IgE allergy diagnostics and other relevant tests in allergy, a World Allergy Organization position paper

Currently, testing for immunoglobulin E (IgE) sensitization is the cornerstone of diagnostic evaluation in suspected allergic conditions. This review provides a thorough and updated critical appraisal of the most frequently used diagnostic tests, both in vivo and in vitro. It discusses skin tests, challenges, and serological and cellular in vitro tests, and provides an overview of indications, advantages and disadvantages of each in conditions such as respiratory, food, venom, drug, and occupational allergy. Skin prick testing remains the first line approach in most instances; the added value of serum specific IgE to whole allergen extracts or components, as well as the role of basophil activation tests, is evaluated. Unproven, non-validated, diagnostic tests are also discussed. Throughout the review, the reader must bear in mind the relevance of differentiating between sensitization and allergy; the latter entails not only allergic sensitization, but also clinically relevant symptoms triggered by the culprit allergen

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Research needs in allergy: an EAACI position paper, in collaboration with EFA

Abstract In less than half a century, allergy, originally perceived as a rare disease, has become a major public health threat, today affecting the lives of more than 60 million people in Europe, and probably close to one billion worldwide, thereby heavily impacting the budgets of public health systems. More disturbingly, its prevalence and impact are on the rise, a development that has been associated with environmental and lifestyle changes accompanying the continuous process of urbanization and globalization. Therefore, there is an urgent need to prioritize and concert research efforts in the field of allergy, in order to achieve sustainable results on prevention, diagnosis and treatment of this most prevalent chronic disease of the 21 st century. The European Academy of Allergy and Clinical Immunology (EAACI) is the leading professional organization in the field of allergy, promoting excellence in clinical care, education, training and basic and translational research, all with the ultimate goal of improving the health of allergic patients. The European Federation of Allergy and Airways Diseases Patients' Associations (EFA) is a non-profit network of allergy, asthma and Chronic Obstructive Pulmonary Disorder (COPD) patients' organizations. In support of their missions, the present EAACI Position Paper, in collaboration with EFA, highlights the most important research needs in the field of allergy to serve as key recommendations for future research funding at the national and European levels. Although allergies may involve almost every organ of the body and an array of diverse external factors act as triggers, there are several common themes that need to be prioritized in research efforts. As in many other chronic diseases, effective prevention, curative treatment and accurate, rapid diagnosis represent major unmet needs. Detailed phenotyping/endotyping stands out as widely required in order to arrange or re-categorize clinical syndromes into more coherent, uniform and treatment-responsive groups. Research efforts to unveil the basic pathophysiologic pathways and mechanisms, thus leading to the comprehension and resolution of the pathophysiologic complexity of allergies will allow for the design of novel patient-oriented diagnostic and treatment protocols. Several allergic diseases require well-controlled epidemiological description and surveillance, using disease registries, pharmacoeconomic evaluation, as well as large biobanks. Additionally, there is a need for extensive studies to bring promising new biotechnological innovations, such as biological agents, vaccines of modified allergen molecules and engineered components for allergy diagnosis, closer to clinical practice. Finally, particular attention should be paid to the difficult-to-manage, precarious and costly severe disease forms and/or exacerbations. Nonetheless, currently arising treatments, mainly in the fields of immunotherapy and biologicals, hold great promise for targeted and causal management of allergic conditions. Active involvement of all stakeholders, including Patient Organizations and policy makers are necessary to achieve the aims emphasized herein

Validation of novel recipes for masking peanuts in double-blind, placebo-controlled food challenges

Background: Double-blind, placebo-controlled oral food challenges are the gold standard in food allergy diagnosis. Nevertheless, proper masking of peanuts is particularly complex owing to their intense flavor and odor. Thus, it is important to use validated recipes to ensure their adequate masking during oral food challenges. Objective: To design and validate recipes containing masked peanuts for double-blind, placebo-controlled oral food challenges. Methods: Two types of products (cookies and a custard‐type dessert) containing the masked peanuts and other ingredients with low allergenic potential were designed and validated. For this purpose, of the 24 initial cookie recipes and 12 initial custard recipes developed, those that did not exhibit significant differences in their texture were selected for sensory validation. Results: Similarity triangle tests were performed using a panel of 36 selected tasters, enabling the validation of 1 pair of cookie recipes and 1 pair of custard-type dessert recipe, both with low allergenic potential and suitable for those with celiac disease and for vegans. Conclusion: The validated recipes are of clinical and research interest because they allow to confirm a peanut allergy and detect a wide range of tolerated threshold doses, which makes it possible to provide specific indica- tions for each patient

