Evidence for common genetic elements in allergic disease

Inflammatory and infectious upper respiratory diseases associate with 41 genomic loci and type 2 inflammation

Inflammatory and infectious upper respiratory diseases (ICD-10: J30-J39), such as diseases of the sinonasal tract, pharynx and larynx, are growing health problems yet their genomic similarity is not known. We analyze genome-wide association to eight upper respiratory diseases (61,195 cases) among 260,405 FinnGen participants, meta-analyzing diseases in four groups based on an underlying genetic correlation structure. Aiming to understand which genetic loci contribute to susceptibility to upper respiratory diseases in general and its subtypes, we detect 41 independent genome-wide significant loci, distinguishing impact on sinonasal or pharyngeal diseases, or both. Fine-mapping implicated non-synonymous variants in nine genes, including three linked to immune-related diseases. Phenome-wide analysis implicated asthma and atopic dermatitis at sinonasal disease loci, and inflammatory bowel diseases and other immune-mediated disorders at pharyngeal disease loci. Upper respiratory diseases also genetically correlated with autoimmune diseases such as rheumatoid arthritis, autoimmune hypothyroidism, and psoriasis. Finally, we associated separate gene pathways in sinonasal and pharyngeal diseases that both contribute to type 2 immunological reaction. We show shared heritability among upper respiratory diseases that extends to several immune-mediated diseases with diverse mechanisms, such as type 2 high inflammation.

Development and Evaluation of a Nomogram for INCS Insensitivity in Chinese Adults with Allergic Rhinitis

Objective

The objective of this study was to design and validate a nomogram of intranasal corticosteroid (INCS) insensitivity for adult patients with allergic rhinitis (AR).

Methods

Training and validation datasets comprised randomly divided groups of AR patients diagnosed between 2019 and 2022, with a 7 : 3 ratio. These patients were categorized according to their INCS insensitivity status, and LASSO and multivariate logistic regression analyses were conducted to identify associated risk factors. These factors were incorporated into a nomogram for predicting INCS insensitivity. The performance of the nomogram was assessed using receiver operating characteristic (ROC) curves, calibration curves, and discrimination techniques.

Results

In this study, 313 patients were included, of which 120 (38.3%) showed INCS insensitivity. The type of AR, comorbidities, family history of AR, and duration of AR were identified as predictors and incorporated into the nomogram using least absolute shrinkage and selection operator and multivariate logistic regression. The calibration curves showed excellent agreement between predicted and actual probabilities of INCS insensitivity in both the training and validation sets. The area under the curve values observed in the validation set were 0.918 (95% confidence interval, 0.859-0.943), and 0.932 (95% confidence interval, 0.849-0.953) in the training set, indicating strong performance on both sets. Decision curve analysis showed that the constructed nomogram yielded a net clinical benefit for AR patients.

Conclusion

The nomogram constructed from risk predictors of INCS insensitivity in patients with AR demonstrated strong predictive power and enabled clinicians to identify high-risk patients, aiding them in developing an optimal treatment plan for AR.

Polymorphisms and AR: A Systematic Review and Meta-Analyses

Background: Allergic rhinitis (AR) is an especially common disorder associated with both environmental and genetic factors, and a lot of researchers have attempted to find polymorphisms which predisposed to the disease. We conducted a meta-analysis of the most frequently researched polymorphisms to find those genes which may be susceptible to AR and then may be of value in diagnosis.

Methods: Pubmed and China National Knowledge Infrastructure (CNKI) databases were searched to screen out eligible studies focusing on the correlation between polymorphisms and AR susceptibility, and then polymorphisms cited in at least 3 studies were selected.

Results: The 142 papers originally selected cited 78 genes. Twelve genes (coinciding with 23 polymorphisms) were reported in more than three papers. Twenty-three polymorphisms were involved in the meta-analysis. Among the 23 polymorphisms, only 4 were found to be related to the risk of AR: IL-13 rs20541, CTLA-4 rs11571302, IL-4R RS1801275 and ACE (I/D). The remaining 19 of the 23 polymorphisms were not associated with AR.

Conclusion: We found polymorphisms that could be used for AR diagnosing and those that were unrelated to AR. This may be the first step in detecting polymorphic combinations susceptible to AR (IL-13 RS20541, CTLA-4 RS11571302, IL-4R RS1801275 and ACE (I/D). In addition, our results may improve AR diagnosis and contribute to the intensive study of AR.

Rhinosinusitis and its impact on quality of life in children

Rhinitis and rhinosinusitis are common conditions which have a significant burden on healthcare services and can lead to reduced productivity in patients across the entire age spectrum. Three disease-specific quality of life tools were analysed in hospital and community settings to explore prevalence, disease characteristics and financial costs to sufferers, and to compare these aspects between cohorts (young children, young adult and adults). These tools were Modified Sino-Nasal Outcome Test-20 (MSNOT-20) questionnaire for adults, MSNOT-20 Young Persons Questionnaire (MSYPQ) for 11–16-year-olds and Sami's Rhinosinusitis Diagnosis and Impact questionnaire for 5–10-year-olds. One of the top three symptoms in children aged 5–10 years was cough, which is a much less common symptom in adults. These validated, disease-specific, quality of life questionnaires provide a fuller illustration of the patient experience, allowing comprehensive comparative analysis across the ages.

[Allergic rhinitis in children: from diagnosis to therapy]

Allergic rhinitis, according to modern data, affects up to a quarter of the population of developed countries. The disease affects not only the nasal mucosa, but also affects the receptors and mediators of inflammation in the bone marrow. A significant decrease in the quality of life of patients against the background of exacerbation of allergic rhinitis makes us look for new approaches to both the treatment of attacks and their prevention. Correction, including surgical, of concomitant pathology of the nasal cavity and paranasal sinuses significantly improves the quality of life of patients with allergic rhinitis. For a long time, surgical treatment of concomitant pathology of the nasal cavity in children was extremely limited due to the risk of damage to the growth zones and, as a consequence, a high probability of recurrence of deformation of the structures of the nose and paranasal sinuses. With the development of endoscopic methods of surgical treatment of the nasal cavity and paranasal sinuses, operations with minimal invasiveness and, as a consequence, safe at any age were introduced into practice. Surgical intervention on the structures of the lymphoid pharyngeal ring in children with allergic rhinitis is causing heated debate in the pediatric community to date. The article considers modern approaches to the diagnosis and treatment of allergic rhinitis in children. Topical problems of conservative and surgical treatment are discussed. Special attention is paid to the safety of various treatment regimens. The discussed practical issues of tactics of treatment of allergic rhinitis are relevant for both pediatric allergists and ENT pediatricians.

Allergic Disease, Short Sleep Duration, and Suicidal Ideation and Plans Among Korean Adolescents

The purpose of the study is to identify the relationships between allergic disease, suicidal ideation, and plans among Korean adolescents. Additionally, we examined the mediating role of short sleep duration. We analyzed nationally representative cross-sectional data from the 12th to 14th Korea Youth Risk Behavior Web-Based Survey; the final sample included 164,725 middle school-aged and high school-aged adolescents (mean age = 15.17 years, standard deviation = .13; 51.1% male). Allergic disease was a statistically significant risk factor for suicidal ideation (crude odds ratio [COR] = 1.284, 95% confidence interval [CI] = [1.246, 1.323]) and suicide plans (COR = 1.165, 95% CI = [1.108, 1.224]). Short sleep duration was a statistically significant mediator (p < .001). We advised school nurses to assess warning signs of poor sleep-including irritability, depression, sleep problems, poor concentration, and poor academic achievement-and that programs be created to improve sleep and mental health in adolescents with allergic disease.

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.

