Immuno Solid-phase Allergen Chip Research Articles

Clinical and serological characteristics of patients allergic to LTP.

Allergy to lipid transfer proteins (LPT) is common in Mediterranean Europe, and it causes severe reactions in patients and affects multiple foods, impairing the quality of life. This study aimed to describe the clinical and sensitization profile of patients with LTP syndrome and to determine a clinical pattern of severity. Molecular diagnosis is shown in a broad population through microarrays. This study was performed at the LTP Allergy Consultation of the Reina Sofia Hospital in Murcia, Spain. We analyzed the patients' characteristics, reactions, cofactors, food implicated, quality of life, skin prick test to food and aeroallergens, and serologic parameters, such as total immunoglobulin E, peach LTP (Pru p 3 IgE) and immunoglobulin G4, and microarray Immuno Solid-phase Allergen Chip (ISAC). We related the severity of the reactions with other variables. We presented a series of 236 patients diagnosed with LTP allergy, 54.66% suffering from anaphylaxis, 36.02% from urticaria angioedema, and 9.32% from oral allergy syndrome. The most frequently implicated food was peach, producing symptoms in 70% of patients, followed by walnut in 55%, peanut in 45%, hazelnut in 44%, and apple in 38% patients. Regarding the food that provoked anaphylaxis, walnut was the most frequent instigator, along with peach, peanut, hazelnut, almond, sunflower seed, and apple. According to the severity of LPT reaction, we did not discover significant differences in gender, age, food group involved, and serologic parameters. We found differences in the presence of cofactors, with 48.84% of cofactors in patients with anaphylaxis, compared to 27.1% in patients without anaphylaxis and in family allergy background (P < 0.0001). In our series of patients, 54% presented anaphylaxis, and the foods that most frequently produced symptoms were peaches, apples, and nuts. Cofactors and family allergy backgrounds were associated with the severity of LPT reaction.

ПРОФИЛИ МОЛЕКУЛЯРНОЙ СЕНСИБИЛИЗАЦИИ К АЛЛЕРГЕНАМ ПУШНЫХ ЖИВОТНЫХ У ПАЦИЕНТОВ РОССИЙСКОЙ ФЕДЕРАЦИИ

Molecular sensibilization patterns have not been yet described for the Russian population, which makes it difficult to develop prevention, elimination and treatment methods for patients with allergic pathology. The purpose of this research was to analyze patterns of sensibilization to components of fur animal allergens in patients examined in order to exclude the sensibilization. Materials and methods used: results of 1113 Immuno Solid-phase Allergen Chip (ISAC) in patients with suspected atopy were analyzed. In all patients, sIgE concentrations to allergenic components of fur animals were determined. Results: 468 (58.21%) of 1113 were found to have sensibilization to fur animal allergens. Of these, 396 (84.62%) were sensibilized to the cat, 277 (59.19%) to the dog, 98 (20.94%) to the horse, and 26 (5.55%) to the mouse. sIgE to Fel d 1 was determined in 90.91% of patients with cat sensibilization, and the median concentration of sIgE to Fel d 1 was higher than to Fel d 2 (p=0.011) and Fel d 4 (p&lt;0.001) (5.4 [1,7; 15]). ISU-E, sIgE to Can f 1 was detected in 73.29%, to Can f 2 - in 18.05%, to Can f 5 - in 41.52% of patients sensibilized to dogs. Among children under 9 y/o, the frequency of detection of sensitization to Can f 5 was less frequent than in the group of children aged over 10 y/o and adults (p&lt;0.001). Conclusion: the Russian population is characterized by a high prevalence of sensibilization to fur animal allergens. Most patients had polysensibilization to components of cat (Fel d 1) and dog (Can f 1, 2 and 5) allergens. It was revealed that Can f 2 has a higher allergenic potential, which in its turn allows it to be identified as a major dog allergen. 92.55% of patients with sensibilization to Fur-bearing animals have an increased risk of developing asthma.