Improvement of the Elevated Tryptase Criterion to Discriminate IgE- From Non–IgE-Mediated Allergic Reactions

BACKGROUND: Differentiating between immunoglobulin E (IgE)-dependent and IgE-independent hypersensitivity reactions may improve the etiologic orientation and clinical management of patients with allergic reactions in the anesthesia setting. Serum tryptase levels may be useful to discriminate the immune mechanism of allergic reactions, but the diagnostic accuracy and optimal cutpoint remain unclear. We aimed to compare the diagnostic accuracy of tryptase during reaction (TDR) alone and the TDR/basal tryptase (TDR/BT) ratio for discriminating IgE- from non–IgE-mediated allergic reac- tions, and to estimate the best cut point for these indicators. METHODS: We included 111 patients (45% men; aged 3–99 years) who had experienced an allergic reaction, even though the allergic reaction could be nonanaphylactic. Allergy tests were performed to classify the reaction as an IgE- or non–IgE-mediated one. The area under the curve (AUC) of the receiver operating characteristic analysis was performed to estimate the discrimi- native ability of TDR and TDR/BT ratio. RESULTS: An IgE-mediated reaction was diagnosed in 49.5% of patients, of whom 56% met ana- phylaxis criteria. The median (quartiles) TDR for the IgE-mediated reactions was 8.0 (4.9–19.6) and 5.1 (3.5–8.1) for the non–IgE-mediated (P = .022). The median (quartiles) TDR/BT ratio was 2.7 (1.7–4.5) in IgE-mediated and 1.1 (1.0–1.6) in non–IgE-mediated reactions (P < .001). The TDR/BT ratio showed the greatest ability to discriminate IgE- from non–IgE-mediated reac- tions compared to TDR (AUC TDR/BT = 0.79 [95% confidence interval (CI), 1.1–2.2] and AUC TDR = 0.66 [95% CI, 1.1–2.2]; P = .003). The optimal cut point for TDR/BT (maximization of the sum of the sensitivity and specificity) was 1.66 (95% CI, 1.1–2.2). CONCLUSIONS: The TDR/BT ratio showed a significantly better discriminative ability than TDR to discriminate IgE- from non–IgE-mediated allergic reactions. An optimal TDR/BT ratio thresh- old of approximately 1.66 may be useful in clinical practice to classify allergic reactions as IgE- or non–IgE-mediated. (Anesth Analg 2018;127:414–9

Serum Amyloid A as a potential biomarker for disease activity in chronic spontaneous urticaria

Background: Chronic spontaneous urticaria (CSU) is an inflammatory skin disease with a complex physiopathology. Serum amyloid A (SAA), an acute-phase reactant, has been proposed as a potential biomarker in urticaria but has yet to be studied in a population with CSU or correlated with disease activity as indicated by the Urticaria Activity Score summed over 7 days (UAS7). Objective: We sought to determine SAA-1 levels in patients with CSU and correlate them with its activity and control, as well as with clinical features of CSU and other potential blood biomarkers. Methods: We conducted a retrospective multicenter study of 67 patients with CSU, from whom we obtained demographic and clinical data, UAS7 as an indicator of CSU activity, and blood and serum markers. Results: SAA-1 levels positively correlated with UAS7 (rs = 0.47, P 6) CSU than in those with controlled (UAS ≤ 6) CSU (P < .001) and were also higher in patients with concomitant angioedema (P = .003) or delayed pressure urticaria (P = .003). Conclusion: We propose SAA-1 as a potential biomarker for activity in CSU. Further studies are required to evaluate its potential role as a biomarker for other CSU outcomes, such as response to treatment

Improvement of the elevated tryptase criterion to discriminate IgE- from non-IgE-mediated allergic reactions