Replication study of susceptibility variants associated with allergic rhinitis and allergy in Han Chinese

Background

Allergic rhinitis (AR) is believed to be a complex genetic disease. The last decade has been marked by the publication of more than 20 genome-wide association studies (GWASs) of AR and associated allergic phenotypes and allergic diseases, which have shown allergic diseases and traits to share a large number of genetic susceptibility loci. The aim of present study was therefore to investigate the highly replicated allergy related genes and variants as candidates for AR in Han Chinese subjects.

Methods

A total of 762 AR patients and 760 control subjects were recruited, and a total of 58 susceptible variants previously reported to be associated with allergic traits were choose for replication.

Results

Logistic regression analyses revealed that in the co-dominant-effect model as assessed by the AIC, compared with wild-type carriers, significant AR risk were associated with rs9865818 in LPP (P = 0.029, OR = 1.469 for GG vs. AA); rs6554809 in DNAH5 (P = 0.000, OR = 1.597 for TC vs. CC); rs1438673 in WDR36-CAMK4 loci (P = 0.037, OR = 1.396 for CC vs.TT), rs7775228 in HLA region (P = 0.000, OR = 1.589 for TC vs.TT), rs7203459 in CLEC16A (P = 0.025, OR = 0.731 for TC vs. TT).

Conclusion

We replicated Han Chinese AR-specific susceptibility loci in LPP, DNAH5, HLA, CLEC16A and WDR36-CAMK4. Further understanding the molecular mechanisms underlying these associations may provide new insights into the etiology of allergic disease.

Association between MCP-1 -2518A>G polymorphism and asthma susceptibility: a meta-analysis

The published data on the association between MCP-1 -2518A>G polymorphism and asthma susceptibility are inconclusive. Therefore, we performed a meta-analysis to estimate the impact of MCP-1 -2518A>G polymorphism on asthma susceptibility. PubMed, Web of Science, Wanfang, and China National Knowledge Infrastructure (CNKI) databases were used to identify eligible studies. The pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were used to calculate the strength of association. Sensitivity analysis was performed to evaluate the influence of individual studies on the estimates of overall effect, and funnel plots and Egger's test were used to assess publication bias. Eight publications with 1562 asthma patients and 1574 controls were finally identified. Overall, we found no significant association between MCP-1 -2518A>G polymorphism and asthma susceptibility in any of the genetic model comparisons. After stratified analysis by ethnicity, the results showed that a significant association with asthma risk was found in Caucasians in all the genetic models. However, a protective association was found in Africans under the dominant model. The present meta-analysis suggested that the MCP-1 -2518 A>G polymorphism is a risk factor for asthma in the Caucasian population, nevertheless it has a protective effect in the African population.

Identification of rare variants of allergic rhinitis based on whole genome sequencing and gene expression profiling: A preliminary investigation in four families

Background

Despite the success of genome-wide association studies for allergic rhinitis (AR), no definitive causal variants have been identified, and a substantial portion of the heritability of the disease is yet to be discovered.

Methods

Four families, each with at least 1 parent and one child suffering from dust mite (DM) AR, were recruited, and whole-genome sequencing was performed on samples from 9 eligible individuals from these families. Conjoint analysis was performed for existing gene expression profiling data in the literature and the whole genome sequencing data obtained for these individuals; for presence of family-specific variants segregating with AR and the pathways involved. Similar analyses were also performed with data obtained for 96 sporadic house dust mite (HDM) AR patients and 96 healthy controls.

Results

Three rare variants in three genes (FLT1_c.603A ​> ​T; VEGFB_c.322A ​> ​C; and ITGA2_c.502+1G ​> ​A), which are involved in Focal Adhesion pathway, were identified in affected, but not unaffected, subjects in two families. VEGFB_c.322A ​> ​C and/or ITGA2_c.502+1G ​> ​A were further detected in all DM AR patients but not in any healthy individuals in 1 family; which was further investigated for members. The 3 identified variants were not found in any of the sporadic DM AR patients or healthy controls.

Conclusion

Despite the relatively small sample size, this study has identified several potentially functional rare variants in AR candidate genes, and it provides a platform for future work in larger numbers of families and sporadic individuals for a better understanding of the genetic basis of AR.

Association of Ugrp2 gene polymorphisms with adenoid hypertrophy in the pediatric population

INTRODUCTION

Adenoid hypertrophy is a condition that presents itself as the chronic enlargement of adenoid tissues; it is frequently observed in the pediatric population. The Ugrp2 gene, a member of the secretoglobin superfamily, encodes a low-molecular weight protein that functions in the differentiation of upper airway epithelial cells. However, little is known about the association of Ugrp2 genetic variations with adenoid hypertrophy.

OBJECTIVE

The aim of this study is to investigate the association of single nucleotide polymorphisms in the Ugrp2 gene with adenoid hypertrophy and its related phenotypes.

METHODS

A total of 219 children, comprising 114 patients suffering from adenoid hypertrophy and 105 healthy patients without adenoid hypertrophy, were enrolled in this study. Genotypes of the Ugrp2 gene were determined by DNA sequencing.

RESULTS

We identified four single nucleotide polymorphisms (IVS1-189G>A, IVS1-89T>G, c.201delC, and IVS2-15G>A) in the Ugrp2 gene. Our genotype analysis showed that the Ugrp2 (IVS1-89T>G) TG and (c.201delC) CdelC genotypes and their minor alleles were associated with a considerable increase in the risk of adenoid hypertrophy compared with the controls (p=0.012, p=0.009, p=0.013, and p=0.037, respectively). Furthermore, Ugrp2 (GTdelCG, GTdelCA) haplotypes were significantly associated with adenoid hypertrophy (four single nucleotide polymorphisms ordered from 5' to 3'; p=0.0001). Polymorfism-Polymorfism interaction analysis indicated a strong interaction between combined genotypes of the Ugrp2 gene contributing to adenoid hypertrophy, as well as an increased chance of its diagnosis (p<0.0001). In addition, diplotypes carrying the mutant Ugrp2 (c.201delC) allele were strongly associated with an increased risk of adenoid hypertrophy with asthma and with allergies (p=0.003 and p=0.0007, respectively).

CONCLUSION

Some single nucleotide polymorphisms and their combinations in the Ugrp2 gene are associated with an increased risk of developing adenoid hypertrophy. Therefore, we tried to underline the importance of genetic factors associated with adenoid hypertrophy and its related clinical phenotypes.

IL-13 -1112 polymorphism and periodontitis susceptibility: a meta-analysis

Background

Several studies have examined the association between the IL-13 -1112C/T polymorphism and the risk of periodontitis. However, these studies have reached different conclusions. The aim of the current study was to investigate the link between this IL-13 -1112 polymorphism and susceptibility to periodontitis.

Methods

We utilized electronic databases, including the CNKI (China National Knowledge Infrastructure), Wanfang, PubMed, Embase, and Cochrane Library databases, to manually search for relevant research published through November 30, 2016. The Chinese and English terms used to search the literature included “periodontitis”, “periodontal disease”, “IL 13”, “IL-13”, and “interleukin-13”. In accordance with our inclusion criteria, we selected studies that involved case-control trials. All of these case-control trials described their objectives, design and specific statistical methods. For all included studies, odds ratios (ORs) and 95% confidence intervals (95% CIs) were provided or could be calculated from the study data. The quality of the included literature was evaluated using the Newcastle-Ottawa scale (NOS). STATA 12.0 was used to calculate the sizes of the combined effects and conduct a sensitivity analysis of the results.

