Diagnóstico e tratamento da DREA: realidades da prática clínica / Diagnosis and treatment of AERD: clinical practice reality

Introdução: A doença respiratória exacerbada por aspirina (DREA), caracterizada por asma, rinossinusite, polipose nasal e hipersensibilidade à aspirina, pode ser sugerida pela história, porém, o teste de provocação oral com a aspirina é o padrão ouro para o diagnóstico, e a dessensibilização com aspirina, uma boa opção terapêutica. O objetivo do trabalho foi avaliar as características clínicas e os resultados dos procedimentos de provocação e/ou de dessensibilização com aspirina nos pacientes com suspeita de DREA, bem como observar se houve correlação com a literatura. Métodos: Neste estudo retrospectivo, foram avaliados prontuários de pacientes adultos com suspeita de DREA, em acompanhamento em um hospital terciário e que foram submetidos à provocação e/ ou dessensibilização com aspirina. Dois protocolos foram utilizados para o teste de provocação: (a) cetorolaco nasal/aspirina oral, e (b) apenas aspirina oral. Foram avaliados: características clínicas, a positividade do teste e da dessensibilização e a comparação deste resultado com a história prévia. Resultados: Participaram do estudo 24 pacientes, com média de idade de 50,8 anos, sendo 54,2% do sexo feminino. Treze pacientes (54,2%) tinham asma grave, e seis (25%), asma alérgica. Média do volume expiratório forçado no primeiro segundo (VEF1) foi de 81,5% do valor predito. Dezenove pacientes (79,2%) referiam broncoespasmo e/ou urticária com anti-inflamatórios não esteroidais. Cinco pacientes não faziam associação com essas medicações. Independente do protocolo usado, onze pacientes (45,8%) apresentaram teste positivo, confirmando a DREA, sendo que seis pacientes (25%) foram submetidos à dessensibilização com aspirina. Oito pacientes (33,3%) apresentaram provocação negativa, e cinco (20,8%) não conseguiram completar a investigação devido à presença de urticária. Conclusões: Pacientes com suspeita de DREA deveriam ser submetidos à provocação com aspirina para confirmar o diagnóstico. Um quarto dos pacientes foi submetido à dessensibilização, entretanto, para a maioria dos pacientes não foi possível confirmar o diagnóstico ou o teste foi negativo.

Introduction: Aspirin-exacerbated respiratory disease (AERD) is characterized by asthma, rhinosinusitis, nasal polyps, and aspirin hypersensitivity. The condition may be suggested by the patient's medical history; however, oral provocation test with aspirin is the gold standard for diagnosis, and desensitization with aspirin, a good therapeutic option. The aim of this study was to evaluate the clinical characteristics and results obtained with aspirin provocation tests and/or desensitization in patients with suspected AERD, as well as to correlate these data with the literature available. Methods: In this retrospective study, the medical records of adult patients with suspected AERD followed at a tertiary hospital who underwent aspirin challenge and/or desensitization were evaluated. Two protocols were used for the challenge test: (a) nasal ketorolac/ oral aspirin; and (b) oral aspirin alone. Clinical characteristics and both test and desensitization positivity were evaluated, and the results were compared with data from the patient's history. Results: Twenty-four patients participated in the study, with a mean age of 50.8 years; 54.2% were female. Thirteen patients (54.2%) had severe asthma, and six (25%) had allergic asthma. Mean forced expiratory volume in 1 second (FEV1) was 81.5% of the predicted value. Nineteen patients (79.2%) reported bronchospasm and/or urticaria with nonsteroidal anti-inflammatory drugs. Five patients had no association with these medications. Regardless of the protocol used, eleven patients (45.8%) presented positive tests, confirming the diagnosis of AERD, and six patients (25%) underwent aspirin desensitization. Eight patients (33.3%) had negative results in the provocation test, and five (20.8%) failed to complete the investigation due to the presence of urticaria. Conclusions: Patients with suspected AERD should undergo aspirin challenge to confirm the diagnosis. One-fourth of our patients underwent desensitization, but for most patients, either it was not possible to confirm the diagnosis or the test resulted negative.

