Can component-based microarray replace fluorescent enzimoimmunoassay in the diagnosis of grass and cypress pollen allergy?

Cupressus arizonica: an emerging aeroallergen for East Mediterranean children

Background/aim

Cupressus sempervirens is a tree native to the Mediterranean region. We aimed to investigate the frequency of sensitization/allergy to Cupressus arizonica pollen, which is not native to Anatolia.

Materials and methods

Patients aged 5-18 years who underwent respiratory allergy screening in Türkiye's largest referral center over a 1-year period were reviewed retrospectively for a diagnostic study of Cupressus allergy.

Results

Of 246 patients, 207 (67.6% male) with a median age of 11.7 (IQR 9.2-15) years were found to be aeroallergen-sensitive and C. arizonica (32%) was the second most common sensitivity after grass pollen (83.6%). In the C. arizonica-sensitive subgroup, only 3% (2/67) were monosensitive, and grass (77.6%), cat (38.8%), and weeds (38.8%) were the most common co-sensitivities. Cup a 1 specific IgE (sIgE) was measured in 26 patients with C. arizonica sensitivity and all were found to be positive. A nasal allergen challenge (NAC) was performed for 44 of 67 patients with C. arizonica sensitivity, and 13 of 44 patients had a positive outcome (NAC+) at the highest two extract concentrations. The Cupressus wheal sizes and Cup a 1 sIgE levels of the NAC+ subgroup were higher than those of the NAC- subgroup but reached significance only for wheal size [6 (5-7.5) vs. 4.5 (4-6), p=0.004]. The NAC+ subgroup reported more frequent nasal discharge, congestion, and eye symptoms than the NAC- subgroup during the relevant pollen season.

Conclusion

C. arizonica sensitivity has increased in the East Mediterranean region, similarly to North Mediterranean data, and this is associated with the presence of allergy both clinically and in laboratory findings. C. arizonica should be included in the aeroallergen screening panels of children from the East Mediterranean.

[Diagnosis of allergy in asthma]

Allergy is a hypersensitivity reaction induced by immunological mechanisms. In asthma, allergy has a complex role and is usually IgE mediated. Allergy must be evaluated during the work up but evidence of IgE sensitivity does not mean that allergens play a role in the pathophysiology of the disease. The clinical relevance of the sensitivity has to be considered. This paper describes current available tools to screen for IgE sensitivity, allergen exposure and their role in asthma.

IgE responses to multiple allergen components among school-aged children in a general population birth cohort in Tokyo

BACKGROUND

Response patterns to allergen components among Japanese children have not been studied extensively.

OBJECTIVE

Our aim was to examine the differences in sensitization patterns at ages 5 years and 9 years to identify longitudinal changes in the degree and patterns of sensitization in a birth cohort of Japanese children.

METHODS

Our study enrolled 984 children at aged 5 years between 2008 and 2010, and 729 children aged 9 years between 2012 and 2014. Allergic diseases were assessed using the ISAAC and UK Working Party's Diagnostic Criteria. Serum-specific IgE titers to allergen components were measured by multiplex array ImmunoCAP ISAC when the children were aged 5 and 9 years. Principal component analysis (PCA) was performed to characterize IgE sensitization to allergen components.

RESULTS

The prevalence of allergic rhinitis increased considerably over time (10.6%-31.2%). Furthermore, the sensitization prevalence to allergen-specific IgE (sIgE) also increased from 57.8% at age 5 years to 74.8% at age 9 years. IgE sensitization prevalence to Der f 1 (mites) was 42.1% at age 5 years and 54.3% at age 9 years. Furthermore, children were highly sensitized to Cry j 1 (Japanese cedar) (32.8% at age 5 years and 57.8% at age 9 years). Principle component analysis showed that sensitization to PR-10 cross-reactive components was independent of sensitization to mite and that no children acquired sensitization to pollen before acquiring sensitization to mite.

CONCLUSIONS

The prevalence of allergic rhinitis and related allergen components increased from age 5 years to age 9 years in Japanese children.