A case of a 6-year-old boy diagnosed with lipid transfer protein syndrome using the ImmunoCAP and ImmunoCAP Immuno Solid-phase Allergen Chip

A case of a 6-year-old boy diagnosed with lipid transfer protein syndrome using the ImmunoCAP and ImmunoCAP Immuno Solid-phase Allergen Chip

Development of allergy to LTP in children and adults

Background. The importance of issue is the rising incidence of allergies to volatile organic compounds, particularly in children and adults. This necessitates understanding the causes, risk factors, and methods for prevention and treatment. The purpose of the study was to clarify the relationship between the development of allergy to lipid transfer proteins (LTP) and various environmental influences, nutrition and the immune state of the body. Materials and methods. To achieve goal, the following research methods were used: content analysis of the database of medical organizations, the method of a representative sample and quantitative examination. In the practical part of the study, we used the Immuno Solid-phase Allergen Chip test. Results. The study results demonstrated adverse reactions in both children and adults with LTP allergies. Peach (Prunus persica) was identified as an allergenic product. It was found that childhood is a particularly sensitive period for the development of allergic reactions to LTP due to incomplete immune development. Additionally, the peculiarities of food allergy were investigated, taking into account its connection with antibodies and cause-and-effect relationships. Conclusions. Sensitization to lipid transfer proteins occurs in various groups, including children and adults, and depends on the sources of exposure.

The Role of Peamaclein (Pru p 7) in PFAS Patients: An Italian Real-Life Study

Pollen food allergy syndrome (PFAS) is an allergic reaction to specific foods in persons previously sensitised to pollen. The diagnosis of PFAS is made after taking a patient’s medical history and, in some cases, conducting skin tests and oral food tests with raw fruit or vegetables. The aim of the present study was to evaluate the role of Pru p 7 in patients suspected of having PFAS, who show clinical symptoms, positivity for Cup a 1 and negativity for Pru p 1 and Pru p 3. A total of 51 patients (mean age ± standard deviation, 33 ± 15 years; 20 men and 31 women), referred to the respiratory diseases and allergology units of Siena University Hospital, were enrolled retrospectively. All of them underwent allergy consultation and IgE evaluation for Cup a 1, Pru p 1 and Pru p 3 by immuno solid-phase allergen chip (ISAC). Pru p 7 assay was performed by the ImmunoCAP Phadia method in patients who tested positive for Cup a 1 and simultaneously negative for Pru p 1 and Pru p 3 by ISAC. The serum of 51 patients was tested for sensitisation to Pru p 7 by the ImmunoCAP Phadia method, and nine patients (17.65%) were found positive. An area under the receiver operating characteristic (AUROC) curve of 99.51% made it possible to distinguish PFAS and non-PFAS patients on the basis of Pru p 7 values. The best cut-off value was 0.16 kUA/l, which gave a 85.7% sensitivity and 97.73% specificity. This study helps define the role of Pru p 7 in PFAS patients sensitised to cypress pollen and testing negative to Pru p 1 and Pru p 3. A fast, easy and non-invasive diagnostic method is proposed to detect IgE specific for Pru p 7. Inclusion of Pru p 7 in the ISAC assay panel would facilitate the diagnosis of PFAS.

Microarray Analysis Confirms ImmunoCAP-Fluorescence Enzyme Immunoassay Results on Specific IgE in Patients with Atopic Dermatitis and Suspected Birch Pollen-Related Food Allergy

