Evaluation of a new multiplex assay for allergy diagnosis

Comparison of the new RIDA qLine Allergy multiparameter immunoblot and the ImmunoCAP Specific IgE test for the identification of clinically relevant food and aeroallergen allergies

Background

Multiparameter immunoblot testing is increasingly used as an alternative to multiple individual IgE analyses for type 1 allergies. This study investigated the performance of an inexpensive immunoblot method, the RIDA qLine allergy test system (R-Biopharm AG), vs. the current gold standard.

Methods

Three study-specific panels with 57 individual allergens (food and aeroallergens) were analyzed in serum samples from 200 patients with signs and symptoms of IgE-mediated allergies, using both the RIDA qLine Allergy and the reference method, the ImmunoCAP Specific IgE test (Thermo Fisher Scientific). In case of divergent results, corresponding allergens were remeasured using the secondary reference method, the 3gAllergy Specific IgE Universal Kit (Siemens). The clinical diagnoses of the 200 patients were included. In addition, a cross-reactive carbohydrate determinant (CCD)-inhibitor was used in the testing to decrease the incidence of positive CCD bands.

Results

The mean overall agreement of all food and aeroallergens with the reference methods was 94.9%. Qualitative evaluation showed an average negative percent agreement of 98.9% and an average positive percent agreement of 75.1% for all individual allergens after testing with both reference methods. The additional treatment of samples with the CCD inhibitor successfully reduced the occurrence of positive CCD reactivity after retesting.

Conclusion

The comparative analysis of RIDA qLine Allergy with the reference methods for specific IgE detection revealed a strong correlation between serum IgE levels measured across these platforms and clinical presentations, while also highlighting the necessity for careful contextual interpretation of results. Standardized allergen extracts would improve independent comparisons of different allergy testing methods.

A microarray-based IgE-molecular mimicry index (IgE-MMI): A biomarker for disease severity, clinical phenotypes, and therapeutic response in atopic dermatitis?

BACKGROUND

The role of autoimmune IgE responses in atopic dermatitis (AD) is highly debated. While IgE targeting self-proteins has been extensively studied, IgE responses induced by human-homologous exogenous molecular allergens (HEMAs) remains less understood.

AIM

To investigate whether IgE antibody responses to HEMAs are associated with AD, its severity, and response to dupilumab.

METHODS

We enrolled 3325 participants with a history of allergic diseases, including 577 (17.3%) diagnosed with AD. Serum IgE antibodies against 183 exogenous allergenic molecules were measured using the IgE microarray (Allergy Explorer-ALEX-2®, MADX, Vienna). Based on international classification criteria, participants were stratified by AD severity and clinical phenotypes. For each patient, we developed an 'IgE molecular-mimicry index' (IgE-MMI), calculated from IgE reactivity to a panel of five HEMA protein families: arginine kinase, enolase (ENO), cyclophilin (CYP), lipocalin, and MnSOD. Logistic regression was employed to assess the association between IgE to HEMAs or IgE-MMI and AD, its severity, and response to dupilumab.

RESULTS

IgE sensitization to most HEMAs (32/48, 67%), but only to a small fraction of non-HEMAs (3/135, 2.2%), was significantly more common in patients with severe AD compared to other patient groups. The IgE-MMI was positive in 295/2748 (10.7%) of allergic patients without AD, and in 58/283 (20%), 52/134 (39%), and 86/160 (54%) of patients with remitting, moderate, or severe AD, respectively. It was strongly associated with specific phenotypes, such as flexural dermatitis (OR 8.4, 95% CI: 6.3-11.2), head and neck dermatitis (OR: 16.5, 95% CI: 7.4-37.2), and generalized eczema (OR: 8.6, 95% CI: 4.9-15.6). Poor response to dupilumab was associated with IgE antibodies to ENO (OR: 22.7, 95% CI: 1.7-302.9), but inversely associated with IgE antibodies to MnSOD (OR: 0.1, 95% CI: 0.02-0.8) and NPC-2 from dust mites (OR: 0.1, 95% CI: 0.01-0.9).

CONCLUSION

IgE microarrays are useful for broadly assessing IgE to HEMAs in allergic patients. IgE reactivity to HEMAs and a positive IgE-MMI may serve as valuable biomarkers for severe AD, its clinical phenotypes, and the response to dupilumab.

Molecular allergology: a clinical laboratory tool for precision diagnosis, stratification and follow-up of allergic patients

Identification of the molecular culprits of allergic reactions leveraged molecular allergology applications in clinical laboratory medicine. Molecular allergology shifted the focus from complex, heterogeneous allergenic extracts, e.g. pollen, food, or insect venom, towards genetically and immunologically defined proteins available for in vitro diagnosis. Molecular allergology is a precision medicine approach for the diagnosis, stratification, therapeutic management, follow-up and prognostic evaluation of patients within a large range of allergic diseases. Exclusively available for in vitro diagnosis, molecular allergology is nonredundant with any of the current clinical tools for allergy investigation. As an example of a major application, discrimination of genuine sensitization from allergen cross-reactivity at the molecular level allows the proper targeting of the culprit allergen and thus dramatically improves patient management. This review aims at introducing clinical laboratory specialists to molecular allergology, from the biochemical and genetic bases, through immunological concepts, to daily use in the diagnosis and management of allergic diseases.

Validation of a Multiplex Molecular Macroarray for the Determination of Allergen-Specific IgE Sensitizations in Dogs

Detecting IgE sensitizations in the serum of allergic dogs is commonly performed using allergen extracts, but these are difficult to standardize. This article details the development and validation of the Pet Allergy Xplorer (PAX; Nextmune, Stockholm, Sweden), the first multiplex macroarray for the detection of IgE sensitization in dogs using allergen extracts and molecular components; the PAX is derived from the Allergy Xplorer (ALEX2; MacroArray Diagnostics, Vienna, Austria). The selection of allergens, cartridge processing, strategy for identifying and blocking IgE directed against cross-reactive carbohydrate determinants (CCDs), and the method used for determining the positivity threshold are described. The validation of the PAX included evaluations of the specificity of its anti-IgE monoclonal antibody, specificity of IgE binding to target allergens, assay precision, and internal consistency. Additionally, the influence of possible confounding factors, such as sample type, the influence of hemolysis, lipemia, bilirubinemia, and elevated CCD-IgE, was tested. Finally, the sensitization rates of 23,858 European dogs to 145 environmental and Hymenoptera venom allergens were summarized. The PAX is accurate and reproducible and has a unique CCD-detection and blocking strategy; its molecular allergens offer a unique window on allergen cross-reactivity.