Eicosanoid Mediators in the Airway Inflammation of Asthmatic Patients: What is New?

Lipid mediators contribute to inflammation providing both pro-inflammatory signals and terminating the inflammatory process by activation of macrophages. Among the most significant biologically lipid mediators, these are produced by free-radical or enzymatic oxygenation of arachidonic acid named "eicosanoids". There were some novel eicosanoids identified within the last decade, and many of them are measurable in clinical samples by affordable chromatography-mass spectrometry equipment or sensitive immunoassays. In this review, we present some recent advances in understanding of the signaling by eicosanoid mediators during asthmatic airway inflammation. Eicosanoid profiling in the exhaled breath condensate, induced sputum, or their metabolites measurements in urine is complementary to the cellular phenotyping of asthmatic inflammation. Special attention is paid to aspirin-exacerbated respiratory disease, a phenotype of asthma manifested by the most profound changes in the profile of eicosanoids produced. A hallmark of this type of asthma with hypersensitivity to non-steroid anti-inflammatory drugs (NSAIDs) is to increase biosynthesis of cysteinyl leukotrienes on the systemic level. It depends on transcellular biosynthesis of leukotriene C₄ by platelets that adhere to granulocytes releasing leukotriene A₄. However, other abnormalities are also reported in this type of asthma as a resistance to anti-inflammatory activity of prostaglandin E₂ or a robust eosinophil interferon-γ response resulting in cysteinyl leukotrienes production. A novel mechanism is also discussed in which an isoprostane structurally related to prostaglandin E₂ is released into exhaled breath condensate during a provoked asthmatic attack. However, it is concluded that any single eicosanoid or even their complex profile can hardly provide a thorough explanation for the mechanism of asthmatic inflammation.

Update on the Management of Aspirin-Exacerbated Respiratory Disease

Aspirin-exacerbated respiratory disease (AERD) is an adult-onset upper and lower airway disease consisting of eosinophilic nasal polyps, asthma, and respiratory reactions to cyclooxygenase 1 (COX-1) inhibitors. Management includes guideline-based treatment of asthma and sinus disease, avoidance of COX-1 inhibitors, and for some patients aspirin desensitization followed by high-dose aspirin therapy. Despite this, many patients have inadequately controlled symptoms and require multiple sinus surgeries. In this review, we discuss the current standard approaches to the management of AERD, and we introduce several therapeutics under development that may hold promise for the treatment of AERD.

Polymorphisms of ATF6B Are Potentially Associated With FEV1 Decline by Aspirin Provocation in Asthmatics

PURPOSE: Endoplasmic reticulum (ER) stress has recently been observed to activate NF-kappaB and induce inflammatory responses such as asthma. Activating transcription factor 6beta (ATF6B) is known to regulate ATFalpha-mediated ER stress response. The aim of this study is to investigate the associations of ATF6B genetic variants with aspirin-exacerbated respiratory disease (AERD) and its major phenotype, % decline of FEV1 by aspirin provocation. METHODS: Four common single nucleotide polymorphisms (SNPs) of ATF6B were genotyped and statistically analyzed in 93 AERD patients and 96 aspirin-tolerant asthma (ATA) as controls. RESULTS: Logistic analysis revealed that 2 SNPs (rs2228628 and rs8111, P=0.008; corrected P=0.03) and 1 haplotype (ATF6B-ht4, P=0.005; corrected P=0.02) were significantly associated with % decline of FEV1 by aspirin provocation, whereas ATF6B polymorphisms and haplotypes were not associated with the risk of AERD. CONCLUSIONS: Although further functional and replication studies are needed, our preliminary findings suggest that ATF6B may be related to obstructive phenotypes in response to aspirin exposure in adult asthmatics.

