Association study on ADAM33 polymorphisms in mite-sensitized persistent allergic rhinitis in a Chinese population

Polymorphism -509C/T in TGFB1 Promoter Is Associated With Increased Risk and Severity of Persistent Allergic Rhinitis in a Chinese Population

BACKGROUND

Polymorphism -509C/T in the promoter of transforming growth factor beta1 (TGFB1) gene is implicated in the pathogenesis of asthma. This polymorphism might also act to regulate the development of allergic rhinitis (AR).

OBJECTIVES

To investigate whether -509C/T is associated with AR susceptibility and severity in a Han Chinese population.

METHODS

The study enrolled 263 patients with persistent AR and 249 healthy controls. AR patients were classified as mild or moderate/severe AR groups according to the Allergic Rhinitis and its Impact on Asthma classification. TGFB1 gene polymorphism -509C/T was genotyped with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Serum total Immunoglobulin E (IgE) and specific IgE levels were determined using an ImmunoCAP.

RESULTS

Significant difference was found in the allele frequency of TGFB1 -509C/T between AR patients and healthy controls (P = .027) but not in the genotype frequency (P =.051). However, the genotype frequency of TGFB1 -509C/T showed significant difference between the mild AR group, the moderate/severe AR group, and the control group (P = .012); between the moderate/severe AR group and the control group (P =.036); between the mild AR group and the moderate/severe AR group (P = .038); but not between the mild AR group and the control group (P =.075).

CONCLUSION

TGFB1 promoter polymorphism -509C/T may be associated with the susceptibility and the severity of persistent AR of Han Chinese, but the functional relationship still needs clarification.

Genetic association of ADAM33 polymorphisms with childhood asthma in Chinese Han population: A case-control study

To explore the association of a disintegrin and metalloprotease 33 (ADAM33) polymorphisms with childhood asthma susceptibility, we conducted this case-control study.In this case-control study, we selected 96 asthma children and 86 healthy children to conduct the genotyping of ADAM33 polymorphisms through polymerase chain reaction-direct sequencing (PCR-DS). Hardy-Weinberg equilibrium (HWE) status in the control group was detected adopting chi-square test. Frequency differences of genotypes, alleles, and haplotypes were compared by chi-square test between the case and control groups. Linkage disequilibrium (LD) between polymorphisms was checked using Haploview software. Association intensity of the polymorphisms with the disease risk was assessed by odds ratio (OR) and 95% confidence interval (95%CI).The frequency of rs678881 GA genotype was obviously higher in cases than in controls (P = .03) and the carriage of this genotype conferred higher risk of asthma among children than GG genotype (OR = 2.03, 95%CI = 1.05-3.91). However, neither rs2280089 nor rs2853209 polymorphism was significantly associated with the risk of childhood asthma. Strong LD was found among rs678881, rs2280089 and rs2853209, and haplotype GGT was distinctly associated with the risk of asthma in children (OR = 0.28, 95%CI = 0.13-0.57).ADAM33 rs678881 polymorphism is significantly correlated with increased susceptibility to asthma in Chinese Han children. Besides, haplotype GGT among the 3 polymorphisms was obviously associated with decreased risk of childhood asthma.

Chinese Society of Allergy Guidelines for Diagnosis and Treatment of Allergic Rhinitis

Allergic rhinitis (AR) is a global health problem that causes major illnesses and disabilities worldwide. Epidemiologic studies have demonstrated that the prevalence of AR has increased progressively over the last few decades in more developed countries and currently affects up to 40% of the population worldwide. Likewise, a rising trend of AR has also been observed over the last 2-3 decades in developing countries including China, with the prevalence of AR varying widely in these countries. A survey of self-reported AR over a 6-year period in the general Chinese adult population reported that the standardized prevalence of adult AR increased from 11.1% in 2005 to 17.6% in 2011. An increasing number of Journal Articles and imporclinical trials on the epidemiology, pathophysiologic mechanisms, diagnosis, management and comorbidities of AR in Chinese subjects have been published in international peer-reviewed journals over the past 2 decades, and substantially added to our understanding of this disease as a global problem. Although guidelines for the diagnosis and treatment of AR in Chinese subjects have also been published, they have not been translated into English and therefore not generally accessible for reference to non-Chinese speaking international medical communities. Moreover, methods for the diagnosis and treatment of AR in China have not been standardized entirely and some patients are still treated according to regional preferences. Thus, the present guidelines have been developed by the Chinese Society of Allergy to be accessible to both national and international medical communities involved in the management of AR patients. These guidelines have been prepared in line with existing international guidelines to provide evidence-based recommendations for the diagnosis and management of AR in China.

Association between ADAM33 S2 and V4 polymorphisms and susceptibility to allergic rhinitis: A meta-analysis

BACKGROUND

It has been reported that ADAM33 (a disintegrin and metalloproteinase domain 33) polymorphisms might be associated with susceptibility to allergic rhinitis (AR).

OBJECTIVE

Owing to mixed and inconclusive results, we conducted a meta-analysis to systematically summarise and clarify the association between ADAM33 S2, V4, T1, T2 and T+1 polymorphisms and AR risk.