Agreement of Peru-Based Allergy Tests for Respiratory Allergens in Allergic Rhinitis Patients

Background

The Peruvian Immunoblot panel, together with traditional skin prick tests (SPT), are widely used in vitro allergy tests in Peru. In addition to this, Peruvian allergists are increasingly adopting multiplex tests such as the ALEX-2 (Macro Array Diagnostics). Previous studies have revealed limited agreement between Immunoblot and SPT results. Therefore, our study aimed to evaluate the concordance between these three tests in patients with allergic rhinitis (AR) in a private center in Arequipa, Peru.

Materials and Methods

We enrolled 35 patients, including children over 3 years and adults, with AR. Clinical and demographic data were collected, and patients underwent allergic sensitization testing using the Immunoblot Peruvian panel (32 allergens), ALEX-2 (295 allergens), and SPT (12 allergens). Concordance was calculated using Cohen's kappa coefficient and analyzed with IBM SPSS V26.

Results

Among the patients, 34.3% exhibited moderate-to-severe persistent AR, and 14.3% had asthma. Additionally, 85.7% reported a family history of AR. Sensitization rates varied notably between the SPT and ALEX-2, particularly for olive pollen (34.3% vs. 17.4%), Blomia tropicalis (11.4% vs. 17.1%), and grasses (11.4% vs. 28.5%). Remarkably, these allergens were not included in the Peruvian Immunoblot panel. Concordance analysis included seven allergens and showed significant concordance between ALEX-2 and SPT for five allergens, between Immunoblot and SPT for two allergens, and between ALEX-2 and Immunoblot for two allergens.

Conclusion

This preliminary study shows us a better concordance between ALEX-2 and SPT rather than between Immunoblot and SPT.

Focused allergic rhinitis practice parameter for Canada

Allergic rhinitis (AR) is a prevalent disease in Canada that affects both children and adults. Several guidelines for the management of AR have been published by professional allergy societies worldwide. However, there are regional differences in the clinical management of AR, and regulatory approval of some AR pharmacotherapies varies among countries. Thus, six research questions specific to the treatment of AR in Canada were identified for this focused practice parameter. Reviews of the literature published since 2016 were conducted to obtain evidence-based support for the responses of the Work Group to each research question. In response to research question 1 "In patients with symptoms indicative of AR, is serum-specific IgE sufficient to identify candidates for immunotherapy or is a skin prick test mandatory?" the Work Group concluded that either sIgE testing or skin prick test are acceptable for diagnosing AR and guiding immunotherapy. In response to research question 2 "When taking into account the preferences of the patient and the prescriber (stakeholder engagement) should second-generation oral antihistamine (OAH) or intranasal corticosteroid (INCS) be first line?" the Work Group concluded that existing guidelines generally agree on the use of INCS as a first-line therapy used for AR, however, patient and provider preferences and considerations can easily shift the first choice to a second-generation OAH. In response to research question 3 "Is a combination intranasal antihistamine (INAH)/INCS formulation superior to INCS plus OAH? Do they become equivalent after prolonged use?" the Work Group concluded that that the combination INAH/INCS is superior to an INCS plus OAH. However, there was insufficient evidence to answer the second question. In response to research question 4 "Do leukotriene receptor antagonists (LTRA) have a greater benefit than OAH in AR for some symptoms to justify a therapeutic trial in those who cannot tolerate INCS?" the Work Group concluded that LTRAs have inferior, or at best equivalent, daytime or overall symptom control compared with OAH, but LTRAs may improve nighttime symptom control and provide benefits in patients with AR and concomitant asthma. In response to research question 5 "Should sublingual immunotherapy (SLIT) tablets be considered first-line immunotherapeutic options over subcutaneous immunotherapy (SCIT) based on the evidence of efficacy?" the Work Group concluded that the choice of SLIT or SCIT cannot be made on efficacy alone, and differences in other factors outweigh any differences in efficacy. In response to research question 6 "Based on efficacy data, should ALL patients seen by an allergist be offered SLIT or SCIT as a treatment option?" the Work Group concluded that the efficacy data suggests that SLIT or SCIT should be used broadly in patients with AR, but other clinical concerns also need to be taken into consideration.

Allergen Microarrays and New Physical Approaches to More Sensitive and Specific Detection of Allergen-Specific Antibodies

The prevalence of allergic diseases has increased tremendously in recent decades, which can be attributed to growing exposure to environmental triggers, changes in dietary habits, comorbidity, and the increased use of medications. In this context, the multiplexed diagnosis of sensitization to various allergens and the monitoring of the effectiveness of treatments for allergic diseases become particularly urgent issues. The detection of allergen-specific antibodies, in particular, sIgE and sIgG, is a modern alternative to skin tests due to the safety and efficiency of this method. The use of allergen microarrays to detect tens to hundreds of allergen-specific antibodies in less than 0.1 mL of blood serum enables the transition to a deeply personalized approach in the diagnosis of these diseases while reducing the invasiveness and increasing the informativeness of analysis. This review discusses the technological approaches underlying the development of allergen microarrays and other protein microarrays, including the methods of selection of the microarray substrates and matrices for protein molecule immobilization, the obtainment of allergens, and the use of different types of optical labels for increasing the sensitivity and specificity of the detection of allergen-specific antibodies.

Method to develop a regional guide for the allergenic potential of tree pollen

Allergic rhinitis, caused by airborne pollen, is a common disease with a great impact on the quality of life for patients and high costs for society. Prevention of high pollen concentrations in the air is relevant for creating a safe environment for allergic patients. Due to climate change, the heat in cities during the summer is a recurring problem. The local climate can be improved by using the cooling properties of trees, providing shade and cooling by evapotranspiration. When deciding which tree species will be planted, it is important to take into account the allergenicity of the pollen that the tree produces. Available guides, used all over the world, on the allergenicity of pollen are very divers in content and interpretation and not applicable for the Netherlands. In this study a method is described to develop a guide for the allergenic potential of tree pollen in a region, in this case the Netherlands. For the most common tree species in the Netherlands the scientific knowledge on the allergenicity of the pollen was collected, followed by an inventory on regional pollen abundance. Subsequently, the sensitization pattern in a patient group with possible inhalation allergy was analyzed. Based on these data allergenicity of the tree pollen was classified into five classes. Eight tree species/genera of the 61 most planted tree species in the Netherlands are considered to have a very strong to moderate allergenic potential. We propose to use this methodology to develop regional-specific guides classifying the allergenic potential of tree pollen.