Background: Previous studies demonstrated that birch pollen-related foods can cause late eczematous responses in birch pollen-sensitized patients with atopic dermatitis (AD). However, suitable markers to predict birch pollen-related food allergy in patients with AD are still lacking. Objective: We evaluated the correlation of the results from ImmunoCAP® fluorescence enzyme immunoassay (FEIA) singleplex and ImmunoCAP® immuno solid-phase allergen chip (ISAC) multiplex system in AD patients and investigated the diagnostic validity of allergen microarray analysis, measuring specific IgE (sIgE) with ImmunoCAP® ISAC to predict birch pollen-related food allergy in patients with AD. Methods: A total of 19 children and adults with AD, existing IgE-mediated birch pollen sensitization, and suspected birch pollen-related food allergy underwent a double-blind placebo-controlled food challenge (DBPCFC) in the clinical routine. Total and sIgE levels to birch pollen, Bet v 1, Bet v 2, and birch pollen-related foods (apple, carrot, celery, and hazelnut) were determined prior to the DBPCFC by ImmunoCAP®-FEIA. Additionally, allergen microarray ImmunoCAP® ISAC analysis was performed. Data were analyzed retrospectively. Results: Twelve out of 19 patients (63% responders) experienced an allergic reaction upon DBPCFC. Overall, 7 patients (37%) developed a significant deterioration of AD with a median increase of 12.4 points in the scoring of atopic dermatitis (SCORAD) index (range 10.0–15.7). Oral allergy syndrome was the predominant immediate-type symptom (n = 11/12 responders). There were no differences in sensitization frequencies regarding allergens of the pathogenesis-related protein family 10 between responders and non-responders. In all patients, correlation of IgE levels determined with ImmunoCAP® ISAC and ImmunoCAP®-FEIA, respectively, was significant with high correlation coefficients regarding birch pollen allergen extract, rBet v 1, and rBet v 2 (r_s > 0.8, p < 0.001) and lower but also significant correlation coefficients regarding food allergens (r_s < 0.8, p < 0.05–<0.001). Conclusion: ImmunoCAP® ISAC microarray allows displaying a differentiated sensitization profile in birch pollen-sensitized patients with AD. However, IgE-mediated sensitization against birch pollen-related allergens revealed by the allergen multiplex system does not predict late eczematous reactions upon DBPCFC with birch pollen-related foods.

Correlation between sensitization to house dust mite major allergens, age, and symptoms in Japanese house dust mite allergic subjects

Der p 23 has recently been recognized as a new house dust mite (HDM) major allergen that may be linked to the development of asthma in HDM allergic patients. This study aimed to investigate the frequency of sensitization to HDM major allergen components including Der p 23 and to examine the correlation between HDM-sensitization and AR symptom score in Japanese HDM allergic rhinitis (AR) patients without allergic asthma.Serum samples (n = 120) collected from Japanese HDM AR patients (12 to 64 years) without asthma were assessed for allergen-specific IgE (s-IgE) by ImmunoCAP (Dermatophagoides pteronyssinus (D. pteronyssinus; Der p) extract, Der p 23) or immunosolid-phase allergen chip (Der p 1, Der p 2).Japanese HDM AR patients without asthma showed a high prevalence of allergic sensitization to the HDM major allergens Der p 1 (94.2%), Der p 2 (97.5%) and Der p 23 (71.7%). No difference in the prevalence was detected for Der p 1 and Der p 2 s-IgE among three age groups. However, the prevalence of Der p 23 s-IgE was significantly higher in the younger group compared to the elderly group. No significant correlation was found between AR symptom scores and concentration of s-IgE towards Der p extract and any of the three HDM major allergens.Although the prevalence of sensitization towards D. pteronyssinus major allergens is high in Japanese AR patients without asthma, there was no correlation between allergen specific IgE including IgE towards Der p 23 and AR symptom in this population.

Методи мультикомпонентного (мультиплексного) імуноаналізу специфічних IGE до алергокомпонентів у хворих на IGE-залежну алергію

Abstract. Component-resolved diagnostics or molecular allergy diagnostics has found application in the practice of an allergist. It is used to map a patient’s allergenic sensitization at the molecular level, using purified natural or recombinant allergenic molecules in place of extracts. Multiplex methods for determining the concentration of specific IgE in the blood serum allow to characterize the repertoire of IgE sensitization of the patient, to create an allergological «passport» of the patient. There are ISAC (Immuno Solid-Phase Allergen Chip — ISAC), which includes the determination of IgE to 112 allergens and ALEX2 (Allergy Explorer — ALEX2), which includes the determination of IgE to 295 allergens.