Results

Our meta-analysis included 4 articles representing 5 case-control studies with a total of 710 cases and 671 control subjects. The meta-analysis results indicated that the CC vs TT model, CT vs TT model and TT vs CT + CC model (CC VS TT: OR = 0.615, 95% CI = 0.395–0.957; CT vs TT: OR = 0.518, 95% CI = 0.323–0.830; and TT vs CT + CC: OR = 1.739, 95% CI = 1.130–2.676) were significant in five IL-13 -1112 gene polymorphism and periodontitis susceptibility models. Subgroup analysis indicated that the CC vs TT, CT vs TT and TT vs CT + CC models were significant in the chronic periodontitis (CP) group, whereas no significant differences were found in the five aggressive periodontitis (AgP) group models. The sensitivity analysis showed that dropping any single study did not affect the pooled analysis results.

Conclusion

The IL-13 -1112 polymorphism may be associated with susceptibility to periodontitis. The IL-13 -1112 gene polymorphism may be associated with susceptibility to CP but not to AgP. Thus, large-scale, multi-ethnic case-control trials are still warranted.

Is the atopic march related to confounding by genetics and early-life environment? A systematic review of sibship and twin data

A popular hypothesis known as the atopic march proposes a set of sequential allergy and respiratory disorders in early childhood contributes enormously to the burden of disease in developed countries. Although the concept of the atopic march has been refined and strengthened by many cross-sectional and longitudinal studies linking eczema as the initial manifestation with progression to hay fever and then asthma, there is yet no definitive proof that the atopic march is the primary causal factor in childhood allergic disease. This debate is mainly related to the controversy around potential confounding of these associations by genetic and environmental factors. Family studies are ideally suited to unravelling the role of these factors. While multiple reviews have synthesized evidence from studies investigating this question, no review to date has explored specific evidence generated by twin and sibling studies to understand the aetiology of atopic march diseases. Our aim was to conduct a systematic review of twin and sibling studies that examine the allergic phenotypes that form the atopic march, to determine whether such analyses of data from these studies attempt to control for the effect confounding by shared factors, and to report estimates of the magnitude of associations between multiple phenotypes. Our review suggests that (1) genetics play a bigger role predisposing eczema to hay fever and eczema to asthma than environmental factors, and (2) the link between eczema and asthma and hay fever is independent of shared early-life environmental factors.

Association between HLA Class II Locus and the Susceptibility to Artemisia Pollen–Induced Allergic Rhinitis in Chinese Population

OBJECTIVE

The aim of the study was to determine whether susceptibility or resistance to Artemisia pollen-induced allergic rhinitis was associated with HLA class II DQA1, DQB1 loci. Study design and setting Forty-one subjects with allergic rhinitis and 41 healthy controls from Beijing were genotyped at HLA class II DQA1, DQB1 alleles by polymerase chain reaction amplification with sequence-specific primers-based technique.

RESULTS

The allele frequencies of HLA-DQA1*0201, DQB1*0602 were lower in patients with allergic rhinitis compared with the controls (24.39% versus 46.34%, P = 0.038; 4.88% versus 26.83%, P = 0.007), and the frequency of DQA1*0302 was higher among patients than the controls (58.54% versus 14.63%, P = 0.00004, Pc = 0.0004).

CONCLUSION AND SIGNIFICANCE

HLA-DQA1 and -DQB1 genes may be involved in the development of Artemisia pollen-induced allergic rhinitis. HLA-DQA1*0201, DQB1*0602 alleles may be a protective factor and DQA1*0302 may be a susceptible factor for Artemisia pollen-induced allergic rhinitis.

Common immune-related exposures/conditions and risk of non-Hodgkin lymphoma: a case-control study of disease-discordant twin pairs

We evaluated the association between common immune system-altering experiences and non-Hodgkin lymphoma (NHL) risk using a case-control study of 162 like-sex twin pairs discordant for NHL, identified from the International Twin Study. Information on medical history and evidence of childhood exposure to microbes was obtained by questionnaire from 1998 to 2002. Conditional logistic regression was used to estimate odds ratios and 95% confidence intervals. Intra-twin-pair agreement between twins on individual exposures was high (76%-97%). A negative association between NHL and seasonal hay fever (odds ratio (OR) = 0.28, 95% confidence interval (CI): 0.10, 0.75) and certain allergies (OR = 0.29, 95% CI: 0.13, 0.68) was observed. The number of atopic diseases was negatively associated with NHL (P for trend = 0.0003). A history of infectious mononucleosis was negatively associated with NHL risk (OR = 0.35, 95% CI: 0.14, 0.90). NHL risk was associated with more frequent childhood exposure to microbes during early life (P for trend = 0.04). No differences in association by NHL subtype were observed, although statistical power for these comparisons was low. These observations support the hypothesis that immune-related exposures, especially atopy, are associated with decreased NHL risk. Use of the within-twin-pair study design mitigates confounding by genome, family structure, and unmeasured characteristics of early childhood factors.

Single-Nucleotide Polymorphisms on the RYD5 Gene in Nasal Polyposis

Nasal polyposis (NP) is a chronic inflammatory disease. Several genes play major roles in the pathophysiology of the disease. We analyzed RYD5 gene polymorphisms to determine the effect of these variants or their genetic combinations on NP. We genotyped the RYD5 gene in 434 participants (196 patients with NP and 238 controls). Data were analyzed with SPSS, SNPStats, and multifactor dimensionality reduction (MDR) software. We genotyped 10 single-nucleotide polymorphisms (SNPs) in the RYD5 gene. RYD5 (+152G>T) (p.Gly51Va) has not been reported previously. The PolyPhen and PROVEAN predicted the missense mutation as deleterious, but sorting intolerant from tolerant (SIFT) did not. In the genotype analysis, we found that four SNPs (RYD5 [-264A>G], [-103G>A], [+57-14C>T], and [+66A>G]) were significantly associated with NP. The individuals with combined genotypes of six risk alleles (RYD5-264G, -103A, +13C, +57-14T, +66G, and +279T) had significantly higher risks for NP compared with the ones with one or four risk alleles. Haplotype analysis revealed that the two haplotypes were associated with risk of NP. As indicated by MDR analysis, RYD5 (-264A>G and -103G>A) and RYD5 (-264A>G, -177C>A, and -103G>A) were the best predictive combinations and they had the highest synergistic interaction on NP. In addition, RYD5 (+13C>T) was significantly associated with increased risk of both NP with asthma and NP with allergy and asthma. Some SNPs and their combinations in the RYD5 gene are associated with increased probability for developing NP. We emphasize the importance of genetic factors on NP and NP-related clinical phenotypes.

Association between the Interaction of Key Genes Involved in Effector T-Cell Pathways and Susceptibility to Develop allergic Rhinitis: A Population-Based Case-Control Association Study

Background

Evidence suggests that interaction between key genes mediating signaling and transcriptional networks involving effector T-cell responses may influence an individual’s susceptibility to develop allergic rhinitis(AR).

Objective

The aim of this study was todetermine whether specific interactions between key genes involved in effector T-cell pathways are associated with an individual’s susceptibility to develop AR in Han Chinese subjects.

Method

A cohort of 489 patients with AR and 421 healthy controls was enrolled from the Han Chinese population in Beijing, China. AR was established by questionnaire and clinical examination, and peripheral blood was drawn from all subjects for DNA extraction. A total of 96 single nucleotide polymorphisms (SNPs) in 26 reprehensive candidate genes involved in T helper 1 (Th1), Th2, Th17, Th9 and T regulatory cell pathways were selected from the International Haplotype Mappingdatabase for Han Chinese in Beijing (CHB) population, and IlluminaGoldenGate assay was conducted for SNP genotyping. The PLINK software package was used to perform statistical analyses.