ImmunoCAP® ISAC and Microtest for multiplex allergen testing in people with difficult to manage allergic disease: a systematic review and cost analysis

BACKGROUND

Allergy is a form of immune-mediated exaggerated sensitivity (hypersensitivity) to a substance that is either inhaled, swallowed, injected or comes into contact with the skin. Foreign substances that provoke allergies are called allergens. It has been claimed that multiplex allergen testing may help in diagnosing the cause of symptoms in patients with an unclear cause of allergy or who are allergic to more than one substance.

OBJECTIVES

To evaluate multiplex allergen testing [devices that can measure the presence of multiple immunoglobulin E (IgE) antibodies in a patient's blood at the same time], by assessing (1) clinical effectiveness (allergy symptoms, incidence of acute exacerbations, mortality, adverse events of testing and treatment, health-care presentations or admissions, health-related quality of life); (2) effects on treatment (diet, immunotherapy medications, other potential testing); (3) any additional diagnostic information provided by multiplex allergen testing; and (4) cost-effectiveness (cost of different assessment strategies).

METHODS

Fifteen databases were searched from 2005 to April 2015, including MEDLINE (via OvidSp), MEDLINE In-Process Citations, MEDLINE Daily Update, PubMed (National Library of Medicine), EMBASE, Cochrane Database of Systematic Reviews (CDSR), Cochrane Central Register of Controlled Trials (CENTRAL), Database of Abstracts of Reviews of Effects (DARE), Health Technology Assessment (HTA) database, Science Citation Index (SCI), Conference Proceedings Citation Index-Science (CPCI-S), BIOSIS Previews, Latin American and Caribbean Health Sciences Literature (LILACS), National Institute for Health Research (NIHR) HTA programme, and the US Food and Drug Administration (FDA); supplementary searches of conference proceedings and trials registries were performed. Review methods followed published guidance from the Cochrane Collaboration and the Centre for Reviews and Dissemination, University of York, UK. The methodological quality of included studies was assessed using appropriate published tools or a review-specific tool designed by the project team. Studies were summarised in a narrative synthesis. Owing to a lack of data on the clinical effectiveness of multiplex allergen testing, no long-term cost-effectiveness model was developed. A conceptual model structure was developed and cost analyses were performed to examine the short-term costs of various possible diagnostic pathways.

RESULTS

Fifteen studies were included in the review. The very limited available data indicated that the addition of multiplex allergen testing [ImmunoCAP(®) Immuno Solid-phase Allergen Chip (ISAC), Thermo Fisher Scientific/Phadia AB, Uppsala, Sweden] to standard diagnostic work-up can change the clinicians' views on the diagnosis, management and treatment of patients. There was some indication that the use of ImmunoCAP ISAC testing may be useful to guide decisions on the discontinuation of restrictive diets, the content of allergen-specific immunotherapy (SIT) prescriptions, and whether or not patients should receive SIT. However, none of the studies that we identified reported any information on clinical outcomes subsequent to changes in treatment or management. There was some evidence that ImmunoCAP ISAC may be useful for discriminating allergens that are structurally similar and are recognised by the same IgE antibody (cross-immunoreactive). No data were available for Microtest (Microtest Matrices Ltd, London, UK). Detailed cost analyses suggested that multiplex allergen testing would have to result in a substantial reduction of the proportions of patients receiving single IgE testing and oral food challenge tests in order to be cost-saving in the short term.

CONCLUSIONS

No recommendations for service provision can be made based on the analyses included in this report. It is suggested that a consensus-based protocol for the use of multiplex allergen testing be developed. The clinical effectiveness and cost-effectiveness of the proposed protocol should then be assessed by comparing long-term clinical and quality of life outcomes and resource use in patients managed using the protocol with those managed using a standard diagnostic pathway.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015019739.

FUNDING

This project was a Diagnostic Assessment Report commissioned by the NIHR HTA programme on behalf of the National Institute for Health and Care Excellence.

Debates in Allergy Medicine: Allergy skin testing cannot be replaced by molecular diagnosis in the near future

Percutaneous skin prick tests (SPT) have been considered the preferred method for confirming IgE-mediated sensitization. This reliable and minimally invasive technique correlates with in vivo challenges, has good reproducibility, is easily quantified, and allows analyzing multiple allergens simultaneously. Potent extracts and a proficient tester improve its accuracy.