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

BackgroundAs the use of multiplex-specific immunoglobulin E (sIgE) detection methods becomes increasingly widespread, proper comparative validation assessments of emerging new platforms are vital. ObjectiveTo 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). MethodsWe 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. ResultsWhen 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. ConclusionALEX2 has sound technical performance and adequate diagnostic capacity, comparable in general with that of ISAC112 and ImmunoCAP.

Combining Allergen Components Improves the Accuracy of Peanut Allergy Diagnosis

IgE to peanut often occurs in the absence of peanut allergy. Detection of allergen component specific IgE (sIgE) has improved diagnosis and birthed molecular allergen component arrays, in which sensitization to multiple allergen components can be measured simultaneously. To improve the diagnostic utility of serology for peanut allergy, by mapping interactions of sIgE to multiple components and IgE functional characteristics. A cohort of 100 children was studied, with a 60-children cohort employed for external validation. Levels of total IgE, sIgE to peanut, and peanut components were measured using singleplex ImmunoCAP and multiplex immuno solid-phase allergen chip (ISAC). Peanut IgE specific activity, avidity, and diversity were determined. Diagnostic modeling was performed using a Bayesian hierarchical model. Sensitization to the 112 allergens on ISAC (model 1) demonstrated the highest accuracy to diagnose peanut allergy (area under the curve [AUC]= 0.92). Sensitization to peanut components on ISAC (model 2) reported an AUC of 0.86 and on singleplex (model 3) an AUC of 0.92, which was greater than that of Ara h 2 sIgE alone (AUC= 0.90). Functional characteristics of peanut sIgE (model 4) reported an AUC of 0.89, which was greater than that of peanut sIgE (AUC= 0.75). Model 3 offered the highest predictive value and the second highest overall diagnostic accuracy. sIgE to a combination of allergen components (Ara h 1, 2, 3, and 6) is highly predictive of peanut allergy and superior to individual markers. Combining the functional characteristics of IgE was superior to peanut sIgE levels alone. These models can be applied in real time during clinical consultations using online calculators.

Peanut components measured by ISAC: comparison with ImmunoCap and clinical relevance in peanut allergic children

BackgroundSpecific IgE (sIgE) against the peanut component Arachis hypogaea (Ara h) 2 has been shown to be the most important allergen to discriminate between peanut allergy and peanut tolerance. Several studies determined sIgE cut off values for Ara h 2, determined by singleplex measurements. However, cut off values for Ara h 2 from multiplex arrays are less well defined. The aim of this study was to evaluate the correlation between Ara h 2 sIgE determined by singleplex versus multiplex measurements and to assess the diagnostic value of the different peanut components included in Immuno Solid-phase Allergen Chip (ISAC) multiplex analysis in children with a suspected peanut allergy.MethodsIn this retrospective study we analyzed Ara h 2 sIgE values with singleplex Fluorescence Enzyme Immunoassay (FEIA, ImmunoCap) and multiplex microarray (ISAC) measurements in 117 children with a suspected peanut allergy. Also, other peanut components measured by ISAC were analyzed. Double blinded placebo controlled oral food challenges were used as golden standard.ResultsAmong all studied peanut components FEIA Ara h 2 sIgE showed the highest area under the curve (AUC, 0.922), followed by ISAC Ara h 6 and Ara h 2 sIgE with AUCs of respectively 0.906 and 0.902. Best cut off values to diagnose peanut allergy were 4.40 kU/l for FEIA Ara h 2 sIgE and, 7.43 ISU and 8.13 ISU for respectively Ara h 2 and Ara h 6 sIgE in ISAC microarray. Ara h 2 sIgE determined in FEIA and ISAC showed a good correlation (r = 0.88; p < 0.01).ConclusionAra h 6 and Ara h 2 sIgE in multiplex ISAC are both good predictors of clinical peanut allergy in Dutch children, and their performance is comparable to the use of Ara h 2 in singleplex FEIA. The simultaneous measurement of different peanut components using ISAC is an advantage and clinically useful to detect peanut allergic children that are Ara h 2 negative but sensitized to other peanut proteins such as Ara h 6.

