Effect of in vitro aspirin stimulation on basophils in patients with aspirin-exacerbated respiratory disease

Flow-based basophil activation test in immediate drug hypersensitivity. An EAACI task force position paper

Diagnosing immediate drug hypersensitivity reactions (IDHRs) can pose a significant challenge and there is an urgent need for safe and reliable tests. Evidence has emerged that the basophil activation test (BAT), an in vitro assay that mirrors the in vivo response, can be a complementary test for many drugs. In this position paper, members of Task Force (TF) "Basophil activation test in the evaluation of Drug Hypersensitivity Reactions" from the European Academy of Allergy and Clinical Immunology (EAACI) present the data from a survey about the use and utility of BAT in IDHRs in Europe. The survey results indicate that there is a great interest for using BAT especially for diagnosing IDHRs. However, there are still main needs, mainly in the standardization of the protocols. Subsequently consensus-based recommendations were formulated for: (i) Technical aspects of BAT in IDHRs including type of sample, management of drugs, flow cytometry protocols, interpretation of the results; and (ii) Drug-specific aspects that should be taken into account when performing BAT in relation to betalactams, neuromuscular blocking agents, fluoroquinolones, chlorhexidine, opioids, radio contrast media, chemotherapeutics, biological agents, nonsteroidal anti-inflammatory drugs, COVID vaccine, and excipients. Moreover, aspects in the evaluation of pediatric population have also been considered. All this indicates that BAT offers the clinician and laboratory a complementary tool for a safe diagnostic for IDHRs, although its place in the diagnostic algorithm depends on the drug class and patient population (phenotype, geography, and age). The standardization of BAT is important for generalizing this method beyond the individual laboratory.

Diagnostic utility of basophil CD203c expression in β-lactam allergy

Background: A diagnosis of immunoglobulin E (IgE) mediated reactions to β-lactam (BL) antibiotics is still challenging because of the limited availability of skin-prick test (SPT), and standardization issues, particularly with newer BLs, are still ongoing. Because encouraging data are increasingly emerging in the use of basophil activation tests in the diagnosis of IgE-mediated drug hypersensitivity reactions, in this study, we aimed to determine CD203c expression, a basophil surface marker, in the diagnosis of IgE-mediated hypersensitivity to BL antibiotics. Methods: This study included two groups of subjects. The first group (group 1) (n = 20) included patients with a diagnosis of IgE-mediated allergy to BLs as confirmed through STs or drug provocation tests, and the control group consisted of healthy volunteers (group 2) (n = 24). Expression of CD203c by flow cytometry was studied in samples stimulated by two different concentrations of six different BL antibiotics. A stimulation index ≥ 2 was considered a positive response. Results: The study groups had comparable age and sex distribution. In the entire group, the sensitivity and specificity of CD203c were 29.4% (5 out of 17) and 82.6% (19 out of 23), respectively. When considering the single reactors, two among four patients who were allergic to amoxicillin demonstrated upregulation of CD203c with amoxicillin, which makes 50% sensitivity. The specificity was 100%. Conclusion: Our data demonstrated that assessment of CD203c in the diagnosis of IgE-mediated reactions to BLs provided encouraging results, particularly with amoxicillin allergy. However, this finding needs to be verified in a larger number of cases.

What happens to basophils and tryptase, LXA4 and CysLTs during aspirin desensitization?

INTRODUCTION

Aspirin desensitization (AD) is an effective treatment in patients with non-steroidal anti-inflammatory drugs (NSAID)-exacerbated respiratory disease (NERD) by providing inhibitory effect on symptoms and polyp recurrence. However, limited data is available on how AD works. We aimed to study comprehensively the mechanisms underlying AD by examining basophil activation (CD203c upregulation), mediator-releases of tryptase, CysLT, and LXA₄, and LTB₄ receptor expression for the first 3 months of AD.

METHODS

The study was conducted in patients with NERD who underwent AD (group 1: n = 23), patients with NERD who received no desensitization (group 2: n = 22), and healthy volunteers (group 3, n = 13). All participants provided blood samples for flow cytometry studies (CD203c and LTB₄ receptor), and mediator releases (CysLT, LXA_4, and tryptase) for the relevant time points determined.

RESULTS

All baseline parameters of CD203c and LTB₄ receptor expressions, tryptase, CysLT, and LXA₄ releases were similar in each group (p > 0.05). In group 1, CD203c started to be upregulated at the time of reactions during AD, and continued to be high for 3 months when compared to controls. All other study parameters were comparable with baseline and at the other time points in each group (p > 0.05).

CONCLUSION

Although basophils are active during the first 3 months of AD, no releases of CysLT, tryptase or LXA₄ exist. Therefore, our results suggest that despite active basophils, inhibition of mediators can at least partly explain underlying the mechanism in the first three months of AD.

