Improvements in an oral aspirin challenge protocol for the diagnosis of aspirin hypersensitivity

Refractory drug-induced systemic small-vessel vasculitis with two varied extracutaneous manifestations: a case report and review of the literature

BACKGROUND

Clopidogrel and ticagrelor are rarely reported to cause vasculitis via drug hypersensitivity reaction, largely mediated by T cells and immunoglobulin E (IgE). Despite therapeutic advances, the etiology of refractory vasculitides remains incompletely understood. Recently, (non)immunological mechanisms bypassing T cells and IgE have been proposed to explain resistance to standard immunosuppressants. Herein, we report a case of refractory drug-induced systemic small-vessel vasculitis with varied extracutaneous manifestations and incorporate multiple sources of data to provide detailed accounts of complex (non)immunological phenomena involved in this case. Study objectives are to provide an insight about rare presentations of commonly used drugs, upgrade the pathophysiological concepts of drug-induced vasculitis, raise need for further investigation to define causes and risk factors for refractory vasculitis, and discuss most of the current knowledge suggesting novel therapeutic approaches to treat this vasculitis. To our knowledge, this is the first case of the two flares of systemic small-vessel vasculitis in a single patient in response to clopidogrel and ticagrelor exposure, respectively. However, this report is limited by attribution/observer bias.

CASE PRESENTATION

We herein report a 24-year-old Caucasian male student with a medical history of mild seasonal allergic rhinoconjunctivitis, tension-type headaches, posttraumatic arterial stenosis, and previous exposure to ibuprofen, acetylsalicylic acid, and mRNA coronavirus disease 2019 (COVID-19) vaccine who suffered largely from acute urticaria and dyspnea after 20 days of acetylsalicylic acid and clopidogrel introduction. A skin punch biopsy confirmed leukocytoclastic vasculitis. Serologic antibody testing, complement analysis, microbiologic testing, and cancer biomarkers revealed no abnormalities. Regarding the patient's medical history, both acetylsalicylic acid and clopidogrel were exchanged for ticagrelor. Furthermore, the addition of naproxen, cyclosporine, bilastine, prednisolone, and montelukast resulted in complete recovery. After 7 days, diarrhea and hematuria occurred. Urinalysis and computed tomography showed reversible proteinuria with gross hematuria and hypodense changes in kidney medulla, respectively, associated with discontinuation of ticagrelor and naproxen. In addition, the patient recovered completely without any immunosuppression up-titration.

CONCLUSIONS

This case highlights the role of clopidogrel and ticagrelor as possible triggering agents for systemic small-vessel vasculitis and offers an insight into novel therapeutic strategies for refractory vasculitides. Further research is needed to build on the findings of a current report.

Symptom Control of Patients With Chronic Rhinosinusitis With Nasal Polyps Under Maintenance Therapy With Daily Acetylsalicylic Acid

INTRODUCTION

Nonsteroidal anti-inflammatory drugs (NSAID)-exacerbated respiratory disease (NERD) is defined by intolerance to cyclooxygenase 1 inhibitors, chronic rhinosinusitis with recurrent nasal polyps, and/or intrinsic bronchial asthma. Long-term administration of acetylsalicylic acid (ASA) after desensitization has been used to mitigate these sequelae, but the optimal dose and balancing symptom relief and side effects remain unsettled.

METHODS

Retrospective data analysis of 85 patients with NERD receiving maintenance therapy of 300 mg ASA was followed by questionnaires (our own, not validated and the Sino-Nasal Outcome Test-20). We received responses from 55 patients and examined 30 of them clinically.

RESULTS

Patients with no ASA-associated side effects were 56.4% (56 of 85 patients) of the cohort. In this study, 60% (33 of 55 patients) continued prophylaxis of 300 mg ASA daily for an average of 34.7 months. Elective surgery was the most frequent cause of discontinuation of ASA (21.8%; 12 of 55 patients). Rhinomanometry values were significantly improved with ASA (P < .05; Wilcoxon), but there was no significant reduction in nasal polyposis or improvement in olfaction at the time of follow-up examination.

CONCLUSIONS

Minor clinical improvements were identified. Side effects were well tolerated by most patients, and no serious sequelae occurred. The indications for long-term ASA therapy in NERD patients remain unsettled.

A Multicenter Retrospective Study on Hypersensitivity Reactions to Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) in Children: A Report from the European Network on Drug Allergy (ENDA) Group

BACKGROUND

Diagnosis of hypersensitivity (HS) reactions to nonsteroidal anti-inflammatory drugs (NSAIDs) in children is complex. The real prevalence of NSAID HS remains unknown because a drug provocation test (DPT) is not always performed with the culprit NSAID.

OBJECTIVE

To describe and compare the diagnostic workup among different European centers and to find out the real proportion of NSAID HS by performing a DPT with the culprit drug.

METHODS

We retrospectively collected data from children (0-10 years) and adolescents (10-18 years) with a history of NSAID reactions and who underwent a complete allergy workup including DPTs with the culprit in 6 different pediatric centers: Belgrade, Florence, Geneva, Madrid, Porto, and Rome.

RESULTS

A total of 693 children with a history of NSAID reactions were enrolled, and a total of 526 DPTs were performed with the culprit NSAID. The diagnosis of NSAID HS was confirmed in 19.6% (103 of 526) of children by performing a DPT with the culprit drug. The major differences in the allergy workup among the 6 centers concerned the duration of the DPT and the practical use of skin tests for diagnosing NSAID HS. In addition, the use of acetyl salicylic acid to differentiate single reactor or cross-intolerance patients is not common, except in Spain.

CONCLUSION

The value of this study is that although different approaches are used around Europe to diagnose NSAID HS, we found that the percentage of confirmed NSAID HS is less than 20%. This highlights the importance of the DPT in confirming or excluding NSAID HS in the pediatric population.

Multiple Drug Intolerance Syndrome: An Underreported Distinct Clinical Entity

Aim:

Multiple drug intolerance syndrome (MDIS) is a unique clinical entity distinct from other drug hypersensitivity syndromes. The aim of this review was to critically appraise the various aspects of MDIS.

Methods

A review was conducted to search for the causes, mechanism, clinical features, and management of MDIS.

Results

The most common cause of MDIS is antibiotics followed by non-steroidal anti-inflammatory drugs (NSAIDs). Although some non-specific immunological mechanisms are involved, the immunological tests for MDIS are negative. Rashes, gastrointestinal reflux, headache, cough, muscle ache, fever, dermatitis, hypertension, and psychiatric symptoms are the usual manifestations. Treatment is mostly symptomatic with the withdrawal of the offending drug. Drug re-challenges and desensitization may be required for the management of this syndrome.

