Validation of Quantitative Structure-Activity Relationship (QSAR) and Quantitative Structure-Property Relationship (QSPR) approaches as alternatives to skin sensitization risk assessment

The aim of this study was conducted to validate the physicochemical properties of a total of 362 chemicals [305 skin sensitizers (212 in the previous study + 93 additional new chemicals), 57 non-skin sensitizers (38 in the previous study + 19 additional new chemicals)] for skin sensitization risk assessment using quantitative structure-activity relationship (QSAR)/quantitative structure-property relationship (QSPR) approaches. The average melting point (MP), surface tension (ST), and density (DS) of the 305 skin sensitizers and 57 non-sensitizers were used to determine the cutoff values distinguishing positive and negative sensitization, and correlation coefficients were employed to derive effective 3-fold concentration (EC3 (%)) values. QSAR models were also utilized to assess skin sensitization. The sensitivity, specificity, and accuracy were 80, 15, and 70%, respectively, for the Toxtree QSAR model; 88, 46, and 81%, respectively, for Vega; and 56, 61, and 56%, respectively, for Danish EPA QSAR. Surprisingly, the sensitivity, specificity, and accuracy were 60, 80, and 64%, respectively, when MP, ST, and DS (MP+ST+DS) were used in this study. Further, MP+ST+DS exhibited a sensitivity of 77%, specificity 57%, and accuracy 73% when the derived EC3 values were classified into local lymph node assay (LLNA) skin sensitizer and non-sensitizer categories. Thus, MP, ST, and DS may prove useful in predicting EC3 values as not only an alternative approach to animal testing but also for skin sensitization risk assessment.

Atopic Dermatitis: Identification and Management of Complicating Factors

Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disease, associated with impaired skin barrier function and an atopic background. Various complicating factors, such as irritants, aeroallergens, food, microbial organisms, contact allergens, sweat, and scratching can induce the development of AD symptoms. Irritants, including soap/shampoo and clothes, can cause itching and eczematous lesions. In addition, young children with AD tend to become sensitized to eggs, milk, or peanuts, while older children and adults more often become sensitized to environmental allergens, such as house dust mites (HDM), animal dander, or pollen. Serum-specific IgE levels and skin prick test reactions to food tend to show high negative predictive values and low specificity and positive predictive values for diagnosing food allergy. On the other hand, AD adult patients tend to have severe skin symptoms and exhibit high HDM-specific IgE levels. Microbial organisms, e.g., Staphylococcus aureus and Malassezia furfur, might contribute to the pathogenetic mechanisms of AD. While sweat plays a major role in maintaining skin homeostasis, it can become an aggravating factor in patients with AD. Furthermore, scratching often exacerbates eczematous lesions. Several patient-specific complicating factors are seen in most cases. The identification and management of complicating factors are important for controlling AD.

Shotgun proteomics, in-silico evaluation and immunoblotting assays for allergenicity assessment of lesser mealworm, black soldier fly and their protein hydrolysates

Since 2018, insects have belonged the category of Novel Foods and the presence of allergens represents one of the main hazards connected to their consumption, also due to the potential cross-reactivity with Arthropoda pan-allergens. In the present work, the allergenicity assessment of black soldier fly and lesser mealworm was performed with a shotgun bottom-up proteomic approach combined with in-silico assessment, followed by IgG- and IgE-immunoblotting experiments. The peptides identified, filtered for their abundance and robustness, belonged mainly to muscle proteins, which represented the most abundant protein group. The relevant potential allergens were in-silico identified by sequence similarity to known allergens, and among them tropomyosin resulted the most abundant insect allergen. IgG-immunoblotting analysis with anti-Tropomyosin I antibodies and IgE-immunoblotting assay with serum from patient allergic to crustacean tropomyosin were performed in order to assess the immunoreactivity in both insects. The immunoassays were carried out also on protein hydrolysates extracted by treating insects with Protease from Bacillus licheniformis (1%, 60 °C, pH 7.5). While IgG-immunoblotting demonstrated the loss of immunoreactivity for both hydrolysates, IgE-immunoblotting showed a partial immunoreactivity preservation, also after hydrolysis, in the case of black soldier fly hydrolysate, and a total loss of immunoreactivity for lesser mealworm hydrolysate.