The Effect of Prickly Pear, Pumpkin, and Linseed Oils on Biological Mediators of Acute Inflammation and Oxidative Stress Markers

Medicinal plants have been used as a source of effective and safe alternative therapeutic agents for various ailments including inflammation. In fact, the aim of this study is to assess the topical anti-inflammatory and antioxidative potential effects of Cucurbita pepo (pumpkin), Linum usitatissimum (linseed), and Opuntia ficus indica (prickly pear) oils on acute inflammation using carrageenan-induced paw edema model. The study was conducted on 36 rats splitted in 6 groups: a normal control group and 5 carrageenan-treated groups (1%), each treated with either a normal saline, the reference drug (“Inflocine®” 2 mg/paw), pumpkin, linseed, or prickly pear oils (25 μl/paw). The response to these treatments was mainly assessed by the measuring of edema paw size, hematological and biochemical analysis, oxidative stress testing, and histological study. All the studied seed oils especially prickly pear oil proved to be efficient in treating acute inflammation. The oil-treated groups revealed a significant (p < 0.05) decrease in the clinical signs of inflammation, hematological parameters (white blood cells and platelets), concentrations of CRP and fibrinogen, and congestion compared to the normal saline-treated group. The results also showed that the tested oils, endowed with a radical scavenging ability, could significantly increase the activities of SOD, CAT, and GPx in carrageenan-treated skin by reducing the lipid peroxidation and protein oxidation (TBARS, AOPP). The anti-inflammatory effect of the tested oils was closely related to both their antioxidant properties as well as their bioactive compounds (polyunsaturated fatty acids, vitamin E, and phytosterols). For the first time, the findings of the current study highlight the “in vivo” anti-inflammatory property of pumpkin, linseed, and prickly pear oils on carrageenan-induced acute inflammation by regulating inflammatory mediators and oxidative stress markers.

BAT in the Diagnosis of Drug Allergy: a Novel Tool in Clinical Daily Practice?

PURPOSE OF REVIEW

The aim of this study is to critically review the relevant literature published on basophil activation test, presenting the current knowledge and future perspectives.

RECENT FINDINGS

Basophil activation test (BAT) results varied accordingly to the class of the drug studied, and have promising results in immediate hypersensitivity reactions to pyrazolone (selective reactors), neuromuscular blockers, beta-lactams, and platinum compounds, all examples of classical IgE-mediated hypersensitivity drug reactions. Currently, BAT is applied in research settings, but based in the results of our review, the test can be considered as a diagnostic tool for daily practice for selected patients and selected drugs, when the test is available, particularly for patients who experienced severe reactions and when diagnosis cannot be stablished by serum-specific IgE and skin testing, in order to avoid unnecessary drug provocations tests.

Biomarkers for evaluation of mast cell and basophil activation

Mast cells and basophils play a pathogenetic role in allergic, inflammatory, and autoimmune disorders. These cells have different development, anatomical location and life span but share many similarities in mechanisms of activation and type of mediators. Mediators secreted by mast cells and basophils correlate with clinical severity in asthma, chronic urticaria, anaphylaxis, and other diseases. Therefore, effective biomarkers to measure mast cell and basophil activation in vivo could potentially have high diagnostic and prognostic values. An ideal biomarker should be specific for mast cells or basophils, easily and reproducibly detectable in blood or biological fluids and should be metabolically stable. Markers of mast cell and basophil include molecules secreted by stimulated cells and surface molecules expressed upon activation. Some markers, such as histamine and lipid mediators are common to mast cells and basophils whereas others, such as tryptase and other proteases, are relatively specific for mast cells. The best surface markers of activation expressed on mast cells and basophils are CD63 and CD203. While these mediators and surface molecules have been associated to a variety of diseases, none of them fulfills requirements for an optimal biomarker and search for better indicators of mast cell/basophil activation in vivo is ongoing.

EAACI/ENDA Position Paper: Diagnosis and management of hypersensitivity reactions to non-steroidal anti-inflammatory drugs (NSAIDs) in children and adolescents

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used in the pediatric population as antipyretics/analgesics and anti-inflammatory medications. Hypersensitivity (HS) reactions to NSAID in this age group, while similar to adults, have unique diagnostic and management issues. Although slowly accumulating, published data in this age group are still relatively rare and lacking a unifying consensus. This work is a summary of current knowledge and consensus recommendations utilizing both published data and expert opinion from the European Network of Drug Allergy (ENDA) and the Drug Hypersensitivity interest group in the European Academy of Allergy and Clinical Immunology (EAACI). This position paper summarizes diagnostic and management guidelines for children and adolescents with NSAIDs hypersensitivity.

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.

In Vitro Diagnosis of Immediate Drug Hypersensitivity Anno 2017: Potentials and Limitations

Background

For most physicians, quantification of drug-specific immunoglobulin E (drug-sIgE) antibodies constitutes the primary in vitro measure to document immediate drug hypersensitivity reactions (IDHR). Unfortunately, this is often insufficient to correctly identify patients with IgE-mediated IDHR and impossible for non-IgE-mediated IDHR that result from alternative routes of basophil and mast cell activation. In these difficult cases, diagnosis might benefit from cellular tests such as basophil activation tests (BAT).