Evaluating sensitization patterns on ImmunoCAP-detected polysensitized patients with microarray-based multiplex assay (ISAC)

Limited availability of validated allergy tests prevents assessment of the true extent of allergic problems in the Indian sub-continent. We utilised Immuno-Solid phase Allergen Chip (ISAC) results from polysensitized patients as revealed by the extensively validated ImmunoCAP to further develop accurate sensitization profiles.

In vitro evaluation of IgE mediated sensitization to tropomyosin

Tropomyosins are part of a muscular protein family that includes a large number of cross-reactive allergens originating mainly from invertebrates. Tropomyosins have been identified as food allergens of animal origin from shellfish, such as crustaceans and mollusks, and rarely from parasitic nematodes from fish or some edible insects, and as aeroallergens from arthropods (house dust mites, storage mites, cockroaches). In current allergy practice, in vitro analysis of IgE-mediated sensitization to tropomyosins can be performed using singleplex immunoassays such as fluorencence enzyme immunoassay and chemiluminescence or multiplex ones such as microarray on immuno solid phase allergen chip and macroarray nanotechnology based immunoassay used as a next‑generation molecular allergy explorer.

Molecular allergodiagnostics capabilities in determining the indications for allergen-specific immunotherapy with house dust mites allergen and its effectiveness in atopic dermatitis patients

BACKGROUND:Atopic dermatitis (AD) is a widespread chronic inflammatory skin disease, in the development of which complex genetic and immune mechanisms, environmental factors, allergens, are involved. An effective method of treating IgE-mediated allergic diseases is allergen-specific immunotherapy (ASIT), which affects all pathogenetically significant links of the allergic process. It is known that as a result of ASIT tissue sensitivity to an allergen, nonspecific tissue hyperreactivity and the intensity of allergic inflammation decrease, which testifies to the rearrangement of the cellular response from Th2 to Th1 with a corresponding change in the cytokine profile. Currently, dozens of scientific papers on the efficacy and safety of subcutaneous and sublingual ASIT in AD have been published; however, the question of the advisability of its appointment still remains unresolved.&#x0D; AIM:To investigate the ASIT with house dust mite (HDM) allergens efficacy in AD patients, considering the results of molecular allergy diagnosis.&#x0D; MATERIALS AND METHODS:The study was conducted as a prospective comparative open study, including 32 patients with AD (20 children and 12 adults), 90.6% were diagnosed with concomitant respiratory allergic diseases. Molecular allergodiagnostics was performed using microchip technology with purified natural or recombinant allergen components immobilized in the solid phase (Immuno-Solid phase Allergen Chip, ISAC) to quantify allergen-specific IgE (asIgE) against 112 allergen molecules from 51 allergen sources in one study (ImmunoCAP ISAC (Thermofisher, Phadia, Uppsala, Sweden). Patients were divided into two groups depending on the profile of molecular sensitization: with the presence or absence of asIgE to the major allergens ofD. farinaeand/orD. pteronyssinusDer p 1 (p 2) and/or Der f 1 (f 2). All patients passed three consecutive courses of subcutaneous ASIT with water-salted HDM allergens produced by I.I. Mechnikov Biomed (Russia) under an accelerated scheme for 3 years. To assess the severity of the disease, the SCORAD indices, the Investigators Global Assessment (IGA), and the dermatological quality of life index (DLQI) were used.&#x0D; RESULTS:Patients with sensitization to major allergens ofD. farinaeand/orD. pteronyssinusDer p 1 (f 1) and/or Der p 2 (f 2) more often achieved a significant improvement of AD symptoms according to the SCORAD index (OR 3.929, 95% CI: 0.879; 17.56), as well as they more often achieved IGA values of 1 or 0 after three courses of ASIT (OR 3.556, CI 95% 0.73017.324) and more often assessed the effectiveness of ASIT as excellent and good in comparison with patients without sensitization to these components. The median and interquartile range of the DLQI index before treatment in group 1 was 17 [14; 20] points, in group 2 14 [12; 18], after the 3rdcourse of ASIT: 6 [2; 10] and 8 [3; 10] points in groups 1 and 2, respectively. Adverse events were rare, their frequency did not significantly differ in both groups.&#x0D; CONCLUSION:ASIT with HDM allergens is an effective and safe method of treatment of AD patients. Determination of the molecular spectrum of sensitization to HDM allergens components allows to justify the indications and predict the effectiveness of ASIT.

