Significant association of FcepsilonRIalpha promoter polymorphisms with aspirin-intolerant chronic urticaria

Aspirin-induced urticaria in a recently diagnosed ischemic stroke patient: A case report and literature review

Key Clinical Message

NSAIDs may be rare but an important cause of urticarial which should not be missed.

Abstract

The aspirin and urticaria correlation has not been fully understood. The pharmacological inference is suspected to be the diversion of arachidonic acid metabolism. Aspirin sensitivity can aggravate preexisting chronic urticaria and in some instances causes acute urticaria. We report a case of a 53-year-old male, recently diagnosed with a stroke, who presented with complaints of multiple rashes over the trunk and upper extremities with aspirin. NSAIDs induced urticarial are usually neglected by physicians during diagnosis.

Fc Receptor Variants and Disease: A Crucial Factor to Consider in the Antibody Therapeutics in Clinic

The fragment crystallizable (Fc) domain of antibodies is responsible for their protective function and long-lasting serum half-life via Fc-mediated effector function, transcytosis, and recycling through its interaction with Fc receptors (FcRs) expressed on various immune leukocytes, epithelial, and endothelial cells. Therefore, the Fc-FcRs interaction is a control point of both endogenous and therapeutic antibody function. There are a number of reported genetic variants of FcRs, which include polymorphisms in (i) extracellular domain of FcRs, which change their affinities to Fc domain of antibodies; (ii) both cytoplasmic and intracellular domain, which alters the extent of signal transduction; and (iii) the promoter region of the FcRs gene, which affects the expression level of FcRs, thus being associated with the pathogenesis of disease indications. In this review, we firstly describe the correlation between the genetic variants of FcRs and immunological disorders by individual differences in the extent of FcRs-mediated regulations. Secondly, we discuss the influence of the genetic variants of FcRs on the susceptibility to infectious diseases or cancer in the perspective of FcRs-induced effector functions. Overall, we concluded that the genetic variants of FcRs are one of the key elements in the design of antibody therapeutics due to their variety of clinical outcomes among individuals.

Pharmacogenomics of Hypersensitivity to Non-steroidal Anti-inflammatory Drugs

Non-steroidal anti-inflammatory drugs (NSAIDs) are extensively prescribed in daily clinical practice. NSAIDs are the main cause of drug hypersensitivity reactions all over the world. The inhibition of cyclooxygenase enzymes by NSAIDs can perpetuate arachidonic acid metabolism, shunting to the 5-lipoxygenase pathway and its downstream inflammatory process. Clinical phenotypes of NSAID hypersensitivity are diverse and can be classified into cross-reactive or selective responses. Efforts have been made to understand pathogenic mechanisms, in which, genetic and epigenetic backgrounds are implicated in various processes of NSAID-induced hypersensitivity reactions. Although there were some similarities among patients, several genetic polymorphisms are distinct in those exhibiting respiratory or cutaneous symptoms. Moreover, the expression levels, as well as the methylation status of genes related to immune responses were demonstrated to be involved in NSAID-induced hypersensitivity reactions. There is still a lack of data on delayed type reactions. Further studies with a larger sample size, which integrate different genetic pathways, can help overcome current limitations of gen etic/epigenetic studies, and provide valuable information on NSAID hypersensitivity reactions.

Interaction between functional polymorphisms in FCER1A and TLR2 and the severity of atopic dermatitis

Dendritic cell toll-like receptors (TLRs) and the high-affinity immunoglobulin E (IgE) receptor (FcεRI) may biologically interact with regard to atopic dermatitis (AD) development and, especially, severity. Our aim here was to test if such interaction can be detected on the genetic level. The combined effect of the TLR2 gene (TLR2) rs4696480 and the FcεRI α-chain gene (FCER1A) rs2252226 and rs2251746 polymorphisms on the AD severity as measured by SCORAD was assessed. The FCER1A rs2252226 and TLR2 rs4696480 polymorphisms interacted with regard to SCORAD. Higher SCORAD was observed in patients being the TLR2 rs4696480 major homozygotes and carrying at the same time the FCER1A rs2252226 minor allele, compared to those characterized by (any other of) the remaining combined rs2252226 and rs4696480 genotypes. The observation of the epistatic effect of TLR2 and FCER1A genetic variants on SCORAD is in line with the involvement of the interaction TLRs-FcεRI in the pathophysiology of AD.

Update on the Management of Nonsteroidal Anti-Inflammatory Drug Hypersensitivity

The clinical phenotypes of nonsteroidal anti-inflammatory drug (NSAID) hypersensitivity are heterogeneous with various presentations including time of symptom onset, organ involvements, and underlying pathophysiology. Having a correct diagnosis can be challenging. Understanding their respective mechanisms as well as developing a comprehensive classification and diagnostic algorithm are pivotal for appropriate management strategy. Treatment modalities are based on the subtypes and severity of hypersensitivity reactions. Insights into the phenotypes and endotypes of hypersensitivity reactions enable personalized management in patients with suboptimal control of disease. This review updated the recent evidence of pathophysiology, classification, diagnostic algorithm, and management of NSAID hypersensitivity reactions.

Drug-induced anaphylaxis in children

Anaphylaxis represents one of the most frequent medical emergencies in childhood. However, as compared to adults, drugs are less common triggers of anaphylaxis in children, with a frequency which is increasing  from infancy to adolescence. Deaths seldom occur, maybe because of the paucity of comorbidities in children.  Antibiotics and non-steroidal anti-inflammatory drugs  (NSAIDs) are the main elicitors in drug-induced anaphylaxis in children. Both immune-mediated (mainly IgE-mediated) and non immune-mediated may be involved. IgG-mediated and complement-mediated mechanisms has been also hypothesized. Correct management relies on a right diagnosis and prompt therapy. A proper work-up is also important to prevent further potentially fatal re-exposures to the same drug or other structurally similar molecules but also unnecessary avoidance of medications not representing the culprit of the episode.