Aim

The aim was to review the potential and limitations of quantification of sIgE and BAT in diagnosing IDHR. The utility of quantification of serum tryptase is discussed.

Methods

A literature search was conducted using the key words allergy, basophil activation, CD63, CD203c, diagnosis, drugs, hypersensitivity, flow cytometry, specific IgE antibodies; this was complemented by the authors’ own experience.

Results

The drugs that have been most studied with both techniques are β-lactam antibiotics and curarizing neuromuscular blocking agents (NMBA). For sIgE morphine, data are available on the value of this test as a biomarker for sensitization to substituted ammonium structures that constitute the major epitope of NMBA, especially rocuronium and suxamethonium. For the BAT, there are also data on non-steroidal anti-inflammatory drugs (NSAIDs) and iodinated radiocontrast media. For β-lactam antibiotics, sensitivity and specificity of sIgE varies between 0 and 85% and 52 and 100%, respectively. For NMBA, sensitivity and specificity varies between 38.5 and 92% and 85.7 and 100%, respectively. Specific IgE to morphine should not be used in isolation to diagnose IDHR to NMBA nor opiates. For the BAT, sensitivity generally varies between 50 and 60%, whereas specificity attains 80%, except for quinolones and NSAIDs.

Conclusions

Although drug-sIgE assays and BAT can provide useful information in the diagnosis of IDHR, their predictive value is not absolute. Large-scale collaborative studies are mandatory to harmonize and optimize test protocols and to establish drug-specific decision thresholds.

Practical approach to the treatment of NSAID hypersensitivity

INTRODUCTION

Non-steroidal anti-inflammatory drugs (NSAIDs) are the most frequently involved in drug hypersensitivity reactions (DHR). NSAIDs are prescribed for different processes and some NSAIDs can be obtained over the counter. Areas covered: We analyse the practical approaches for managing and treating NSAID-DHR considering the five major groups of entities recognised, divided into two categories: those responding to strong COX-1 inhibitors and possibly weak COX-1 or selective COX-2 inhibitors named cross-intolerant (CI), and those induced by a single drug or drug group with good tolerance to strong COX-1 inhibitors, known as allergic reactions (SR). An analysis of the recent literature indicates that two approaches can be followed for CI: to give acetyl salicylic acid to confirm NSAID hypersensitivity or to give alternative drugs to provide a solution for the treatment of pain, fever, inflammation or other conditions. Desensitisation approaches have been undertaken, but mainly for CI cases with respiratory airway involvement and they are very rarely used for CI with cutaneous involvement or SR. Expert commentary: DHR to NSAIDs are now recognised as one of the most important problems in the evaluation and management of drug allergy. Because no diagnostic tests exist, important resources are needed to evaluate these patients.

Approach to the diagnosis of drug hypersensitivity reactions: similarities and differences between Europe and North America

Drug hypersensitivity reactions (DHRs) affect an unknown proportion of the general population, and are an important public health problem due to their potential to cause life-threatening anaphylaxis and rare severe cutaneous allergic reactions. DHR evaluations are frequently needed in both ambulatory and hospital settings and have a complex diagnosis that requires a detailed clinical history and other tests that may include in vitro tests and in vivo procedures such as skin tests and drug provocation tests. Although over the years both European and U.S. experts have published statements on general procedures for evaluating DHRs, a substantial discordance in their daily management exists. In this review, we highlight both the differences and the similarities between the European and U.S. perspectives. While a general consensus exists on the importance of skin tests for evaluating DHRs, concordance between Americans and Europeans exists solely regarding their use in immediate reactions and the fact that a confirmation of a presumptive diagnosis by drug provocation tests is often the only reliable way to establish a diagnosis. Finally, great heterogeneity exists in the application of in vitro tests, which require further study to be well validated.

Bioactive food chemicals and gastrointestinal symptoms: a focus of salicylates

Bioactive food chemicals are substances present in food that are capable of interacting with living cells causing changes in physiological functions. Salicylic acid (SA), a plant hormone involved in plant immune response, is one such bioactive food chemical. Aspirin, a commercially available SA, might play beneficial roles in cardiovascular health and colon cancer. It may also cause urticaria, angioedema, asthma, and gastrointestinal symptoms in SA-sensitive individuals. Dietary SA might exert similar beneficial effects and/or may induce similar symptoms in hypersensitive individuals. Food-related SA sensitivity in relation to gastrointestinal symptoms is not well documented besides a few self-reported questionnaires and the knowledge that low doses of aspirin (equivalent of high dietary intake) can cause gastrointestinal injury. The only direct evidence that suggests benefits of reducing dietary SA was reported in asthmatic individuals. Although SA sensitivity in relation to gut symptoms in susceptible individuals is accepted by clinicians, the detection of this disease remains a challenge because of the complicated nature of dietary challenges and the risk of oral aspirin provocation tests in patients with severe hypersensitivity reactions. Given the non-IgE mediated nature of the disease, in vitro assays like basophil activation may have failed to produce reliable results. However, given the simplicity of this assay, further studies need to be formulated to firmly establish its reliability. Formulation of proper dietary strategies for symptom control is also impossible given the controversial and scant nature of the data on SA content of food. This issue needs to be resolved to formulate proper dietary strategies for effective symptom control.

