Genetic and Epigenetic Components of Aspirin-Exacerbated Respiratory Disease

Pre-asthma: a useful concept? A EUFOREA paper. Part 2-late onset eosinophilic asthma

The concept of pre-diabetes has led to provision of measures to reduce disease progression through identification of subjects at risk of diabetes. We previously considered the idea of pre-asthma in relation to allergic asthma and considered that, in addition to the need to improve population health via multiple measures, including reduction of exposure to allergens and pollutants and avoidance of obesity, there are several possible specific means to reduce asthma development in those most at risk (pre- asthma). The most obvious is allergen immunotherapy (AIT), which when given for allergic rhinitis (AR) has reasonable evidence to support asthma prevention in children (2) but also needs further study as primary prevention. In this second paper we explore the possibilities for similar actions in late onset eosinophilic asthma.

Aspirin-exacerbated respiratory disease is associated with variants in filaggrin, epithelial integrity, and cellular interactions

Background

Previous studies have determined that up to 6% of patients with aspirin-exacerbated respiratory disease (AERD) have family history of AERD, indicating a possible link with genetic polymorphisms. However, whole exome sequencing (WES) studies of such associations are currently lacking.

Objectives

We sought to examine whether WES can identify pathogenic variants associated with AERD.

Methods

Diagnoses of AERD were confirmed in patients with nasal polyps and asthma. WES was performed using an Illumina sequencing platform. Human Phenotype Ontology terms were used to define the patients' phenotypes. Exomiser was used to annotate, filter, and prioritize possible disease-causing genetic variants.

Results

Of 39 patients with AERD, 41% reported a family history of asthma and 5% reported a family history of AERD. Pathogenic exome variants in the filaggrin gene (FLG) were found in 2 patients (5%). Other variants not known to be pathogenic were detected in an additional 16 patients (41%) in genes related to epithelial integrity and cellular interactions, including genes encoding desmoglein 3 (DSG3), dynein axonemal heavy chain 9 (DNAH9), collagen type VII alpha 1 chain (COL7A1), collagen type XVII alpha 1 chain (COL17A1), chromodomain helicase DNA binding protein-7 (CHD7), TSC complex subunit 2/tuberous sclerosis-2 protein (TSC2), P-selectin (SELP), and platelet-derived growth factor receptor-alpha (PDGFRA).

Conclusion

WES identified a monogenic susceptibility to AERD in 5% of patients with FLG pathogenic variants. Other variants not previously identified as pathogenic were found in genes relevant to epithelial integrity and cellular interactions and may further reveal genetic factors that contribute to this condition.

Inheritance of NSAID-Exacerbated Respiratory Disease

Nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (N-ERD) has been considered an acquired condition. Positive first-degree family history has been reported in 1% of cases. The geographic and genetic isolation of the Finnish population offers exceptional opportunities for inheritance studies. In this questionnaire study, we explored the familial aggregation of N-ERD in 66 Finnish families of patients with N-ERD. The majority of patients (67%) had a positive family history of NSAID intolerance, asthma, nasal polyposis, or N-ERD. Furthermore, 55% had a positive first-degree family history of asthma, 21% nasal polyposis, 20% NSAID intolerance, and 11% N-ERD. The prevalence of asthma, nasal polyposis, NSAID intolerance, and N-ERD among first-degree relatives was 13%, 5%, 4%, and 2%, respectively. We present the pedigrees of the 44 affected families. According to our findings, Finnish patients with N-ERD seem to have a genetic susceptibility to it.

Genetics and epigenetics of chronic rhinosinusitis

Discerning the genetics and epigenetics of chronic rhinosinusitis (CRS) may optimize outcomes through early diagnostics, personalized and novel therapeutics, and early prognostication. CRS associated with cystic fibrosis and primary ciliary dyskinesia has well-characterized genetic mutations. Most CRS subjects, however, do not exhibit identifiable monogenic alterations. Clustering in related individuals is seen in CRS with nasal polyps. Spouses of subjects with CRS without nasal polyps also may be at increased risk of the same disease. These observations generate questions on genetic and environmental influences in CRS. Genome-wide association studies have identified variations and polymorphisms between CRS and control subjects in genes related to innate and adaptive immunity. Candidate gene and transcriptomics studies have investigated and identified genetic variations related to immunity, inflammation, epithelial barrier function, stress-response, antigen processing, T-cell regulation, and cytokines in CRS. Epigenetic studies have identified mechanisms through which environmental factors may affect these gene functions. However, causality is not determined for most variations. Inferences drawn from these data must be measured because most investigations report unreplicated results from small study populations. Large, replicated studies in tight cohorts across diverse populations remain a pressing need in studying CRS genetics.