[NSAID urticaria: Similar management to acute urticaria]

Non-steroidal anti-inflammatory drugs (NSAIDs) are the most common providers of immediate hypersensitivity reactions. Among these reactions, isolated acute urticaria is the most common clinical feature with a non-allergic origin. It is a pharmacological side effect resulting from the alteration of arachidonic acid metabolism induced by NSAIDs. Diagnosis of this acute urticaria is clinical, requiring no allergy testing. Currently, the recommended therapeutic management of NSAID urticaria is the avoidance of all NSAID with COX-1 inhibitor activity (even if when reintroduced, they are most often well tolerated) and the use of selective COX-2 inhibitors. This review focuses on urticaria reactions to NSAIDs, which are simple to manage.

Hypersensitivity reactions to nonsteroidal anti-inflammatory drugs: an update on pharmacogenetics studies

Nonsteroidal anti-inflammatory drugs are the medications most frequently involved in hypersensitivity reactions to drugs. These can be induced by specific immunological and nonimmunological mechanisms, being the latter the most frequent. The nonimmunological mechanism is related to an imbalance of inflammatory mediators, which is aggravated by the cyclooxygenase inhibition. Genetic studies suggest that multiples genes and additional mechanisms might be involved. The proposals of this review is summarize the contribution of variations in genes involved in the arachidonic acid, inflammatory and immune pathways as well as the recent genome-wide association studies findings related to cross-intolerant nonsteroidal anti-inflammatory drugs hypersensitivity reactions. In addition, using integration of different genetic studies, we propose new target genes. This will help to understand the underlying mechanism of these reactions.

Aspirin-exacerbated respiratory disease: an update

PURPOSE OF REVIEW

The pathophysiology of aspirin-exacerbated respiratory disease (AERD) is not fully understood and diagnostic methods and so far, treatments for AERD have not been standardized. We summarize recent research into the pathological mechanisms of AERD, diagnostic methods, and treatments for AERD patients.

RECENT FINDINGS

In AERD pathophysiology, not only the reduced expression of E prostanoid 2 but also the dysfunction of its pathway could be involved. Moreover, eosinophils of AERD patients could be directly activated by aspirin to produce prostaglandin D2. Platelet activations are well known to be involved in AERD; however, plasma markers do not change during aspirin challenge tests. Additionally, novel genetic polymorphisms, such as P2RY12 and dipeptidyl peptidase 10 gene, and epigenetic predispositions of AERD were found. In AERD diagnosis, bronchial and nasal aspirin challenges have been applied in addition to oral challenge. Serum periostin has been suggested as a potential biomarker for AERD. Apart from standard pharmacological treatment and aspirin desensitization, biologics, including omalizumab and mepolizumab, as well as CRTH2 antagonists have been suggested as promising therapies for AERD treatment.

SUMMARY

AERD is usually associated with severe asthma phenotypes. AERD pathophysiology mainly involves the dysregulation of eicosanoid metabolisms, activations of effector cells, which could be influenced by genetic/epigenetic factors. Understanding the pathophysiology of AERD is key to improve the diagnostic methods and proper management of AERD patients.

An Updated Review of the Molecular Mechanisms in Drug Hypersensitivity

Drug hypersensitivity may manifest ranging from milder skin reactions (e.g., maculopapular exanthema and urticaria) to severe systemic reactions, such as anaphylaxis, drug reactions with eosinophilia and systemic symptoms (DRESS)/drug-induced hypersensitivity syndrome (DIHS), or Stevens–Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN). Current pharmacogenomic studies have made important strides in the prevention of some drug hypersensitivity through the identification of relevant genetic variants, particularly for genes encoding drug-metabolizing enzymes and human leukocyte antigens (HLAs). The associations identified by these studies are usually drug, phenotype, and ethnic specific. The drug presentation models that explain how small drug antigens might interact with HLA and T cell receptor (TCR) molecules in drug hypersensitivity include the hapten theory, the p-i concept, the altered peptide repertoire model, and the altered TCR repertoire model. The broad spectrum of clinical manifestations of drug hypersensitivity involving different drugs, as well as the various pathomechanisms involved, makes the diagnosis and management of it more challenging. This review highlights recent advances in our understanding of the predisposing factors, immune mechanisms, pathogenesis, diagnostic tools, and therapeutic approaches for drug hypersensitivity.

What we know about nonsteroidal anti-inflammatory drug hypersensitivity

Nonsteroidal anti-inf lammatory drugs (NSAIDs) are widely prescribed for the treatment of inflammatory diseases, but their use is frequently related to hypersensitivity reactions. This review outlines our current knowledge of NSAID hypersensitivity (NHS) with regard to its pathogenic, molecular, and genetic mechanisms, as well as diagnosis and treatment. The presentation of NHS varies from a local (skin and/or airways) reaction to systemic reactions, including anaphylaxis. At the molecular level, NHS reactions can be classified as cross-reactive (mediated by cyclooxygenase inhibition) or selective (specific activation of immunoglobulin E antibodies or T cells). Genetic polymorphisms and epigenetic factors have been shown to be closely associated with NHS, and may be useful as predictive markers. To diagnose NHS, inhalation or oral challenge tests are applied, with the exclusion of any cross-reactive NSAIDs. For patients diagnosed with NHS, absolute avoidance of NSAIDs/aspirin is essential, and pharmacological treatment, including biologics, is often used to control their respiratory and cutaneous symptoms. Finally, desensitization is recommended only for selected patients with NHS. However, further research is required to develop new diagnostic methods and more effective treatments against NHS.