Molecular-based allergy diagnostics (MA-Dx) quantifies allergenic components obtained either from purification of natural sources or recombinant technology to identify the patient’s reactivity to those specific allergenic protein components. For a correct allergy diagnosis, the patient selection is crucial. MA-Dx has been shown to have a high specificity, however, as MA-Dx testing can be ordered by any physician, the pre-selection of patients might not always be optimal, reducing test specificity. Also, MA-Dx is less sensitive than in vitro testing with the whole allergen or SPT. Secondly, no allergen-specific immunotherapy (AIT) trial has yet shown efficacy with patients selected on the basis of their MA-Dx results. Thirdly, why would we need molecular diagnosis, as no molecular treatment can yet be offered? Then there are the practical arguments of costs (SPT highly cost-efficient), test availability for MA-Dx still lacking in wide areas of the world and scarce in others. As such, it is hard physicians can build confidence in the test and their interpretation of the MA-Dx results. In conclusion: as of now these techniques should be reserved for situations of complex allergies and polysensitization; in the future MA-Dx might help to reduce the number of allergens for AIT, but trials are needed to prove this concept.

Molecular diagnosis and immunotherapy

PURPOSE OF REVIEW

To describe recent insights into how molecular diagnosis can improve indication and selection of suitable allergens for specific immunotherapy and increase the safety of this therapy.

RECENT FINDINGS

As specific allergen immunotherapy targets specific allergens, identification of the disease-eliciting allergen is a prerequisite for accurate prescription of treatment. In areas of complex sensitization to aeroallergens or in cases of hymenoptera venom allergy, the use of molecular diagnosis has demonstrated that it may lead to a change in indication and selection of allergens for immunotherapy in a large proportion of patients when compared with diagnosis based on skin prick testing and/or specific IgE determination with commercial extracts. These changes in immunotherapy prescription aided by molecular diagnosis have been demonstrated to be cost-effective in some scenarios. Certain patterns of sensitization to grass or olive pollen and bee allergens may identify patients with higher risk of adverse reaction during immunotherapy.

SUMMARY

Molecular diagnosis, when used with other tools and patients' clinical records, can help clinicians better to select the most appropriate patients and allergens for specific immunotherapy and, in some cases, predict the risk of adverse reactions. The pattern of sensitization to allergens could potentially predict the efficacy of allergen immunotherapy provided that these immunotherapy products contain a sufficient amount of these allergens. Nevertheless, multiplex assay remains a third-level approach, not to be used as screening method in current practice.

Comparison of Component-Resolved Diagnosis by Using Allergen Microarray With the Conventional Tests in Allergic Rhinitis Patients: The First Using in Korea

Objectives

The aim of this study was to evaluate the component-resolved diagnosis using a microarray allergen chip (Immuno Solid-phase Allergen Chip, ImmunoCAP ISAC) and to compare this new diagnostic tool with the established ImmunoCAP methods for allergen-specific IgE detection in allergic rhinitis patients.

Methods

One hundred sixty-eight allergic rhinitis patients were included in this study. All the patients were diagnosed with allergic rhinitis according to their clinical symptoms, physical examination and a positive skin prick test. We analyzed their specific IgEs for house dust mites (Dermatophagoides farine [DF] and Dermatophagoides pteronyssinus [DP]), Alternaria alternata, birch, and mugwort using ImmunoCAP and ImmunoCAP ISAC in the same patient sample. We compared the sensitivity and correlation between the two tests.

Results

In cases of allergies to DP and DF, the sensitivity of the specific IgE was 80% and that of the allergen microarray was 78.9%. The correlation between the two tests was significant for both DP and DF (P<0.001). For the A. alternata, birch and mugwort allergens, the sensitivity of ImmunoCAP ISAC was slightly lower than that of ImmunoCAP.

Conclusion

These results suggest that the allergen microarray chip method is a reliable new method to diagnose the components of an allergen in patients with allergic rhinitis sensitive to house dust mites. Further study about the utility of the allergen microarray is needed.

Different IgE recognition of mite allergen components in asthmatic and nonasthmatic children

BACKGROUND

House dust mites (HDMs) represent one of the most important inducers of respiratory allergies worldwide.