In vitro tests for drug hypersensitivity reactions: an ENDA/EAACI Drug Allergy Interest Group position paper

Drug hypersensitivity reactions (DHRs) are a matter of great concern, both for outpatient and in hospital care. The evaluation of these patients is complex, because in vivo tests have a suboptimal sensitivity and can be time-consuming, expensive and potentially risky, especially drug provocation tests. There are several currently available in vitro methods that can be classified into two main groups: those that help to characterize the active phase of the reaction and those that help to identify the culprit drug. The utility of these in vitro methods depends on the mechanisms involved, meaning that they cannot be used for the evaluation of all types of DHRs. Moreover, their effectiveness has not been defined by a consensus agreement between experts in the field. Thus, the European Network on Drug Allergy and Drug Allergy Interest Group of the European Academy of Allergy and Clinical Immunology has organized a task force to provide data and recommendations regarding the available in vitro methods for DHR diagnosis. We have found that although there are many in vitro tests, few of them can be given a recommendation of grade B or above mainly because there is a lack of well-controlled studies, most information comes from small studies with few subjects and results are not always confirmed in later studies. Therefore, it is necessary to validate the currently available in vitro tests in a large series of well-characterized patients with DHR and to develop new tests for diagnosis.

Basophil Reactivity as Biomarker in Immediate Drug Hypersensitivity Reactions-Potential and Limitations

Immediate drug hypersensitivity reactions (DHRs) resemble typical immunoglobulin E (IgE)-mediated symptoms. Clinical manifestations range from local skin reactions, gastrointestinal and/or respiratory symptoms to severe systemic involvement with potential fatal outcome. Depending on the substance group of the eliciting drug the correct diagnosis is a major challenge. Skin testing and in vitro diagnostics are often unreliable and not reproducible. The involvement of drug-specific IgE is questionable in many cases. The culprit substance (parent drug or metabolite) and potential cross-reacting compounds are difficult to identify, patient history and drug provocation testing often remain the only means for diagnosis. Hence, several groups proposed basophil activation test (BAT) for the diagnosis of immediate DHRs as basophils are well-known effector cells in allergic reactions. However, the usefulness of BAT in immediate DHRs is highly variable and dependent on the drug itself plus its capacity to spontaneously conjugate to serum proteins. Stimulation with pure solutions of the parent drug or metabolites thereof vs. drug-protein conjugates may influence sensitivity and specificity of the test. We thus, reviewed the available literature about the use of BAT for diagnosing immediate DHRs against drug classes such as antibiotics, radio contrast media, neuromuscular blocking agents, non-steroidal anti-inflammatory drugs, and biologicals. Influencing factors like the selection of stimulants or of the identification and activation markers, the stimulation protocol, gating strategies, and cut-off definition are addressed in this overview on BAT performance. The overall aim is to evaluate the suitability of BAT as biomarker for the diagnosis of immediate drug-induced hypersensitivity reactions.

Aspirin-Exacerbated Diseases: Advances in Asthma with Nasal Polyposis, Urticaria, Angioedema, and Anaphylaxis

Aspirin-exacerbated diseases are important examples of drug hypersensitivities and include aspirin-exacerbated respiratory disease (AERD), aspirin- or non-steroidal anti-inflammatory drug (NSAID)-induced urticaria/angioedema, and aspirin- or NSAID-induced anaphylaxis. While each disease subtype may be distinguished by unique clinical features, the underlying mechanisms that contribute to these phenotypes are not fully understood. However, the inhibition of the cyclooxygenase-1 enzyme is thought to play a significant role. Additionally, eosinophils, mast cells, and their products, prostaglandins and leukotrienes, have been identified in the pathogenesis of AERD. Current diagnostic and treatment strategies for aspirin-exacerbated diseases remain limited, and continued research focusing on each of the unique hypersensitivity reactions to aspirin is essential. This will not only advance the understanding of these disease processes, but also lead to the subsequent development of novel therapeutics that patients who suffer from aspirin-induced reactions desperately need.

In vitro Diagnosis of Immediate Drug Hypersensitivity: Should We Go with the Flow

BACKGROUND

Diagnosis of immediate drug hypersensitivity reactions (IDHRs) is based upon history taking, skin prick or intradermal tests and quantification of specific immunoglobulin E (IgE) antibodies. Unfortunately, this is often insufficient to correctly identify patients with IgE-mediated IDHRs and is impossible in the case of non-IgE-mediated IDHRs. Drug provocation tests (DPT) are considered the 'gold standard' diagnostic but are not always possible, for ethical and practical reasons. Therefore, the validation of new cellular tests such as basophil activation testing (BAT) was necessary. This review focuses on the applications of BAT in IDHRs.

METHODS

A literature search was conducted, using the words basophil, flow cytometry, immediate drug allergy and drugs; this was complemented by the authors' own expertise.