Genetic variants associated with drugs-induced immediate hypersensitivity reactions: a PRISMA-compliant systematic review

Drug hypersensitivity includes allergic (AR) and nonallergic reactions (NARs) influenced by genetic predisposition. We performed a systematic review of genetic predictors of IgE-mediated AR and NAR with MEDLINE and PubMed search engine between January 1966 and December 2014. Among 3110 citations, the search selected 53 studies, 42 of which remained eligible. These eligible studies have evaluated genetic determinants of immediate reactions (IR) to beta-lactams (n = 19), NAR against aspirin (n = 12) and other nonsteroidal anti-inflammatory drugs (NSAIDs) (n = 8), and IR to biologics (n = 3). We reported two genomewide association studies and four case-control studies on candidate genes validated by replication. Genes involved in IR to beta-lactams belonged to HLA type 2 antigen processing, IgE production, atopy, and inflammation, including 4 genes validated by replications, HLA-DRA, ILR4, NOD2, and LGALS3. Genes involved in NAR to aspirin belonged to arachidonic acid pathway, membrane-spanning 4A gene family, histamine production pathway, and pro-inflammatory cytokines, while those involved in NAR to all NSAIDs belonged to arachidonic acid pathway and HLA antigen processing pathway. ALOX5 was a common predictor of studies on NAR to both aspirin and NSAIDs. Although these first conclusions could be drawn, this review highlights also the lack of reliable data and the need for replicating studies in contrasted populations, taking into account worldwide allele frequencies, gene-gene interactions, and contrasted situations of environmental exposure.

Genetic basis of hypersensitivity reactions to nonsteroidal anti-inflammatory drugs

PURPOSE OF REVIEW

NSAIDs are the main triggers of hypersensitivity reactions to drugs. However, the full genetic and molecular basis of these reactions has yet to be uncovered. In this article, we have summarized research from recent years into the effects of genetic variants on the different clinical entities induced by NSAID hypersensitivity, focusing on prostaglandin and leukotriene-related genes as well as others beyond the arachidonic acid pathway.

RECENT FINDINGS

We introduce recent contributions of high-throughput approaches including genome-wide association studies as well as available information from epigenetics and next-generation sequencing. Finally, we give our thoughts on future directions in this field, including the scope for bioinformatics and systems biology and the need for clear patient phenotyping.

SUMMARY

The full genetic and molecular basis of clinical entities induced by NSAIDs hypersensitivity has yet to be uncovered, and despite commendable efforts over recent years, no clinically proven genetic markers currently exist for these disorders. It is clear that we will continue to find more about these reactions in the coming years, concurrently with improvements in technology and experimental techniques, and a precise definition of different phenotypes.

Approaches to the diagnosis and management of patients with a history of nonsteroidal anti-inflammatory drug-related urticaria and angioedema

Nonsteroidal anti-inflammatory drug (NSAID)-induced urticarial and angioedema reactions are among the most commonly encountered drug hypersensitivity reactions in clinical practice. Three major clinical phenotypes of NSAID-induced acute skin reactions manifesting with angioedema, urticaria, or both have been distinguished: NSAID-exacerbated cutaneous disease, nonsteroidal anti-inflammatory drug-induced urticaria/angioedema (NIUA), and single NSAID-induced urticaria and angioedema. In some patients clinical history alone might be sufficient to establish the diagnosis of a specific type of NSAID hypersensitivity, whereas in other cases oral provocation challenges are necessary to confirm the diagnosis. Moreover, classification of the type of cutaneous reaction is critical for proper management. For example, in patients with single NSAID-induced reactions, chemically nonrelated COX-1 inhibitors can be safely used. However, there is cross-reactivity between the NSAIDs in patients with NSAID-exacerbated cutaneous disease and NIUA, and thus only use of selective COX-2 inhibitors can replace the culprit drug if the chronic treatment is necessary, although aspirin desensitization will allow for chronic treatment with NSAIDs in some patients with NIUA. In this review we present a practical clinical approach to the patient with NSAID-induced urticaria and angioedema.

An Exploratory Pilot Study of Genetic Marker for IgE-Mediated Allergic Diseases with Expressions of FcεR1α and Cε

The high affinity immunoglobulin E (IgE) receptor-FcεR1 is mainly expressed on the surface of effector cells. Cross-linking of IgE Abs bound to FcεR1 by multi-valent antigens can induce the activation of these cells and the secretion of inflammatory mediators. Since FcεR1 plays a central role in the induction and maintenance of allergic responses, this study aimed to investigate the association of FcεR1 with the allergic phenotype of Cε expression and cytokine and histamine release from peripheral leukocytes. Peripheral leukocytes from 67 allergic and 50 non-allergic subjects were used for genotyping analysis. Peripheral mononuclear cells (PBMCs) were used for Cε expression and ELISpot analysis, while polymorphonuclear cells (PMNs) were used for histamine release. The association between genotype polymorphism of the FcεR1α promoter region (rs2427827 and rs2251746) and allergic features of Cε expression and histamine were analyzed, and their effects on leukocytes function were compared with wild type. The genotype polymorphisms of FcεR1α promoter region with CT and TT in rs2427827 and TC in rs2251746 were significantly higher in allergic patients than in non-allergic controls. Patients with single nucleotide polymorphism (SNP) of FcεR1α promoter region had high levels of total IgE, mite-specific Der p 2 (Group 2 allergen of Dermatophagoides pteronyssinus)-specific IgE and IgE secretion B cells. The mRNA expression of FcεR1α was significantly increased after Der p2 stimulation in PBMCs with SNPs of the FcεR1α promoter region. Despite the increased Cε mRNA expression in PBMCs and histamine release from PMNs and the up-regulated mRNA expression of interleukin (IL)-6 and IL-8 secretions after Der p2 stimulation, there was no statistically significant difference between SNPs of the FcεR1α promoter region and the wild type. SNPs of FcεR1α promoter region were associated with IgE expression, IgE producing B cells, and increased Der p2-induced FcεR1α mRNA expression. These SNPs may be used as a disease marker for IgE-mediated allergic inflammation caused by Dermatophagoides pteronyssinus.