BACKGROUND: Differentiating between immunoglobulin E (IgE)-dependent and IgE-independent hypersensitivity reactions may improve the etiologic orientation and clinical management of patients with allergic reactions in the anesthesia setting. Serum tryptase levels may be useful to discriminate the immune mechanism of allergic reactions, but the diagnostic accuracy and optimal cutpoint remain unclear. We aimed to compare the diagnostic accuracy of tryptase during reaction (TDR) alone and the TDR/basal tryptase (TDR/BT) ratio for discriminating IgE- from non–IgE-mediated allergic reactions, and to estimate the best cut point for these indicators. METHODS: We included 111 patients (45% men; aged 3–99 years) who had experienced an allergic reaction, even though the allergic reaction could be nonanaphylactic. Allergy tests were performed to classify the reaction as an IgE- or non–IgE-mediated one. The area under the curve (AUC) of the receiver operating characteristic analysis was performed to estimate the discriminative ability of TDR and TDR/BT ratio. RESULTS: An IgE-mediated reaction was diagnosed in 49.5% of patients, of whom 56% met anaphylaxis criteria. The median (quartiles) TDR for the IgE-mediated reactions was 8.0 (4.9–19.6) and 5.1 (3.5–8.1) for the non–IgE-mediated (P = .022). The median (quartiles) TDR/BT ratio was 2.7 (1.7–4.5) in IgE-mediated and 1.1 (1.0–1.6) in non–IgE-mediated reactions (P < .001). The TDR/BT ratio showed the greatest ability to discriminate IgE- from non–IgE-mediated reactions compared to TDR (AUC TDR/BT = 0.79 [95% confidence interval (CI), 1.1–2.2] and AUC TDR = 0.66 [95% CI, 1.1–2.2]; P = .003). The optimal cut point for TDR/BT (maximization of the sum of the sensitivity and specificity) was 1.66 (95% CI, 1.1–2.2). CONCLUSIONS: The TDR/BT ratio showed a significantly better discriminative ability than TDR to discriminate IgE- from non–IgE-mediated allergic reactions. An optimal TDR/BT ratio threshold of approximately 1.66 may be useful in clinical practice to classify allergic reactions as IgEor non–IgE-mediated. (Anesth Analg 2018;127:414–9

Unraveling the Diagnosis of Kiwifruit Allergy: Usefulness of Current Diagnostic Tests

Objectives: To determine the usefulness of the in vitro and in vivo methods used in the diagnosis of kiwifruit allergy and to specifically assess the impact of seed proteins on sensitivity. Methods: We performed skin prick tests (SPTs) using various commercial extracts, homemade pulp, and seed extracts and prick-prick tests with kiwifruit on 36 allergic patients. The presence of specific IgE (sIgE) was assessed using the ImmunoCAP (kiwifruit extract), ELISA (Act d 1, Act d 2), ISAC, and FABER assays. Immunoblotting of seed extract was carried out, and a single-blind oral food challenge was performed with whole seeds in seed-sensitized individuals. Results: The prick prick test with kiwifruit demonstrated the highest diagnostic capacity (81.8% sensitivity and 94.1% specificity) among the in vivo tests. The sIgE levels measured using ImmunoCAP (kiwifruit extract) showed a similar sensitivity to that of global ISAC and FABER (63.9%, 59.5%, and 58.3%, respectively). Act d 1 was the major allergen. Sensitization to Act d 1 was associated with positive sIgE results to whole kiwifruit extract detected by ImmunoCAP (P<.000). A positive SPT result to kiwifruit seeds was associated with severe symptoms induced by kiwifruit (P=.019) as a marker of advanced disease, but not with clinically relevant sensitization. Challenge testing with kiwifruit seeds performed on 8 seed-sensitized patients yielded negative results. Conclusions: Sensitization to Act d 1 is associated with a positive result in conventional diagnostic techniques, whereas kiwifruit seed sensitization does not increase the sensitivity of the diagnostic techniques evaluated.Objetivos: Determinar la rentabilidad diagnóstica de las técnicas in vitro e in vivo utilizadas en el diagnóstico de alergia al kiwi y estudiar la influencia de las proteínas alergénicas de las semillas en su sensibilidad. Métodos: Se seleccionaron 36 pacientes alérgicos a kiwi. Se les realizó prick test con cuatro extractos comerciales diferentes y prick-prick con kiwi. Se determinó IgE específica mediante ImmunoCAP (extracto de kiwi), ELISA (Act d 1, Act d 2), las micromatrices ISAC y FABER e Immunoblotting de extracto de semilla de kiwi. Se realizó exposición oral simple ciego frente a semilla de kiwi en pacientes sensibilizados a la semilla. Resultados: El prick-prick de kiwi fue la prueba in vivo con mayor rendimiento (sensibilidad 81,8%, especificidad 94,1%). El ImmunoCAP de extracto de kiwi mostró una sensibilidad similar a la global del ISAC y del FABER (63,9%, 59,5% y 58,3%, respectivamente). Act d 1 fue el alérgeno mayoritario. Se encontró asociación entre los niveles de IgE específica frente a Act d 1 (ISAC) y el extracto de kiwi mediante ImmunoCAP (p <0,000). La prueba cutánea positiva con semilla se asoció con mayor gravedad de síntomas frente a kiwi (p = 0,019), como marcador de enfermedad avanzada, pero no como sensibilización clínicamente relevante. La prueba de provocación con semillas fue negativa en los ocho pacientes provocados. Conclusiones: La sensibilización a Act d 1 se asocia con resultados positivos con las técnicas diagnósticas convencionales. La sensibilización frente a semillas no mejora el rendimiento de las técnicas evaluadas