Results

Simple SNP-phenotype association analysis using logistic regression showed SNP rs8193036 in IL17A gene, rs2569254 in IL-12 and rs1898413 in RORα weresignificantlyassociatedwith AR.Simple SNP-phenotype association analysis with genetic models demonstrated thatrs2569254 in IL-12, rs1031508 in STAT4, and rs3741809 in IL-26 were likely to be recessive, rs8193036 in IL17A allelic, rs897200in STAT4 genotypic, and rs1898413 in RORα dominant. Epistasis analyses exhibited that 83 SNPs in 23 genes were significantly interactive; of which 59 interactions/SNP pairs demonstrated OR values higher than 2 or lower than 0.5, and 12 interactions/SNP pairs OR values higher than 4 or lower than 0.25. STAT3, RORα and IL-26, involved in Th17 pathway,were the mostfrequentlyinteractive genes.

Conclusion

This study suggests that interactions between several SNPs in key genes involved in effector T-cell pathways are likely to influence an individual’s susceptibility to develop AR.

Exploring the origins of asthma: Lessons from twin studies

This thesis explores the contribution of twin studies, particularly those studies originating from the Danish Twin Registry, to the understanding of the aetiology of asthma. First, it is explored how twin studies have established the contribution of genetic and environmental factors to the variation in the susceptibility to asthma, and to the variation in several aspects of the clinical expression of the disease such as its age at onset, its symptomatology, its intermediate phenotypes, and its relationship with other atopic diseases. Next, it is explored how twin studies have corroborated theories explaining asthma's recent increase in prevalence, and last, how these fit with the explanations of the epidemiological trends in other common chronic diseases of modernity.

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

Background

The ADAM33 gene has been identified as a potentially important asthma candidate gene and polymorphisms in this gene have been shown to be associated with asthma and seasonal allergic rhinitis.

Objective

To assess whether the ADAM33 polymorphisms are associated with persistent allergic rhinitis (PER) due to house dust mites in a Chinese population.

Methods

In a hospital-based case-control study of 515 patients with mite-sensitized PER and 495 healthy controls, we genotyped seven single nucleotide polymorphisms (SNPs) in ADAM33. Serum levels of eosinophil cationic protein, total IgE and allergen-specific IgE against Dermatophagoides pteronyssinus and Dermatophagoides farinae were measured by the ImmunoCAP assays.

Results

In the single-locus analysis, three polymorphisms, rs3918392 (F1), rs528557 (S2) and rs2787093, were significantly associated with mite-sensitized PER. SNP S2 was associated with significantly increased risk both of asthmatic and nonasthmatic mite-sensitized PER. In the combined genotypes analysis, individuals with 2–4 risk alleles had a significantly higher risk of mite-sensitized PER (adjusted OR = 1.99, 95% CI = 1.50–2.62) than those with 0–1 risk alleles. Haplotype-based association analysis revealed that the ACAGCCT haplotype might have potential to protect against mite-sensitized PER (adjusted OR = 0.67; 95% CI = 0.49–0.90).

Conclusions

Polymorphisms in the ADAM33 gene may contribute to susceptibility of mite-sensitized PER in this Chinese population.

Grass pollen allergy in children and adolescents-symptoms, health related quality of life and the value of pollen prognosis

INTRODUCTION

An association between pollen count (Poaceae) and symptoms is well known, but to a lesser degree the importance of priming and lag effects. Also, threshold levels for changes in symptom severity need to be validated. The present study aims to investigate the relationship between pollen counts, symptoms and health related quality of life (HRQL), and to validate thresholds levels, useful in public pollen warnings.

MATERIAL AND METHODS

Children aged 7-18 with grass pollen allergy filled out a symptom diary during the pollen season for nose, eyes and lung symptoms, as well as a HRQL questionnaire every week. Pollen counts were monitored using a volumetric spore trap.

RESULTS

89 (91%) of the included 98 children completed the study. There was a clear association between pollen count, symptom severity and HRQL during the whole pollen season, but no difference in this respect between early and late pollen season. There was a lag effect of 1-3 days after pollen exposure except for lung symptoms. We found only two threshold levels, at 30 and 80 pollen grains/m(3) for the total symptom score, not three as is used today. The nose and eyes reacted to low doses, but for the lung symptoms, symptom strength did hardly change until 50 pollen grains/m(3).

CONCLUSION

Grass pollen has an effect on symptoms and HRQL, lasting up to 5 days after exposure. Symptoms from the lungs appear to have higher threshold levels than the eyes and the nose. Overall symptom severity does not appear to change during the course of season. Threshold levels need to be revised. We suggest a traffic light model for public pollen warnings directed to children, where green signifies "no problem", yellow signifies "can be problems, especially if you are highly sensitive" and red signifies "alert - take action".

Expressions of nuclear factor-kappa B p50 and p65 and their significance in the up-regulation of intercellular cell adhesion molecule-1 mRNA in the nasal mucosa of allergic rhinitis patients

The purpose of the study was to investigate expressions of nuclear factor-kappa B (NF-κB) and intercellular cell adhesion molecule-1 mRNA (ICAM-1 mRNA) in the nasal mucosa of allergic rhinitis (AR) patients. Expressions of NF-κB and ICAM-1 mRNA were studied using immunohistochemistry and reverse transcription-PCR (RT-PCR) in AR tissues and corresponding normal nasal mucosa. The correlation between NF-κB and ICAM-1 mRNA was studied using linear correlation analysis. The results of immunohistochemistry showed that expression of NF-κB was significantly up-regulated in the nasal mucosa of AR compared with that in normal tissue (P < 0.01), over-expression of NF-κB p50 was found in the cytoplasm and nucleus (P < 0.01), and NF-κB p65 was mainly expressed in the cytoplasm (P < 0.01). ICAM-1 mRNA was strongly expressed in the nasal mucosa of AR compared with that in normal tissue as shown by RT-PCR (P < 0.01). Up-regulation of ICAM-1 mRNA was significantly correlated with over-expressions of NF-κB p50 and NF-κB p65 (r = 0.8995, P < 0.01; r = 0.7601, P < 0.01). In conclusion, NF-κB plays a key role in AR. Excessively activated NF-κB promotes the transcription of ICAM-1 mRNA. ICAM-1 is related to the pathogenesis and development of AR.

Association between maternal allergic rhinitis and asthma on the prevalence of atopic disease in offspring

BACKGROUND

Asthma is a common co-morbidity of allergic rhinitis (AR). The prevalence of these two allergic diseases has increased in China and has been shown to cluster in families independently. This study evaluated the association between maternal AR (presenting with or without asthma) and the allergic conditions in offspring.

METHODS

Women (n = 592) diagnosed with AR were recruited for this study; 379 patients presented with AR and 213 presented with both AR and asthma. Total serum IgE levels and nasal eosinophil counts were analyzed and correlated with disease presentation.

RESULTS

The prevalence of allergic conditions in offspring of mothers diagnosed with AR and asthma was significantly higher than the prevalence observed in children born to mothers presenting with AR only. Maternal total serum IgE and eosinophil counts were predictive of atopy in offspring. Children born to mothers presenting with persistent moderate-to-severe AR had the highest risk of developing atopic conditions (OR 6.26, 95% CI 3.26-12.02). Maternal age of 25-30 years at delivery was also associated with a higher risk for the allergic disease in offspring compared to maternal age of 36-40 (OR 2.13, 95% CI 1.31-3.47).

CONCLUSIONS

The severity of maternal AR, asthma co-morbidity, elevated serum IgE levels and nasal eosinophilia were all associated with an increased risk of offspring developing allergic conditions. Children born to older mothers were protected against developing atopic disease.