Association of ATP8B3 gene polymorphisms with aspirin-exacerbated respiratory disease in asthmatics

BACKGROUND

Aspirin-exacerbated respiratory disease (AERD), an asthma phenotype, often presents with severe manifestations and it remains widely underdiagnosed because of insufficient awareness of the relationship between the ingestion of nonsteroidal anti-inflammatory drugs, including acetylsalicylic acid (ASA), and asthma exacerbation. Our previous genome-wide association study demonstrated an association between a single nucleotide polymorphism (SNP) of the ATP8B3 gene and the risk of AERD. This study examined AERD-related SNPs of the ATP8B3 gene in a large population.

METHODS

Twenty-five SNPs of ATP8B3 were genotyped with the GoldenGate assay using VeraCode microbeads in 141 asthmatics with AERD and 995 Aspirin-tolerant asthma (ATA). The genotype distribution was analyzed using logistic regression models. The declines in forced expiratory volume in 1 second (FEV1)following an ASA challenge were compared among the genotypes and haplotypes using a type III generalized linear model.

RESULTS

The minor allele frequencies (MAFs) of rs10421558 A>G in the 5'UTR and rs10403288 G>A in the intron were significantly lower in the AERD than the ATA [34.0% vs. 43.8%, OR = 0.66 (0.62-0.92), Pcorr = 0.03 and 28.4% vs. 35.4%, OR = 0.62 (0.59-0.89), Pcorr = 0.016, respectively]. BL1ht5 was significantly higher in the AERD [7.6% vs. 1.6%, OR = 12.23 (0.2-0.51), P = 4.7 × 10 -4 , Pcorr = 0.001]. Among them, rs10421558 A>G and BL1ht5 were associated with the percent decline in FEV1 on the oral ASA challenge test.

CONCLUSION

The minor allele of rs10421558 A>G in the 5'UTR may protect against the development of AERD via the increased production of ATP8B3.

NSAID-exacerbated respiratory disease (N-ERD): a population study

Background

Nonsteroidal anti-inflammatory drugs (NSAIDs) may exacerbate respiratory symptoms. A recent European Academy of Allergy and Clinical Immunology position paper recommended the use of an acronym, N-ERD (NSAID-exacerbated respiratory disease), for this hypersensitivity associated with asthma or chronic rhinosinusitis with or without nasal polyposis. Our aim was to estimate the prevalence of N-ERD and identify factors associated with N-ERD.

Methods

In 2016, a cross-sectional questionnaire survey of a random adult population of 16 000 subjects aged 20–69 years was performed in Helsinki and Western Finland. The response rate was 51.5%.

Results

The prevalence was 1.4% for N-ERD, and 0.7% for aspirin-exacerbated respiratory disease (AERD). The prevalence of N-ERD was 6.9% among subjects with asthma and 2.7% among subjects with rhinitis. The risk factors for N-ERD were older age, family history of asthma or allergic rhinitis, long-term smoking and exposure to environmental pollutants. Asthmatic subjects with N-ERD had a higher risk of respiratory symptoms, severe hypersensitivity reactions and hospitalisations than asthmatic subjects without N-ERD. The subphenotype of N-ERD with asthma was most symptomatic. Subjects with rhinitis associated with N-ERD, which would not be included in AERD, had the fewest symptoms.

Conclusion

We conclude that the prevalence of N-ERD was 1.4% in a representative Finnish adult population sample. Older age, family history of asthma or allergic rhinitis, cumulative exposure to tobacco smoke, secondhand smoke, and occupational exposures increased odds of N-ERD. N-ERD was associated with significant morbidity.