Conclusion

MDIS occurs by a nonimmune mechanism which requires a prompt withdrawal of the offending drug(s), and in some cases may require drug re-challenge and desensitization.

A 1-Day, 90-Minute Aspirin Challenge and Desensitization Protocol in Aspirin-Exacerbated Respiratory Disease

BACKGROUND

Aspirin challenge and desensitization remains the criterion standard in diagnosis and treatment for patients with aspirin-exacerbated respiratory disease (AERD), but the protocols can be time and resource intensive.

OBJECTIVE

To provide evidence that oral aspirin challenge and desensitization can be safely performed in an outpatient setting in 1 day.

METHODS

Forty-four patients with a confirmed diagnosis of AERD, stable asthma, and baseline FEV₁ value greater than or equal to 70% of predicted completed an oral aspirin challenge and desensitization protocol. The starting dose was 40.5 mg with escalating doses of aspirin (81, 162.5, 325 mg) at 90-minute intervals until symptoms were provoked. Desensitization was defined as tolerating a repeated administration of the provocative aspirin dose and at least 1 subsequent dose, bringing the total aspirin ingested during the in-clinic desensitization to 325 mg or more.

RESULTS

Ninety-three percent of patients completed the challenge and desensitization in 1 day, with an average protocol completion time of 9 hours and 29 minutes. Two patients (4.6%) chose to complete the protocol over 2 days. One patient (2.3%) was discontinued from the protocol because of ongoing abdominal discomfort and diarrhea. No patient required epinephrine, emergency department visit, or hospitalization.

CONCLUSIONS

Patients with AERD on a stable asthma regimen and with a baseline FEV₁ value greater than or equal to 70% can be safely desensitized to aspirin using a 90-minute dose escalation protocol, starting at a dose of 40.5 mg, and defining desensitization as tolerance of the repeated provocation dose and at least 1 subsequent aspirin dose, bringing total cumulative daily dose to 325 mg or more. This protocol can routinely be completed in 1 day.

Predictive value of a negative oral provocation test in patients with hypersensitivity to analgesics

INTRODUCTION

Nonsteroidal anti-inflammatory drugs (NSAIDs) take first or second place as the cause of drug-induced hypersensitivity reactions. The oral provocation test (OPT) is a gold standard for the diagnosis of NSAID hypersensitivity. We investigated which analgesics patients took after a negative OPT and determined the proportion of patients that experienced a hypersensitivity reaction despite a negative OPT.

METHODS

We selected 115 patients (67.8% female, age 54.9 ± 16.7 years) with a negative aspirin OPT and a convincing history of immediate hypersensitivity to aspirin or NSAIDs. In a telephone survey, we identified the analgesics taken after the OPT and possible adverse events.

RESULTS

The mean follow-up time was 5.1 ± 2.0 years. All subjects needed at least one analgesic drug. Despite the negative outcome of the aspirin OPT, only 33.9% of subjects took aspirin and 0.9% had a hypersensitivity reaction. The negative predictive value (NPV) of the aspirin OPT was 97.4%. Overall, 16 (13.9%) subjects experienced a hypersensitivity reaction, 12 of which occurred after taking a drug not tested with the OPT. The NPV of the OPT for all NSAIDs was 96.4%.

CONCLUSIONS

Our results support the available data that most subjects do not re-take the tested drug regardless of the high NPV of the OPT.

Hypersensitivity to Aspirin and other NSAIDs: Diagnostic Approach in Patients with Chronic Rhinosinusitis

Hypersensitivity to nonsteroidal anti-inflammatory drugs (NSAIDs) associated with chronic rhinosinusitis (CRS) and/or asthma comprises a distinct clinical syndrome referred to as NSAIDs exacerbated respiratory disease (NERD). Patients with NERD tend to have more severe course of both upper (CRS and nasal polyps) and lower airway (asthma) diseases and are usually recalcitrant to conventional treatment modalities. Diagnosing and phenotyping of patients with NERD are critical for prevention of drug-induced adverse reactions and open novel options for management of underlying chronic airway inflammatory diseases. Diagnosis of NERD is based on detailed clinical history confirmed by challenge with aspirin, but new diagnostic approaches are currently being developed. This review article focuses on the diagnostic approach to a patient with CRS and hypersensitivity to NSAIDs, emphasizing the importance of diagnosis for proper patient's management.

NSAID-exacerbated respiratory disease: a meta-analysis evaluating prevalence, mean provocative dose of aspirin and increased asthma morbidity

BACKGROUND

The prevalence and mean provocative dose of oral aspirin (MPDA) triggering respiratory reactions in people with asthma have been inconsistently reported, and the relationship between NSAID-exacerbated respiratory disease (NERD) and asthma morbidity was less well quantified.

METHODS

A systematic review was performed by identifying studies diagnosing NERD using blinded, placebo-controlled oral provocation challenge tests (OPCTs) or by self-reported history in people with asthma. Data were extracted, and effect estimates for changes in respiratory function, MPDA and asthma morbidity were pooled using random-effects meta-analysis.

RESULTS

The prevalence of NERD in adults with asthma was 9.0% (95% CI 6-12%) using OPCTs and 9.9% (95% CI 9.4-10.5%) using self-reported history from questionnaires. The MPDA in adults with NERD was 85.8 mg (95% CI 73.9-97.6). In people with NERD, the risk of: uncontrolled asthma was increased twofold (RR 1.96 (95% CI 1.25-3.07)); severe asthma and asthma attacks was increased by 60% (RR 1.58 (95% CI 1.15-2.16) and RR 1.59 (95% CI 1.21-2.09), respectively); emergency room visits was increased by 80% (RR 1.79 (95% CI 1.29-2.49)); and asthma hospitalization was increased by 40% (RR 1.37 (95% CI 1.12-1.67)) compared to people with NSAID-tolerant asthma.

CONCLUSIONS

Respiratory reactions triggered by oral aspirin in people with asthma are relatively common. At the population level, the prevalence of NERD was similar when measured using appropriately conducted OPCTs or by self-reported history. On average, respiratory reactions were triggered by clinically relevant doses of oral aspirin. Asthma morbidity was significantly increased in people with NERD who potentially require more intensive monitoring and follow-up.