Linkage of atopic dermatitis to chromosomes 4q22, 3p24 and 3q21

Atopic dermatitis (AD) is a common, itchy skin disease of complex inheritance characterized by dermal and epidermal inflammation. The heritability is considerable and well documented. To date, four genome scans have examined the AD phenotype, showing replicated linkage at 3p26-22, 3q13-21 and 18q11-21. Our previous AD scan showed evidence of linkage to loci at 3p and 18q, and furthermore at 4p15-14. In order to further investigate the genetic basis of AD, we collected and analysed a new Danish family sample consisting of 130 AD sib pair families (555 individuals including 295 children with AD). AD was diagnosed after clinical examination, AD severity was scored and specific IgE was determined. A linkage scan of chromosome 3, 4 and 18 was performed using 91 microsatellite markers. Linkage analyses were performed of dichotomous phenotypes and semi-quantitative traits including the AD severity score. We analysed the novel AD sample alone and together with the previously examined sample. AD severity showed a maximum Z-score of 3.7 at 4q22.1 suggesting the localization of a novel gene for AD severity. A maximum MOD score of 4.6 was obtained at 3p24 for the AD phenotype, providing the first significant linkage of AD at this locus. A maximum MLS score of 3.3 was obtained at 3q21 for IgE-associated AD, and evidence of linkage was also obtained at 3p22.2-21.31, 3q13, 4q35, and 18q12. The results presented should provide a firm basis for gene-targeting studies of AD and related disorders.

Detecting anti-FcepsilonRI autoantibodies in patients with asthma by flow cytometry

Autoimmune diseases have been implicated in the development of intrinsic asthma, however little data are available on the role of autoimmunity in the pathogenesis of asthma. The purpose of this study was to investigate circulating autoantibodies against the high-affinity receptor for immunoglobulin E, FcepsilonRI, in patients with asthma. Seventy-eight patients with asthma and 32 healthy control subjects were included. All individuals were tested using a triple-staining flow cytometry-based basophil activation test (BAT) for the potential presence of autoantibodies against FcepsilonRI. Of the 78 asthma patients, 29 (37.2%) had a positive BAT result, indicating that their serum was able to activate basophils, compared with only four (12.5%) of the control group, a statistically significant between-group difference. These data suggest that some asthma patients have aberrant anti-FcepsilonRI autoantibodies, which implies that autoimmunity may be one factor involved in the pathogenesis of intrinsic asthma.

Allergy: a systemic disease? The HUNT and Young-HUNT study, Norway

A systemic nature of allergic diseases has been hypothesized. As part of this discussion, we studied if adolescent allergic wheeze and increasing combinations of allergic organ involvements (lung, nose and skin) would also increase the reporting of other health problems (headache, muscle pain and abdominal pain). In addition, we studied if parental asthma was associated with adolescent clustering of allergic expressions and if parental asthma with additional health problems (headache or muscle pain) was associated with adolescent reporting allergy in combination with headache, muscle pain and abdominal pain. Adolescents 13-19 yr (n = 8817, 89%) participated in the Young-HUNT study, Norway, 1995-97. Parental data on asthma were eligible in n = 5620. Health and lifestyle were measured by questionnaires and interviews. Associations with additional health problems were significantly strengthened with combinations of wheeze and other allergic expressions. Odds Ratio for associations 'wheeze only', 'wheeze and rhinitis' and 'wheeze, rhinitis and eczema' were for headache 2.1, 3.4 and 3.7; for muscle pain 2.8, 3.2 and 4.9; for abdominal pain 3.6, 4.0 and 4.9. All p for trend were <0.010. Similar results were obtained when studying allergic wheeze; p for trend <0.001. Parental asthma was associated with clustering of adolescent allergic expressions, and parental asthma with headache or muscle pain was significantly associated with reported allergy combined with similar health problems in their offspring. The results indicate that allergy may be expressed beyond organs commonly viewed as part of an allergic disease, and hence may support a hypothesis of a systemic nature of allergic diseases.

Etiological relationships in atopy: a review of twin studies

The genetics of asthma and atopy has been studied frequently in twin populations from various parts of the world. However, emphasis has been put on univariate analysis of questionnaire data, whereas clinical and intermediate traits only sporadically have been studied, especially in multivariate settings. This review focuses on multivariate twin studies of atopy and related traits. We conclude that the genetic liability to most atopic traits is significantly correlated but that trait-specific genes also play a role. Previous studies have estimated the genetic correlation between upper and lower respiratory allergic symptoms, that is, asthma and hay fever, to be between .47 and .95. Furthermore, atopic traits share a portion of their genetic determinants with other complex disorders like obesity and behavioral traits. A correlation of about .3 and .34 has been reported between genes associated with asthma and obesity, and between genes associated with asthma and depression, respectively. We emphasize that multivariate methods applied to twin studies, especially when genetic marker information is available, provide a valuable framework within which complex etiological mechanisms underlying atopy can be disentangled.

Asthma from a pharmacogenomic point of view

Pharmacogenomics, a fascinating, emerging area of biomedical research is strongly influenced by growing availability of genomic databases, high-throughput genomic technologies, bioinformatic tools and artificial computational modelling approaches. One main area of pharmacogenomics is the discovery of new drugs and drug targets with molecular genetic, genomic or even bioinformatic methods; the other is the study of how genomic differences influence the variability in patients' responses to drugs. From a genetic point of view, asthma is multifactorial, which means that the susceptibility to the disease is determined by interactions between multiple genes, and involves important non-genetic factors such as the environment for their expression. In this review, we summarize collective evidence from linkage and association studies that have consistently reported suggestive linkage or association of asthma or its associated phenotypes to polymorphic markers and single nucleotide polymorphisms in selected chromosomes. Genes that have been found implicated in the disease are potential new drug targets and several pharmacological investigations are underway to utilize these new discoveries. Next, we will focus on the inter-individual variability in anti-asthmatic drug responses and review the recent results in this topic.

The genetics of atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is a complex genetic disorder influenced by environmental factors. The mode of inheritance and genes involved are not clear.

RESULTS

This report here is focusing on the current progress in searching the disease-susceptibility genes of AD via both the linkage studies and candidate gene approaches. Genome-wide linkage studies have identified multiple susceptibility loci on 3q and 17q. Candidate region linkage studies identify other susceptibility loci on 5q23-33, 11q13, and 13q12-14. At least 28 candidate genes have to date been verified in association studies, but only association with genes of interleukin (IL)-4, IL-13, IL-4RA, mast cell chymase, and serine protease inhibitor, kazal-type 5 have been replicated in more than two different studies. More halpotype tests and family-based association studies may help to shed more light for the candidate gene approach.

CONCLUSION

Determining the candidate susceptibility genes for AD is not only helping understanding the pathophysiology but also affecting the response to therapy, which is important in pharmacogenetics. The effect of environmental trigger may also have to be considered to elucidate the real face of the disease.

Autologous serum skin test for autoantibodies is associated with airway hyperresponsiveness in patients with asthma

BACKGROUND

Autoimmune diseases have been implicated as a cause of intrinsic asthma; however, there is little data on the role of autoimmunity in the pathogenesis of asthma.

OBJECTIVE

The purpose of this study was to investigate circulating functional autoantibodies against the high-affinity IgE receptor FcepsilonRI or IgE in patients with asthma.

METHODS

Twenty-eight patients with asthma and 19 control subjects were included. All subjects were skin tested with autologous serum to assess for the potential presence of receptor FcepsilonRI or IgE autoantibodies. If the serum-induced wheal diameter was 1.5 mm larger than the histamine-induced wheal diameter and that was 3 mm larger than the saline-induced wheal diameter at 30 min, the reaction was defined positive.