Challenge-proven aspirin hypersensitivity in children with chronic spontaneous urticaria

BACKGROUND

Nonsteroidal anti-inflammatory drug (NSAID) exacerbated cutaneous disease is defined as the exacerbation of wheals and/or angioedema in patients with a history of chronic spontaneous urticaria (CSU). The objective of this study was to define 'aspirin-hypersensitive' children and adolescents in a clearly defined group of patients with CSU and to describe their clinical features.

METHODS

Eighty-one children with a history of CSU were enrolled over a 3-year period. The daily or almost daily (>4 days a week) presence of urticaria was defined as 'chronic persistent urticaria' (CPU), while the presence of urticaria for 2-4 days a week was defined as 'chronic recurrent urticaria' (CRU). Single-blind, placebo-controlled provocation tests (SBPCPTs) with aspirin were performed for children with CSU.

RESULTS

Patients with CRU had a longer duration of cutaneous symptoms [1.6 (0.5-4) vs 0.6 (0.3-1.5) years], and stress was less frequently experienced as an eliciting factor in patients with CRU compared with the patients with CPU (P < 0.016, P = 0.024, respectively). SBPCPTs with aspirin revealed that 14 of 58 patients (24%) with CPU and one of 10 patients with CRU (10%) were aspirin hypersensitive. Aspirin hypersensitivity rate was 26.5% in patients <12 years of age. All of the 15 aspirin-hypersensitive patients (aged between 6.6 and 17.4 years), except for three, experienced an unequivocal angioedema of the lips as a positive reaction in SBPCPT.

CONCLUSIONS

Nearly a quarter of children and adolescents with CSU were hypersensitive to aspirin. For children with chronic urticaria, determination of NSAID hypersensitivity in a well-controlled clinical setting will help to avoid severe drug hypersensitivity reactions.

Unravelling adverse reactions to NSAIDs using systems biology

We introduce the reader to systems biology, using adverse drug reactions (ADRs), specifically hypersensitivity reactions to multiple non-steroidal anti-inflammatory drugs (NSAIDs), as a model. To disentangle the different processes that contribute to these reactions - from drug intake to the appearance of symptoms - it will be necessary to create high-throughput datasets. Just as crucial will be the use of systems biology to integrate and make sense of them. We review previous work using systems biology to study related pathologies such as asthma/allergy, and NSAID metabolism. We show examples of their application to NSAIDs-hypersensitivity using current datasets. We describe breakthroughs in high-throughput technology and speculate on their use to improve our understanding of this and other drug-induced pathologies.

Genetic determinants in the development of sensitization to environmental allergens in early childhood

Sensitization to environmental allergens remains one of the strongest risk factors for asthma, and there is likely a genetic basis. We sought to identify genetic determinants for the development of allergic sensitization to environmental allergens, particularly cockroach allergen, in early childhood. A total of 631 children with the information about genotypic data on 895 single nucleotide polymorphisms (SNPs) in 179 candidate genes were selected from an existing dataset (Boston Birth Cohort). Genetic analysis was performed for allergic sensitizations among all subjects and sub-population, Black/African, respectively. Eight SNPs in seven genes showed significant association with allergic sensitization with P < 0.05, including two top SNPs, rs7851969 in JAK2 (P = 0.003) and rs11739089 in CNOT6 (P = 0.008). When analyses were specifically performed for cockroach sensitization, 16 SNPs in 13 genes showed P < 0.05, including five genes with SNPs at P < 0.01 (JAK1, JAK3, IL5RA, FCER1A, and ADAM33). Particularly, haplotype analyses demonstrated that multiple-haplotypes in FCER1A were significantly associated with cockroach sensitization with the strongest association for a 2-marker haplotype (rs6665683T-rs12136904T, P = 0.001). Furthermore, SNP rs6665683 was marginally associated with the levels of cockroach allergen specific IgE. When a similar analysis was performed for house dust mite, four SNPs in three genes (JAK2, MAML1, and NOD1) had P < 0.01. Of these, JAK2 appeared to be an only gene showing association across the sensitizations we analyzed. Some of findings were further validated when analysis was limited to black population. Our study identified several loci that may confer the susceptibility to allergic sensitization, and suggested that sensitization to allergens may depend on their unique loci.

Aspirin-exacerbated cutaneous disease (AECD) is a distinct subphenotype of chronic spontaneous urticaria

BACKGROUND

A subset of patients with chronic spontaneous urticaria (CSU) experience disease exacerbations after receiving non-steroidal anti-inflammatory drugs (NSAIDs). This condition has been designated as Aspirin-Exacerbated Cutaneous Disease (AECD).

OBJECTIVES

The purpose of this study was twofold: (i) Investigate the demographic and clinical features of patients affected by AECD; (ii) To compare patients with AECD and NSAID-tolerant CSU patients for those characteristics.

METHODS

Patients with AECD and a group of unselected CSU patients tolerant to NSAIDs were studied. Demographic and clinical data were obtained by direct questioning and physical examination. Laboratory investigations and allergen skin prick tests were performed only in selected patients, as guided by the medical history.

RESULTS

Of 423 CSU patients admitted in the clinics, 52 (12.2%) had AECD. Compared with NSAID-tolerant CSU patients, AECD patients had significantly longer disease duration (57.7 ± 118.4 vs. 24.4 ± 36.6 months, P < 0.05), higher prevalence of angio-oedema (72.7 vs. 30.9%, P < 0.05) and atopy (83.8% vs. 58.4%, P < 0.05) and more frequent involvement of the face and upper respiratory tract (54.5% vs. 29.6%, P < 0.05).

CONCLUSIONS

AECD is a distinct phenotype that should be considered for inclusion as a separate subtype of chronic spontaneous urticaria.

Elevated platelet activation in patients with chronic urticaria: a comparison between aspirin-intolerant and aspirin-tolerant groups

BACKGROUND

Platelets are actively involved in immune inflammatory processes that release inflammatory mediators. Platelet activation has been reported in various inflammatory diseases; however, few studies have described platelet involvement in chronic urticaria (CU).