Decreased skin colonization with Malassezia spp. and increased skin colonization with Candida spp. in patients with severe atopic dermatitis

Background

Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disease in which patients are sensitized towards a plethora of allergens. The hosts fungal microbiota, the mycobiota, that is believed to be altered in patients suffering from AD acts as such an allergen. The correlation context of specific sensitization, changes in mycobiota and its impact on disease severity however remains poorly understood.

Objectives

We aim to enhance the understanding of the specific sensitization towards the mycobiota in AD patients in relation to their fungal skin colonization.

Methods

Sensitization pattern towards the Malassezia spp. and Candida albicans of 16 AD patients and 14 healthy controls (HC) were analyzed with the newly developed multiplex-assay ALEX2® and the established singleplex-assay ImmunoCAP®. We compared these findings with the fungal skin colonization analyzed by DNA sequencing of the internal transcribed spacer region 1 (ITS1).

Results

Sensitization in general and towards Malassezia spp. and C. albicans is increased in AD patients compared to HC with a quantitative difference in severe AD when compared to mild to moderate AD. Further we saw an association between sensitization towards and skin colonization with Candida spp. yet a negative correlation between sensitization towards and skin colonization with Malassezia spp.

Conclusion

We conclude that AD in general and severe AD in particular is associated with increased sensitization towards the hosts own mycobiota. There is positive correlation in Candida spp. skin colonization and negative in Malassezia spp. skin colonization when compared to AD, AD severity as well as to specific sensitization patterns.

Mite allergen sensitization patterns in Turkish children: Age-related changes and molecular correlations

BACKGROUND

Mites are ubiquitous aeroallergens found worldwide. Elucidating individual mite allergen sensitization patterns provides critical insights for managing allergic diseases. This study aimed to investigate molecular allergen (MA) sensitization patterns across different age groups and explore cluster relationships among mite-sensitized children.

METHODS

We analyzed 76 children who exhibited sensitization to at least one of the 17 distinct mite MAs through microarray testing.

RESULTS

Dermatophagoides farinae exhibited a slightly higher prevalence of sensitization compared with Dermatophagoides pteronyssinus. Der p 1/2 and Der f 1/2 demonstrated an almost 40% sensitization rate, while Der p 10/Blo t 10, Der p 20, Der p 23, and Gly d 2/Lep d 2 displayed an approximately 20% sensitization rate. Sensitization levels and ratios increased significantly with age for Der p 23 but showed numerical rises for other MAs, except for Der p 10/Blo t 10. The presence of various types of atopic diseases had only a minimal impact on sensitization profiles. Strong correlations emerged between Der f 2 and Der p 2, Der p 10 and Blo t 10, Der p 21 and Blo t 5, as well as Gly d 2 and Lep d 2. Hierarchical cluster analysis substantiated these relationships. Der p 10 and its homolog Blo t 10-sensitive patients (15/76) were mostly seen as mono sensitization(12/15). Ten patients exhibited monosensitization to Der p 20, suggesting a possible association with scabies infection.

CONCLUSION

In children, mite sensitization diversity and levels increased with age. The presence of significant correlations/cluster relationships among these sensitizations underscores homologies among specific MAs.

Allergic Rhinitis: Tailoring Immunotherapy Through Innovative Diagnostics

Allergic rhinitis (AR) is a chronic ailment triggered by immunoglobulin E (IgE)-mediated reactions to allergens. Generally, AR is accompanied by asthma and conjunctivitis. The risk factors of AR include both inhalant and occupational allergens and genetic factors. Although AR is not a life-threatening condition, it poses a significant risk of morbidity and hampers work-related performance. Currently, the diagnosis of AR is based on clinical history and physical examination of the patients. Furthermore, several laboratory tests such as skin pricking test (SPT), nasal allergen challenge (NAC), and computed tomography (CT) are also recommended in some cases. Nasal cytology can aid in the differentiation of rhinitis because of allergy or infection. Apart from this, molecular diagnostic modalities such as basophil activation test (BAT) and Immune Solid-Phase Allergy Chip (ISAC) can also be employed for the confirmatory diagnosis of AR. Immunotherapy has demonstrated efficacy in the management of AR, with only mild side effects. With the advancement in the diagnostic realm of AR, personalized treatment approach has also gained significant popularity. Immunotherapy is gaining evidence on becoming a personalized treatment approach for the management of AR. This article provides a comprehensive overview, aiming to bridge the gap between evolving diagnostics and personalized therapeutic strategies for allergic rhinitis.

Would the choice of multiplex platform impact the management of the allergic patient? A first approach focusing on LTPs

BACKGROUND

In the Mediterranean area, patients with LTP syndrome who are sensitized to multiple allergens are often tested for sIgE using multiplex platforms. The results obtained from different commercial platforms are not interchangeable, so it is important to compare and validate the platform selected for use. The objective of this study is to compare and validate the performance of the ImmunoCAP ISAC E112i and the macroarray ALEX2 in our daily practice.

METHODS

From August 2021 to March 2022, we tested 20 random serum samples from polysensitized patients using the ALEX2 test (MADx) and ImmunoCAP tIgE and ISAC E112i (Thermo Fisher Scientific). We compared the total IgE (tIgE) and sIgE levels for shared allergens.

RESULTS

The heatmap generally showed more intense results for ISAC. The overall correlation was good, but some exceptions were noted. The main discrepancies were found for Ole e 7, which was positive for 11 patients in ISAC but negative for all patients in ALEX2, and for nut LTPs, for which ISAC showed a threefold higher detection rate for Ara h 9 and a fivefold higher detection rate for Cor a 8 and Jug r 3 compared to ALEX2. The regression model showed no interchangeability of tIgE results.

CONCLUSIONS

Despite our small sample size and the complexity of comparing a quantitative and a semi-quantitative platform, our results suggest that patient diagnosis and management can be influenced by the platform used. Therefore, our findings must be taken into consideration when choosing a platform to use for some profiles of LTP-polysensitized patients, even though more data is needed.