OBJECTIVE

We sought to investigate the IgE and IgG reactivity profiles to a comprehensive panel of HDM allergens in children with allergic asthma and to compare them with those of nonasthmatic atopic children.

METHODS

Sera from clinically well-characterized asthmatic children with HDM allergy (n = 105), nonasthmatic children (n = 53), and nonatopic nonasthmatic children (n = 53) were analyzed for IgE and IgG reactivity to a panel of 7 HDM allergens (nDer p 1, rDer p 2, rDer p 5, rDer p 7, rDer p 10, rDer p 21, and rDer p 23) by means of allergen microarray technology.

RESULTS

Asthmatic children with HDM allergy more frequently showed an IgE response to each of the HDM allergens and recognized more allergens than nonasthmatic children with HDM allergy. Furthermore, IgE levels to certain HDM allergens (nDer p 1, P = .002; rDer p 2, P = .007; rDer p 5, P = .031; and rDer p 23, P < .001) were significantly higher in asthmatic children than in children without asthma. By contrast, fewer asthmatic children showed IgG reactivity to HDM allergens than nonasthmatic children, but allergen-specific IgG levels were comparable.

CONCLUSION

The IgE and IgG reactivity profiles to HDM allergens, as well as IgE levels to certain allergen components, differed considerably between children with and without asthmatic symptoms caused by HDM allergy. In fact, asthmatic children were characterized by an expanded IgE repertoire regarding the numbers of recognized allergen components and by increased specific IgE levels.

Comparison of molecular and extract-based allergy diagnostics with multiplex and singleplex analysis

Background

ImmunoCAP ISAC 112, is a commercially available molecular allergy IgE multiplex test. Data on the comparison of this rather novel test with extract-based as well as molecular ImmunoCAP singleplex IgE tests is missing.

Objective

To perform a comparison between the ISAC multiplex IgE assay and the ImmunoCAP singleplex test results.

Methods

Serum samples of 101 adults with grass pollen allergy were analysed for sIgE to 112 allergenic molecules represented on the ISAC test as well as to common atopy-related extract-based allergy tests with the ImmunoCAP System (house dust mite [d1], cat [e1], dog [e5], cow’s milk [f2], hen’s egg [f1], hazelnut [f17], celery [f85], Alternaria alternate [m6], as well as pollen from birch [t3], hazel [t4], mugwort [w6], and ragweed [w1]). Subsequently statistical analysis was performed with the Spearman rank correlation test and the Clopper-Pearson method in order to compare the ISAC multiplex results with the sIgE singleplex results.

Results

The positive percent agreements (PPA) and negative percent agreement (NPA) of corresponding allergens between the ISAC sIgE test and the extract-based singleplex ImmunoCAP results at cutoff 0.1 kUA/l varied between 60–100 % for PPA and 78–97 % for NPA.

Conclusion

When taking into account corresponding allergens molecular testing with the ISAC multiplex test correlates well with ImmunoCAP singleplex results.

Molecular approach to allergy diagnosis and therapy

Presently, allergy diagnosis and therapy procedures are undergoing a transition phase in which allergen extracts are being step-by-step replaced by molecule-based products. The new developments will allow clinicians to obtain detailed information on sensitization patterns, more accurate interpretation of allergic symptoms, and thus improved patients' management. In this respect, recombinant technology has been applied to develop this new generation of molecule-based allergy products. The use of recombinant allergens allows full validation of identity, quantity, homogeneity, structure, aggregation, solubility, stability, IgE-binding and the biologic potency of the products. In contrast, such parameters are extremely difficult to assay and standardize for extract-based products. In addition to the possibility of bulk production of wild type molecules for diagnostic purposes, recombinant technology opened the possibility of developing safer and more efficacious products for allergy therapy. A number of molecule-based hypoallergenic preparations have already been successfully evaluated in clinical trials, bringing forward the next generation of allergy vaccines. In this contribution, we review the latest developments in allergen characterization, molecule-based allergy diagnosis, and the application of recombinant allergens in therapeutic setups. A comprehensive overview of clinical trials using recombinant allergens as well as synthetic peptides is presented.