OBJECTIVE

To investigate platelet-activation markers, namely P2Y12 receptor and P-selectin expression, and soluble P-selectin level in patients with aspirin-intolerant CU (AICU) and aspirin-tolerant CU (ATCU).

METHODS

Forty-eight patients with CU and 25 normal controls were enrolled in this study. Aspirin intolerance in patients with CU was confirmed by an oral provocation test. P2Y12 and P-selectin expressions on platelets were measured using flow cytometry; soluble P-selectin level in plasma was measured by enzyme-linked immunosorbent assay. To study the functional effects of aspirin, platelets were treated with aspirin (2 mmol/L) and the expressions of P2Y12 and P-selectin were compared between the AICU and ATCU groups.

RESULTS

The expression of P2Y12 was significantly higher in patients with CU compared with controls, whereas no significant difference was noted in the expression of P-selectin level. The levels were not significantly different according to urticaria symptom score, symptom control status, and aspirin intolerance. Soluble P-selectin level was significantly higher in the AICU group than in the ATCU group compared with controls. Aspirin did not significantly suppress P2Y12 and P-selectin expressions on platelets in the AICU group, whereas significant suppression was noted in the ATCU group.

CONCLUSION

These findings suggest that increased platelet activation contributes to skin inflammation in patients with AICU and those with ATCU. The functional difference of platelets in response to aspirin may contribute to persistent skin inflammation in patients with AICU.

A disease marker for aspirin-induced chronic urticaria

There are currently no diagnostic methods in vitro for aspirin-induced chronic urticaria (AICU) except for the provocation test in vivo. To identify disease markers for AICU, we investigated the single nucleotide polymorphism (SNP) of the promoter loci of high-affinity IgE receptor (FcεRIα) and CD203c expression level in Chinese patients with AICU. We studied two genotypic and allelic frequencies of rs2427827 (–344C/T) and rs2251746 (–66T/C) gene polymorphisms of FcεRIα in 20 patients with AICU, 52 subjects with airway hypersensitivity without aspirin intolerance, and 50 controls in a Chinese population. The results showed that the frequencies of two SNPs (–344C>T, –66C>T) were similar to the normal controls. The allele frequency of –344CC was significantly higher in the patients with AICU compared to those with airway sensitivity (p = 0.019). We also studied both histamine release and CD203c expression on KU812 cells to assess aspirin-induced basophil activation. We found that the activity of basophil activation of AICU was significantly higher in the patients with AICU compared to those with airway hypersensitivity without aspirin intolerance. The mean fluorescence intensity of the CD203c expression were 122.5 ± 5.2 vs. 103.3 ± 3.3 respectively, (p < 0.05), and the percentages of histamine release were 31.3% ± 7.4% vs. −24.0% ± 17.5%, (p < 0.05) respectively. Although the mean fluorescence intensity of CD203c expression and the percentage of histamine release were significantly up-regulated by aspirin, they were not affected by anti-IgE antibodies. These results suggest that a single SNP of FcεRIα (–344C>T) is less likely to develop AICU and the basophil activation activity in the sera by measuring CD203c expression can be applicable to confirm the diagnosis of AICU.

Human FcR polymorphism and disease

Fc receptors play a central role in maintaining the homeostatic balance in the immune system. Our knowledge of the structure and function of these receptors and their naturally occurring polymorphisms, including single nucleotide polymorphisms and/or copy number variations, continues to expand. Through studies of their impact on human biology and clinical phenotype, the contributions of these variants to the pathogenesis, progression, and/or treatment outcome of many diseases that involve immunoglobulin have become evident. They affect susceptibility to bacterial and viral pathogens, constitute as risk factors for IgG or IgE mediated inflammatory diseases, and impact the development of many autoimmune conditions. In this chapter, we will provide an overview of these genetic variations in classical FcγRs, FcRLs, and other Fc receptors, as well as challenges in achieving an accurate and comprehensive understanding of the FcR polymorphisms and genomic architecture.

Multiple nonsteroidal anti-inflammatory drug-induced cutaneous disease: what differentiates patients with and without underlying chronic spontaneous urticaria?

BACKGROUND

Multiple nonsteroidal anti-inflammatory drug (NSAID) cutaneous reactors may be otherwise normal or have underlying chronic spontaneous urticaria (CSU). This study compared these two phenotypes of NSAID-hypersensitive subjects.

METHODS

A total of 97 multiple NSAID reactors underwent oral challenges with paracetamol, etoricoxib and tramadol. Atopic status was investigated in all patients, and autoreactivity was ascertained in some cases as well. Otherwise normal multiple NSAID reactors were reevaluated after 1-5 years in order to detect their proneness to CSU.

RESULTS

At the first visit, 41 patients had CSU and 56 had multiple NSAID intolerance without any underlying cutaneous disease. Altogether, 22, 10 and 6% of patients did not tolerate paracetamol, etoricoxib and tramadol, respectively, on oral challenge. Intolerance to these alternative drugs showed a strong association (p < 0.01 with all combinations). The two subgroups of patients did not show any difference in terms of mean age, gender distribution, prevalence of atopic diseases, prevalence of single offending NSAIDs and prevalence of intolerance to paracetamol, etoricoxib or tramadol on oral challenge. In all, 20% of multiple NSAID reactors without CSU at presentation developed CSU between 6 months and 5 years after the initial clinical evaluation.

CONCLUSIONS

Multiple NSAID cutaneous reactors with or without CSU seem identical from a clinical point of view, and some of the latter group show a propensity to acquire the former phenotype over time. A subset of patients apparently identical to the general population of multiple NSAID reactors also react to drugs exerting little or no cyclooxygenase-1 enzyme inhibition and might represent a distinct phenotype of NSAID-hypersensitive patients possibly characterized by a different underlying pathogenesis.