RESULTS

BAT/HistaFlow® is a useful diagnostic tool in IDHRs, mainly used to diagnose allergy to neuromuscular blocking agents (NMBAs), antibiotics, nonsteroidal anti-inflammatory drugs (NSAIDs) and iodinated radiocontrast media. Its sensitivity varies between 50 and 60%, and specificity attains 80%, except for with quinolones and NSAIDs.

CONCLUSIONS

The diagnostic utility of BAT (and to lesser extent HistaFlow) has been demonstrated and is mostly applied in IDHRs. However, larger-scale collaborative studies are necessary to optimize test protocols and validate the entry of BAT as a diagnostic instrument in drug allergy.

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.

In vitro diagnosis of immediate IgE-mediated drug hypersensitivity: warnings and (unmet) needs

Immediate drug hypersensitivity reactions (DHR) constitute an important health condition, with serious consequences of inadequate diagnosis. In this article, some of the most important issues related to in vitro diagnosis of IgE-mediated allergies are discussed. In vitro diagnostics will benefit from expanded and novel insights and understandings in drug chemical reactivity, protein binding, biotransformation, degradation, identification of (cross-reactive) drug antigenic determinants, and deeper understanding of sensitization routes. Collective efforts should be undertaken to activate fundamental and clinical investigations.

Aspirin-intolerant asthma: a comprehensive review of biomarkers and pathophysiology

Aspirin-exacerbated respiratory disease is a tetrad of nasal polyps, chronic hypertrophic eosinophilic sinusitis, asthma, and sensitivity to aspirin. Unawareness of this clinical condition by patients and physicians may have grave consequences because of its association with near-fatal asthma. The pathogenesis of aspirin-intolerant asthma is not related with an immunoglobin E mechanism, but with an abnormal metabolism of the lipoxygenase (LO) and cyclooxygenase (COX) pathways. At present, a diagnosis of aspirin sensitivity can be established only by provocative aspirin challenge, which represents a health risk for the patient. This circumstance has encouraged the search for aspirin intolerance-specific biomarkers. Major attempts have focused on mediators related with inflammation and eicosanoid regulation. The use of modern laboratory techniques including high-throughput methods has facilitated the detection of dozens of biological metabolites associated with aspirin-intolerant asthma disease. Not surprisingly, the majority of these is implicated in the LO and COX pathways. However, substantial amounts of data reveal the participation of many genes deriving from different ontologies. Biomarkers may represent a powerful, noninvasive tool in the diagnosis of aspirin sensitivity; moreover, they could provide a new way to classify asthma phenotypes.

Basophil activation after nonsteroidal anti-inflammatory drugs stimulation in patients with immediate hypersensitivity reactions to these drugs

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the drugs most frequently involved in allergic reactions of which two main types exist: IgE-mediated and crossintolerance. The diagnosis of crossintolerance reactions is often based on the drug provocation test. The potential value of the basophil activation test (BAT) was evaluated using different basophil markers in the diagnosis of patients with crossintolerance to NSAIDs and cutaneous symptoms. We studied 46 patients with crossintolerance to NSAIDs and 45 tolerant controls. BAT was performed with acetyl salicylic acid, paracetamol, diclofenac, dipyrone, naproxen, and ibuprofen at four different concentrations using CD193 and CD203c as basophil markers and CD63 as activation marker. We compared BAT results using CD193⁺ or CD193⁺ CD203c⁺ for basophil selection and found a significant increase in the stimulation index when using CD193⁺ CD203c⁺ in both patients and controls (P = 0.004 and P = 0.017, respectively). Selection of living cells only produced an increase in basophil stimulation in patients for both CD193⁺ and CD193⁺ CD203c⁺ (P < 0.001 for both), whereas in controls there was no change with CD193⁺ and a decrease with CD193⁺ CD203c⁺ (P = 0.001). We found that CD193⁺ CD203c⁺ increased the percentage of positive cases in patients and controls when compared with CD193⁺. When excluding dead cells, there was an increase of 21.7% in patients and 10% in controls. These results indicate that using CD193⁺ CD203⁺, excluding dead cells, is the best approach for BAT although this test is not recommended for the diagnosis of patients with crossintolerance to NSAIDs owing to its low sensitivity and specificity.

Recent applications of basophil activation tests in the diagnosis of drug hypersensitivity

Immediate-type drug hypersensitivity is an increasingly significant clinical issue; however, the diagnosis is frequently hindered due to lack of safe and precise diagnostic tests. Flow cytometry-assisted basophil activation test is a safe in vitro diagnostic tool for assessing basophil activation upon allergen stimulation. In this review, we have summarized current literature on the diagnostic utilities, new indications, and methodological aspects of the basophil activation test for the diagnosis of drug hypersensitivity.