Air pollution and IgE sensitization in 4 European birth cohorts—the MeDALL project

Whether long-term exposure air to pollution has effects on allergic sensitization is controversial. Our aim was to investigate associations of air pollution exposure at birth and at the time of later biosampling with IgE sensitization against common food and inhalant allergens, or specific allergen molecules, in children aged up to 16 years. A total of 6163 children from 4 European birth cohorts participating in the Mechanisms of the Development of ALLergy [MeDALL] consortium were included in this meta-analysis of the following studies: Children, Allergy, Milieu, Stockholm, Epidemiology (BAMSE) (Sweden), Influences of Lifestyle-Related Factors on the Human Immune System and Development of Allergies in Childhood (LISA)/German Infant Study on the Influence of Nutrition Intervention PLUS Environmental and Genetic Influences on Allergy Development (GINIplus) (Germany), and Prevention and Incidence of Asthma and Mite Allergy (PIAMA) (The Netherlands). The following indicators were modeled by land use regression: individual residential outdoor levels of particulate matter with aerodynamic diameters less than 2.5 μm, less than 10 μm, and between 2.5 and 10 μm; PM2.5 absorbance (a measurement of the blackness of PM2.5 filters); and nitrogen oxides levels. Blood samples drawn at ages 4 to 6 (n= 5989), 8 to 10 (n= 6603), and 15 to 16 (n= 5825) years were analyzed for IgE sensitization to allergen extracts by ImmunoCAP. Additionally, IgE against 132 allergen molecules was measured by using the MedALL microarray chip (n= 1021). Air pollution was not consistently associated with IgE sensitization to any common allergen extract up to age 16 years. However, allergen-specific analyses suggested increased risks of sensitization to birch (odds ratio [OR]= 1.12 [95% CI= 1.01-1.25] per 10-μg/m3 increase in NO2 exposure). In a subpopulation with microarray data, IgE to the major timothy grass allergen Phleum pratense 1 (Phl p 1) and the cat allergen Felis domesticus 1 (Fel d 1) greater than 3.5 Immuno Solid-phase Allergen Chip standardized units for detection of IgE antibodies were related to PM2.5 exposure at birth (OR= 3.33 [95% CI= 1.40-7.94] and OR= 4.98 [95% CI= 1.59-15.60], respectively, per 5-μg/m3 increase in exposure). Air pollution exposure does not seem to increase the overall risk of allergic sensitization; however, sensitization to birch as well as grass pollen Phl p 1 and cat Fel d 1 allergen molecules may be related to specific pollutants.

A Retrospective Clinical Audit of the ImmunoCAP ISAC 112 for Multiplex Allergen Testing

Introduction: Complex cases of multiple allergies can be particularly difficult to diagnose using standard methods such as skin prick tests and assessment of a patient’s allergic history. Multiplex allergy testing may improve outcomes for allergy patients by avoiding misdiagnosis and providing reassurance. The ImmunoCAP Immuno Solid-Phase Allergen Chip (ISAC) 112 is a CE-marked, molecular, multiplex, allergy test that can test for IgE antibodies to 112 components from 51 allergen sources. However, its clinical utility is unknown and is difficult to estimate due to the complexity of the diagnostic pathway in which it is used. Objective: To assess how the ImmunoCAP ISAC 112 is currently being used in UK practice. The patient populations in which it may have the most benefit were examined, and the sequence of other tests implemented alongside ISAC was determined. Methods: A retrospective audit of 100 patient cases from 2 UK tertiary allergy clinics was performed. Fifty paediatric and fifty adult cases were selected for audit. The indications for ordering an ISAC test, the other tests used alongside ISAC, and changes in management actioned by the ISAC test were investigated. Results: 73.6% of paediatric and 78% of adult patients referred for an ISAC test were suspected to have multiple sensitizations. The sequence of testing varied greatly between cases, but 70% of adult and 98% of paediatric patients had at least one other investigation prior to an ISAC test. In most cases, ISAC testing confirmed clinical suspicion. Conclusions: A prospective research study is necessary to further investigate the clinical utility and cost-effectiveness of the ISAC. A UK national registry would be of great benefit but will require a large resource base.