Population-based prevalence of N-ERD is 1.4%. N-ERD is symptomatic, with a rhinitis subgroup. The risk factors for N-ERD are older age, family history of asthma or allergic rhinitis, long-term smoking and exposure to environmental pollutants.https://bit.ly/3HxGftP

Emerging Biomarkers Beyond Leukotrienes for the Management of Nonsteroidal Anti-inflammatory Drug (NSAID)-Exacerbated Respiratory Disease

Nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (NERD) is a unique condition characterized by aspirin/NSAID hypersensitivity, adult-onset asthma, and/or chronic rhinosinusitis with nasal polyps. Arachidonic acid metabolism dysregulation and intense eosinophilic/type 2 inflammation are central mechanisms in NERD. Studies have been conducted on various biomarkers, and urinary leukotriene E4 is considered the most available biomarker of NERD. However, the pathophysiology of NERD is heterogeneous and complex. Epithelial cells and platelets can interact with immune cells in NERD, and novel biomarkers related to these interactions have recently been investigated. We summarize emerging novel biomarkers of NERD and discuss their roles in the management of NERD.

IL10 rs1800872 Is Associated with Non-Steroidal Anti-Inflammatory Drugs Exacerbated Respiratory Disease in Mexican-Mestizo Patients

Non-steroidal anti-inflammatory drugs (NSAID) exacerbated respiratory disease (N-ERD) is a disease integrated by asthma, nasal polyps, and hypersensitivity to non-steroidal anti-inflammatory drugs (NSAID). Genetic association studies have explored single nucleotide polymorphisms (SNPs) in genes involved in theoretical pathophysiological mechanisms, but most of these lack replication of findings in second populations. Our objective was to evaluate the association of SNPs in candidate genomic regions described in Asian and European subjects with N-ERD in Mexican-mestizo patients. We designed a replicative study in two stages. We included 381 SNPs selected by fine mapping of associated genes in a microarray, which were tested in three groups: N-ERD (N), asthma (A), and control group (CG); by means of GoldenGate array, positive results by genetic models were validated in the second stage in another population through qPCR with the same methodology. In the allelic model, we identified 11 SNPs in N vs. CG comparison, and five in N vs. A and A vs. CG, respectively. By genetics models, all SNPs in PPARG, rs13239058 in TBXAS1, and rs1554286 and rs1800872 in IL10 were associated in both models. In the second stage, only rs1800872CC showed an association in the dominant model comparing N vs. GC, p = 0.004, OR = 0.44. In conclusion, rs1800872 in IL10 was the only associated with N-ERD in Mexican-mestizo patients.

The nuts and bolts of omics for the clinical allergist

OBJECTIVE

Omics, aka multi-omics, is an emerging area of research that is advancing the use of personalized medicine in clinical practice and is therefore relevant for the practicing allergist.

DATA SOURCES

We performed a literature search of a selection of scientific findings in omics and allergy, including variants that may be important to allergy outcomes in the genome, transcriptome, metabolome, microbiome, epigenome, and exposome, among others.

STUDY SELECTIONS

Basic science papers and review articles.

RESULTS

The use of multi-omic data in clinical practice is changing how clinicians treat their patients whereby more personalized approaches are becoming standard in medical practice and has the potential to transform the treatment of allergies.

CONCLUSION

Multi-omic data are relevant and will become increasingly important for the clinical allergist.

Lessons Learned From GWAS of Asthma

Asthma is a common complex disease of the airways. Genome-wide association studies (GWASs) of asthma have identified many risk alleles and loci that have been replicated in worldwide populations. Although the risk alleles identified by GWAS have small effects and explain only a small portion of prevalence, the discovery of asthma loci can provide an understanding of its genetic architecture and the molecular pathways involved in disease pathogenesis. These discoveries can translate into advances in clinical care by identifying therapeutic targets, preventive strategies and ultimately approaches for personalized medicine. In this review, we summarize results from GWAS of asthma from the past 10 years and the insights gleaned from these discoveries.