Pathogenic Mechanisms and In Vitro Diagnosis of AERD

Aspirin-exacerbated respiratory disease (AERD) refers to chronic rhinosinusitis, nasal polyposis, bronchoconstriction, and/or eosinophilic inflammation in asthmatics following the exposure to nonsteroidal anti-inflammatory drugs (NSAIDs). A key pathogenic mechanism associated with AERD is the imbalance of eicosanoid metabolism focusing on prostanoid and leukotriene pathways in airway mucosa as well as blood cells. Genetic and functional metabolic studies on vital and non-vital cells pointed to the variability and the crucial role of lipid mediators in disease susceptibility and their response to medication. Eicosanoids, exemplified by prostaglandin E(2) (PGE(2)) and peptidoleukotrienes (pLT), are potential metabolic biomarkers contributing to the AERD phenotype. Also other mediators are implicated in the progress of AERD. Considering the various pathogenic mechanisms of AERD, a multitude of metabolic and genetic markers is suggested to be implicated and were introduced as potential biomarkers for in vitro diagnosis during the past decades. Deduced from an eicosanoid-related pathogenic mechanism, functional tests balancing PGE(2) and pLT as well as other eicosanoids from preferentially vital leukocytes demonstrated their applicability for in vitro diagnosis of AERD.

Reliability of basophil activation test using CD203c expression in diagnosis of pollen allergy

BACKGROUND

CD203c is a basophil surface marker and its expression is rapidly up-regulated after cross-linking of high-affinity immunoglobulin E (IgE) receptor (FcepsilonR1) by an allergen. CD203c basophil activation tests have been studied for the in vitro diagnosis of several allergic conditions. However, there is limited data about its diagnostic usefulness. The optimum allergen concentrations for stimulation and allergen specific cutoff values remain unknown for a number of allergens. This study was designed to investigate the efficacy of basophil activation test via CD203c in the diagnosis of pollen allergy.

METHODS

The CD203c basophil activation was determined in 31 allergic rhinitis patients with pollen allergy and 9 healthy nonatopic controls during the off-season. CD203c expression was evaluated using three-color staining protocol by flow cytometry.

RESULTS

After an in vitro stimulation with grass pollen extract, the CD203c assay clearly discriminated pollen-allergic patients from controls (p < 0.001). A dose-dependent increase in the percentages of CD203c-activated basophils was shown in rhinitis patients with pollen allergy (p < 0.001). The sensitivity and specificity was 100% and optimal cutoff values were 14.05 and 10.05% with 45.1 and 4.5 μg/mL Phl p 5 stimulation, respectively. Although the specificity was also 100%, the sensitivity was 93 and 87% and the cutoff values were 5.40 and 5.35% with 4.5 × 10(-4) and 4.5 × 10(-5) micrograms/mL Phl p 5 stimulation, respectively.

CONCLUSION

The CD203c basophil activation test seems to be a reliable tool in the diagnosis of grass pollen allergy. It could be used when conventional diagnostic tests fail or can not be performed.

Food choice as a key management strategy for functional gastrointestinal symptoms

Recognition of food components that induce functional gut symptoms in patient's functional bowel disorders (FBD) has been challenging. Food directly or indirectly provides considerable afferent input into the enteric nervous system. There is an altered relationship between the afferent input and perception/efferent response in FBD. Defining the nature of food-related stimuli may provide a means of minimizing such an input and gut symptoms. Using this premise, reducing the intake of FODMAPs (fermentable oligo-, di-, and mono-saccharides and polyols)--poorly absorbed short-chain carbohydrates that, by virtue of their small molecular size and rapid fermentability, will distend the intestinal lumen with liquid and gas--improves symptoms in the majority of patients. Well-developed methodologies to deliver the diet via dietician-led education are available. Another abundant source of afferent input is natural and added food chemicals (such as salicylates, amines, and glutamates). Studies are needed to assess the efficacy of the low food chemical dietary approach. A recent placebo-controlled trial of FODMAP-poor gluten provided the first valid evidence that non-celiac gluten intolerance might actually exist, but its prevalence and underlying mechanisms require elucidation. Food choice via the low FODMAP and potentially other dietary strategies is now a realistic and efficacious therapeutic approach for functional gut symptoms.

The values of nasal provocation test and basophil activation test in the different patterns of ASA/NSAID hypersensitivity

BACKGROUND

The oral provocation test (OPT) is the current gold standard to diagnose aspirin hypersensitivity syndrome although it is time-consuming and contains some systemic risks. Other reliable methods with lower side effects and shorter test duration are being investigated.

OBJECTIVE

The purpose of this study was to evaluate the efficacy of the nasal provocation test (NPT) and the basophil activation test (BAT) in the diagnosis of different subtypes of aspirin sensitivity.

METHODS

Thirty aspirin sensitivity patients with cutaneous and respiratory manifestations underwent NPT and BAT with lysine-ASA. NPT result was interpreted as recommended in EAACI/GA2LEN guidelines and receiver operating characteristic analysis of BAT was performed by using 15 NSAIDs tolerant volunteers as a control group.

RESULTS

NPT was positive in 60% (18/30) of patients and BAT was positive in 76.7% (23/30) of patients. The incubation of basophils with 0.31 mg/ml of lysine-aspirin and using 4.6% activated basophils gives the best predictive values to diagnose aspirin sensitivity. The combination of both tests yielded positive results in 80% and 93.3% of aspirin-induced cutaneous and respiratory patterns. The agreement between NPT and BAT results was 63.3%.