Validation of a commercial allergen microarray platform for specific immunoglobulin E detection of respiratory and plant food allergens

Background As the use of multiplex-specific immunoglobulin E (sIgE) detection methods becomes increasingly widespread, proper comparative validation assessments of emerging new platforms are vital. Objective To evaluate the clinical and technical performance of a newly introduced microarray platform, Allergy Explorer (ALEX) (MacroArray Diagnostics), in the diagnosis of pollen (cypress, grass, olive), dust mite (Dermatophagoides pteronyssinus), mold (Alternaria alternata), fruit (apple, peach), and nut (walnut, hazelnut and peanut) allergies and to compare it with those of the ImmunoCAP Immuno Solid-phase Allergen Chip (ISAC) 112 microarray and the ImmunoCAP singleplex method (ThermoFisher Scientific). Methods We enrolled 153 patients with allergy and 16 controls without atopy. The sIgE assays were conducted using ISAC112, ALEX version 2 (ALEX2), and ImmunoCAP for whole extracts and major components. Technical validation of ALEX2 was performed by measuring repeatability and interassay, interbatch, and interlaboratory reproducibility. Results When measured globally (detection by 1 or more allergen components), ALEX2 had adequate sensitivity and specificity for most of the allergens studied, comparable in general with that of ISAC112 (except for olive pollen and walnut) and similar to that of ImmunoCAP whole extract measurements. Component-by-component analysis revealed comparable results for all techniques, except for Ole e 1 and Jug r 3, in both ISAC112 and ImmunoCAP comparisons, and Alt a 1, when compared with ISAC112. Continuous sIgE levels correlate with sIgE by ImmunoCAP. Good reproducibility and repeatability were observed for ALEX2. Conclusion ALEX2 has sound technical performance and adequate diagnostic capacity, comparable in general with that of ISAC112 and ImmunoCAP

Validation of a commercial allergen microarray platform for specific immunoglobulin E detection of respiratory and plant food allergens - Improvement of the Elevated Tryptase Criterion to Discriminate IgE- From Non–IgE-Mediated Allergic Reactions - Validation of novel recipes for masking peanuts in double-blind, placebo-controlled food challenges

Background: As the use of multiplex-specific immunoglobulin E (sIgE) detection methods becomes increasingly widespread, proper comparative validation assessments of emerging new platforms are vital. Objective: To evaluate the clinical and technical performance of a newly introduced microarray platform, Allergy Explorer (ALEX) (MacroArray Diagnostics), in the diagnosis of pollen (cypress, grass, olive), dust mite (Dermato- phagoides pteronyssinus), mold (Alternaria alternata), fruit (apple, peach), and nut (walnut, hazelnut and peanut) allergies and to compare it with those of the ImmunoCAP Immuno Solid-phase Allergen Chip (ISAC) 112 microar- ray and the ImmunoCAP singleplex method (ThermoFisher Scientific). Methods: We enrolled 153 patients with allergy and 16 controls without atopy. The sIgE assays were conducted using ISAC112, ALEX version 2 (ALEX2), and ImmunoCAP for whole extracts and major components. Technical validation of ALEX2 was performed by measuring repeatability and interassay, interbatch, and interlaboratory reproducibility. Results: When measured globally (detection by 1 or more allergen components), ALEX2 had adequate sensitivity and specificity for most of the allergens studied, comparable in general with that of ISAC112 (except for olive pol- len and walnut) and similar to that of ImmunoCAP whole extract measurements. Component-by-component analysis revealed comparable results for all techniques, except for Ole e 1 and Jug r 3, in both ISAC112 and Immu- noCAP comparisons, and Alt a 1, when compared with ISAC112. Continuous sIgE levels correlate with sIgE by ImmunoCAP. Good reproducibility and repeatability were observed for ALEX2. Conclusion: ALEX2 has sound technical performance and adequate diagnostic capacity, comparable in general with that of ISAC112 and ImmunoCAP