A comprehensive analysis of middle-European molecular sensitization profiles to pollen allergens

Molecular diagnosis of allergy and microarray technology have opened a completely new avenue of insight into sensitization profiles from both the clinical and the epidemiological point of view. We used this innovative tool in the description of sensitization patterns in pollen-sensitized patients in Middle Europe. Immunoglobulin E detection using 112 different allergenic molecules was carried out employing the ImmunoCAP ISAC microarray system. Sera from 826 patients sensitized to at least one pollen-derived molecule were subjected to analysis. The highest observed sensitization rate was 81.0% to grass-specific molecules (the most frequent being Phl p 1; 69.6%). The second most frequent sensitization was 54.8% to Betulaceae-specific molecules (Bet v 1; 54.2%). Together, grasses and Betulaceae components (and their cosensitizations with other components) comprised the vast majority of pollen sensitizations. Unexpectedly frequently observed sensitizations were those to Cupressaceae-specific molecules (14.1%), Oleaceae-specific molecules (10.8%), and the plane tree-derived molecule Pla a 2 (15.5%). The sensitization rates for all other molecules were within the expected range (Art v 1, 13.6%; Pla l 1, 9.6%; Che a 1, 8.4%; Par j 2, 0.9%; Amb a 1, 0.8%, and Sal k 1, 0.5%). Cross-reacting molecule sensitization rates were found to be 12.4% for profilins, 5.0% for polcalcins, and 6.4% for lipid transfer proteins. Molecular diagnosis of allergy gives a more precise and comprehensive insight into pollen sensitization patterns than extract-based testing, allowing a better understanding of the sensitization process and regional differences. The data presented here may help to improve the diagnostic and allergen-specific treatment procedures in the respective region.

Advances in allergen-microarray technology for diagnosis and monitoring of allergy: the MeDALL allergen-chip

Allergy diagnosis based on purified allergen molecules provides detailed information regarding the individual sensitization profile of allergic patients, allows monitoring of the development of allergic disease and of the effect of therapies on the immune response to individual allergen molecules. Allergen microarrays contain a large variety of allergen molecules and thus allow the simultaneous detection of allergic patients' antibody reactivity profiles towards each of the allergen molecules with only minute amounts of serum. In this article we summarize recent progress in the field of allergen microarray technology and introduce the MeDALL allergen-chip which has been developed for the specific and sensitive monitoring of IgE and IgG reactivity profiles towards more than 170 allergen molecules in sera collected in European birth cohorts. MeDALL is a European research program in which allergen microarray technology is used for the monitoring of the development of allergic disease in childhood, to draw a geographic map of the recognition of clinically relevant allergens in different populations and to establish reactivity profiles which are associated with and predict certain disease manifestations. We describe technical advances of the MeDALL allergen-chip regarding specificity, sensitivity and its ability to deliver test results which are close to in vivo reactivity. In addition, the usefulness and numerous advantages of allergen microarrays for allergy research, refined allergy diagnosis, monitoring of disease, of the effects of therapies, for improving the prescription of specific immunotherapy and for prevention are discussed.

Is the determination of specific IgE against components using ISAC 112 a reproducible technique?

Background

The ImmunoCAP ISAC 112 is a fluoro-immunoassay that allows detection of specific IgE to 112 molecular components from 51 allergenic sources. We studied the reliability of this technique intra- and inter- assay, as well as inter-batch- and inter-laboratory-assay.

Methods

Twenty samples were studied, nineteen sera from polysensitized allergic patients, and the technique calibrator provided by the manufacturer (CTR02). We measured the sIgE from CTR02 and three patients' sera ten times in the same and in different assays. Furthermore, all samples were tested in two laboratories and with two batches of ISAC kit. To evaluate the accuracy of ISAC 112, we contrasted the determinations of CTR02 calibrator with their expected values by T Student test. To analyse the precision, we calculated the coefficient of variation (CV) of the 15 allergens that generate the calibration curve, and to analyse the repeatability and the reproducibility, we calculated the intraclass coefficient correlation (ICC) to each allergen.