Relationship between IgE Levels Specific for Ragweed Pollen Extract, Amb a 1 and Cross-Reactive Allergen Molecules

Ragweed (Ambrosia artemisiifolia) pollen is a major endemic allergen source responsible for severe allergic manifestations in IgE-sensitized allergic patients. It contains the major allergen Amb a 1 and cross-reactive allergen molecules, such as the cytoskeletal protein profilin, Amb a 8 and calcium-binding allergens Amb a 9 and Amb a 10. To assess the importance of Amb a 1, profilin and calcium-binding allergen, the IgE reactivity profiles of clinically well-characterized 150 ragweed pollen-allergic patients were analysed regarding specific IgE levels for Amb a 1 and cross-reactive allergen molecules by quantitative ImmunoCAP measurements, IgE ELISA and by basophil activation experiments. By quantifying allergen-specific IgE levels we found that Amb a 1-specific IgE levels accounted for more than 50% of ragweed pollen-specific IgE in the majority of ragweed pollen-allergic patients. However, approximately 20% of patients were sensitized to profilin and the calcium-binding allergens, Amb a 9 and Amb a 10, respectively. As shown by IgE inhibition experiments, Amb a 8 showed extensive cross-reactivity with profilins from birch (Bet v 2), timothy grass (Phl p 12) and mugwort pollen (Art v 4) and was identified as a highly allergenic molecule by basophil activation testing. Our study indicates that molecular diagnosis performed by the quantification of specific IgE to Amb a 1, Amb a 8, Amb a 9 and Amb a 10 is useful to diagnose genuine sensitization to ragweed pollen and to identify patients who are sensitized to highly cross-reactive allergen molecules present in pollen from unrelated plants, in order to enable precision medicine-based approaches for the treatment and prevention of pollen allergy in areas with complex pollen sensitization.

Utility of biomarkers in the diagnosis and monitoring of asthmatic children

Asthma imposes a heavy morbidity burden during childhood; it affects over 10% of children in Europe and North America and it is estimated to exceed 400 million people worldwide by the year 2025. In clinical practice, diagnosis of asthma in children is mostly based on clinical criteria; nevertheless, assessment of both physiological and pathological processes through biomarkers, support asthma diagnosis, aid monitoring, and further lead to better treatment outcomes and reduced morbidity. Recently, identification and validation of biomarkers in pediatric asthma has emerged as a top priority across leading experts, researchers, and clinicians. Moreover, the implementation of non-invasive biomarkers for the assessment and monitoring of paediatric patients with asthma, has been prioritized; however, only a proportion of them are currently included in the clinical practise. Although, the use of non-invasive biomarkers is highly supported in recent asthma guidelines for documenting diagnosis and supporting monitoring of asthmatic patients, data on the Pediatric population are limited. In the present report, the Pediatric Asthma Committee of the World Allergy Organization (WAO), aims to summarize and discuss available data for the implementation of non-invasive biomarkers in the diagnosis and monitoring in children with asthma. Information on the most studied biomarkers, including spirometry, oscillometry, markers of allergic sensitization, fractional exhaled nitric oxide, and the most recent exhaled breath markers and "omic" approaches, will be reviewed. Practical limitations and considerations based on both experts' opinion and critical review of the literature, on the utility of all "well-known" and newly introduced non-invasive biomarkers will be presented. A critical commentary on biomarkers' use in diagnosing and monitoring asthma during the COVID-19 pandemic, cost and availability of biomarkers in different settings and in developing countries, the differences on the biomarkers use between Primary Practitioners, Pediatricians, and Specialists and their role on the longitudinal aspect of asthma is provided.

Identification of Potentially Tolerated Fish Species by Multiplex IgE Testing of a Multinational Fish-Allergic Patient Cohort

BACKGROUND

Although recent studies indicated that many fish-allergic patients may safely consume certain fish species, no clinical guidelines are available for identification of the exact species tolerated by specific patients.

OBJECTIVE

To investigate whether multiplex immunoglobulin E (IgE) testing reveals potentially tolerated fish through absence of IgE to parvalbumin (PV) and extracts from specific species.

METHODS

Sera from 263 clinically well-defined fish-allergic patients from Austria, China, Denmark, Luxembourg, Norway, and Spain were used in a research version of the ALEX² multiplex IgE quantification assay. Specific IgE to PVs from 10 fish species (9 bony and 1 cartilaginous), and to extracts from 7 species was quantified. The IgE signatures of individual patients and patient groups were analyzed using SPSS and R.

RESULTS

Up to 38% of the patients were negative to cod PV, the most commonly used molecule in fish allergy diagnosis. Forty-five patients (17%) tested negative to PVs but positive to the respective fish extracts, underlining the requirement for extracts for accurate diagnosis. Between 60% (Spain) and 90% (Luxembourg) of the patients were negative to PV and extracts from ray, a cartilaginous fish, indicating its potential tolerance. Up to 21% of the patients were negative to at least 1 bony fish species. Of the species analyzed, negativity to mackerel emerged as the best predictive marker of negativity to additional bony fish, such as herring and swordfish.

CONCLUSIONS

Parvalbumins and extracts from multiple fish species relevant for consumption should be used in fish-allergy diagnosis, which may help identify potentially tolerated species for individual patients.

Real-life evaluation of molecular multiplex IgE test methods in the diagnosis of pollen associated food allergy

BACKGROUND

Diagnosis of food allergies is challenging, as combining information from specific IgE (sIgE)-sensitization pattern and skin prick tests (SPTs) with clinical history is necessary for a personalized management of allergic patients. The aim of this study was to compare two molecular tests, the ImmunoCAP ISAC (ISAC) and the Allergy Explorer, version 2 (ALEX² ) in the context of pollen food syndrome (PFS) diagnosis in a real-life scenario, to assess the benefit of multiplex testing in PFS patients.

METHODS

Diagnosis of food allergy was performed in 53 patients. Allergen-sIgE concentrations were measured with ISAC and ALEX² . Results for sIgE were statistically compared with each other, with SPT results and with clinical presentation of the patients.

RESULTS

Using ISAC as reference test for sIgE measurements, the average sensitivity of ALEX² for PR-10 allergens was 83.2% and the average specificity 88.0%. If only low sIgE concentrations were included, the sensitivity was 60.8% and the specificity 91.1%. Apple and hazelnut sensitizations were confirmed in most patients by concordance of sIgE and SPT results. Significant correlations were shown between clinical symptoms and Mal d 1- and Gly m 4-sIgE levels measured by both tests and for Cor a 1-sIgE levels measured by ALEX² . In eight patients, profilin related symptoms were supported by Hev b 8-sensitization.