Potential association between ANXA4 polymorphisms and aspirin-exacerbated respiratory disease

Aspirin-exacerbated respiratory disease (AERD) is a clinical syndrome characterized by bronchoconstriction after ingestion of nonsteroidal anti-inflammatory drugs including aspirin. The Ca concentration in bronchial epithelial cells is an important factor for bronchoconstriction. Human annexin A4 (ANXA4) is predominantly expressed in the secretory epithelia in the lung, stomach, intestine, and kidney. Furthermore, translocation and induction of ANXA4 have been observed in human Ca-depleted neutrophils. To investigate the association between annexin A4 polymorphisms and the risk of AERD, we have genotyped 21 variants from 102 AERD subjects and 429 aspirin-tolerant asthma (ATA) controls. Logistic analyses controlling for sex, smoking status, and atopy as covariates were performed to estimate the association between the annexin A4 polymorphisms and AERD. Among these variants, 8 polymorphisms (rs2168116, rs4853017, rs6546547, rs13428251, rs7577864, rs7559354, rs7588022, and rs3816491) and 2 haplotypes (ANXA4-ht3 and ANXA4-ht5) were significantly associated with the risk of AERD. One common polymorphism in intron 11, rs3816491, showed the strongest association signal with susceptibility to aspirin-AERD even after multiple testing corrections (OR=0.57; 95% confidence interval 0.40-0.83; P=0.003; P=0.045 in the codominant model). Although further functional evaluations of replication studies in larger cohorts are required, our findings suggest that the annexin A4 could have susceptibility for AERD.

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.

Potential association of DDR1 genetic variant with FEV1 decline by aspirin provocation in asthmatics

BACKGROUND

The discoidin domain receptor tyrosine kinase 1 (DDR1) is positioned within the major histocompatibility complex (MHC) region which plays an important role in the immune system. In addition, DDR1 has been elucidated to be downregulated during the epithelial-mesenchymal transition of bronchial epithelium.

OBJECTIVE

To investigate the potential genetic associations between DDR1 and aspirin-exacerbated respiratory disease (AERD), this study conducted association studies of DDR1 single nucleotide polymorphisms (SNPs) with AERD and the obstructive symptom of forced expiratory volume in 1 s (FEV(1)) decline after aspirin provocation.

METHODS

Nine common SNPs were genotyped in 93 AERD patients and 96 aspirin-tolerant asthma (ATA) controls. The genotype distributions of all loci were in Hardy-Weinberg equilibrium (HWE; p > .05). Results. In the results of logistic analyses using age, sex, smoking status, and atopy as covariates, DDR1 rs1264320 in the intronic region showed a potent association signal with FEV(1) decline by aspirin provocation in asthmatics of this study even after corrections for multiple testing (p = .003 and corrected p = .01). However, the variants of DDR1 were not significantly associated with the AERD development (corrected p > .05). On further comparison of FEV(1) decline by aspirin provocation between AERD and ATA, the variant rs1264320 was found to be associated with the FEV(1) decline of ATA rather than AERD.

CONCLUSION

Despite the need for further functional evaluations and replications, we conclude that DDR1 polymorphisms are not likely to contribute to predispositions of AERD, but may be potentially associated with FEV(1) decline by aspirin provocation in asthmatics.

[Allergic and non-allergic hypersensitivity to non-opioid analgesics, antipyretics and nonsteroidal anti-inflammatory drugs in children: epidemiology, clinical aspects, pathophysiology, diagnosis and prevention]

Non-opioid analgesics, antipyretics and nonsteroidal anti-inflammatory drugs are widely used, but suspected allergic reactions to these drugs are rare, especially in children. Most frequent reactions are cutaneous (urticaria, angioedema) and respiratory (rhinitis, asthma). Other reactions (anaphylaxis, potentially harmful toxidermias) are rare. In a few patients, reactions may result from a specific (allergic) hypersensitivity, with positive responses in prick and intradermal tests (anaphylaxis, immediate urticaria and/or angioedema) and in intradermal and patch tests (non-immediate reactions). However, most reactions result from a non-specific (non-allergic) hypersensitivity (intolerance), with a frequent cross-reactivity between the various families of analgesics, antipyretics and nonsteroidal anti-inflammatory drugs, including paracetamol. Based on a convincing clinical history and/or positive responses in challenge tests, intolerance to non-opioid analgesics, antipyretics and nonsteroidal anti-inflammatory drugs has been diagnosed in 13 to 50% of the patients with allergic-like reactions to these drugs. Risk factors are a personal atopy and age. Prevention is based on administration of other (families of) analgesics, antipyretics and nonsteroidal anti-inflammatory drugs in patients with allergic hypersensitivity to these drugs. In patients with non-allergic hypersensitivity, prevention is based on administration of drugs with a low cyclo-oxygenase-1 inhibitory activity (if tolerated). Desensitization is efficient in patients with respiratory reactions, but does not work in patients with mucocutaneous reactions and anaphylaxis.

Contribution of the OBSCN nonsynonymous variants to aspirin exacerbated respiratory disease susceptibility in Korean population

Airway remodeling and exacerbated airway narrowing in asthma have been attributed to the regulation of intracellular Ca(2+) by sarcoplasmic reticulum (SR) of the airway smooth muscle cells. The protein encoded by obscurin, cytoskeletal calmodulin and titin-interacting RhoGEF (OBSCN) is a crucial factor in determining the SR architecture in Obscn(-/-) mice. This study genotyped a total of 55 common single-nucleotide polymorphisms (SNPs) in 592 Korean asthmatics including 163 aspirin exacerbated respiratory disease (AERD) cases and 429 aspirin-tolerant asthma (ATA) controls. Eight SNPs, including two nonsynonymous polymorphisms rs1188722C>T (Leu2116Phe) and rs1188729G>C (Cys4642Ser), and one haplotype BL2_ht1 showed statistically significant associations with AERD development (p=0.003-0.03). Two variants, rs1188722C>T (Leu2116Phe) and rs369252C>A, also revealed nominal association with FEV1 decline by aspirin provocation in asthmatics (p=0.03-0.04). Intriguingly, rs1188722C>T (Leu2116Phe) is a highly conserved amino acid residue among species, suggesting its functional relevance to AERD. In addition, the A allele of rs369252C>A, which was more prevalent in AERD than in ATA, was predicted as a potential branch point (BP) site for alternative splicing (BP score=4.29). Although further functional evaluation is required, our findings suggest that OBSCN polymorphisms, in particular, highly conserved nonsynonymous Leu2116Phe variant, might contribute to aspirin hypersensitivity in asthmatics.