Management of an Integrated Project (Sens-it-iv) to Develop In Vitro Tests to Assess Sensitisation

Sens-it-iv is an integrated project, funded by European Commission Framework Programme 6, the overall objective of which is to develop in vitro tests and test strategies to be used by the chemical, cosmetic and pharmaceutical industries to assess the risk for potential contact and respiratory sensitisers. Such tests, once formally validated and accepted, will permit the evaluation of the sensitising potential of existing and new chemical entities and the products of the European industries for classification and labelling, as required by the new EU REACH legislation on chemicals, or for the purpose of risk assessment as required by the 7th Amendment to the EU Cosmetics Directive. Sens-it-iv involves 28 partners, representing industries, universities and regulatory bodies, including various institutes in the EU Member States and different competencies, all with the common aim of achieving a final deliverable — increasing the safety of consumer products, whilst reducing animal experimentation. This paper provides an overview of the structure of the project and a detailed description of the organisation of its management.

A review on methodologies for extraction, identification and quantification of allergenic proteins in prawns

Prawn allergy is one of the most common food-borne allergies and current prevention is by avoidance. This review paper summarised different methodologies for the extraction, identification and quantification of prawn protein allergens, reported in various research studies. Following extraction, allergenic components have been analysed using well-established methodologies, such as SDS-PAGE, Immunoblotting, ELISA, CD Spectroscopy, HPLC, DBPCFC, SPT etc. Moreover, the preference towards Aptamer-based technique for allergenicity analysis has also been highlighted in this review paper. The summary of these methodologies will provide a reference platform for present and future research directions.

Patterns of sensitization to inhalant and food allergens among pediatric patients from the Moscow region (Russian Federation)

The immunological profiles of human specific IgE (sIgE) and specific IgG4 (sIgG4) vary by genetic predisposition, living conditions in different geographical locations and patient’s age. The aim of our study was to analyze sIgE and sIgG4 patterns and their age-dependent changes in patients from the Moscow region. For identifying sIgE and sIgG4 profiles the blood samples from 513 patients aged 6 months to 17 years who were showing symptoms of allergic diseases were analyzed using microarrays containing 31 allergens. The highest sIgE prevalence was observed for birch pollen (32%) among pollen allergens, cat dander (24%) among indoor allergens, and egg whites (21%) among food allergens. The most common sIgG4 response was developed toward egg whites (80% of patients). Age-related elevation was identified for patients with increased sIgE to pollen allergens and indoor allergens (cat or dog dander and house dust mites). For each allergen, the proportion of cases with significant levels of sIgG4 appeared to increase with patients’ age. The data on allergen-specific sIgE and sIgG4 prevalence show both general trends and some local special aspects that are indicative for the Moscow region. This information should be useful in terms of epidemiology of allergic diseases.

Fresh water, marine and terrestrial cyanobacteria display distinct allergen characteristics

During the last decades, global cyanobacteria biomass increased due to climate change as well as industrial usage for production of biofuels and food supplements. Thus, there is a need for thorough characterization of their potential health risks, including allergenicity. We therefore aimed to identify and characterize similarities in allergenic potential of cyanobacteria originating from the major ecological environments. Different cyanobacterial taxa were tested for immunoreactivity with IgE from allergic donors and non-allergic controls using immunoblot and ELISA. Moreover, mediator release from human FcεR1-transfected rat basophilic leukemia (RBL) cells was measured, allowing in situ examination of the allergenic reaction. Phycocyanin content and IgE-binding potential were determined and inhibition assays performed to evaluate similarities in IgE-binding epitopes. Mass spectrometry analysis identified IgE-reactive bands ranging between 10 and 160kDa as phycobiliprotein compounds. Levels of cyanobacterial antigen-specific IgE in plasma of allergic donors and mediator release from sensitized RBL cells were significantly higher compared to non-allergic controls (p<0.01). Inhibition studies indicated cross-reactivity between IgE-binding proteins from fresh water cyanobacteria and phycocyanin standard. We further addressed IgE-binding characteristics of marine water and soil-originated cyanobacteria. Altogether, our data suggest that the intensive use and the strong increase in cyanobacterial abundance due to climate change call for increasing awareness and further monitoring of their potential health hazards.

Factors associated with poor controller medication use in children with high asthma emergency department use

BACKGROUND

Understanding health and social factors associated with controller medication use in children with high-risk asthma may inform disease management in the home and community.

OBJECTIVE

To examine health and social factors associated with the Asthma Medication Ratio (AMR), a measure of guideline-based care and controller medication use, in children with persistent asthma and frequent emergency department (ED) use.

METHODS

Study questionnaires, serum allergen sensitization, salivary cotinine, and pharmacy record data were collected for 222 children enrolled from August 2013 to February 2016 in a randomized clinical trial that tested the efficacy of an ED- and home-based intervention. Logistic regression was used to examine factors associated with an AMR greater than 0.50, reflecting appropriate controller medication use.