Complementary Participation of Genetics and Epigenetics in Development of NSAID-exacerbated Respiratory Disease

Nonsteroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (NERD) has attracted a great deal of attention because of its association with severe asthma. However, it remains widely underdiagnosed in asthmatics as well as the general population. Upon pharmacological inhibition of cyclooxygenase 1 by NSAIDs, production of anti-inflammatory prostaglandin E2 and lipoxins ceases, while release of proinflammatory cysteinyl leukotrienes increases. To determine the underlying mechanisms, many studies have attempted to elucidate the genetic variants, such as single nucleotide polymorphisms, responsible for alterations of prostaglandins and leukotrienes, but the results of these genetic studies could not explain the whole genetic pathogenesis of NERD. Accordingly, the field of epigenetics has been introduced as an additional contributor to genomic alteration underlying the development of NERD. Recently, changes in CpG methylation, as one of the epigenetic components, have been identified in target tissues of NERD. This review discusses in silico analyses of both genetic and epigenetic components to gain a better understanding of their complementary roles in the development of NERD. Although the molecular mechanisms underlying NERD pathogenesis remain poorly understood, genetic and epigenetic variations play significant roles. Our results enhance the understanding of the genetic and epigenetic mechanisms involved in the development of NERD and suggest new approaches toward better diagnosis and management.

MS4A2-rs573790 Is Associated With Aspirin-Exacerbated Respiratory Disease: Replicative Study Using a Candidate Gene Strategy

Aspirin exacerbated respiratory disease (AERD) is a set of diseases of the unified airway, and its physiopathology is related to disruption of the metabolism of arachidonic acid (AA). Genetic association studies in AERD had explored single nucleotide polymorphism (SNPs) in several genes related to many mechanisms (AA metabolism, inflammation, drug metabolism, etc.) but most lack validation stages in second populations. Our aim is to evaluated whether contribution to susceptibility of SNPs reported in other populations are associated with AERD in Mexican Mestizo patients. We developed a replicative study in two stages. In the first, 381 SNPs selected by fine mapping of associated genes, (previously reported in the literature), were integrated into a microarray and tested in three groups (AERD, asthma and healthy controls -HC-) using the GoldenGate array. Results associated to risk based on genetic models [comparing: AERD vs. HC (comparison 1, C1), AERD vs. asthma (C2), and asthma vs. HC (C3)] were validated in the second stage in other population groups using qPCR. In the first stage, we identified 11 SNPs associated with risk in C1.The top SNPs were ACE-rs4309C (p = 0.0001) and MS4A2-rs573790C (p = 0.0002). In C2, we detected 14 SNPs, including ACE-rs4309C (p = 0.0001). In C3, we found MS4A2-rs573790C (p = 0.001). Using genetic models, C1 MS4A2-rs57370 CC (p = 0.001), and ACE-rs4309 CC (p = 0.002) had associations. In C2 ACE-rs4309 CC (p = 0.0001) and C3 MS4A2-rs573790 CC (p = 0.001) were also associate with risk. In the second stage, only MS4A2-rs573790 CC had significance in C1 and C3 (p = 0.008 and p = 0.03). We concluded that rs573790 in the MS4A2 gene is the only SNP that supports an association with AERD in Mexican Mestizo patients in both stages of the study.

An update on the management of aspirin-exacerbated respiratory disease

INTRODUCTION

Clinical features of aspirin-exacerbated respiratory disease (AERD) consist of moderate to severe asthma associated with chronic rhinosinusitis (CRS), which are derived from overproduction of cysteinyl leukotrienes along with chronic type 2 mediated inflammation in the upper and lower airway mucosa. Area covered: This review provides recent up-to-date information regarding phenotypes of AERD and encompasses comprehensive diagnostic methods and treatment options. To confirm the diagnosis of AERD, provocation testing via nasal, inhalation or the oral route of aspirin remains the gold standard; in vitro diagnostic methods are still not available. Essential management is to avoid cross-reacting cyclooxygenase 1 (COX-1) inhibitors along with use of highly selective COX-2 inhibitors and to maintain pharmacologic treatment depending on the severity of asthma and chronic rhinosinusitis. Recent biologics, including anti-IgE and anti-IL5 antibodies, are required in severe AERD patients with CRS. Aspirin desensitization can be recommended when indicated. Expert commentary: AERD is a heterogeneous disease in terms of severity and associated allergic disease. When performing diagnosis and treatment for AERD, such disease characteristics need to be kept in mind.