Fatty acid binding protein 1 is related with development of aspirin-exacerbated respiratory disease

Background

Aspirin-exacerbated respiratory disease (AERD) refers to the development of bronchoconstriction in asthmatics following the ingestion of aspirin. Although alterations in eicosanoid metabolites play a role in AERD, other immune or inflammatory mechanisms may be involved. We aimed to identify proteins that were differentially expressed in nasal polyps between patients with AERD and aspirin-tolerant asthma (ATA).

Methodology/Principal Findings

Two-dimensional electrophoresis was adopted for differential display proteomics. Proteins were identified by liquid chromatography-tandem mass spectrometry (LC-MS). Western blotting and immunohistochemical staining were performed to compare the amount of fatty acid-binding protein 1 (FABP1) in the nasal polyps of patients with AERD and ATA. Fifteen proteins were significantly up- (seven spots) or down-regulated in the nasal polyps of patients with AERD (n = 5) compared to those with ATA (n = 8). LC-MS revealed an increase in seven proteins expression and a decrease in eight proteins expression in patients with AERD compared to those with ATA (P = 0.003–0.045). FABP1-expression based on immunoblotting and immunohistochemical analysis was significantly higher in the nasal polyps of patients with AERD compared to that in patients with ATA. FABP1 was observed in epithelial, eosinophils, macrophages, and the smooth-muscle cells of blood vessels in the polyps.

Conclusions/Significance

Our results indicate that alterations in 15 proteins, including FABP1, may be related to the development of AERD.

Genetic association analysis of TAP1 and TAP2 polymorphisms with aspirin exacerbated respiratory disease and its FEV1 decline

Aspirin exacerbated respiratory disease (AERD) induces bronchoconstriction in asthmatic patients characterized with a clinical condition of severe decline in forced expiratory volume in one second (FEV1) after ingestion of aspirin. Two genes consisting a heterodimer, transporter 1 and 2, ATP-binding cassette, sub-family B (MDR/TAP) (TAP1 and TAP2) within the major histocompatibility complex (MHC) region, have been implicated in immunodeficiency and bronchiectasis development. To investigate the associations of TAP1 and TAP2 genetic polymorphisms with AERD and phenotypic FEV1 decline, a total of 43 common single-nucleotide polymorphisms (SNPs) including 12 SNPs of TAP1 and 31 SNPs of TAP2 were genotyped in 93 AERD patients and 96 aspirin-tolerant asthma controls. Interestingly, regression analysis revealed that polymorphisms and haplotypes of TAP2 were associated with FEV1 decline by aspirin provocation (P=0.002-0.04), with about twofold decline rate of FEV1 in most of minor homozygotes compared with major homozygotes. In addition, nominal evidences of association between TAP2 and AERD development were observed (P=0.02-0.04). However, TAP1 polymorphisms showed no relations to both AERD and FEV1 decline after aspirin challenge (P>0.05). Although further functional evaluations and replications are required, our preliminary findings provide supporting information that variants of TAP2 might be predisposing factors for FEV1 decline-related symptoms.

Association analysis of thromboxane A synthase 1 gene polymorphisms with aspirin intolerance in asthmatic patients

AIM

Thromboxane A synthase (TBXAS1) converts prostaglandin H to thromboxane A, a potent constrictor of smooth respiratory muscle. Thus, functional alterations of the TBXAS1 gene may contribute to aspirin-intolerant asthma (AIA).

MATERIALS & METHODS

We investigated the relationship between SNPs in the TBXAS1 gene and AIA. Asthmatics (n = 470) were categorized into AIA (20% or greater decreases in forced expiratory volume in 1 s [FEV(1)], or 15% to 19% decreases in FEV(1) with naso-ocular or cutaneous reactions) and aspirin-tolerant asthma (ATA). A total of 101 SNPs were genotyped. mRNA expression of the TBXAS1 gene by peripheral blood mononuclear cells and plasma thromboxane B2 (TXB2) concentrations were measured by reverse transcriptase (RT)-PCR and ELISA.

RESULTS

Logistic regression analysis showed that the rare allele frequency of rs6962291 in intron 9 was significantly lower in the AIA group (n = 115) than in the ATA group (n = 270) (p(corr) = 0.04). The linear regression analysis revealed a strong association of rs6962291 with the aspirin challenge-induced FEV(1) fall (p = 0.003). RT-PCR revealed an exon-12-deleted splice variant. We measured TBXAS1 mRNA levels in peripheral blood mononuclear cells. The mRNA levels of the full-length wild-type and splice variant were significantly higher in the TT homozygotes than in the AA homozygotes of rs6962291 (1.00 ± 0.18 vs 0.57 ± 0.03 and 1.00 ± 0.18 vs 0.21 ± 0.05, p = 0.047 and 0.001, respectively). The plasma TXB2 level was significantly lower in rs6962291 AA carriers than in rs6962291 TT (p = 0.016) carriers.

CONCLUSION

The rare allele of rs6962291 may play a protective role against aspirin hypersensitivity via a lower catalytic activity of the TBXAS1 gene, attributed to the increase of a nonfunctioning isoform of TBXAS1.

Lack of association between CD58 genetic variations and aspirin-exacerbated respiratory disease in a Korean population

BACKGROUND

Exacerbation of asthma symptoms due to aspirin ingestion may lead to life-threatening lung failure. The adhesion molecule CD58 gene may play a crucial role in aspirin-exacerbated respiratory disease (AERD) pathogenesis by mediating the biological functions of asthma-inducing mechanisms including T helper cells, proinflammatory cytokines, and natural killer T cells.

OBJECTIVE

This study aimed to investigate the association of CD58 variations with aspirin-induced bronchospasm in Korean asthma patients.

METHODS

Seven single-nucleotide polymorphisms were selected for genotyping based on previously reported polymorphisms in the International HapMap database. Genotyping was carried out using TaqMan assay and 2 major haplotypes were obtained in 163 AERD cases and 429 aspirin-tolerant asthma controls. Frequency distributions of CD58 variations were analyzed using logistic and regression models.

RESULTS

Results showed that none of the analyzed CD58 single-nucleotide polymorphisms and haplotypes was significantly associated with AERD development and fall rate of FEV(1) by aspirin provocation, an important diagnostic marker of aspirin hypersensitivity.

CONCLUSIONS

This preliminary study suggests that CD58 does not affect AERD susceptibility in a Korean population, and may provide a new direction for future disease etiology.