RESULTS

Most children were male (64%), African American (93%), Medicaid insured (93%), and classified as having uncontrolled asthma (44%). Almost half (48%) received non-guideline-based care or low controller medication use based on an AMR less than 0.50. The final regression model predicting an AMR greater than 0.50 indicated that children receiving specialty care (odds ratio [OR], 4.87; 95% confidence interval [CI], 2.06-11.50), caregivers reporting minimal worry about medication adverse effects (OR, 0.50; 95% CI, 0.25-1.00), positive sensitization to ragweed allergen (OR, 3.82; 95% CI, 1.63-8.96), and negative specific IgE for dust mite (OR, 0.33; 95% CI, 0.15-0.76) were significantly associated with achieving an AMR greater than 0.50.

CONCLUSION

Clinical decision making for high-risk children with asthma may be enhanced by identification of sensitization to environmental allergens, ascertaining caregiver's concerns about controller medication adverse effects and increased referral to specialty care.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01981564.

Prediction of protein allergenicity based on signal-processing bioinformatics approach

Current bioinformatics tools accomplish high accuracies in classifying allergenic protein sequences with high homology and generally perform poorly with low homology protein sequences. Although some homologous regions explained Immunoglobulin E (IgE) cross-reactivity in groups of allergens, no universal molecular structure could be associated with allergenicity. In addition, studies have showed that cross-reactivity is not directly linked to the homology between protein sequences. Therefore, a new homology independent method needs to be developed to determine if a protein is an allergen or not. The aim of this study is therefore to differentiate sets of allergenic and non-allergenic proteins using a signal-processing based bioinformatics approach. In this paper, a new method was proposed for characterisation and classification of allergenic protein sequences. For this method hydrophobicity amino acid index was used to encode proteins to numerical sequences and Discrete Fourier Transform to extract features for each protein. Finally, a classifier was constructed based on Support Vector Machines. In order to demonstrate the applicability of the proposed method 857 allergen and 1000 non-allergen proteins were collected from UniProt online database. The results obtained from the proposed method yielded: MCC: 0.752 ± 0.007, Specificity: 0.912 ± 0.005, Sensitivity: 0.835 ± 0.008 and Total Accuracy: 87.65% ± 0.004.

Origin and Functional Prediction of Pollen Allergens in Plants

Pollen allergies have long been a major pandemic health problem for human. However, the evolutionary events and biological function of pollen allergens in plants remain largely unknown. Here, we report the genome-wide prediction of pollen allergens and their biological function in the dicotyledonous model plant Arabidopsis (Arabidopsis thaliana) and the monocotyledonous model plant rice (Oryza sativa). In total, 145 and 107 pollen allergens were predicted from rice and Arabidopsis, respectively. These pollen allergens are putatively involved in stress responses and metabolic processes such as cell wall metabolism during pollen development. Interestingly, these putative pollen allergen genes were derived from large gene families and became diversified during evolution. Sequence analysis across 25 plant species from green alga to angiosperms suggest that about 40% of putative pollen allergenic proteins existed in both lower and higher plants, while other allergens emerged during evolution. Although a high proportion of gene duplication has been observed among allergen-coding genes, our data show that these genes might have undergone purifying selection during evolution. We also observed that epitopes of an allergen might have a biological function, as revealed by comprehensive analysis of two known allergens, expansin and profilin. This implies a crucial role of conserved amino acid residues in both in planta biological function and allergenicity. Finally, a model explaining how pollen allergens were generated and maintained in plants is proposed. Prediction and systematic analysis of pollen allergens in model plants suggest that pollen allergens were evolved by gene duplication and then functional specification. This study provides insight into the phylogenetic and evolutionary scenario of pollen allergens that will be helpful to future characterization and epitope screening of pollen allergens.

American Academy of Allergy, Asthma & Immunology membership experience with allergen immunotherapy safety in patients with specific medical conditions

BACKGROUND

Little data in the literature exist concerning patients with certain underlying medical conditions who receive allergen subcutaneous immunotherapy (SCIT).

OBJECTIVE

To survey allergists' experience with SCIT in patients with medical conditions considered to impose an elevated risk for untoward outcomes.

METHODS

A Web-based survey was conducted among members of the American Academy of Allergy, Asthma & Immunology to query about their experience with SCIT in patients with certain medical conditions.