CONCLUSIONS

NPT and BAT are beneficial to detect patients with aspirin sensitivity. The combination of both tests have additional diagnostic values; less time-consuming than OPT and their complications are negligible. A reliable alternative method with minimum side effects is needed to diagnose aspirin sensitivity in suspected patients who have contraindications for OPT.

Challenge of isolated sputum cells supports in vivo origin of intolerance reaction to aspirin/non-steroidal anti-inflammatory drugs in asthma

BACKGROUND

There is no in vitro test to diagnose aspirin-intolerant asthma (AIA). The aim of this study was to test if challenge with aspirin of sputum cells from subjects with AIA triggers the release of cysteinyl leukotrienes (CysLTs), known to be mediators of bronchoconstriction in AIA.

METHODS

Sputum induction was performed at baseline and at another visit 2 h after a lysine-aspirin bronchoprovocation in 10 subjects with AIA and 9 subjects with aspirin-tolerant asthma (ATA). The isolated sputum cells were incubated for ex vivo challenge.

RESULTS

Release of CysLTs by sputum cells from patients with AIA was not induced by lysine-aspirin ex vivo, neither when cells were collected at baseline nor in sputum cells recovered after lysine-aspirin-induced bronchoconstriction, whereas release of CysLTs from sputum cells was triggered by an ionophore on both occasions. However, the CysLT levels elicited by the ionophore were higher in the AIA group both at baseline (AIA vs. ATA: 3.3 vs. 1.6 ng/million cells; p < 0.05) and after the lysine-aspirin bronchoprovocation (3.9 vs. 1.7 ng/million cells; p < 0.05). This difference in the amount of CysLTs released between the groups appeared to be related to the number of eosinophils.

CONCLUSIONS

Intolerance to aspirin could not be triggered in sputum cells isolated from subjects with AIA. Together with the previous inability to demonstrate intolerance to non-steroidal anti-inflammatory drugs in isolated blood cells, these results support the requirement of tissue-resident cells in the adverse reaction. However, ex vivo stimulation of sputum cells may be developed into a new test of capacity for LT release in inflammatory cells recovered from airways.

Flow Cytometry-Assisted Basophil Activation Test as a Safe Diagnostic Tool for Aspirin/NSAID Hypersenstivity

Purpose

Aspirin and non-steroidal anti-inflammatory drugs (ASA/NSAIDs) are common causes of drug hypersensitivity. An oral provocation test is the only definitive diagnostic test. This study assessed the reliability of a flow cytometry-assisted basophil activation test (FAST) as a safe diagnostic method for ASA/NSAID-induced hypersensitivity, as its high sensitivity and specificity have been demonstrated for many other drugs.

Methods

Eighteen patients and 11 controls were enrolled. Using a Flow-CAST kit® (Bühlmann Laboratories AG, Schönenbuch, Switzerland), 29 analyses with aspirin, ibuprofen, and diclofenac were performed by flow cytometry to detect double-positive staining of anti-IgE and anti-CD63. The stimulation index was defined as the activated basophil percentage after drug stimulation/basally active basophil percentage. A stimulation index≥2 and an absolute activated basophil percentage≥5 were considered positive.

Results

Patients with hypersensitivity to ASA/NSAIDs were predominantly female, and the prevalence of atopy was higher in patients than in controls. A sensitivity of 61%, specificity of 91%, positive predictive value of 92%, and negative predictive value of 59% were achieved.

Conclusions

FAST is a useful additional method for diagnosis of hypersensitivity reactions to ASA/NSAIDs. Further development is required to increase the sensitivity of the test.

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.

The in vitro diagnosis of drug allergy: status and perspectives

Adverse drug reactions (ADR) can result from immune-mediated (drug allergy) and nonimmune-mediated mechanisms. In both types of reaction, conclusive diagnosis and appropriate management remain major problems in daily clinical practice. This review summarizes the potentials and shortcomings of the currently available in vitro tests in the diagnosis of immediate (mostly IgE mediated) and nonimmediate (mostly T-cell mediated) drug allergy, particularly quantification of specific IgE, flow-assisted analysis of in vitro activated lymphocytes and basophils and the enzyme-linked immunosorbent spot.

Basophil allergen threshold sensitivity, CD-sens, is a measure of allergen sensitivity in asthma

BACKGROUND

Allergic asthma is IgE-mediated and the IgE-sensitisation is usually demonstrated by skin prick tests (SPT) and IgE antibody determinations in serum. The SPT and IgE-antibody values do not directly predict if the allergy clinically contributes to the asthma. There is therefore a need for new objective tests that may indicate the clinical importance of an IgE-sensitisation.

OBJECTIVE

To evaluate basophil allergen threshold sensitivity (CD-sens) as a measure of allergen sensitivity in allergic asthma.