METHODS/RESULTS

A systematic search of studies on the association of ADAM33 polymorphisms with susceptibility to AR was conducted in Pubmed and Embase. A total of five case-control studies with 1251 patients and 1634 controls were included. Meta-analysis indicated an association between the ADAM33 S2 and AR in allele comparison (G/C:OR=1.40, 95% CI 1.08-1.82, P=0.012), heterozygote comparison (

CG/CC

OR=1.24, 95% CI 1.04-1.48, P=0.015), and dominant comparison (CG+GG/CC:OR=1.39, 95% CI 1.05-1.85, P=0.023). The meta-analysis also revealed an association between the ADAM33 V4 and AR in allele comparison (G/C:OR=1.67, 95% CI 1.01-2.75, P=0.044). However, no association was found between AR and the ADAM33 T1, T2 and T+1 polymorphisms in any gene model comparison.

CONCLUSIONS

This meta-analysis demonstrates that the ADAM33 S2 and V4 polymorphisms confer susceptibility to AR. However, these results should be interpreted with caution due to limited sample and heterogeneity. Large-scale and well-designed studies are needed to validate our findings.

Association of VDR and CYP2R1 Polymorphisms with Mite-Sensitized Persistent Allergic Rhinitis in a Chinese Population

As recent studies have described an association between vitamin D and allergic rhinitis, we hypothesized that vitamin D pathway-related genes may be candidate genes for susceptibility to allergic rhinitis. Thus, we sought to evaluate whether polymorphisms in the vitamin D receptor (VDR) and CYP2R1 genes are associated with mite-sensitized persistent allergic rhinitis (PER) in a Han Chinese population. A hospital-based case-control study consisting of 519 patients with mite-sensitized PER and 447 healthy controls was conducted. Five single nucleotide polymorphisms (SNPs) in VDR and CYP2R1 were selected for genotyping. The genotype and allele frequencies of rs9729, rs2228570, rs1544410, and rs731236 in VDR as well as rs2060793 in CYP2R1 were not significantly associated with susceptibility to mite-sensitized PER. After stratification analyses, however, both the CT and CT/TT genotypes of rs2228570 in VDR exhibited a significantly decreased risk (CT: adjusted odds ratio (OR)=0.58, 95% confidence intervals (CI)=0.37-0.91; CT/TT: adjusted OR=0.61, 95% CI=0.40-0.93) of mite-sensitized PER, while the AA genotype of rs2060793 in CYP2R1 exhibited a significantly increased risk (adjusted OR=1.85, 95% CI=1.03-3.34) of PER in the age subgroup of <16 years old. Both the AG and AG/GG genotypes of rs731236 in VDR exhibited a significantly decreased risk (AG: adjusted OR=0.43, 95% CI=0.21-0.89; AG/GG: adjusted OR=0.46, 95% CI=0.23-0.94) of PER in the female subgroup. Analysis of the locus-locus interactions of VDR and CYP2R1 revealed two models that involved combined SNPs of VDR and CYP2R1 were statistically significant (P<0.05). Our data suggest that age and gender may have an impact on the association of three SNPs (rs2228570, rs731236, and rs2060793) in genes of the vitamin D pathway with the risk of mite-sensitized PER in this Chinese population. The VDR and CYP2R1 variants may be involved in genetic interactions in the pathogenesis of PER.

Association of Single Nucleotide Polymorphisms in the MD-2 Gene Promoter Region With Der p 2 Allergy

Purpose

Sensitization to house dust mite (Dermatophagoides pteronyssinus) is a considerable risk factor for the progression of allergic disease. The group 2 allergen from Dermatophagoides pteronyssinus, Der p 2, is considered a major one in patients with specific immunoglobulin E (IgE) to Der p 2. Der p 2 has structural homology with myeloid differentiation 2 (MD-2), which is involved in the lipopolysaccharide-binding component of the Toll-like receptor 4 signaling pathway and the development of inflammation. The aim of this study was to examine the genetic association of single nucleotide polymorphisms (SNPs) in the promoter region of MD-2 with Der p 2-sensitive allergy.

Methods

We investigated associations between cohort's characteristics, including 280 allergic and 80 healthy subjects by examining total IgE, eosinophils, D. pteronyssinus-specific IgE, Der p 2-specific IgE, the number of IgE-producing B cells induced by Der p 2, and the odds ratio of allergic symptoms.

Results

Based on the 1,000 genome project data, the minor allele frequencies of the rs1809441 and rs1809442 are 0.467 and 0.474, respectively. However, the correlation of linkage disequilibrium (LD) between these 2 SNPs is D'=1, the genotype frequencies of the 2 MD-2 (LY96) SNPs (rs1809441 and rs1809442) that are located nearby were significantly different between allergic and health subjects: the TT genotype of rs1809441 and the GG genotype of rs1809442 were more frequent in allergic subjects than in healthy subjects (16.1% vs 2.5% in both genotypes). The allergic patients with these genotypes exhibited significantly higher levels of D. pteronyssinus-specific IgE and Der p 2-specific Ig E, and a larger number of Der p 2-activated B cells. In addition, these 2 SNPs in the MD-2 promoter region were significantly associated with the prevalence of nasal, skin, and asthmatic allergic symptoms.

Conclusions

Our results indicated that 2 SNPs in the MD-2 promoter region were significantly associated with Der p 2-specific Ig E, and thereby suggest that these SNPs may play a major role in susceptibility to Der p 2-triggered immune responses in a Taiwanese population.