Links between allergy and cardiovascular or hemostatic system

In addition to a well-known immunologic background of atherosclerosis and influences of inflammation on arterial and venous thrombosis, there is growing evidence for the presence of links between allergy and vascular or thrombotic disorders. In this interpretative review, five pretty well-documented areas of such overlap are described and discussed, including: (1) links between atherosclerosis and immunoglobulin E or atopy, (2) mutual effects of blood lipids and allergy, (3) influence of atopy and related disorders on venous thromboembolism, (4) the role of platelets in allergic diseases, and (5) the functions of protein C system in atopic disorders.

Molecular genetic mechanisms of chronic urticaria

Chronic urticaria (CU) is a common allergic skin disease that requires long-term pharmacological treatment. Some patients with severe CU suffer a poor quality of life. Although the pathogenic mechanisms of CU are not clearly understood, several groups have suggested that genetic mechanisms are involved in various CU cohorts. To further understand the molecular genetic mechanisms of CU, we summarize recent genetic data in this review. Although a few HLA alleles were suggested to be candidate markers in different ethnic groups, further replication studies that apply the recent classification are needed. Genetic polymorphisms in histamine-related genes, including FcεRI and HNMT, were suggested to be involved in mast cell activation and histamine metabolism. Several genetic polymorphisms of leukotriene-related genes, such as ALOX5, LTC4S, and the PGE2 receptor gene PTGER4, were suggested to be involved in leukotriene overproduction, a pathogenic mechanism. Further investigations using candidate gene approaches and genome-wide association studies (GWAS) will provide new insights into the molecular genetic mechanisms of CU, which will provide new marker genes for differentiation of CU phenotypes and identification of potential therapeutic targets.

Different FCER1A polymorphisms influence IgE levels in asthmatics and non-asthmatics

BACKGROUND

Recently, three genome-wide association studies (GWAS) demonstrated FCER1A, the gene encoding a ligand-binding subunit of the high-affinity IgE receptor, to be a major susceptibility locus for serum IgE levels. The top association signal differed between the two studies from the general population and the one based on an asthma case-control design. In this study, we investigated whether different FCER1A polymorphisms are associated with total serum IgE in the general population and asthmatics specifically.

METHODS

Nineteen polymorphisms were studied in FCER1A based on a detailed literature search and a tagging approach. Polymorphisms were genotyped by the Illumina HumanHap300Chip (6 polymorphisms) or MALDI-TOF MS (13 polymorphisms) in at least 1303 children (651 asthmatics) derived from the German International Study of Asthma and Allergies in Childhood II and Multicentre Asthma Genetics in Childhood Study.

RESULTS

Similar to two population-based GWAS, the peak association with total serum IgE was observed for SNPs rs2511211, rs2427837, and rs2251746 (mean r(2) > 0.8), with the lowest p-value of 4.37 × 10(-6). The same 3 polymorphisms showed the strongest association in non-asthmatics (lowest p = 0.0003). While these polymorphisms were also associated with total serum IgE in asthmatics (lowest p = 0.003), additional polymorphisms (rs3845625, rs7522607, and rs2427829) demonstrated associations with total serum IgE in asthmatics only (lowest p = 0.01).

CONCLUSIONS

These data suggest that FCER1A polymorphisms not only drive IgE levels in the general population but that specific polymorphisms may also influence IgE in association with asthma, suggesting that disease-specific mechanisms in IgE regulation exist.

Current concepts of IgE regulation and impact of genetic determinants

Immunoglobulin E (IgE) mediated immune responses seem to be directed against parasites and neoplasms, but are best known for their involvement in allergies. The IgE network is tightly controlled at different levels as outlined in this review. Genetic determinants were suspected to influence IgE regulation and IgE levels considerably for many years. Linkage and candidate gene studies suggested a number of loci and genes to correlate with total serum IgE levels, and recently genome-wide association studies (GWAS) provided the power to identify genetic determinants for total serum IgE levels: 1q23 (FCER1A), 5q31 (RAD50, IL13, IL4), 12q13 (STAT6), 6p21.3 (HLA-DRB1) and 16p12 (IL4R, IL21R). In this review, we analyse the potential role of these GWAS hits in the IgE network and suggest mechanisms of how genes and genetic variants in these loci may influence IgE regulation.

Urticaria in monozygotic and dizygotic twins

Aim. To identify risk factors for urticaria, to determine the relative proportion of the susceptibility to urticaria that is due to genetic factors in an adult clinical twin sample, and to further determine whether the genetic susceptibility to urticaria overlaps with the genetic susceptibility to atopic diseases. Methods. A total of 256 complete twin pairs and 63 single twins, who were selected from sibships with self-reported asthma via a questionnaire survey of 21,162 adult twins from the Danish Twin Registry, were clinically interviewed about a history of urticaria and examined for atopic diseases. Data were analysed with Cox proportional hazards regression and variance components models. Results. A total of 151 individuals (26%) had a history of urticaria, whereas 24 (4%) had had symptoms within the past year. Female sex, HR = 2.09 (1.46–2.99), P = 0.000; hay fever, HR = 1.92 (1.36–2.72), P = 0.000; and atopic dermatitis, HR = 1.44 (1.02–2.06), P = 0.041 were significant risk factors for urticaria. After adjustment for sex and age at onset of urticaria in the index twin, the risk of urticaria was increased in MZ cotwins relative to DZ cotwins, HR = 1.42 (0.63–3.18), P = 0.394. Genetic factors explained 45% (16–74%), P = 0.005, of the variation in susceptibility to urticaria. The genetic correlation between urticaria and hay fever was 0.45 (0.01–0.89), P = 0.040. Conclusions. Susceptibility to urticaria is partly determined by genetic factors. Urticaria is more common in women, and in subjects with hay fever and atopic dermatitis, and shares genetic variance with hay fever.