CONCLUSION

Multiplex testing is beneficial to understand patient-specific individual sensitization profiles and to providing personalized management recommendations. In the future, custom-designed test kits might enable reducing costs of multiplex testing for specific patient groups without compromising the diagnostic value.

Feasibility of the ALEX multiplex platform in the diagnosis of nut allergy from a Mediterranean population

BACKGROUND

ALEX multiplex platform has been recently commercialized but its clinical utility as quantitative technique respect to ImmunoCAP-singleplex as the reference method has not yet been confirmed on patients suffering from nut allergy and co-sensitization to different nuts.

METHODS

58 serum samples from patients with nut allergy from a Mediterranean population were assayed in parallel by ALEX-multiplex and ImmunoCAP-singleplex techniques. Patients were diagnosed based on clinical symptoms and positive skin prick tests (SPTs). The following whole extracts were compared between both techniques: walnut, hazelnut, peanut, almond, pistachio and sunflower seed; besides the recombinant Pru p 3. A qualitative and quantitative study was carried out.

RESULTS

Both techniques had similar sensitivities respect to whole extracts from walnut, hazelnut and peanut as well as to Pru p 3 (p > 0.05). However for whole extracts from almond, pistachio and sunflower seed the sensitivity obtained by ALEX was much lower than ImmunoCAP (9.09 % vs 88.63 %; 14.81 vs 70.37 %; and 8.51 % vs 88.88 %; respectively). The concordance between both techniques showed only a substantial agreement for Pru p 3 (k = 0.791); moderate agreement for hazelnut and peanut (k = 0.550 and k = 0.544, respectively); fair agreement for walnut (k = 0.386) and poor agreement for almond, pistachio and sunflower seed (k < 0.2). Quantitative analysis showed that ImmunoCAP for walnut, peanut and sunflower seed had higher mean values than ALEX. Relationships were significant for all specific IgE levels except to for almond, pistachio and sunflower seed.

CONCLUSIONS

ALEX platform is a suitable technique to patients with nut allergy from the Mediterranean area except to for those suffering from allergy to almond, pistachio and sunflower seed.

A comprehensive comparison between ISAC and ALEX2 multiplex test systems

OBJECTIVES

Diagnosis of type I hypersensitivity is based on anamnesis, provocation as well as blood- and skin testing. Multiplex specific IgE (sIgE) testing enables determination of sIgE antibodies against multiple recombinant or purified natural allergen components. The aim of this study was to evaluate the performance of the novel ALEX^2® (Allergy Explorer, ALEX² test introduced on the market November 2019) multiplex platform and to compare it with the ImmunoCAP ISAC^® test system.

METHODS

Serum samples of 49 patients, routinely determined with ISAC, were selected based on positive results covering in total most of the 112 ISAC components. Cohen's kappa, negative percent agreement (NPA), and positive percent agreement (PPA) of ALEX² data compared to ISAC data (as a non-reference standard) were computed for those allergen components present on both platforms (n=103). Furthermore, in some samples sIgE results against allergen extracts and/or -components tested with either ImmunoCAP^® (ThermoFisher) or IMMULITE^® (Siemens) were available and compared to ALEX² results.

RESULTS

The overall agreement between ISAC and ALEX² common allergen components was 94%. NPA and PPA were respectively 95 and 90%. Kappa values differed for specific allergen groups and varied between 0.60 and 0.92 showing moderate to almost perfect agreement. Of the qualitative discrepancies between ALEX² and ISAC, 59% were related to weak positive results i.e. results under 1 kUA/L or 1 ISU, respectively.

CONCLUSIONS

The method comparison between ISAC and ALEX² multiplex tests showed a high concordance for those allergen components present on both platforms.

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.

Diagnostic Tools in Allergic Rhinitis

Allergic mechanisms account for most cases of chronic rhinitis. This condition is associated with significant impairment of quality of life and high indirect costs. The identification of the allergic triggers of rhinitis has been historically based on the performance of atopy test [skin prick test (SPT) and serum allergen-specific (s)IgE]. Nevertheless, these tests only denote sensitization, and atopy and allergy represent two different phenomena. It is now clear that allergic phenotypes of rhinitis can exist in both atopic (allergic rhinitis, AR) and non-atopic (local allergic rhinitis, LAR) individuals. Moreover, both allergic phenotypes can coexist in the same rhinitis patient (dual allergic rhinitis, DAR). Therefore, a diagnostic approach merely based on atopy tests is associated with a significant rate of misdiagnosis. The confirmation of the allergic etiology of rhinitis requires the performance of in vivo test like the nasal allergen challenge (NAC). NAC is mandatory for the diagnosis of LAR and DAR, and helps decide the best management approach in difficult cases of AR. Nevertheless, NAC is a laborious technique requiring human and technical resources. The basophil activation test (BAT) is a patient-friendly technique that has shown promising results for LAR and DAR diagnosis. In this review, the diagnostic usefulness for chronic rhinitis of SPT, NAC, olfactory tests, serum sIgE, BAT and the quantification of inflammatory mediators in nasal samples will be discussed. The accurate performance of an etiologic diagnosis of rhinitis patients will favor the prescription of specific therapies with disease-modifying potential like allergen immunotherapy.

A qualitative and quantitative comparison of IgE antibody profiles with two multiplex platforms for component-resolved diagnostics in allergic patients

BACKGROUND

Clinically complex phenotypes require more and more sophisticated and comprehensive diagnostic approaches, able to discriminate genuine sensitizations from cross-reactivity. Interpretative complexity of multiplex diagnostic arrays has somewhat limited their diffusion. This study compares two currently available methods, namely ISAC^® test and ALEX2^® test.

METHODS

In total, 140 allergic individuals, with a history of atopic dermatitis, adverse food reactions, allergic rhinitis and/or bronchial asthma were studied by Allergy Explorer-ALEX2^® macroarray and ImmunoCAP ISAC112^® . Lin's concordance correlation coefficient, intraclass correlation coefficient and Bland-Altman plots were used to verify the agreement between continuous values. Cohen's kappa coefficient (k) was assessed for the molecules available in both tests. The degree of relationship was analysed using Spearman's correlation (quantitative variables) and Pearson's χ² or Fisher's exact test (categorical variables).