METHODS

Twenty-six subjects with stable, intermittent allergic asthma were tested with SPT and spirometry, and methacholine and allergen inhalation challenges to determine methacholine PD(20) (provocative dose causing a 20% drop in forced expiratory volume in 1 s) and allergen PD(20) . The results were compared with CD-sens and serological parameters, i.e. IgE- and IgG4 antibodies to the relevant allergens.

RESULTS

A significant correlation was found between CD-sens and allergen PD(20) (P = 0.01; r = 0.49; n = 26) as well as between CD-sens and the ratio of allergen PD(20) to methacholine PD(20) (P = 0.007; r = 0.52; n = 26). In patients with a moderate to low degree of bronchial hyperresponsiveness there was an excellent correlation (P = 0.0001; r = 0.88, n = 13) between CD-sens and allergen sensitivity. No relation to either allergen PD(20) or the ratio was found for basophil allergen reactivity measured as CD63 up-regulation at high concentrations of the respective allergen.

CONCLUSIONS AND CLINICAL RELEVANCE

CD-sens was found to be an objective marker of airway allergen sensitivity in stable allergic asthmatics, that may be used to predict airway responsiveness when bronchial challenge tests cannot be performed.

[Cellular in-vitro assays. Applicability in daily routine]

Cellular in-vitro assays are able to detect antigen-dependent cellular processes without any risk for the patient. After antigen stimulation, both the cellular antigen stimulation test assessing sulfidoleukotriene production in leukocyte suspension, and flow cytometric basophil activation assays determining surface activation markers (CD63, CD203c), represent accepted models for in-vivo mast cell stimulation particularly in IgE-dependent reactions of immediate type. The value of these assays should be estimated considering the type of antigen and further diagnostic options. Most studies can not be compared due to different allergen concentrations, conditions of stimulation, methods, and defined cut-offs. Therefore, it is difficult to evaluate published evidence. Because of the logistic effort, cellular assays are often available only in specialized laboratories. However, in daily routine they are important in cases with clear-cut history but negative conventional allergy diagnostic procedures, in case of rare allergens (drugs, exotic food), as well as contraindications for skin and/or provocation test (hymenoptera venom allergy, anaphylaxis).

Developments in the field of allergy in 2009 through the eyes of Clinical and Experimental Allergy

In 2009 the journal published in the region of 200 papers including reviews, editorials, opinion pieces and original papers that ran the full gamut of allergic disease. It is instructive to take stock of this output to determine patterns of interest and where the cutting edge lies. We have surveyed the field of allergic disease as seen through the pages of Clinical and Experimental Allergy (CEA) highlighting trends, emphasizing notable observations and placing discoveries in the context of other key papers published during the year. The review is divided into similar sections as the journal. In the field of Asthma and Rhinitis CEA has contributed significantly to the debate about asthma phenotypes and expressed opinions about the cause of intrinsic asthma. It has also added its halfpennyworth to the hunt for meaningful biomarkers. In Mechanisms the considerable interest in T cell subsets including Th17 and T regulatory cells continues apace and the discipline of Epidemiology continues to invoke a steady stream of papers on risk factors for asthma with investigators still trying to explain the post-second world war epidemic of allergic disease. Experimental Models continue to make important contributions to our understanding of pathogenesis of allergic disease and in the Clinical Allergy section various angles on immunotherapy are explored. New allergens continue to be described in the allergens section to make those allergen chips even more complicated. A rich and vibrant year helpfully summarized by some of our associate editors.

Basophil responsiveness and clinical picture of acetylsalicylic acid intolerance

BACKGROUND

Exposure to acetylsalicylic acid (ASA) may exacerbate respiratory or skin diseases or induce anaphylactoid reactions in apparently healthy individuals. We wanted to evaluate specific responsiveness of basophils to ASA in correlation with the clinical picture.

METHODS

We performed a prospective single-blind study of 59 subjects involved in clinical evaluation and/or ASA provocation testing. Whole blood basophils were stained with anti-CD63/CD123/HLA-DR mAbs after stimulation with 0.25 or 1 mg/ml ASA.

RESULTS

We found that 40 subjects were ASA tolerant and 19 were ASA intolerant. Both groups had comparable manifestations of asthma and/or rhinitis (13 in the tolerant and 9 in the intolerant group). Intolerant subjects showed significantly higher basophil responsiveness to ASA in comparison to tolerant subjects, which was concentration-dependent in both groups. The ratio between responses at 1 mg/ml of ASA and at baseline (activation index) was analyzed according to the clinical picture. We demonstrate that the activation index was higher only in the intolerant subjects with anaphylactoid reactions, but not in a subgroup of subjects with asthma/rhinitis. The ROC calculations show that the optimal threshold activation index was more than 2.18. The sensitivity was 80% and the specificity was 83% in the subgroup with anaphylactoid reactions. In the asthma/rhinitis subgroup, the sensitivity was 78% and the specificity was 50%.

CONCLUSIONS

Our study demonstrates that there is a significantly higher in vitro basophil response to ASA in intolerant as compared to tolerant subjects. ROC analyses suggest that this measurement might only have a diagnostic value in subjects without asthma and/or rhinitis.