Genetics of hypersensitivity to aspirin and nonsteroidal anti-inflammatory drugs

Various hypersensitivity reactions have been reported with aspirin and nonsteroidal anti-inflammatory drugs. Hypersensitivity can occur regardless of a chemical drug structure or its therapeutic potency. Allergic conditions include aspirin-exacerbated respiratory disease (AERD or aspirin-induced asthma), aspirin-induced urticaria/angioedema (AIU), and anaphylaxis. Several genetic studies on aspirin hypersensitivity have been performed to discover the genetic predisposition to aspirin hypersensitivity and to gain insight into the phenotypic diversity. This article updates data on the genetic mechanisms that govern AERD and AIU and summarizes recent findings on the molecular genetic mechanism of aspirin hypersensitivity.

Clinical management of patients with a history of urticaria/angioedema induced by multiple NSAIDs: an expert panel review

Nonsteroidal anti-inflammatory drugs (NSAIDs) represent one of the most frequent causes of drug-induced urticaria/angioedema worldwide. Recent review articles have classified patients experiencing NSAID-induced urticaria/angioedema into different categories, including single reactors, multiple reactors, and multiple reactors with underlying chronic urticaria. Each of these categories requires a different clinical approach. The present article, written by a panel of experts, reports the main recommendations for the practical clinical management of patients with a history of urticaria/angioedema induced by multiple NSAID based on current knowledge.

Chronic spontaneous urticaria: an autoimmune disease? A revision of the literature

The cause of chronic spontaneous urticaria has been an enigma for decades, but the recognition of functional autoantibodies in some patients with the spontaneous chronic urticaria has opened up a new concept of autoimmune urticaria. Clinical and laboratory features are in keeping with an autoimmune aetiology for many patients with otherwise inexplicable disease, but there is still debate about the importance of functional autoantibodies in the disease pathogenesis, how to test them and the clinical implications for treatment and prognosis. This review will look at the evidence for there being an autoimmune subset of urticaria, the strengths and weaknesses of the available tests in current use.

Association of polymorphisms in the promoter region of FCER1A gene with atopic dermatitis, chronic uticaria, asthma, and serum immunoglobulin E levels in a Han Chinese population

The high-affinity receptor for immunoglobulin E (IgE) plays a central role in allergy diseases. Previous studies have reported the association of variants in the proximal promoter of FCER1A with IgE levels as well as allergy disorders. Another promoter gene polymorphism that is located upstream of exon 1 has not been investigated. We investigated the association of variants in the promoter located upstream of FCER1A exon 1 with serum IgE levels and allergy diseases in a Han Chinese population. A total of 97 patients with atopic dermatitis (AD), 123 patients with chronic urticaria (CU), 286 children with asthma, and control groups were screened for polymorphisms in the promoter region located upstream of FCER1A exon 1 by the polymerase chain reaction-ligation detection reaction method. Total serum IgE levels were tested in groups. The rare allele A of the rs2427837 A/G polymorphism was significantly different in the AD group compared with the controls. No association with the polymorphism was observed in the CU group. In asthmatic patients, IgE levels were higher in the mutation genotypes GA of rs2427837 and TC of rs2251746 compared with normal genotype individuals. The minor allele of rs2427837 and rs2251746 in FCER1A is a genetic risk factor of high IgE levels.

Comparison of CD63 Upregulation Induced by NSAIDs on Basophils and Monocytes in Patients with NSAID Hypersensitivity

Background. An in vitro basophil activation test, based on the detection of CD63 upregulation induced by NSAIDs, has been described. Its clinical significance remains controversial. Objectives. In patients with a history of nonallergic NSAID hypersensitivity, stratified according to the severity of the symptoms, to assess with NSAIDs the predictive value of basophil (BAT) and monocyte (MAT) activation tests. Patients/Methods. Sixty patients who had NSAIDs-induced or exacerbated urticaria/angiooedema and 20 controls was included. After incubation with NSAIDs or acetaminophen, leukocytes were analysed for CD63 upregulation. Results. With aspirin, the sensitivity (37%) and specificity (90%) of BAT agree with already published results. In contrast, when patients had had cutaneous and visceral reactions, the frequency of positive BAT 14/22 (64%, P < 0.001) or MAT 10/22 (46%, P < 0.01) were increased. Conclusions. Positive tests were more frequent among patients having a severe hypersensitivity contrasting with the other patients who had results similar to controls.

A functional promoter polymorphism of the human IL18 gene is associated with aspirin-induced urticaria

BACKGROUND

Urticaria is the commonest cutaneous reaction caused by aspirin or other nonsteroidal anti-inflammatory drugs. The pathogenesis of aspirin-induced urticaria (AIU) is not fully understood, but appears to involve mast cell activation and neutrophil infiltration.

OBJECTIVES

To investigate the genetic contribution of interleukin (IL)-18, which can amplify acute inflammation by promoting mast cell activation, neutrophil migration and cytokine production, to the pathogenesis of AIU.

METHODS

A case-control association study was performed using 275 patients with AIU and 196 normal healthy controls in a Korean population. Two promoter polymorphisms of the IL18 gene (-607A/C and -137G/C) were genotyped using the primer extension method. The functional effect of the IL18 gene promoter polymorphism was investigated through in vitro studies including a luciferase reporter assay and electrophoretic mobility shift assays (EMSAs) and ex vivo studies involving neutrophil chemotaxis assays.

RESULTS

A significant association was detected between both AIU in general and the aspirin-intolerant acute urticaria (AIAU) phenotype and the IL18 promoter polymorphism -607A/C. Patients with AIAU showed higher frequencies of the C(-607) G(-137) haplotype, ht1 [CG], compared with controls (P=0·02). Moreover, ht1 [CG] showed a high transcript haplotype by the luciferase activity assay, and EMSAs identified a -607C allele-specific DNA-binding protein as CREB2. Neutrophil chemotactic activity was highest in subjects with AIU exhibiting the high transcript haplotype, ht1 [CG] (P=0·019).

CONCLUSIONS

The high transcript haplotype ht1 [CG] of the IL18 gene may contribute to the development of acute cutaneous inflammation sensitive to aspirin, leading to the clinical presentation of AIAU.