RESULTS

A substantial agreement (κ = 0.795) was observed between the two methods with 94,3% concordant results when results were dichotomized as negative or positive, but if double-negative results were discarded, the agreement dropped to 71%. Conversely, little or no concordance was observed comparing raw data. Considering the 102 molecules shared by both systems, 28/102 (27%) showed an almost perfect agreement (k > 0.81), and concordance was good (k > 0.61) in a further 32 (31%) cases. A perfect to substantial agreement was observed by comparing species-specific aeroallergens. Heterogeneous results emerged comparing panallergens (co-recognition ranging from 30% for tropomyosin/serum albumins to 70% for PR-10/profilin). The correlation among LTP, profilin and PR-10 assayed with ISAC^® was better than ALEX2^® , but the latter identified more positive cases due to the wider number of molecules available. The CCD blocker provided by ALEX^® test abolishes the carbohydrate determinants signal in 60% of the 33 cases reactive to MUXF3 on the ISAC^® test.

CONCLUSION

Despite the excellent concordance of the species-specific markers, the analysis of the panallergens provided in both methods suggests a better performance of the ISAC^® test on those components, while the ALEX2^® test, which includes a larger number of allergens, allowing a broader molecular detection.

New technologies in molecular allergodiagnostics

The article presents the characteristics of the ALEX2 (MacroArrayDX, Wien, Austria). It is designed for simultaneous detection of IgE total and specific IgE-aB to 120 extracts and 180 molecules by solid-phase enzyme immunoassay. Extracts and allergen molecules combined with nano-particles are sorbed on a solid-phase substrate, forming a macroscopic multiplex matrix - the immune allergy chip. The Institute of Clinical and Laboratory Standards (CLSI) conducted research on the verification and validation of the ALEX2 in relation to the ImmunoCAP macroarray test system (ThermoFisher Scientific, Uppsala, Sweden), which is often used in allergodiagnostics. The results obtained on the two test systems were comparable. One of the most important features of the ALEX2 test system is that unique allergen molecules and allergenic extracts are included in its composition, and a method has been found to inhibit cross-reactive hydrocarbon determinants (CCDs), which cause frequent non-specific binding of IgE-aT. The use of this test system makes it possible to carry out component allergy diagnostics with the determine of the dominant sensitizing factor in cases of mono- and polyvalent sensitization. The test results affect the determination of indications and the effectiveness of ASIT, allow assessing the risk of anaphylaxis and predicting further treatment tactics for the patient.

Allergen extract- and component-based diagnostics in children of the ALLIANCE asthma cohort

BACKGROUND

Current in vitro allergen-specific IgE (sIgE) detection assays measure IgE against allergen extracts or molecules in a single- or multiplex approach. Direct comparisons of the performance of such assays among young children with common presentations of allergic diseases regardless of sensitization status are largely missing.

OBJECTIVES

The aim of this study was a comparison of the analytical and diagnostic performance for common clinical questions of three commonly used technologies which rely upon different laboratory methodologies among children of the All Age Asthma (ALLIANCE) cohort (clinicaltrials.gov: NCT02496468).

METHODS

Sera from 106 paediatric study participants (mean age 4 years) were assessed for the presence of sIgE by means of the ImmunoCAP™ sx1 and fx5 mixes, the ImmunoCAP ISAC™ 112 microarray and a Euroline™ panel.

RESULTS

Total and negative concordance was high (>82%->89%), while positive concordance varied considerably (0%-100%) but was also >50% for the most common sensitizations analysed (house dust mite and birch). All three test systems showed good sensitivity and specificity (AUC consistently > 0.7). However, no significant differences with regard to identifying sIgE sensitizations associated with symptoms in children with suspected pollen- or dust-triggered wheeze or presenting with symptoms of allergic rhinoconjunctivitis or food allergy were detected. Extending the number of allergens did not change the similar performance of the three assay systems.

CONCLUSION AND CLINICAL RELEVANCE

Among young children, the three sIgE assays showed good analytical and diagnostic concordance. Our results caution that the identification of larger numbers of sensitizations by more comprehensive multiplex approaches may not improve the clinical utility of sIgE testing in this age group.

Allergen Immunotherapy in Pediatric Respiratory Allergy

Purpose of Review

Atopic diseases such as asthma and allergic rhinitis are highly prevalent in children. Common triggers include tree and grass pollens, house dust mites, molds, and animal dander. These diseases are most often treated symptomatically; however, many patients show partial or poor response and require long-term medication use. Allergen immunotherapy (AIT) stands as the only treatment modality that can alter the underlying disease process and potentially offer a cure. In this review article, we discuss the merits of AIT with particular emphasis on its efficacy and safety in pediatric patients. We also discuss the challenges for AIT implementation and present an overview of current research that aims at improving its applicability for the treatment of allergic diseases.

Recent Findings

Subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) are both safe and efficacious treatment options in children with allergic rhinitis and allergic asthma. Additionally, AIT has efficacy in preventing the development of asthma in children. Although there are clear advantages with AIT, there are challenges to overcome to optimize treatment. Solutions include improved diagnostics with pre-treatment biomarkers and molecular multiplex assays, biomarkers for prediction of response (e.g., basophil activation markers), improved allergen immunogenicity with the use of recombinant AIT, adjuvants, and allergoids, and lastly improved safety with the concurrent use of omalizumab.

Summary

AIT has shown safety and efficacy in major clinical trials for the treatment of allergic rhinitis and allergic asthma in children. AIT provides a curative treatment option for atopic disorders and should be considered in children with allergic rhinitis and allergic asthma. There are many continued advances being made in the field of allergy to further improve the safety and efficacy profile and shorten the duration of AIT treatment.

Personalized medicine for allergy treatment: Allergen immunotherapy still a unique and unmatched model

The introduction of personalized medicine (PM) has been a milestone in the history of medical therapy, because it has revolutionized the previous approach of treating the disease with that of treating the patient. It is known today that diseases can occur in different genetic variants, making specific treatments of proven efficacy necessary for a given endotype. Allergic diseases are particularly suitable for PM, because they meet the therapeutic success requirements, including a known molecular mechanism of the disease, a diagnostic tool for such disease, and a treatment blocking the mechanism. The stakes of PM in allergic patients are molecular diagnostics, to detect specific IgE to single-allergen molecules and to distinguish the causative molecules from those merely cross-reactive, pursuit of patient's treatable traits addressing genetic, phenotypic, and psychosocial features, and omics, such as proteomics, epi-genomics, metabolomics, and breathomics, to forecast patient's responsiveness to therapies, to detect biomarker and mediators, and to verify the disease control. This new approach has already improved the precision of allergy diagnosis and is likely to significantly increase, through the higher performance achieved with the personalized treatment, the effectiveness of allergen immunotherapy by enhancing its already known and unique characteristics of treatment that acts on the causes.