Association Analysis of TEC Polymorphisms with Aspirin-Exacerbated Respiratory Disease in a Korean Population

The tyrosine-protein kinase Tec (TEC) is a member of non-receptor tyrosine kinases and has critical roles in cell signaling transmission, calcium mobilization, gene expression, and transformation. TEC is also involved in various immune responses, such as mast cell activation. Therefore, we hypothesized that TEC polymorphisms might be involved in aspirin-exacerbated respiratory disease (AERD) pathogenesis. We genotyped 38 TEC single nucleotide polymorphisms in a total of 592 subjects, which comprised 163 AERD cases and 429 aspirin-tolerant asthma controls. Logistic regression analysis was performed to examine the associations between TEC polymorphisms and the risk of AERD in a Korean population. The results revealed that TEC polymorphisms and major haplotypes were not associated with the risk of AERD. In another regression analysis for the fall rate of forced expiratory volume in 1 second (FEV1) by aspirin provocation, two variations (rs7664091 and rs12500534) and one haplotype (TEC_BL2_ht4) showed nominal associations with FEV1 decline (p = 0.03-0.04). However, the association signals were not retained after performing corrections for multiple testing. Despite TEC playing an important role in immune responses, the results from the present study suggest that TEC polymorphisms do not affect AERD susceptibility. Findings from the present study might contribute to the genetic etiology of AERD pathogenesis.

A genetic effect of IL-5 receptor alpha polymorphism in patients with aspirin-exacerbated respiratory disease

Persistent eosinophil activation in both the upper and lower airway mucosa is a central feature of aspirin-exacerbated respiratory disease (AERD). Eosinophil activation and survival are profoundly influenced by interleukin 5 (IL-5) and its receptor, IL-5R. In patients susceptible to allergic disorders, IL-5 receptor alpha (IL5RA) polymorphisms have been reported; however, an association with AERD remains unclear. We hypothesize that IL5RA polymorphisms may contribute to eosinophil activation in AERD patients. We recruited 139 AERD patients, 171 aspirin-tolerant asthma patients and 160 normal controls. IL5RA polymorphisms (-5993G>A, -5567C>G and -5091G>A) were genotyped and functional activity of polymorphism was assessed by luciferase reporter assay and electrophoretic mobility shift assay (EMSA). There was no significant difference in the genotype frequency of the three polymorphisms among the three groups. AERD patients carrying the AA genotype at -5993G>A had a significantly higher presence of serum-specific immunoglobulin E (IgE) to staphylococcal enterotoxin A (P=0.008) than those with the GG/GA genotype. In vitro, the -5993A allele had a higher promoter activity compared with the -5993G allele in human mast cell (HMC-1; P=0.030) and human promyelocytic leukemia (HL-60; P=0.013) cells. In EMSA, a -5993A probe produced a specific shifted band than the -5993G had. These findings suggest that a functional polymorphism in IL5RA may contribute to eosinophil and mast cell activation along with specific IgE responses to staphylococcal enterotoxin A in AERD patients.

Association Analysis Between FILIP1 Polymorphisms and Aspirin Hypersensitivity in Korean Asthmatics

PURPOSE: Aspirin exacerbated respiratory disease (AERD) results in a severe asthma attack after aspirin ingestion in asthmatics. The filamin A interacting protein 1 (FILIP1) may play a crucial role in AERD pathogenesis by mediating T cell activation and membrane rearrangement. We investigated the association of FILIP1 variations with AERD and the fall rate of forced expiratory volume in one second (FEV1). METHODS: A total of 34 common FILIP1 single nucleotide polymorphisms (SNPs) were genotyped in 592 Korean asthmatic subjects that included 163 AERD patients and 429 aspirin-tolerant asthma (ATA) controls. RESULTS: This study found that 5 SNPs (P=0.006-0.01) and 2 haplotypes (P=0.01-0.03) of FILIP1 showed nominal signals; however, corrections for the multiple testing revealed no significant associations with the development of AERD (P corr>0.05). In addition, association analysis of the genetic variants with the fall rate of FEV1, an important diagnostic marker of AERD, revealed no significant evidence (P corr>0.05). CONCLUSIONS: Although further replications and functional evaluations are needed, our preliminary findings suggest that genetic variants of FILIP1 might be not associated with the onset of AERD.