Association of FANCC polymorphisms with FEV1 decline in aspirin exacerbated respiratory disease

Aspirin exacerbated respiratory disease (AERD) is a clinical condition characterized by severe decline in forced expiratory volume in one second (FEV1) following the ingestion of non-steroidal anti-inflammatory drugs (NSAIDs), including aspirin. The exacerbated inflammatory response in Fancc-deficient mice has been reported to be associated with hemopoietic responses that are also related to AERD pathogenesis. To investigate associations of FANCC polymorphisms with AERD and related phenotypes, this study genotyped 25 common single nucleotide polymorphisms (SNPs) in a total of 592 Korean asthmatics including 163 AERD and 429 aspirin-tolerant asthma (ATA) subjects. Logistic analysis revealed that genetic polymorphisms of the FANCC gene might not be directly related to AERD development and nasal polyposis (P > 0.05). However, the FEV1 decline by aspirin provocation showed significant associations with FANCC polymorphisms (P = 0.006-0.04) and a haplotype (unique to rs4647416G > A, P = 0.01 under co-dominant, P = 0.006 under recessive model). In silico analysis showed that the "A" allele of rs4647376C > A, which was more prevalent in AERD than in ATA, could act as a potential branch point (BP) site for alternative splicing (BP score = 4.16). Although replications in independent cohorts and further functional evaluations are still needed, our preliminary findings suggest that FANCC polymorphisms might be associated with the obstructive symptoms in allergic diseases.

Association analysis of C6 genetic variations and aspirin hypersensitivity in Korean asthmatic patients

There has been increasing evidence that genetic mechanisms contribute to the development of aspirin-intolerant asthma (AIA), a life-threatening disease. The complement component (C6) is a constituent of a biochemical cascade that has been implicated in airway epithelial damage and nasal polyposis, and therefore, may be a risk factor for AIA. To investigate the association between C6 variations and AIA in a Korean asthma cohort, 27 SNPs were selected for genotyping based on previously reported polymorphisms in the HapMap database. Genotyping was carried out using TaqMan assay, and five major haplotypes were obtained in 163 AIA cases and 429 aspirin-tolerant asthma (ATA) controls subjects. Genotype frequency distributions of C6 polymorphisms and haplotypes were analyzed using logistic and regression models. Subsequent analyses revealed a lack of association between C6 genetic variations and AIA. From the initial analyses, marginal associations of rs10512766 (p = 0.04 in co-dominant model) and rs4957374 (p = 0.05 in dominant model) with AIA did not reach the threshold of significance after multiple testing corrections; thus this study failed to find convincing evidence that variations in C6 gene influence the risk of AIA in a Korean population. However, these preliminary results may contribute to the etiology of aspirin hypersensitivity in Korean asthmatic patients.

Genome-wide methylation profile of nasal polyps: relation to aspirin hypersensitivity in asthmatics

BACKGROUND

In addition to the dysregulation of arachidonic acid metabolism in aspirin-intolerant asthma (AIA), aspirin acetylsalicylic acid (ASA) exerts effects on inflammation and immunity; however, many of these effects are unknown.

OBJECTIVE

The aim of the study was to evaluate the methylation status of whole genome in blood and polyp tissues with and without aspirin hypersensitivity.

METHODS

Genome-wide DNA methylation levels in nasal polyps and peripheral blood cells were examined by microarray analysis using five subjects with AIA and four subjects with aspirin-tolerant asthma (ATA).

RESULTS

In the nasal polyps of the patients with AIA, hypermethylation was detected at 332 loci in 296 genes, while hypomethylation was detected at 158 loci in 141 genes. Gene ontologic and pathway enrichment analyses revealed that genes involved in lymphocyte proliferation, cell proliferation, leukocyte activation, cytokine biosynthesis, cytokine secretion, immune responses, inflammation, and immunoglobulin binding were hypomethylated, while genes involved in ectoderm development, hemostasis, wound healing, calcium ion binding, and oxidoreductase activity were hypermethylated. In the arachidonate pathway, PGDS, ALOX5AP, and LTB4R were hypomethylated, whereas PTGES was hypermethylated.

CONCLUSION

The nasal polyps of patients with AIA have characteristic methylation patterns affecting 337 genes. The genes and pathways identified in this study may be associated with the presence of aspirin hypersensitivity in asthmatics and are therefore attractive targets for future research.

Association analysis of RGS7BP gene polymorphisms with aspirin intolerance in asthmatic patients

BACKGROUND

Signal-regulated palmitoylation of RGS7BP(regulator of G-protein-signaling 7-binding protein) initiates the activation of G-protein-coupled receptors (GPCRs), including muscarinic receptors, which contribute to the development of asthma and its subphenotypes.

OBJECTIVE

To determine the association of RGS7BP gene polymorphisms with the development of aspirin-exacerbated respiratory disease (AERD).

METHODS

We evaluated the association of RGS7BP gene polymorphisms with response to oral aspirin challenge and with responsiveness to methacholine challenge. RGS7BP messenger RNA splice variants in peripheral blood platelets from patients with different single-nucleotide polymorphisms were analyzed by reverse-transcription polymerase chain reaction.

RESULTS

Logistic regression analysis of RGS7BP gene polymorphisms in patients with AERD (n = 102) and aspirin-tolerant asthma (n = 429) revealed that a haplotype of block 3 consisting of rare alleles +98092 C>G, +98853 C>T, and +104450 T>G of the RGS7BP gene was associated with AERD. Multiple linear regression analysis showed that asthmatic patients carrying ht2/ht2 in block 3 were more responsive to aspirin challenge than those not carrying ht2 (P = .008 in a codominant model). The log-transformed provocation concentration that caused a decrease in forced expiratory volume in 1 second of 20% for methacholine was significantly dependent on the BL3-ht2 haplotype. No significant differences in platelet expression of different RGS7BP messenger RNA splice variants were detected between those with and without the BL3-ht2 haplotype.

CONCLUSION

BL3-ht2 of RGS7BP may be an important genetic variant associated with AERD. The haplotype of block 3 may play a protective role against aspirin hypersensitivity in asthma, perhaps by altering the responsiveness of muscarinic receptors.

Association analysis of N-acetyl transferase-2 polymorphisms with aspirin intolerance among asthmatics

AIMS

Cysteinyl leukotrienes are inactivated by acetyl coenzyme A-dependent N-acetyltransferase (NAT). Thus, functional alterations of the NAT gene may contribute to the risk of aspirin-intolerant asthma.

MATERIALS & METHODS

Asthmatics (n = 438) were categorized into aspirin-intolerant asthma (15% or greater decrease in the forced expiratory volume in 1 s or cutaneous reactions, n = 170) or aspirin-tolerant asthma (n = 268) groups. In total, 14 polymorphisms of the NAT2 gene were genotyped by a single-base extension method.