Allergen Components from Foods Declarable as Allergen Sources in The EU Available in Multiplex Immunoassays

Molecular allergy diagnosis in food allergies is a modern approach utilized to characterize the molecular components of food allergens from the point of view of specific IgE-mediated immune responses. In the clinical practice, it can improve diagnosis accuracy and may assist the allergist in many aspects of the specialty work-up. Modern multiplex immunoassay methods used for the detection of serum specific IgE against food allergen components are the immuno solid-phase allergen chip microarray, patient-friendly allergen nano-bead array and macroarray nanotechnology-based immunoassay as a new generation molecular allergy explorer. It is important to know the allergenic molecules available for multiplex diagnosis immunoassays from food sources which must be declared as containing food allergens in the European Union (EU).

Underestimation of House Dust Mite–Specific IgE With Extract-Based ImmunoCAPs Compared With Molecular ImmunoCAPs

To identify the most important house dust mite (HDM) allergens using component-resolved diagnostics (CRD).Patients with HDM allergy (n = 53), including 26 who were challenged in an environmental control chamber and 27 who were not challenged.Testing for serum-specific immunoglobulin E (IgE) to 13 HDM proteins was confirmed by ImmunoCAP Immuno Solid-phase Allergen Chip assays (henceforth referred to as CAP-molecular). Only the 6 proteins to which serum-specific IgE was most prevalent were included in further analysis (Der p 1, 2, 5, 7, 21, and 23), and all patients were sensitized to all 6 HDM allergens. An ImmunoCAP assay containing the 6 HDM allergens was prepared (CAP-allergen) and compared with the commercial extract-based ImmunoCAP assay (CAP-extract) and CAP-molecular. The 2 groups were studied in combination and independently.Specific IgE levels by CAP-extract, CAP-allergen, and CAP-molecular correlated with each other, with the best correlation between CAP-extract and CAP-allergen. CAP-allergen levels were higher than CAP-extract levels in 39 out of 53 (70%) patients and significantly higher overall (P < .0001). However, when allergen-specific IgE levels to the 6 predominant allergens were compared in patients with a CAP-extract level greater or less than 20 kU/L, the CAP-molecular levels were only higher in the group with higher CAP-extract levels, indicating that important allergens might be underrepresented in the commercially available CAP-extract assay (especially Der p 2, 5, 21, and 23). In unpublished data, the authors report that higher CAP-extract levels do not correlate with specific manifestations of HDM allergy, but threshold levels for clinical allergy might be established. There was no significant difference in outcomes between the groups.Replacing CAP-extract assays with highly reproducible CAP-molecular assays or by adding recombinant HDM allergens to HDM extracts might improve differentiation of HDM sensitization from HDM allergy.The easy availability and inaccurate interpretation of in vitro tests for serum-specific IgE may overestimate the prevalence of specific allergies. Practitioners must differentiate between sensitization (a positive test result) and allergy (a positive test result and clinical reactivity). We have entered the era of CRD in which we can measure serum-specific IgE levels to some individual proteins, not just to crude extracts of an allergen. We understand that depending on the food and the individual proteins to which a patient makes specific IgE, we gain knowledge as to the likelihood of him or her tolerating a baked product if not the food per se (eg, milk or egg) or of his or her risk for oropharyngeal versus systemic symptoms (eg, peanut and certain tree nuts). Furthermore, we know that the greater diversity of epitopes to which a person makes specific IgE, the greater the likelihood he or she is to be allergic and, in the case of food allergies, the lesser the likelihood he or she will outgrow the allergy. I anticipate that we will eventually have many more assays for specific allergens, improving our diagnostic specificity and sensitivity. It is important to fully understand the interpretation of tests for specific IgE, especially as CRD evolves.