WDR46 is a Genetic Risk Factor for Aspirin-Exacerbated Respiratory Disease in a Korean Population

PURPOSE: The human WD repeat-containing protein 46 (WDR46; also known as C6orf11), located at the disease-relevant centromere side of the class II major histocompatibility complex region, is hypothesized to be associated with risk of aspirin-exacerbated respiratory disease (AERD) as well as a decline in forced expiratory volume in the first second (FEV1), an important diagnostic marker of asthma. METHODS: To investigate the association between WDR46 and AERD, five single-nucleotide polymorphisms (SNPs) were genotyped in 93 AERD cases and 96 aspirin-tolerant asthma controls of Korean ethnicity. Three major haplotypes were inferred from pairwise comparison of the SNPs, and one was included in the association analysis. Differences in the frequency distribution of WDR46 SNPs and haplotype were analyzed using logistic and regression models via various modes of genetic inheritance. RESULTS: Depending on the genetic model, the logistic and regression analyses revealed significant associations between rs463260, rs446735, rs455567, rs469064, and WDR46_ht2 and the risk of AERD (P=0.007-0.04, Pcorr=0.01-0.04) and FEV1 decline after aspirin provocation (P=0.006-0.03, Pcorr=0.01-0.03). Furthermore, functional analysis in silico showed that the G>A allele of rs463260 located in the 5' untranslated region potentially matched a nucleotide sequence within an upstream open reading frame of WDR46. CONCLUSIONS: These findings show for the first time that WDR46 is an important genetic marker of aspirin-induced airway inflammation and may be useful for formulating new disease-management strategies.

Aspirin-Exacerbated Respiratory Disease: Evaluation and Management

The clinical syndrome of aspirin-exacerbated respiratory disease (AERD) is a condition where inhibition of cyclooxygenase-1 (COX-1) induces attacks of upper and lower airway reactions, including rhinorrhea and varying degrees of bronchospasm and laryngospasm. Although the reaction is not IgE-mediated, patients can also present with anaphylactic hypersensitivity reactions, including hypotension, after exposure to COX-1 inhibiting drugs. All patients with AERD have underlying nasal polyps and intractable sinus disease which may be difficult to treat with standard medical and surgical interventions. This review article focuses on the management of AERD patients with a particular emphasis on aspirin desensitization and continuous treatment with aspirin.

Diagnostic Value of Clinical Parameters in the Prediction of Aspirin-Exacerbated Respiratory Disease in Asthma

PURPOSE: Aspirin-exacerbated respiratory disease (AERD) has attracted a great deal of attention because of its association with increased asthma severity. However, oral aspirin challenge (OAC) to diagnose AERD is a time-consuming procedure, and some patients experience serious complications. Thus, we evaluated diagnostic values of non-invasive clinical parameters to predict AERD in asthmatic patients. METHODS: A total of 836 Korean subjects were recruited from an asthma cohort. They underwent OAC, and clinical parameters including the history of aspirin hypersensitivity, nasal polyposis, and chronic sinusitis of aspirin-tolerant asthma (ATA) and AERD asthmatic patients were compared. RESULTS: Significant differences (P<0.01) were found in eight parameters: age at diagnosis, body mass index, FEV1%, PC20, history of urticaria, nasal polyps, chronic sinusitis, and history of aspirin hypersensitivity. After logistic regression analysis based on the eight clinical parameters, nasal polyps, history of aspirin intolerance, sinusitis, and log [PC20 methacholine] remained significantly associated with AERD (P<0.05). The sensitivity and specificity of the history of aspirin hypersensitivity to predict AERD were 64.7% and 92.0%, respectively, and the positive and negative predictive values were 56.9% and 94.1%, respectively. Overall, the accuracy of the test was 88.2%. The accuracy of the tests for nasal polyps and chronic sinusitis were 67.3% and 60.4%, respectively. CONCLUSIONS: Among clinical parameters associated with AERD, the history of aspirin hypersensitivity has the best positive and negative predictive values for the oral aspirin challenge test. Because the false-positive and -negative rates were still high, additional non-invasive methods are needed to reduce the rate of false outcomes.