RESULTS

The distributions of all loci of the 14 SNPs were in Hardy-Weinberg equilibrium (p > 0.05). Among the 14 SNPs, six common SNPs (minor allele frequency >5%) in a Korean population were used for haplotype construction and further statistical analysis. The logistic regression analysis demonstrated that NAT2 -9246G>C and haplotype 2 (TCACGG) were significantly associated with the risk of aspirin-intolerant asthma. The rare allele frequencies of the SNP and Ht2 were significantly higher in the aspirin-intolerant asthma group than in the aspirin-tolerant asthma group (p(corr) = 0.03 and p(corr) = 0.02 in codominant model).

CONCLUSION

In a large genetic epidemiology study of aspirin-intolerant asthma in a Korean population, genetic polymorphisms of NAT2 were found to be related to a risk of aspirin hypersensitivity among asthmatics.

Putative association of SMAPIL polymorphisms with risk of aspirin intolerance in asthmatics

BACKGROUND

Aspirin-intolerant asthma (AIA), as a clinical syndrome caused by aspirin, is characterized by lung inflammation and reversible bronchoconstriction. Recently, the altered trafficking and diminished airway reactivity have been implicated in allergic airway remodeling. The stromal membrane-associated protein 1-like (SMAP1L) exerts common and distinct functions in vesicle trafficking including endocytosis. The disturbance of pulmonary surfactant synthesis has been elucidated to be associated with asthma experimentally. Moreover, in alveolar type II (ATII) cells that synthesize pulmonary surfactant, alterations of clathrin-dependent endocytosis cause disturbance at the surfactant function, suggesting that SMAP1L, which directly interacts with clathrin, could be associated with asthma and related phenotypes.

OBJECTIVE

To verify our hypothesis that SMAP1L could play a role in the development of AIA, this study investigated associations between single-nucleotide polymorphisms (SNPs) of the SMAP1L gene and AIA.

METHODS

We conducted an association study between 19 SNPs of the SMAP1L gene and AIA in a total of 592 Korean subjects including 163 AIA and 429 aspirin-tolerant asthma (ATA) patients. Associations between polymorphisms of SMAP1L and AIA were analyzed with sex, smoking status, atopy, and body mass index as covariates.

RESULTS

Logistic analyses revealed that three common polymorphisms, rs2982510, rs2294752, and rs446738, were putatively associated with the increased susceptibility to AIA (p = .003, p(corr) = .004, OR = 0.24, 95% CI = 0.09-0.62 for rs2982510 and rs2294752; p = .008, p(corr) = .03, OR = 0.44, 95% CI = 0.24-0.80 for rs446738, in the recessive model). In addition, rs2982510 and rs2294752 were significantly associated with the fall of forced expiratory volume in 1 s (FEV₁) by aspirin provocation (p = .001, p(corr) = .04 in the recessive model for both SNPs).

CONCLUSIONS

Our findings suggest that SMAP1L might be a susceptible gene to AIA, providing a new strategy for the control of aspirin intolerance.

Genome-wide and follow-up studies identify CEP68 gene variants associated with risk of aspirin-intolerant asthma

Aspirin-intolerant asthma (AIA) is a rare condition that is characterized by the development of bronchoconstriction in asthmatic patients after ingestion of non-steroidal anti-inflammatory drugs including aspirin. However, the underlying mechanisms of AIA occurrence are still not fully understood. To identify the genetic variations associated with aspirin intolerance in asthmatics, the first stage of genome-wide association study with 109,365 single nucleotide polymorphisms (SNPs) was undertaken in a Korean AIA (n = 80) cohort and aspirin-tolerant asthma (ATA, n = 100) subjects as controls. For the second stage of follow-up study, 150 common SNPs from 11 candidate genes were genotyped in 163 AIA patients including intermediate AIA (AIA-I) subjects and 429 ATA controls. Among 11 candidate genes, multivariate logistic analyses showed that SNPs of CEP68 gene showed the most significant association with aspirin intolerance (P values of co-dominant for CEP68, 6.0×10⁻⁵ to 4.0×10⁻⁵). All seven SNPs of the CEP68 gene showed linkage disequilibrium (LD), and the haplotype of CEP68_ht4 (T-G-A-A-A-C-G) showed a highly significant association with aspirin intolerance (OR  = 2.63; 95% CI  = 1.64–4.21; P = 6.0×10⁻⁵). Moreover, the nonsynonymous CEP68 rs7572857G>A variant that replaces glycine with serine showed a higher decline of forced expiratory volume in 1s (FEV₁) by aspirin provocation than other variants (P = 3.0×10⁻⁵). Our findings imply that CEP68 could be a susceptible gene for aspirin intolerance in asthmatics, suggesting that the nonsynonymous Gly74Ser could affect the polarity of the protein structure.

Association of PTGER gene family polymorphisms with aspirin intolerant asthma in Korean asthmatics

Aspirin-intolerant asthma (AIA) is characterized by severe asthmatic attack after ingestion of aspirin and/or non-steroidal anti-inflammatory drugs. In this study, we investigated the relationship between Prostaglandin E2 receptor (PTGER) gene family polymorphisms and AIA in 243 AIA patients and 919 aspirin-tolerant asthma (ATA) controls of Korean ethnicity in two separate study cohorts. After genotyping 120 SNPs of the PTGER gene family for the 1(st) cohort study, four SNPs in PTGER1, ten in PTGER3, six in PTGER3, and a haplotype of PTGER2 showed association signals with decreased or increased risk of AIA. Among the positively associated SNPs, one in PTGER1 and four in PTGER3 were analyzed in the 2(nd) cohort study. The results show that rs7543182 and rs959 in PTGER3 retained their effect, although no statistical significance was retained in the 2(nd) cohort study. Our findings provide further evidence that polymorphisms in PTGER3 might play a significant role in aspirin hypersensitivity among Korean asthmatics.

KIF3A, a cilia structural gene on chromosome 5q31, and its polymorphisms show an association with aspirin hypersensitivity in asthma

INTRODUCTION

The kinesin family number 3A (KIF3A) gene on the human chromosomal 5q31-33 region, which is known as a susceptibility locus for immune diseases including asthma, plays a crucial role in generation of cilia.