RESULTS

There were 1085 replies (21% response), of whom, 86% were U.S. based, 51% were suburban, 31% were academic, 42% were medium-sized practices, and 54% had >15 years' experience. In responders' opinion, SCIT was "contraindicated" in patients with the following: acquired immune deficiency syndrome (AIDS) (48%), cancer (and still receiving active treatment) (33%), severe asthma (32%), and a history of transplantation (30%). Even so, survey responders collectively gave SCIT to >2400 patients for each of these conditions: severe asthma, coronary artery disease, cancer in remission, and autoimmune disorders; and to ≥5400 patients with hypertension and ≥4100 women who became pregnant. The experience of colleagues with these patients rarely resulted in major problems (i.e., activation of underlying disease, systemic reactions to SCIT, or SCIT discontinuation), with the exception of severe asthma (12.5%), initiation of SCIT during pregnancy (5.4%), and AIDS (4.2%). For most other conditions, it was ≤1.5% (e.g., continue during pregnancy, cancer in remission, history of transplantation, positive human immunodeficiency virus and no AIDS).

CONCLUSION

According to the experience of a large group of practicing allergists, the American Academy of Allergy, Asthma & Immunology members, few medical conditions seemed to pose an elevated risk for untoward outcomes from SCIT. Because these are survey results, prospective research might yield even more solid data.

Exploring racial differences in IgE-mediated food allergy in the WHEALS birth cohort

BACKGROUND

Suspected food allergies are the cause of more than 200,000 visits to the emergency department annually. Racial differences in the prevalence of food allergy have also been reported, but the evidence is less conclusive. Researchers continue to struggle with the identification of food allergy for epidemiologic studies.

OBJECTIVE

To explore racial differences in IgE-mediated food allergy (IgE-FA) in a birth cohort.

METHODS

We used a panel of board-certified allergists to systematically identify IgE-FA to egg, milk, or peanut in a multiethnic birth cohort in which patient medical history, patient symptoms, and clinical data were available through 36 months of age.

RESULTS

Of the 590 infants analyzed, 52.9% were male and 65.8% African American. Sensitization (serum specific IgE >0.35 IU/mL) to the food allergens was significantly higher for African American children compared with non-African American children as has been previously reported. No statistically significant racial/ethnic differences in IgE-FA were observed; however, a higher proportion of African American children were designated as having peanut allergy, and the percentage of African American children with an IgE level greater than 95% predictive decision points for peanut was 1.7% vs 0.5% for non-African American children. With the use of logistic regression, race/ethnicity was not significantly associated with IgE-FA (adjusted odds ratio, 1.12; 95% confidence interval, 0.58-2.17; P = .75) but was associated with sensitization to more than 1 of the food allergens (adjusted odds ratio, 1.80; 95% confidence interval, 1.22-2.65; P = .003).

CONCLUSION

We did not observe an elevated risk of IgE-FA for African American children, although established differences in sensitization were observed. Racial/ethnic differences in sensitization must be taken into consideration when investigating disparities in asthma and allergy.

Regional differences in vitamin D levels and incidence of food-induced anaphylaxis in South Korea

BACKGROUND

Previous studies have suggested low vitamin D as a potential risk factor for food allergy/anaphylaxis. However, few studies have investigated the association between vitamin D and food-induced anaphylaxis (FIA) in South Korea.

OBJECTIVE

To examine regional differences in serum vitamin D levels and FIA incidence.

METHODS

We used nationwide data collected from 2011 to 2013. Data on vitamin D were obtained from the Korea National Health and Nutrition Examination Survey; data on FIA were obtained from the Health Insurance and Assessment Service. Districts were grouped into region 1 (lower solar radiation) and region 2 (higher solar radiation). We examined differences in FIA incidence and vitamin D levels between the regions, adjusting for age.

RESULTS

The study included 2,814 patients with FIA and 15,367 people with available serum vitamin D measurements. Age-adjusted FIA incidence was 2.2 per 100,000 person-years in region 1 and 1.8 per 100,000 person-years in region 2 (relative risk, 1.23; 95% confidence interval, 1.09-1.39). Age-adjusted serum vitamin D levels were 16.5 ng/mL in region 1 and 17.8 ng/mL in region 2 (mean difference, 1.3 ng/mL; 95% confidence interval, 0.9-1.9). After stratification by age, sex, and area of residence, region 1 still had higher FIA incidence and lower vitamin D levels than region 2.

CONCLUSION

The present study found a higher incidence of FIA in regions with lower vitamin D levels in the population. Further investigation is necessary to identify any direct associations between vitamin D and food allergy/anaphylaxis.