Development of a sensitive and stable chemiluminescent immunoassay for detection of birch pollen allergic specific IgE based on recombinant Bet v1 protein

Background Quantitative detection of allergens is of great significance for clarifying the cause, treatment, and prevention of allergy disease. Birch pollen is one of the most common inhalational allergens and Bet v1 is the major component allergen of birch allergen. This study aims to develop a stable and sensitive chemiluminescence immunoassay (CLIA) for the detection of birch pollen allergic specific IgE (sIgE) based on recombinant Bet v1 (rBet v1) protein. Methods rBet v1 protein was expressed in Escherichia coli and purified. Then rBet v1 was applied to detect sIgE in human serum. The performance of the established CLIA was evaluated and compared with Phadia rBet v1 fluorescence enzyme immunoassay (FEIA) system. Results The developed CLIA for sIgE to rBet v1 detection shows excellent performance. The assay showed a linear range from 0.1 to 100 IU/mL, with a low detection limit of 0.06 IU/mL. A total of 164 samples were evaluated by CLIA and compared with the results of FEIA. The positive, negative, and total coincidence rate was 90.6% (87/96), 91.2% (62/68), and 90.9% (149/164), respectively. The r-value of Spearman's rank correlation analysis was 0.935 (P < 0.001). The use of high levels of bilirubin (50 mg/dL), hemoglobin (400 mg/dL) and lipid (2000 mg/dL) didn't interfere with the results. Conclusions The proposed CLIA exhibits excellent performance for the detection of rBet v1 specific IgE. It can be a reliable tool for the early diagnosis of hypersensitivity.

Modeling the conversion between specific IgE test platforms for nut allergens in children and adolescents

BACKGROUND

Multiplex tests allow for measurement of allergen-specific IgE responses to multiple extracts and molecular allergens and have several advantages for large cohort studies. Due to significant methodological differences, test systems are difficult to integrate in meta-analyses/systematic reviews since there is a lack of datasets with direct comparison. We aimed to create models for statistical integration of allergen-specific IgE to peanut/tree nut allergens from three IgE test platforms.

METHODS

Plasma from Canadian and Austrian children/adolescents with peanut/tree nut sensitization and a cohort of sensitized, high-risk, pre-school asthmatics (total n = 166) were measured with three R&D multiplex IgE test platforms: Allergy Explorer version 1 (ALEX) (Macro Array Dx), MeDALL-chip (Mechanisms of Development of Allergy) (Thermo Fisher), and EUROLINE (EUROIMMUN). Skin prick test (n = 51) and ImmunoCAP (Thermo Fisher) (n = 62) results for extracts were available in a subset. Regression models (Multivariate Adaptive Regression Splines, local polynomial regression) were applied if >30% of samples were positive to the allergen. Intra-test correlations between PR-10 and nsLTP allergens were assessed.

RESULTS

Using two regression methods, we demonstrated the ability to model allergen-specific relationships with acceptable measures of fit (r²  = 94%-56%) for peanut and tree nut sIgE testing at the extract and molecular-level, in order from highest to lowest: Ara h 2, Ara h 6, Jug r 1, Ana o 3, Ara h 1, Jug r 2, and Cor a 9.

CONCLUSION

Our models support the notion that quantitative conversion is possible between sIgE multiplex platforms for extracts and molecular allergens and may provide options to aggregate data for future meta-analysis.

Allergenicity at component level of sub-pollen particles from different sources obtained by osmolar shock: A molecular approach to thunderstorm-related asthma outbreaks

BACKGROUND

The so-called "thunderstorm asthma" (TA) is an uncommon but dramatic outbreak of asthma attacks occurring during a thunderstorm in the pollen and moulds season. Mechanisms which make the pollen able to enter the deeper airways and provoke severe asthma symptoms are still unclear.

OBJECTIVE

To test the hypothesis that sub-pollen particles (SPPs) originated from the rupture by an osmotic shock of pollen associated with TA contain allergens.

METHODS

After hydration, SPPs released from pollen grains of grass, pellitory, olive, cypress, ragweed and birch were isolated and determined by microscopy. Allergens were determined by in vitro ELISA inhibition tests indirectly using the sera from 10 polyreactive patients. An inhibition <50% was considered as negative, 50%-75% moderate and > 75% complete.

RESULTS

The inhibition experiments showed that the SPPs from birch and cypress were unable to inhibit serum IgE reactivity to Bet v 1 and Cup a 1, respectively. Ragweed SPPs inhibited ragweed pollen extract and Amb a 1 by 75.8 ± 0.11% and 81.2 ± 0.15%, respectively. Olive and pellitory SPPs retained almost the whole IgE-binding capability in all cases tested. Grass SPPs inhibited 32 ± 0.06% of Lolium perenne Lol p 1 and 65% of Phleum pratense extracts, but results were highly variable for individual allergens (97.5%-0.03% for Phl p 2, 45.3 ± 0.12% for Phl p 5, 24.7 ± 0.22% for Phl p 6, and 38.3 ± 0.2% for Phl p 1).

CONCLUSIONS

Inhibition experiments confirm the hypothesis that SSPs obtained after the osmotic shock of pollen involved in TA, namely grass, pellitory and olive tree pollen, contain allergens and therefore they can induce severe asthma attacks during thunderstorms.

The use of microarray and other multiplex technologies in the diagnosis of allergy

OBJECTIVE

To give an overview and describe the strengths and weaknesses of immunoglobulin E (IgE) microarray and other multiplex assays that have been developed and are being used for allergy diagnostics.

DATA SOURCES

Queries for IgE microarray and multiplex assays were conducted with PubMed and Google Scholar, searching for primary articles and review papers.

STUDY SELECTIONS

We focused on articles written in English on commercially available IgE multiplex assays that were reported in the allergy and immunology literature.

RESULTS

Several commercial IgE assays that use microarray or other multiplex technology have been developed, and some have been implemented into clinical practice in Europe and Asia, with the Immuno Solid-Phase Allergen Chip being the most widely studied. Results of these assays generally correlate with results using "singleplex" IgE assays (eg, ImmunoCAP), though there can be variability among products and among allergens. A strength of the microarray technology is that IgE to a large number of allergens can be detected simultaneously in a single test, and only a small amount of patient serum is required. Cost, inadequate sensitivity under some scenarios, and difficulties with data interpretation, in some cases of 100 or more allergens, can be limitations.