RESULTS

Of the 47 total subjects (both asthma patients and control subjects), 13 (27.7%) had a positive autologous serum skin test (ASST). Of the 28 asthma patients, 8 (28.6%) were regarded as having autoimmune origin. Autoantibodies against FcepsilonRI or IgE were found in asthma patients, irrespective of atopic status (atopy+ 3/13 vs. atopy- 5/15). The wheal diameter related to ASST was not related to atopy. Asthma patients with ASST-positive results as compared with patients with ASST-negative results exhibited a significant increased airway hyperresponsiveness (PC(20) methacholine, 2.70 +/- 1.27 vs. 9.08 +/- 2.35; p < 0.026).

CONCLUSION

Our data demonstrate that aberrant autoantibodies against the high-affinity IgE receptor FcepsilonRI or IgE are related to airway hyperresponsiveness in patients with asthma.

Pediatric asthmatic patients have low serum levels of monocyte chemoattractant protein-1

Serum levels of MCP-1 were measured in children with and without asthma in order to determine a possible correlation between the MCP-1-2518A/G polymorphism, serum levels of MCP-1 and asthma. Two groups of subjects -160 children with asthma and 158 healthy children were screened with a PCR-based genotyping assay. Serum MCP-1 level was measured by ELISA. The -2518G allele occurred at a significantly higher frequency in asthmatic children than in controls. The mean serum MCP-1 level was significantly lower in the asthmatic than in the control children. There was no significant association between the MCP-1 genotypes and the serum MCP-1 levels.

Highly significant linkage to chromosome 3q13.31 for rhinitis and related allergic diseases

BACKGROUND

Allergic diseases such as asthma and rhinitis have closely related phenotypes and often occur with atopy. They show strong familial and intra-individual clustering, suggesting overlapping disease aetiology. Various loci and candidate genes have been suggested to underlie allergy. Many or all are still inconclusive. Following genome-wide scans on multiple phenotypes, we previously suggested that chromosome 3q13.12-q21.2 harbours an allergy locus.

OBJECTIVE

To identify candidate loci in the Danish population, two additional independent sets of sib-pair families were fine-scale mapped in candidate regions showing maximum likelihood scores (MLS) > or =1.5 in the genome-wide scans.

RESULTS

Twenty eight microsatellite markers in a denser map on chromosome 3q were analysed in 236 allergy sib-pair families including 125 sib pairs with rhinitis. We report significant evidence for linkage to chromosome 3q13.31 for rhinitis (MLS 5.55, identity by descent (IBD) 63.9%) and atopy (increased specific immunoglobulin E) (MLS 3.71, IBD 61.7%). We obtained an MLS of 5.1 (IBD 67.3%) at 3q13.31 when sib pairs with both rhinitis and atopy were analysed.

CONCLUSION

This study reports the first statistically significant evidence for a genetic susceptibility locus for rhinitis and to our knowledge shows the most significant evidence to date of linkage for any allergy phenotype.

Acoustic rhinometry, rhinomanometry and spirometry of the asthmatics patients with rhinitis symptoms before and after oral corticoid

INTRODUCTION

Asthma and rhinitis frequently co-exist in the same patient. It may exist a specific condition witch affects the general respiratory activity and also able to produce symptoms into upper and/ or lower airways.

PURPOSE

To analyze the alteration and functional burst of upper and lower airways before and after oral corticoid.

METHODS

From July of 2000 to August of 2002, sixteen (69 % was female ), acute asthmatics patients with rhinitis symptom assisted in the pneumology department, were analyzed through cross-sectional study using: symptoms questionnaire, physical examination, radiogram, spirometry, acoustic rhinometry, and rhinomanometry.

RESULTS

Sixteen patients presented compromising symptoms of the upper airways. In the spirometry, FEV1, FEV1/FVC e FEF25-75%, presented major statistically differences. The acoustic rhinometry presented important statistical differences in the minimal cross- sectional area 1 e 2 in the left side and total nasal volume, after medicine intervention.

CONCLUSIONS

The functional evaluations upon lower and upper airways, improvements in FEV1, FEV1/FVC e FEF25-75%, were observed through spirometry and total nasal volume, analyzing the acoustic rhinometry after oral corticoid.

Lack of association between the IL13 variant Arg110Gln and susceptibility to cedar pollinosis in a Japanese population

BACKGROUND

Interleukin (IL)-13 has come to be appreciated as a molecule critically involved in allergic inflammatory responses. Recent studies revealed that a common variant in the coding region of the IL13 gene, Arg110Gln, has been implicated in the development of asthma and atopy.

METHODS

To assess whether the IL13 variant Arg110Gln is associated with cedar pollinosis, one of the most common atopic diseases in the Japanese population, we examined the Arg110Gln variant using PCR-RFLP to compare the genotype and allele frequencies between 95 patients with cedar pollinosis and 95 healthy control subjects. Relationships between the Arg110Gln variant and the pollinosis-related traits, e.g. rhinitis severity, eosinophil counts in nasal secretion and serum total and allergen-specific IgE levels, were also investigated.

RESULTS

The frequencies of the minor allele Gln110 were 25.8% in patients with cedar pollinosis and 30.9% in healthy control subjects (p > 0.05). There was also no significant difference in the genotype frequencies between cases and controls (p > 0.05). In addition, we found no significant association of the Arg110Gln variant with any of the pollinosis-related phenotypes (p > 0.05).

CONCLUSIONS

Our data suggest lack of evidence for identifying the variant Arg110Glnat the IL13 locus as a genetic risk factor involved in the development of Japanese cedar pollinosis.

Atopy parameters in asthmatic children increase with accumulation of null-alleles of glutathione-S-transferase M1

Atopy parameters (total IgE, skin prick test, and peripheral blood eosinophil count) in children with atopic bronchial asthma depend on the number of glutathione-S-transferase M1 mutant alleles in the genotype and on family history of asthma.

Asma em menores de cinco anos: dificuldades no diagnóstico e na prescrição da corticoterapia inalatória

O objetivo deste trabalho foi fazer um levantamento bibliográfico focalizando as dificuldades para se diagnosticar a asma e se estabelecer o início da corticoterapia inalatória em menores de cinco anos. As fontes pesquisadas foram as bases de dados LILACS e MEDLINE, no período de 1991 a 2002, em português, espanhol e inglês. A asma, doença crônica mais comum na infância, apresenta o início dos sintomas nos primeiros anos de vida em grande percentagem dos casos. Na atualidade, não existem meios propedêuticos disponíveis rotineiramente que permitam estabelecer com certeza o diagnóstico em menores de cinco anos. De acordo com as manifestações clínicas, lactentes e pré-escolares podem demandar tratamento semelhante ao da asma desde que precedido por avaliação clínica criteriosa. Conclui-se que o diagnóstico da asma nos primeiros anos de vida é complexo e eminentemente clínico. A corticoterapia inalatória constitui recurso eficaz, mas exige ponderação dos riscos e benefícios.

Comparison of a generic and a rhinitis-specific quality-of-life (QOL) instrument in patients with house dust mite allergy: relationship between the SF-36 and Rhinitis QOL Questionnaire

BACKGROUND

Generic and disease-specific quality-of-life (QOL) questionnaires are commonly used in subjects with allergic rhinitis (AR). AR, however, is closely associated with other disorders such as bronchial asthma and atopic dermatitis (AD). These co-morbid associations may have an effect on the inter-relation of generic and disease-specific QOL outcomes and the behaviour of this inter-relation in time.

OBJECTIVE

To unravel the inter-relationships between the outcome of a generic instrument (SF-36) and a disease-specific instrument (Rhinitis QOL Questionnaire (RQLQ)).

MATERIALS AND METHODS

In the framework of a randomized clinical trial with respect to the efficacy of impermeable bedding covers in house dust mite (HDM) allergy, SF-36 and RQLQ were administered to 224 adults with AR and/or allergic asthma and/or AD at baseline and after 12 months of intervention. Regression analysis and canonical correlation were used to estimate overlap.