Results

The results obtained for CTR02 were similar to those expected in 7 of 15 allergens that generate the calibration curve, whereas in 8 allergens the results showed significant differences. The mean CV obtained in the CTR02 determinations was of 9.4%, and the variability of sera from patients was of 22.9%. The agreement in the intra- and inter-assay analysis was very good to 94 allergens and good to one. In the inter-batch analyse, we obtained a very good agreement to 82 allergens, good to 14, moderate to 5 allergens, poor to one, and bad to 1 allergen. In the inter-laboratory analyse, we obtained a very good agreement to 73 allergens, good to 22, moderate to 6 and poor to two allergens.

Conclusion

The allergen microarray immunoassay, ISAC 112, is a repeatable and reproducible in vitro diagnostic tool for determination of sIgE beyond the own laboratory.

Determination of sIgE to rPhl p 1 is sufficient to diagnose grass pollen allergy

BACKGROUND

New diagnostic tools such as the basophil activation test (BAT) and component-resolved diagnosis (CRD) are promising for Hymenoptera venom or food allergy. A clear benefit for inhalant allergens has not yet been shown. Our aim was to compare new and established tests for grass pollen allergy.

METHODS

Forty-nine patients with grass pollen allergy and 47 controls were prospectively enrolled in the study. A symptom score was calculated for each patient. Conjunctival provocation tests (CPT), skin prick tests (SPT), BAT, and sIgE determination including CRD were performed. Sensitivity and specificity were compared and results were correlated with the symptom score.

RESULTS

Single determination of sIgE to rPhl p 1 showed the best balance between sensitivity (98%) and specificity (92%). Use of additional components, such as rPhl p 2 and 5, did not increase sensitivity. Generally, sensitivity of tests was high: SPT 100%, ISAC-112 100%, sIgE to timothy grass 98%, BAT 98%, ISAC-103 84%, and CPT 83%. Specificity ranged from 79% (SPT) to 96% (CPT). All test results and calculated values (e.g. ratio sIgE/tIgE) did not correlate with symptom severity. Asymptomatic sensitization to timothy grass in controls was rare in the CAP (11%) and predominantly due to Phl p 1 sensitization.

CONCLUSION

rPhl p 1 was sufficient to diagnose grass pollen allergy, and sIgE patterns were the same in symptomatically and asymptomatically sensitized subjects. The testing of multiple components was of minor importance, and no test correlated with symptom severity.

A WAO - ARIA - GA²LEN consensus document on molecular-based allergy diagnostics

Molecular-based allergy (MA) diagnostics is an approach used to map the allergen sensitization of a patient at a molecular level, using purified natural or recombinant allergenic molecules (allergen components) instead of allergen extracts. Since its introduction, MA diagnostics has increasingly entered routine care, with currently more than 130 allergenic molecules commercially available for in vitro specific IgE (sIgE) testing.

MA diagnostics allows for an increased accuracy in allergy diagnosis and prognosis and plays an important role in three key aspects of allergy diagnosis: (1) resolving genuine versus cross-reactive sensitization in poly-sensitized patients, thereby improving the understanding of triggering allergens; (2) assessing, in selected cases, the risk of severe, systemic versus mild, local reactions in food allergy, thereby reducing unnecessary anxiety for the patient and the need for food challenge testing; and (3) identifying patients and triggering allergens for specific immunotherapy (SIT).

Singleplex and multiplex measurement platforms are available for MA diagnostics. The Immuno-Solid phase Allergen Chip (ISAC) is the most comprehensive platform currently available, which involves a biochip technology to measure sIgE antibodies against more than one hundred allergenic molecules in a single assay. As the field of MA diagnostics advances, future work needs to focus on large-scale, population-based studies involving practical applications, elucidation and expansion of additional allergenic molecules, and support for appropriate test interpretation. With the rapidly expanding evidence-base for MA diagnosis, there is a need for allergists to keep abreast of the latest information. The aim of this consensus document is to provide a practical guide for the indications, determination, and interpretation of MA diagnostics for clinicians trained in allergology.