FCεRI gene promoter polymorphisms and total IgE levels in susceptibility to atopic dermatitis in Korea

IgE-dependent activation of mast cells and basophils through the high-affinity IgE receptor (FcεRI) is involved in the pathogenesis of allergen-induced immune responsiveness in atopic diseases like atopic dermatitis (AD). We sought to determine FcεRI gene polymorphisms are associated with AD in Korean patients, and analyzed the relevance of FcεRI gene polymorphisms and serum IgE levels. We conducted a case-control association analysis (175 patients and 56 controls) of Korean subjects. Genotyping was performed using the TaqMan fluorogenic 5' nuclease assay, and serum levels of IgE were measured using a fluorescence enzyme immunoassay. We found that there were no significant relationships between FcεRI and AD, although there were trends towards an association between the 66T>C (rs2251746) polymorphism and total serum IgE levels in the Korean AD patients. In conclusion, while the 66T>C (rs2251746) of the FcεRIα polymorphism may be linked to AD and higher serum IgE levels, polymorphisms in the FcεRIβ gene did not confer susceptibility to AD in our patient sample.

Functional variability of the adenosine A3 receptor (ADORA3) gene polymorphism in aspirin-induced urticaria

BACKGROUND

To improve understanding of aspirin hypersensitivity, this study focused on adenosine as a noncyclooxygenase target molecule of aspirin. Adenosine may affect the release of histamine from cutaneous mast cells through a mechanism mediated by the adenosine A3 receptor.

OBJECTIVES

To investigate the genetic contribution of adenosine A3 receptor gene (ADORA3) polymorphisms in the pathogenesis of aspirin-induced urticaria (AIU) in a case-control association study in a Korean population.

METHODS

A case-control association study was performed in 385 patients with AIU and 213 normal controls from a Korean population. The functional variability of genetic polymorphisms in the ADORA3 gene was analysed in in vitro studies that included a luciferase reporter assay and an electrophoretic mobility shift assay (EMSA), and ex vivo studies that included real-time polymerase chain reaction for mRNA expression in peripheral blood mononuclear cells and a histamine release assay.

RESULTS

A significant association of ADORA3 promoter polymorphism at -1050G/T was found with the phenotype of AIU. Patients with AIU showed higher frequency of the haplotype, ht1 (T(-1050) C(-564) ), compared with normal healthy controls. Moreover, ht1 (TC) was found to be a high-transcript haplotype by the luciferase activity assay, and a -564C allele-specific DNA binding protein was found by EMSA. Increased basophil histamine release was noted in subjects who had the high-transcript haplotype, ht1 (TC).

CONCLUSION

These results suggest that the high-transcript haplotype, ht1 (TC), of the ADORA3 gene may contribute to the development of cutaneous hyper-reactivity to aspirin, leading to the clinical presentation of AIU.

SNPs in the FCER1A gene region show no association with allergic rhinitis in a Han Chinese population

Background

Immunoglobulin E (IgE) is a central player in the allergic response, and raised total IgE levels are considered as an indicator of atopy or potential development of atopy. A recent genome-wide scan in a German population-based cohort of adults identified the gene encoding the alpha chain of the high affinity receptor for IgE (FCER1A) as a susceptibility locus influencing total serum IgE levels. The aim of this study was to investigate whether the polymorphisms in the FCER1A gene are associated with allergic rhinitis (AR) in a Han Chinese population.

Methodology/Principal Findings

A population of 378 patients with AR and 288 healthy controls was studied. Precise phenotyping of patients was accomplished by means of a questionnaire and clinical examination. Blood was drawn for DNA extraction and total serum immunoglobulin E (IgE) measurement. A total of 16 single nucleotide polymorphisms (SNPs) in FCER1A were selected and individually genotyped. None of the SNPs in the FCER1A showed an association with AR. Similarly, the lack of association was also evident in subgroup analysis for the presence of different allergen sensitivities. None of the selected SNPs in FCER1A was associated with total IgE level.

Conclusions

Although FCER1A presents itself as a good candidate for contributing to total serum IgE, this study failed to find an association between SNPs in the FCER1A gene region and IgE level or AR susceptibility.

Association of thromboxane A2 receptor (TBXA2R) gene polymorphism in patients with aspirin-intolerant acute urticaria

BACKGROUND

The thromboxane A2 receptor (TBXA2R) is a potent broncho- and vaso-constrictor and is associated with leukotriene synthesis. Polymorphisms in the TBXA2R gene have been linked to atopy, asthma, and atopic dermatitis. This study evaluated the association between genetic TBXA2R variants and the development of acetyl salicylic acid (ASA)-intolerant acute urticaria (AIAU).

METHODS

AIAU patients (n=167), ASA-intolerant chronic urticaria (AICU) patients (n=149), and healthy controls (NC) (n=265) were included. All patients were enrolled at Ajou University Hospital in Suwon, Korea. Two TBXA2R polymorphisms (-4684T>C and 795T>C) were genotyped by primer extension using a SNAPshot ddNTP primer extension kit. Luciferase activity was measured using a dual-luciferase reporter assay kit. An electrophoretic mobility shift assay (EMSA) was performed using a nuclear extract from a human mast cell line (HMC-1).

RESULTS

Genetic association data demonstrated that compared with NC subjects, AIAU patients had a significantly higher frequency of the homozygous TT genotype of TBXA2R-4684T>C (P=0.005, P(corr) =0.03). No differences were identified between the AICU and the NC groups. Luciferase activity, reflecting promoter activity, was significantly lower with the TBXA2R-4684T-containing construct than with the -4684C-containing construct (P<0.001); the activity decreased further upon co-transfection with ETS-like gene transcription factor-1 (ELK-1) (P=0.012). EMSA revealed that the -4684T allele produced a specific shifted band, with a greater affinity than that produced by the -4684C allele.

CONCLUSION AND CLINICAL RELEVANCE

These results suggest that the TBXA2R-4684T allele may be associated with lower TBXA2R expression, which may contribute to the development of the AIAU phenotype.