RESULTS

Overlap between SF-36 and RQLQ domains in terms of explained variance ranged from 6% to 56%. Canonical correlation yielded low coefficients (0.16-0.27). Moreover, both SF-36 and RQLQ scores did not change significantly during the intervention.

CONCLUSION

In patients with HDM allergy characterized by co-morbid associations, SF-36 and RQLQ cover different aspects in QOL. It is advocated to use both simultaneously in performing QOL studies.

Polymorphisms in ADAM33 are associated with allergic rhinitis due to Japanese cedar pollen

BACKGROUND

A recent report provided evidence that a disintegrin and metalloprotease domain 33 (ADAM33), a member of the ADAM family, is a novel susceptibility gene in asthma linked to bronchial hyper-responsiveness. However, there has been no investigation of the genetic role of ADAM33 variants in nasal allergy.

OBJECTIVE

The purpose of this study was to test the association between ADAM33 polymorphisms and Japanese cedar pollinosis (JCPsis), a most common seasonal allergic rhinitis in Japan.

METHODS

We conducted a case-control association study among a Japanese population, involving 95 adult individuals with JCPsis and 95 normal healthy controls. A total of 22 single-nucleotide polymorphisms (SNPs) in ADAM33 were genotyped using PCR-based molecular methods.

RESULTS

Six SNPs of ADAM33 gene, three in introns (7575G/A, 9073G/A and 12540C/T) and three in the coding region (10918G/C, 12433T/C and 12462C/T), were strongly associated with JCPsis (P = 0.0002-0.022 for absolute allele frequencies) and most of the SNPs were in linkage disequilibrium with each other. A higher frequency of the common alleles of these SNPs was noted for the subjects with JCPsis in comparison with healthy controls. We also identified a haplotype associated with the disease susceptibility. In addition, associations were found between ADAM33 polymorphisms and various cedar pollinosis phenotypes including clinical severity, eosinophil counts in nasal secretion and allergen-specific IgE levels in sera, but not total serum IgE levels.

CONCLUSION

These results indicate that polymorphisms in the ADAM33 gene are associated with susceptibility to allergic rhinitis due to Japanese cedar pollen, but the functional relationship still needs clarification.

Loss of Runx3 function in leukocytes is associated with spontaneously developed colitis and gastric mucosal hyperplasia

RUNX transcription factors are key regulators of lineage-specific gene expression and might be involved in autoimmune diseases. Runx3 plays a role during the development of sensory neurons and T cells and regulates transforming growth factor beta (TGF-beta) signaling in dendritic cells. Here, we report that at 4 weeks of age, Runx3 knockout (KO) mice spontaneously develop inflammatory bowel disease (IBD) characterized by leukocyte infiltration, mucosal hyperplasia, formation of lymphoid clusters, and increased production of IgA. Additionally, at a considerably older age (8 months), the KO mice also develop progressive hyperplasia of the gastric mucosa associated with disturbed epithelial differentiation and cellular hyaline degeneration. Analysis of cytokines in the colonic mucosa of Runx3 KO mice revealed a mixed T helper 1/T helper 2 response. By using immunohistochemistry and RNA in situ hybridization, Runx3 expression in the gastrointestinal tract is detected in lymphoid and myeloid populations but not in the epithelium. The data indicate that loss of leukocytic cell-autonomous function of Runx3 results in IBD and gastric lesion in the KO mice. IBD in humans is viewed as a complex genetic disorder. Several susceptibility loci were identified on different human chromosomes including the chromosomal region 1p36 where RUNX3 resides. It is thus tempting to speculate that mutations in RUNX3 may constitute an IBD risk factor in humans.

The common variants/multiple disease hypothesis of common complex genetic disorders

Unlike simple rare Mendelian disorders, the genetic basis for common disorders is unclear. A general model of the genetics of common complex disorders is proposed which emphasizes the shared nature of common alleles in related common disorders, such as schizophrenia and bipolar disorder, Type II diabetes and obesity, and among autoimmune diseases. This model, the common variants/multiple disease hypothesis, emphasizes that many disease genes may not be disease specific. Common deleterious alleles, found at a relatively high frequency in the population may play a role in related clinical phenotypes in the context of different genetic backgrounds and under different environmental conditions.

Promoter polymorphisms of the CD14 gene are not associated with bronchial asthma in Caucasian children

Several studies have investigated the association of a promoter polymorphism in CD14 with atopic phenotypes. We screened this and another polymorphism in 182 asthmatic children and found no association with asthma. Furthermore, there was substantial linkage disequilibrium of the polymorphisms. Thus CD14 does not play a major role in the development of asthma in our population of Caucasian children.

Fine-scale mapping of type I allergy candidate loci suggests central susceptibility genes on chromosomes 3q, 4q and Xp

BACKGROUND

Type I allergy globally affects an increasing number of individuals with the consequence of considerable personal morbidity and socio-economic costs. Identification of disease susceptibility genes would render enormous medical perspectives in terms of improved diagnosis, treatment and prevention. Like for other complex disorders, achievement of the knowledge necessary depends on confirmation of reported genomic candidate regions.

METHODS

We performed a two-stage fine-scale linkage analysis in 11 selected candidate regions on chromosome 3p, 3q, 4p, 4q, 5q, 6p, 9p, 12q, 12qter, 18q and Xp. We analysed 97 polymorphic markers in 424 individuals from 100 sib-pair families and evaluated the data for five phenotypes: Allergic asthma, atopic dermatitis, allergic rhinitis and total and specific immunoglobulin E.

RESULTS

The highest maximum likelihood scores (MLS) were obtained on chromosomes 3q (MLS = 2.69), 4p (MLS = 2.34), 4q (MLS = 2.75), 6p (MLS = 2.22), 12qter (MLS = 2.15) and Xp (MLS = 2.23). All five phenotypes showed MLS >/= 2 in one or more of the candidate regions.

CONCLUSIONS

Susceptibility genes in the 3q, 4q and Xp regions may play a central role in the inheritance of allergic disease, as positive results were obtained for all five phenotypes in these three regions.

Allergic rhinitis and polymorphisms of the interleukin 1 gene complex

BACKGROUND

Allergic rhinitis is a chronic inflammatory disease with a genetic background. Inflammatory reactions are regulated by cytokines. Cytokine genes are polymorphic and have been implicated as candidate genes in allergy.

OBJECTIVES

To study the significance of the interleukin 1 (IL-1) gene complex in allergic rhinitis.

METHODS

Population-based, cross-sectional study. We studied the polymorphisms of 3 IL-1 gene complex genes, IL1A (+4845G>T), IL1B (-511 degrees C>T), and IL1RN (variable number of tandem repeats; IVS2, 86 bp, duplicates 2 to 5), in patients with allergic rhinitis. The study group consisted of 405 nonasthmatic individuals of whom 56 had allergic rhinitis.

RESULTS

The genotype distribution differed significantly in all cytokine genes studied between subjects with and without allergic rhinitis. The difference was mainly due to an increased number of IL1A allele G homozygotes (67.9% vs 43.2%; odds ratio [OR], 2.8; 95% confidence interval [CI], 1.5-5.1), IL1B heterozygotes (72.2% vs 47.4%; OR, 2.8; 95% CI, 1.5-5.3), and IL1RN allele 2 homozygotes (18.5% vs 7.5%; OR, 2.8; 95% CI, 1.3-6.2) in allergic rhinitis. Haplotype analysis revealed a significant difference in the distribution of IL-1 gene complex haplotypes between subjects with and without allergic rhinitis (P = 0.005, 10 df).

CONCLUSIONS

The IL-1 gene complex polymorphism is strongly associated with allergic rhinitis in nonasthmatic individuals.