Developments in the field of allergy in 2011 through the eyes of Clinical and Experimental Allergy

As in previous years, we felt it would be of value to our readership to summarize the new information provided by the authors who have published in Clinical and Experimental Allergy in 2011 and set this in the context of recent advances in our understanding of the pathogenesis and management of allergic disease in all its many manifestations. In 2011, about 210 articles were published in Clinical and Experimental Allergy including editorials, reviews, opinion articles, guidelines, letters, book reviews and of course at the heart of the journal, papers containing original data. As before, this review is divided into sections based on the way the journal is structured, although this year we have grouped together all the papers dealing with mechanisms of allergic disease, whether they involve patients (clinical mechanisms), pure in vitro studies (basic mechanisms) or animal models (experimental models), as we felt this was a more coherent way to deal with the subject. In the field of asthma and rhinitis, the relationship between airway inflammation and airway dysfunction was of perennial interest to investigators, as were phenotypes and biomarkers. Aspirin hypersensitivity appeared in studies in several papers and there was new interest in asthma in the elderly. The mechanisms involved in allergic disease describe advances in our understanding of T cell responses, the relationship between inflammation and disease, mast cell and basophil activation, steroid resistance and novel therapies. In the section dealing with epidemiology, studies seeking to identify risk factors for allergic disease including vitamin D are prominent, as once again are studies investigating gene-environment interactions. The clinical allergy section focuses on drug allergy, food allergy and immunotherapy. The area of oral immunotherapy for food allergy is well covered and we were grateful to Stephen Durham for guest editing an outstanding special issue on immunotherapy in the centenary year of Leonard Noon's pioneering work. Lastly, in the field of allergens, the interest in component-resolved diagnosis continues to grow and there are also articles describing important novel cultivars and the effect of food processing on the allergenic properties of foods. Another terrific year, full of important and high-quality work,which the journal has been proud to bring to the allergy community.

Molecular approaches to allergen standardization

Molecular approaches to allergen standardization include the development of purified natural or recombinant allergen standards whose structural and allergenic properties have been validated, in tandem with certified immunoassays for allergen measurement. Purified allergens can be used individually or incorporated into multiple allergen standards. Multicenter international collaborative studies are required to validate candidate allergen standards and immunoassays, as a prelude to being approved by regulatory agencies. Mass spectrometry is a sophisticated and powerful proteomics tool that is being developed for allergen analysis. Recent results using pollen allergens show that mass spectrometry can identify and measure specific allergens in a complex mixture and can provide precise information of the variability of natural allergen extracts. In future, the combined use of immunoassays and mass spectrometry will provide complete standardization of allergenic products. Molecular standardization will form the basis of new allergy diagnostics and therapeutics, as well as assessment of environmental exposure, and will improve the quality of treatment options for allergic patients.

Detecting local immunoglobulin E from mucosal brush biopsy of the inferior turbinates using microarray analysis

BACKGROUND

It has been previously demonstrated that local, antigen-specific immunoglobulin E (IgE) can be detected using a standard in vitro assay of lysed epithelial cells in saline, harvested via nasal mucosal brush biopsy (MBB). However, compared to surgical biopsy or serum, smaller amounts of IgE are harvested using MBB, making detection much more difficult. Microarray analysis (MA) requires less IgE for detection, making this an attractive option for MBB. The goals of this study were to compare MA to a standard IgE assay for detecting antigen-specific IgE from MBB and to test the association between the presence of multiple positive components on MA with specific IgE on standard assay and skin-prick testing (SPT) grade.

METHODS

MBB samples from 18 allergic rhinitis patients, which were previously tested for antigen-specific IgE to common airborne allergens using a standard IgE assay, underwent MA for antigen-specific IgE to multiple components of airborne and food allergens. Fisher's exact probability testing was used to measure the strength of association between the 2 testing modalities for Timothy grass, ragweed, cat, Alternaria, and D. farinae.

RESULTS

MA correlated very highly with standard assay (p < 0.0001) and 50% of positive antigens on MA detected multiple components to that antigen. The presence of multiple components was not associated with specific IgE levels on standard assay or SPT grade.

CONCLUSION

This is the first demonstration that antigen-specific IgE in saline samples can be measured using MA. The ability of MA to measure smaller amounts of IgE, with similar accuracy, may give it a potential advantage for MBB analysis in the future.