Diagnosis of Sesame Allergy: Analysis of Current Practice and Exploration of Sesame Component Ses i 1

Sesame is an allergen of increasing importance. We sought to characterize the outcomes of oral food challenges (OFCs) to sesame and evaluate the diagnostic accuracy of skin prick testing (SPT), sesame, and Ses i 1-specific IgE (sIgE). We reviewed sesame OFCs performed at the Mount Sinai pediatric allergy clinic between January 2010 and April 2018. We assessed the accuracy of diagnostic tests by calculating the area under the curve (AUC) of the receiver operating characteristic curves. The association between OFC outcome and sesame sensitization was analyzed using a logistic regression, which was then used to estimate the 95% positive predictive value (PPV) of these tests. We identified 341 patients (69% male, mean age 7.7 years) who underwent sesame OFC. Among 106 (31%) positive OFCs, the median cumulative eliciting dose was 500 mg sesame protein (1/2 teaspoon tahini). Sesame SPT wheal ≥6 mm had sensitivity 54.1% and specificity 87.8%; AUC 0.756 (95% confidence interval [CI], 0.699-0.814). SPT wheal size ≥14 mm had 95% PPV. Sesame-sIgE level did not correlate with OFC outcome. Ses i-sIgE levels were analyzed in 30 patients using the Immuno Solid-phase Allergen Chip (ISAC) microarray and were significantly associated with OFC outcome (AUC: 0.715 [95% CI, 0.541-0.890]). Ses i 1-sIgE ≥0.3 ISAC Standardized Units had sensitivity 58.3% and specificity 83.3%. This is the largest study of sesame allergy to date. Sesame SPT is a more accurate predictor of sesame allergy compared with sesame sIgE. Ses i 1-sIgE appears promising but requires further study regarding diagnostic accuracy.

Ash pollen allergy and aerobiology

Abstract Background Allergy to ash pollen is common in some parts of Europe. Sensitization is overlooked if Oleaceae pollen allergens are not included in screening tests. Methods Between 1983 and 2007, sensitization to aeroallergens was systematically investigated using serological methods in 15-year-old school children (Immuno-CAP [carrier polymer] test). Samples from 1986 and 2006 were also tested using the immuno-solid-phase allergen chip (ISAC) assay. School children with sensitizations in 1986 were retested in 2010. Airborne pollen concentrations were determined by the Swiss pollen measuring network. Results Sensitization (&gt;0.7 kU/l) to ash pollen (Fraxinus americana t15)—16.3% (102/627)—was more frequent than to birch pollen (Betula verrucosa t3): 15.3% (96/627). ISAC assays performed in children in 1986 and 2006 revealed higher molecular seroprevalence for nOle e 1 (15%; 15/100) compared to rBet v 1 (12%; 12/100). Followed-up subjects (age, 39) showed an increase in sensitizations to ash pollen. IgE levels to pollen from indigenous ash (Fraxinus excelsior t25) were higher than to pollen from American ash (Fraxinus americana t15). Low ash pollen emission levels were recorded at all measuring sites in Switzerland every 2–4 years. The infection of ashes by Chalara fraxinea resulted in increased emission of ash pollen. Conclusion Symptoms in individuals sensitized to ash pollen vary according to the pollen count and may be masked by pollen from other trees that flower at the same time of year. Sensitization to ash/Ole e 1 can be higher than to birch/Bet v 1. The determination of IgE to common ash (Fraxinus excelsior) is more sensitive than to American ash (Fraxinus americana). Ash dieback due to Chalara appears to increase pollen emission. Allergies to ash pollen can be significantly underestimated due to a failure to (correctly) identify them; they can also be masked by other pollen families (birch). Harmful organisms such as Chalara can intensify pollen emissions at least temporarily.