RESULTS

A treatment with aspirin in the human bronchial epithelial cells increased the mRNA expression level of KIF3A compared to that of the untreated control (P ≤ 0.01), and nasal polyp epithelia from aspirin-intolerant asthma (AIA) patients also showed a higher expression of KIF3A protein than aspirin-tolerant asthma controls. Further logistic analyses revealed that most polymorphisms of KIF3A were significantly associated with AIA (P = 0.0004-0.02; P(corr) = 0.004-0.04) and the decline of forced expiratory volume at 1 s (FEV(1))% by aspirin provocation (P = 0.004-0.04; P(corr) = 0.03).

DISCUSSION

Our findings suggest that the KIF3A gene and/or its polymorphisms might have a susceptibility effect on AIA, providing a new step toward controlling aspirin intolerance in asthmatics.

Positive association between aspirin-intolerant asthma and genetic polymorphisms of FSIP1: a case-case study

BACKGROUND

Aspirin-intolerant asthma (AIA), which is caused by non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin, causes lung inflammation and reversal bronchi reduction, leading to difficulty in breathing. Aspirin is known to affect various parts inside human body, ranging from lung to spermatogenesis. FSIP1, also known as HDS10, is a recently discovered gene that encodes fibrous sheath interacting protein 1, and is regulated by amyloid beta precursor protein (APP). Recently, it has been reported that a peptide derived from APP is cleaved by alpha disintegrin and metalloproteinase 33 (ADAM33), which is an asthma susceptibility gene. It has also been known that the FSIP1 gene is expressed in airway epithelium.

OBJECTIVES

Aim of this study is to find out whether FSIP1 polymorphisms affect the onset of AIA in Korean population, since it is known that AIA is genetically affected by various genes.

METHODS

We conducted association study between 66 single nucleotide polymorphisms (SNPs) of the FSIP1 gene and AIA in total of 592 Korean subjects including 163 AIA and 429 aspirin-tolerant asthma (ATA) patients. Associations between polymorphisms of FSIP1 and AIA were analyzed with sex, smoking status, atopy, and body mass index (BMI) as covariates.

RESULTS

Initially, 18 SNPs and 4 haplotypes showed associations with AIA. However, after correcting the data for multiple testing, only one SNP showed an association with AIA (corrected P-value = 0.03, OR = 1.63, 95% CI = 1.23-2.16), showing increased susceptibility to AIA compared with that of ATA cases. Our findings suggest that FSIP1 gene might be a susceptibility gene for aspirin intolerance in asthmatics.

CONCLUSION

Although our findings did not suggest that SNPs of FSIP1 had an effect on the reversibility of lung function abnormalities in AIA patients, they did show significant evidence of association between the variants in FSIP1 and AIA occurrence among asthmatics in a Korean population.

Asthmatics without rhinitis have more fixed airway obstruction than those with concurrent rhinitis

PURPOSE

Rhinitis and asthma usually occur together. There are increasing evidences that allergic rhinitis (AR) may influence the clinical course of asthma. The aim of this study is to evaluate clinical parameters and therapeutic response in patients with between asthma and asthma with AR.

METHODS

Four-hundred eighty-five patients with asthma and 428 asthmatics with AR, who had lesser than 50 years old and smoked less than 10 pack-years were recruited. We compared FEV1 and FEV1/FVC following bronchodilator, atopy, IgE, emphysema on HRCT, and aspirin intolerance between two groups. Also we compared physiologic fixed airway obstruction defined using FEV1/FVC and FEV1 less than 75% following anti-asthmatic drug for 1 year.

RESULTS

46.8% (428/913) asthmatics suffered from AR. There were no differences of total IgE, body mass index, PC20, sputum eosinophils and emphysema on HRCT between two groups. The age in asthmatics was higher than that in those with AR. FEV1/FVC was lower in asthmatics than in those with AR. The prevalence of atopy was higher in asthmatics with AR than in asthmatics. Aspirin intolerance was higher in asthmatics with AR than in asthmatics (42/218 vs 13/109, P=0.001). Fixed airway obstruction were more observed in asthmatics than in those with AR (39/319 vs 28/355, P=0.001) after anti-asthmatic drug for 1 year.

CONCLUSIONS

Asthmatics with AR had more atopy and aspirin intolerance than asthmatics, and asthmatics had poor response to anti-inflammatory drugs than those with concurrent rhinitis, indicating that asthmatics have more fixed airway obstruction than those with concurrent rhinitis.

Protection of leukotriene receptor antagonist against aspirin-induced bronchospasm in asthmatics

PURPOSE

Leukotriene receptor antagonists (LTRAs) are used to treat aspirin-intolerant asthma (AIA); however, the protective effects of long-term LTRA administration against aspirin-induced bronchospasm have not been evaluated.

OBJECTIVES

We investigated the efficacy of a 12-week treatment with a LTRA in protecting against aspirin-induced asthma in AIA patients.

METHODS

Fifty-two adult patients with AIA underwent an aspirin challenge test just before administration of montelukast (10 mg/day) and just after 12 weeks of treatment. The protective effect was assessed as the disappearance of aspirin-induced bronchospasm after 12 weeks of treatment. The results were compared according to the patients' clinical and physiological parameters.

RESULTS

The decline in FEV1 following aspirin challenge was significantly reduced from 28.6+/-1.9% to 10.2+/-1.7% (P=0.0001) after 12 weeks of montelukast treatment. However, 14 subjects (30%) still showed a positive response (>15% decline in FEV1) to aspirin challenge. Grouping the subjects into good and poor responders according to post-treatment responses revealed that the pretreatment aspirin-induced FEV1 decline was significantly greater in the poor responders and that the triggering dose of aspirin and the induction time for a positive response were lower and shorter, respectively, in the poor responders. Histories of aspirin hypersensitivity and sinusitis were more prevalent among the poor responders than among the good responders.

CONCLUSIONS

Twelve weeks of treatment with montelukast protected against aspirin-induced bronchospasm in 70% of the AIA cases. A poor response was associated with more severe aspirin-induced bronchospasms before treatment and a history of aspirin hypersensitivity or sinusitis.

CLINICAL IMPLICATIONS

A severe response to aspirin challenge may be a predictor of poor responsiveness to leukotriene antagonist treatment.

Association analysis of peroxisome proliferator-activated receptors gamma gene polymorphisms with asprin hypersensitivity in asthmatics

Purpose

Peroxisome proliferator-activated receptors (PPARs) are transcriptional factors activated by ligands of the nuclear hormone receptor superfamily. The activation of PPARγ regulates inflammation by downregulating the production of Th2 type cytokines and eosinophil function. In addition, a range of natural substances, including arachidonate pathway metabolites such as 15-hydroxyeicosatetranoic acid (15-HETE), strongly promote PPARG expression. Therefore, genetic variants of the PPARG gene may be associated with the development of aspirin-intolerant asthma (AIA). We investigated the relationship between single nucleotide polymorphism (SNP) of the PPARG gene and AIA.