Site-specific sensitization in a murine model of allergic rhinitis: role of the upper airway in lower airways disease

BACKGROUND

Allergic rhinitis (AR) is the most common atopic disease with strong links to asthma. We have developed a murine model of AR to study nasal, bronchial, and systemic immune response to local allergen stimulation.

OBJECTIVES

The purpose of this study was to develop and characterize a murine model of AR.

METHODS

Six- to 8-week-old BALB/c mice were sensitized by means of intranasal (local) application of ovalbumin (OVA) or systemic intraperitoneal injection. They were then challenged with intranasal OVA, and allergic response was assessed.

RESULTS

Intranasal particle deposition was found to be exclusively in the nares. All sensitized animals showed increased levels of OVA-specific serum IgE and IgG after challenge, although the timing to maximal response varied with the route and dose of allergen used. Histology of the upper and lower airways showed marked eosinophilic infiltration, and analysis of bronchoalveolar lavage fluid showed increased IL-5 and PMN infiltrates after challenge.

CONCLUSION

Using exclusive local sensitization and challenge of mouse nares, we were able to demonstrate inflammatory changes in both the upper and lower airways, even though distribution of allergen particles appeared to be only in the nares of these animals. This provides further evidence for the importance of the upper airway in lower airways disease. We have shown that the route of administration greatly affects the characteristics of the subsequent immune responses.

Atopic dermatitis: review of immunopathogenesis and advances in immunosuppressive therapy

This paper reviews the theories of the pathogenesis of atopic dermatitis (AD), with a particular emphasis on its immunopathogenesis. The contribution of predisposing factors, immunopathogenic factors and provoking factors in the pathogenesis of AD are considered. Predisposing factors explored in this article include genetics and the disturbance of skin function. Immunopathogenic factors reviewed include T cell dysfunction, biphasic cytokine expression and the role of immunoglobulin E. Provoking factors considered include microbial factors, psychosomatic interactions, contact allergens and irritants, inhalant allergens, food and climate. Immunosuppressive treatments reviewed include cyclosporin, azathioprine, methotrexate, tacrolimus, interferon-gamma, phosphodiesterase inhibitors and pimecrolimus (SDZ ASM 981).

Asthma and atopy - a total genome scan for susceptibility genes

BACKGROUND

Allergic asthma is an increasingly common disease of complex inheritance. Several studies have suggested candidate regions, but genetic heterogeneity, ethnic differences and varying study designs may in part explain the lack of identified and confirmed susceptibility genes. Investigation of different populations will further clarify the topic. We therefore evaluated allergic asthma and increased total and specific IgE in 39, 45 and 57 sib-pairs from 100 Danish allergy families.

METHODS

Affected sib-pairs meeting a narrow phenotype definition were selected for the three phenotypes atopy, allergic asthma and increased total IgE. We performed a total genome scan using 446 microsatellite markers and obtained nonparametric linkage results from the MAPMAKER/SIBS computer program.

RESULTS

Our study revealed four candidate regions (MLS > 2) on chromosome 1p36, 3q21-q22, 5q31 and 6p24-p22, and 15 candidate regions (1 < MLS < 2) that may contain susceptibility genes for asthma and atopy. We did not find linkage to the candidate genes TNF-beta, FcER1beta and Il4R-alpha, except for weak support for linkage of the asthma phenotype to TNF-beta (MLS = 1.18).

CONCLUSIONS

We found evidence for two new asthma and atopy loci, 1p36 and 3q21-q22, and supported linkage in the Danish population to seven previously reported candidate regions.

Prevalence and severity of allergic rhinitis in house dust mite-allergic patients with bronchial asthma or atopic dermatitis

BACKGROUND

Allergic rhinitis, asthma and atopic dermatitis are closely associated. Although population-based studies report a high prevalence of rhinitis among asthma patients, less is known of the association between rhinitis and atopic dermatitis and the severity of concomitant rhinitis.

OBJECTIVES

We aimed to determine the prevalence and severity of allergic rhinitis among asthmatics and patients with atopic dermatitis and assessed whether age and comorbidity influence the severity of rhinitis signs and symptoms.

METHODS

Three hundred and twenty-five patients recruited for a multicentre trial to study the effect of encasings of mattresses, pillows and duvets on signs and symptoms of allergic rhinitis and/or asthma and/or atopic dermatitis recorded visual analogue scores (VAS) and daily symptom scores and underwent nasal challenge tests with house dust mite (HDM).

RESULTS

Based on history and clinical symptoms 92% of the 164 asthmatic patients and 85% of the 86 patients with atopic dermatitis could be diagnosed as having rhinitis. Inclusion of a positive provocation to HDM did not result in a substantial lower prevalence of rhinitis. Subjects reported moderate symptoms, with mean rhinitis VAS scores ranging from 40.0 to 55.0. Presence of atopic dermatitis was associated with lower rhinitis VAS and symptoms scores, whereas in multivariate analysis the presence of asthma was positively associated with nasal responsiveness to HDM.

CONCLUSION

The prevalence of nasal symptoms in patients with bronchial asthma or atopic dermatitis and sensitized to house dust mites is high. Although the majority of patients experience mild to moderate symptoms, the presence of nasal disease needs to be examined in all patients with atopic disorders.

Are antihistamines useful in managing asthma?

There continues to be a great deal of interest in the anti-asthmatic role of antihistamines. Antihistamines have recently been shown to have anti-inflammatory properties that are more extensive than simply the blocking of histamine receptors. For example, new evidence suggests that the suppression of cell adhesion molecule expression occurs with these drugs. The anti-inflammatory and anti-asthmatic effects of antihistamines have been evaluated in patients with both allergic asthma and rhinitis, given the established association between allergic inflammation of the upper and lower airways, with evidence to suggest that antihistamines have clinically relevant anti-asthmatic properties. As well as conferring benefits in asthma symptom control and the measurement of lung function, studies assessing the effect of histamine receptor antagonists on bronchial hyperresponsiveness suggest that there is bronchoprotection during both methacholine and mannitol challenges. Recently, there has also been considerable interest in the effect of combining an antihistamine with a leukotriene receptor antagonist. This combination has an anti-asthmatic effect that is greater than that of either drug given alone and may be comparable to inhaled corticosteroid therapy.

Allergic rhinitis--a total genome-scan for susceptibility genes suggests a locus on chromosome 4q24-q27

Allergic rhinitis is a common disease of complex inheritance and is characterised by mucosal inflammation caused by allergen exposure. The genetics of closely related phenotypes such as asthma, atopy and to some extend atopic dermatitis has attracted attention in recent years. Genetic reports of allergic rhinitis on the contrary have as yet been most sparse. To identify candidate regions holding genes for allergic rhinitis we performed a total genome-scan on affected sib-pair families. From 100 Danish sib-pair families selected for allergy, families containing sib-pairs matching a phenotype definition of both clinical allergic rhinitis and confirmed specific allergy were chosen. Thirty-three affected sib-pair families qualified for the scan that was undertaken using 446 microsatellite markers. Non-parametric linkage results were obtained from MAPMAKER/SIBS computer program. The study revealed one major candidate region on chromosome 4q24-q27 (LOD=2.83) and eight minor candidate regions 2q12-q33, 3q13, 4p15-q12, 5q13-q15, 6p24-p23, 12p13, 22q13, and Xp21 (LOD=1.04-1.63) likely to contain susceptibility genes for allergic rhinitis. Our findings did not support a previous report of linkage of allergic rhinitis to chromosome 12q14-q24 but they added positive evidence to the asthma and atopy candidate regions 2q33 and 6p23. Further identification of the specific genes involved in allergic rhinitis will give opportunities for improved diagnosis and treatment.