CONCLUSION

IgE microarray assays are already a valuable tool in research applications. These assays, and also other forms of IgE multiplex assays, are likely to play an important role in the clinical practice of allergy in the future. Additional studies focused on clinical outcomes, and the development of more targeted allergen panels could facilitate increased clinical use.

IgE Epitope Profiling for Allergy Diagnosis and Therapy - Parallel Analysis of a Multitude of Potential Linear Epitopes Using a High Throughput Screening Platform

Immunoglobulin E (IgE) is pivotal for manifestation and persistence of most immediate-type allergies and some asthma phenotypes. Consequently, IgE represents a crucial target for both, diagnostic purposes as well as therapeutic approaches. In fact, allergen-specific immunotherapy – aiming to re-route an IgE-based inflammatory response into an innocuous immune reaction against the allergen – is the only curative approach for IgE-mediated allergic diseases known so far. However, this requires the cognate allergen to be known. Unfortunately, even in well-characterized allergics or asthmatics, often just a small fraction of total IgE can be assigned to specific target allergens. To overcome this knowledge gap, we have devised an analytical platform for unbiased IgE target epitope detection. The system relies on chemically produced random peptide libraries immobilized on polystyrene beads (“one-bead-one-compound (OBOC) libraries”) capable to present millions of different peptide motifs simultaneously to immunoglobulins from biological samples. Beads binding IgE are highlighted with a fluorophore-labeled anti-IgE antibody allowing fluorescence-based detection and isolation of positives, which then can be characterized by peptide sequencing. Setting-up this platform required an elaborate optimization process including proper choice of background suppressants, secondary antibody and fluorophore label as well as incubation conditions. For optimal performance our procedure involves a sophisticated pre-adsorption step to eliminate beads that react nonspecifically with anti-IgE secondary antibodies. This step turned out to be important for minimizing detection of “false positive” motifs that otherwise would erroneously be classified as IgE epitopes. In validation studies we were able to retrieve artificial test-peptide beads spiked into our library by using IgE directed against those test-peptides at physiological concentrations (≤20 IU/ml of specific IgE), and disease-relevant bead-bound epitopes of the major peanut allergen Ara h 2 by screening with sera from peanut allergics. Thus, we established a platform with which one can find and validate new immunoglobulin targets using patient material which displays a largely unknown immunoglobulin repertoire.

A WAO - ARIA - GA2LEN consensus document on molecular-based allergy diagnosis (PAMD@): Update 2020

Precision allergy molecular diagnostic applications (PAMD@) is increasingly entering routine care. Currently, more than 130 allergenic molecules from more than 50 allergy sources are commercially available for in vitro specific immunoglobulin E (sIgE) testing. Since the last publication of this consensus document, a great deal of new information has become available regarding this topic, with over 100 publications in the last year alone. It thus seems quite reasonable to publish an update. It is imperative that clinicians and immunologists specifically trained in allergology keep abreast of the new and rapidly evolving evidence available for PAMD@.

PAMD@ may initially appear complex to interpret; however, with increasing experience, the information gained provides relevant information for the allergist. This is especially true for food allergy, Hymenoptera allergy, and for the selection of allergen immunotherapy. Nevertheless, all sIgE tests, including PAMD@, should be evaluated within the framework of a patient's clinical history, because allergen sensitization does not necessarily imply clinical relevant allergies.

β-1,3-glucanase rOle e 9 and MnSOD rAsp f 6 IgE reactivity are the signature of atopic dermatitis in the Mediterranean area

BACKGROUND

Atopic dermatitis (AD) represents a chronic skin disorder seriously affecting patients' QoL and is often associated with immunological imbalance, disorders of the skin barrier function and environmental factors.

OBJECTIVE

We extensively studied the proteomic IgE sensitization profile in a large AD Mediterranean cohort.

METHODS

A total of 588 individuals with moderate-severe (70.6%) or mild and/or history of (29.4%) AD were evaluated in comparison to 1285 unselected atopic controls (AC) with a history of adverse reactions to foods, allergic rhinitis and/or bronchial asthma by means of ImmunoCAP ISAC₁₁₂ ® and Allergy Explorer-ALEX® microarray analysis.

RESULTS

The olive tree pollen β-1,3-glucanase rOle e 9 and the manganese superoxide dismutase from Aspergillus rAsp f 6 were the molecules most significantly associated with AD occurrence and allowed to discriminate among the moderate and severe forms of disease. An IgE hyper-reactivity to cypress, grasses, olive tree, house dust mites (including rDer p 11), and to all cross-reactive components except profilin and polcalcin was observed. About 60% of adults with severe AD were sensitized to nsLTPs. Cross-reactive carbohydrate determinants (CCDs) IgE was found in about one-third of AD participants. Hen eggs nGal d 1 IgE sensitization was more prevalent in the paediatric population, whilst rAsp f 6 and rOle e 9 reactivity was found particularly in older patients. Despite the status of widespread IgE sensitization to both environmental and food allergens, a reduced frequency of patient-reported severe reactions to food or of asthma was observed in AD patients compared to AC, particularly in case of concomitant Ole e 9 reactivity.

CONCLUSION AND CLINICAL RELEVANCE

Testing IgE reactivity to a large panel of molecular components unveils important associations between IgE reactivity profiles and AD clinical presentation, highlights the allergens useful for a precise AD signature and allows the detection of interesting sensitisations patterns.

Food allergomics based on high-throughput and bioinformatics technologies

Food allergy is a serious food safety problem worldwide, and the investigation of food allergens is the foundation of preventing and treating them, but relevant knowledge is far from sufficient. With the advent of the "big data era", it has been possible to investigate food allergens by high-throughput methods, proposing the concept of allergomics. Allergomics is the discipline studying the repertoire of allergens, which has relatively higher throughput and is faster and more sensitive than conventional methods. This review introduces the basis of allergomics and summarizes its major strategies and applications. Particularly, strategies based on immunoblotting, phage display, allergen microarray, and bioinformatics are reviewed in detail, and the advantages and limitations of each strategy are discussed. Finally, further development of allergomics is predicted. This provides basic theories and recent advances in food allergomics research, which could be insightful for both food allergy research and practical applications.