Methods

Based on the results of an oral aspirin challenge, asthmatics (n=403) were categorized into two groups: those with a decrease in FEV₁ of 15% or greater (AIA) or less than 15% (aspirin-tolerant asthma, ATA). We genotyped two single nucleotide polymorphisms in the PPARG gene from Korean asthmatics and normal controls (n=449): +34C>G (Pro12Ala) and +82466C>T (His449His).

Results

Logistic regression analysis showed that +82466C>T and haplotype 1 (CC) were associated with the development of aspirin hypersensitivity in asthmatics (P=0.04). The frequency of the rare allele of +82466C>T was significantly higher in AIA patients than in ATA patients in the recessive model [P=0.04, OR=3.97 (1.08-14.53)]. In addition, the frequency of PPARG haplotype 1 was significantly lower in AIA patients than in ATA patients in the dominant model (OR=0.25, P=0.04).

Conclusions

The +82466C>T polymorphism and haplotype 1 of the PPARG gene may be linked to increased risk for aspirin hypersensitivity in asthma.

Effect of aspirin on airway inflammation and pulmonary function in patients with persistent asthma

BACKGROUND

Aspirin can cause bronchoconstriction in some asthmatic patients through increased production of proinflammatory mediators, particularly leukotrienes. However, recent in vivo evidence has suggested that aspirin also triggers the production of lipoxins, which act as natural antagonists of prostaglandins and leukotrienes. Aside from patients with known aspirin-sensitive asthma, physicians have avoided the use of aspirin in asthmatic patients in general because it was believed that this agent might precipitate worsening of their condition.

OBJECTIVE

We sought to establish the effect of aspirin on pulmonary inflammation and function in patients with persistent asthma.

METHODS

After withdrawal of their usual anti-inflammatory medication, patients with mild-to-moderate persistent asthma undertook double-blind, randomized, crossover treatment with 75 mg/d aspirin and placebo for 3 weeks each. Treatment evaluation included histamine challenge, spirometry, impulse oscillometry, total and alveolar exhaled nitric oxide measurement, and serum thromboxane B2 and 15-epilipoxin A4 levels.

RESULTS

Fifteen patients completed the trial. Compared with placebo, there were no differences in histamine PC(20) values (0.17 doubling-dilution shift; 95% CI, -0.38 to 0.73; P = 1), exhaled nitric oxide levels (0.95-fold change; 95% CI, 0.45-2.00; P = 1), or any other inflammatory, spirometric, or oscillometry measurements. Aspirin led to a significant decrease in thromboxane B2 levels (17.53-fold difference; 95% CI, 5.46-56.49; P < .001). Baseline 15-epilipoxin A4 levels were increased at 4.88 ng/mL, and there was no increase with aspirin versus placebo (0.99-fold difference; 95% CI, 0.79-1.24; P = 1).

CONCLUSION

In this preliminary study of 15 patients, low-dose aspirin did not lead to increased 15-epilipoxin A4 synthesis or alter inflammatory markers in patients with mild-to-moderate persistent asthma.

Clinical management of adult patients with a history of nonsteroidal anti-inflammatory drug-induced urticaria/angioedema: update

In the large majority of previous studies, patients with a history of acute urticaria induced by nonsteroidal anti-inflammatory drugs (NSAIDs) seeking safe alternative drugs have undergone tolerance tests uniquely with compounds exerting little or no inhibitory effect on the cyclooxygenase 1 enzyme. In light of recently published studies, however, this approach seems inadequate and should be changed. The present article critically reviews the clinical management of patients presenting with a history of urticaria induced by a single NSAID or multiple NSAIDs and suggests a simple, updated diagnostic algorithm that may assist clinicians in correctly classifying their patients.

Aspirin challenge and desensitization for aspirin-exacerbated respiratory disease: a practice paper

Aspirin desensitization is indicated for patients who have aspirin-exacerbated respiratory disease and whose asthma and/or rhinosinusitis is suboptimally controlled with inhaled corticosteroids and leukotriene-modifying drugs. In this practice paper, the general requirements for aspirin desensitization are presented, the locations where desensitizations can be safely performed are outlined, prechallenge patient preparation is discussed, an oral aspirin challenge protocol is presented, treatment of adverse reactions is reviewed, and maintenance of aspirin desensitization is discussed.

Rapid desensitization protocols for patients with cardiovascular disease and aspirin hypersensitivity in an era of dual antiplatelet therapy

OBJECTIVE

To review the available protocols for rapid desensitization of patients with aspirin hypersensitivity and apply the data for use in patients with cardiovascular disease who would benefit from the dual antiplatelet therapy.

DATA SOURCES

A literature search was conducted via MEDLINE from 1966 to December 2006. Main search terms included: aspirin sensitivity, aspirin allergy, aspirin desensitization, aspirin-induced asthma, aspirin therapy, and aspirin intolerance syndrome.

STUDY SELECTION AND DATA EXTRACTION

Articles describing rapid aspirin desensitization protocols were selected for review. Literature pertaining to aspirin hypersensitivity, drug desensitization, and the use of aspirin and dual antiplatelet therapy was also examined. Three rapid desensitization protocols were identified and evaluated.

DATA SYNTHESIS

While landmark studies demonstrated that dual antiplatelet therapy with aspirin and clopidogrel significantly reduces mortality and morbidity in acute coronary syndromes and coronary stenting, patients with aspirin hypersensitivity are frequently managed with clopidogrel alone with no supporting data. Approximately 10% of the population experiences hypersensitivity to aspirin, which can manifest as asthma exacerbations, rhinorrhea, angioedema, urticaria, and anaphylaxis. The hypersensitivity reaction is mediated through aspirin-directed antibodies or by excessive leukotriene production. The desensitization process involved depletion of these mediators, as well as down-regulation of leukotriene receptors. Two groups of investigators developed rapid protocols to desensitize patients with aspirin hypersensitivity safely and effectively. The rapid protocol developed by Wong provides benefits over other protocols with its low starting dose and completion in less than 3 hours, low incidence of adverse effects, and high success rate in aspirin desensitization.

CONCLUSIONS

The Wong protocol is an attractive option for the rapid desensitization of patients requiring dual antiplatelet therapy with aspirin and clopidogrel in the perimyocardial infarction period.