OR=1.35, 95% CI=0.89-2.05; Gln/Gln versus Arg/Gln+Arg/Arg: OR=1.37, 95% CI=0.93-2.02). This meta-analysis supported that IL-13 SNP rs20541 was associated with AR, particularly in Asians.

FOXP3-marked IL-17a-producing regulatory T cells are increased in patients with allergic rhinitis

CONCLUSION

The deficient regulatory T cells may play a role in the development of allergic rhinitis.

OBJECTIVE

A subpopulation of regulatory T cell that produce IL-17a were proved to show an apparent duality of regulatory T cell and effector T helper-17 cells. We studied this subpopulation in patients with allergic rhinitis.

METHODS

Fresh whole blood from 20 patients with allergic rhinitis and 19 healthy donors was used to investigate the frequencies of CD4(+)IFN-γ(+) T cells (effector T helper-1), CD4(+)IL-4(+) T cells (effector T helper-2) and CD4(+)IL-17a(+) T cells (effector T helper-17) by flow cytometry after stimulation for 4-6 h. Simultaneously, CD4(+) T lymphocytes were isolated from peripheral blood mononuclear cells and then the frequencies of regulatory T cells and IL-17a-producing regulatory T cells in the allergic rhinitis group were compared with healthy controls after T-cell antigen receptor stimulation for 48 h. The suppressive capacity of CD4(+)CD25(high)CD127(low) regulatory T cells that were stimulated by Dermatophagoides pteronyssinus in both groups was isolated and assessed.

RESULTS

The frequencies of effector T helper-17 and effector T helper-2 cells were higher in the allergic group compared with healthy controls. Regulatory T cells were similar in both groups, but IL-17a-producing regulatory T cells were increased in the allergic group. In addition, the capacity of regulatory T cells to suppress effector T helper-17 cytokine production was significantly decreased in the allergic group.

Association of interleukin-13 SNP rs1800925 with allergic rhinitis risk: a meta-analysis based on 1,411 cases and 3169 controls

Studies investigating the association between interleukin-13 (IL-13) single nucleotide polymorphism (SNP) rs1800925 and allergic rhinitis risk have reported conflicting results. The aim of the present study was to conduct a meta-analysis assessing the possible association of IL-13 SNP rs1800925 with allergic rhinitis risk. The relevant studies were identified through a search of PubMed, Embase, ISI Web of Knowledge and Chinese National Knowledge Infrastructure until December 2011 and selected on the basis of the established inclusion criteria for publications. Five studies were included in the present meta-analysis (1411 cases and 3169 controls). The combined results based on all studies showed that IL-13 SNP rs1800925 was not associated with increased allergic rhinitis risk (T versus C: odds ratio (OR)=1.06, 95% confidence interval (CI)=0.94-1.20; C/T versus C/C: OR=1.12, 95% CI=0.97-1.29; T/T versus C/C: OR=1.00, 95% CI=0.69-1.44; C/T+T/T versus CC: OR=1.10, 95% CI=0.96-1.27; T/T versus C/C+C/T: OR=0.91, 95% CI=0.64-1.31). This meta-analysis supported that IL-13 SNP rs1800925 was not associated with allergic rhinitis.

Understanding the complexity of IgE-related phenotypes from childhood to young adulthood: a Mechanisms of the Development of Allergy (MeDALL) seminar

Mechanisms of the Development of Allergy (MeDALL), a Seventh Framework Program European Union project, aims to generate novel knowledge on the mechanisms of initiation of allergy. Precise phenotypes of IgE-mediated allergic diseases will be defined in MeDALL. As part of MeDALL, a scientific seminar was held on January 24, 2011, to review current knowledge on the IgE-related phenotypes and to explore how a multidisciplinary effort could result in a new integrative translational approach. This article provides a summary of the meeting. It develops challenges in IgE-related phenotypes and new clinical and epidemiologic approaches to the investigation of allergic phenotypes, including cluster analysis, scale-free models, candidate biomarkers, and IgE microarrays; the particular case of severe asthma was reviewed. Then novel approaches to the IgE-associated phenotypes are reviewed from the individual mechanisms to the systems, including epigenetics, human in vitro immunology, systems biology, and animal models. The last chapter deals with the understanding of the population-based IgE-associated phenotypes in children and adolescents, including age effect in terms of maturation, observed effects of early-life exposures and shift of focus from early life to pregnancy, gene-environment interactions, cohort effects, and time trends in patients with allergic diseases. This review helps to define phenotypes of allergic diseases in MeDALL.

Case-control study of IL13 polymorphisms, smoking, and rhinoconjunctivitis in Japanese women: the Kyushu Okinawa Maternal and Child Health Study

BACKGROUND

Six previous studies have examined the relationships between single nucleotide polymorphisms (SNPs) in the IL13 gene and allergic rhinitis, but the results have been inconsistent. However, a recent meta-analysis using data from these 6 studies has shown that the A allele of IL13 SNP rs20541 was associated with an increased risk of allergic rhinitis, whereas no such relationship existed between IL13 SNP rs1800925 and allergic rhinitis. We investigated the associations between IL13 SNPs rs1800925 and rs20541 and the risk of rhinoconjunctivitis in Japanese women.

METHODS

Included were 393 cases who met the criteria of the International Study of Asthma and Allergies in Childhood (ISAAC) for rhinoconjunctivitis. Control subjects were 767 women without rhinoconjunctivitis according to the ISAAC criteria, who had also not been diagnosed with allergic rhinitis by a doctor. Adjustment was made for age, region of residence, presence of older siblings, smoking, family history of allergic rhinitis, and education.

RESULTS

Compared with the GG genotype of IL13 SNP rs20541, the AA genotype, occurring in 7.1% of control subjects, was significantly positively related to the risk of rhinoconjunctivitis: the adjusted odds ratio was 1.65 (95% confidence interval: 1.05 - 2.60). SNP rs1800925 was not associated with rhinoconjunctivitis. The haplotype comprising the rs1800925 C allele and the rs20541 A allele was significantly positively related to rhinoconjunctivitis. The multiplicative interactions between the two SNPs under study and smoking on the risk of rhinoconjunctivitis were not statistically significant. Based on the recessive model, however, the additive interaction between SNP rs1800925, but not rs20541, and smoking was significant.

CONCLUSIONS

This study suggests that the minor genotype of IL13 SNP rs20541 and the CA haplotype are significantly positively associated with the risk of rhinoconjunctivitis. In addition, a new pattern of biological interaction that affects the risk of rhinoconjunctivitis is described between SNP rs1800925 and smoking.