Food Allergy: Common Causes, Diagnosis, and Treatment

Food allergy is a growing concern, and recognition of symptoms, knowledge of common food allergens, and management of reactions are important for patients and practitioners. Symptoms of a classic IgE-mediated food allergy vary in severity and can include any combination of laryngeal edema, wheezing, nausea, vomiting, diarrhea, urticaria, angioedema, and hypotension. Many foods can induce an allergic reaction, but the most commonly implicated foods include cow's milk, egg, peanut, tree nut, soy, wheat, fish, and shellfish. Milk and egg allergy generally develop and are outgrown in childhood. Peanut and tree nut allergy can occur during childhood or adulthood, are less likely to be outgrown, and tend to cause more fatal reactions. Given the possibility of life-threatening reactions, it is important to recognize the potential for cross-reactivity among food groups. Diagnosis of food allergy includes skin prick testing, specific serum IgE testing, and oral food challenges. Management is centered on avoidance of allergenic and cross-reacting foods and early recognition and immediate treatment of reactions. Treatment protocols to desensitize patients to food are currently under investigation.

Common food allergens and their IgE-binding epitopes

Food allergy is an adverse immune response to certain kinds of food. Although any food can cause allergic reactions, chicken egg, cow's milk, wheat, shellfish, fruit, and buckwheat account for 75% of food allergies in Japan. Allergen-specific immunoglobulin E (IgE) antibodies play a pivotal role in the development of food allergy. Recent advances in molecular biological techniques have enabled the efficient analysis of food allergens. As a result, many food allergens have been identified, and their molecular structure and IgE-binding epitopes have also been identified. Studies of allergens have demonstrated that IgE antibodies specific to allergen components and/or the peptide epitopes are good indicators for the identification of patients with food allergy, prediction of clinical severity and development of tolerance. In this review, we summarize our current knowledge regarding the allergens and IgE epitopes in the well-researched allergies to chicken egg, cow's milk, wheat, shrimp, and peanut.

A Multiscale Vibrational Spectroscopic Approach for Identification and Biochemical Characterization of Pollen

BACKGROUND

Analysis of pollen grains reveals valuable information on biology, ecology, forensics, climate change, insect migration, food sources and aeroallergens. Vibrational (infrared and Raman) spectroscopies offer chemical characterization of pollen via identifiable spectral features without any sample pretreatment. We have compared the level of chemical information that can be obtained by different multiscale vibrational spectroscopic techniques.

METHODOLOGY

Pollen from 15 different species of Pinales (conifers) were measured by seven infrared and Raman methodologies. In order to obtain infrared spectra, both reflectance and transmission measurements were performed on ground and intact pollen grains (bulk measurements), in addition, infrared spectra were obtained by microspectroscopy of multigrain and single pollen grain measurements. For Raman microspectroscopy measurements, spectra were obtained from the same pollen grains by focusing two different substructures of pollen grain. The spectral data from the seven methodologies were integrated into one data model by the Consensus Principal Component Analysis, in order to obtain the relations between the molecular signatures traced by different techniques.

RESULTS

The vibrational spectroscopy enabled biochemical characterization of pollen and detection of phylogenetic variation. The spectral differences were clearly connected to specific chemical constituents, such as lipids, carbohydrates, carotenoids and sporopollenins. The extensive differences between pollen of Cedrus and the rest of Pinaceae family were unambiguously connected with molecular composition of sporopollenins in pollen grain wall, while pollen of Picea has apparently higher concentration of carotenoids than the rest of the family. It is shown that vibrational methodologies have great potential for systematic collection of data on ecosystems and that the obtained phylogenetic variation can be well explained by the biochemical composition of pollen. Out of the seven tested methodologies, the best taxonomical differentiation of pollen was obtained by infrared measurements on bulk samples, as well as by Raman microspectroscopy measurements of the corpus region of the pollen grain. Raman microspectroscopy measurements indicate that measurement area, as well as the depth of focus, can have crucial influence on the obtained data.

Venom allergen 5 is Associated With Deltamethrin Resistance in Culex pipiens pallens (Diptera: Culicidae)

The mosquito, Culex pipiens pallens (L.), is an important vector of encephalitis and filariasis in northern China. The control of these mosquitoes occurs primarily via the use of pyrethroid insecticides, such as deltamethrin. The widespread and improper application of pyrethroid has resulted in the evolution of pyrethroid resistance amongst many mosquito populations, including Cx. pipiens pallens. Previous studies using high-throughput transcriptome sequencing have identified that the venom allergen 5 gene is differentially expressed between deltamethrin-susceptible and deltamethrin-resistant Cx. pipiens pallens. In this study, quantitative real-time polymerase chain reaction analyses revealed that venom allergen 5 was significantly overexpressed in adult females of both deltamethrin-resistant laboratory populations and two field populations. The transcriptional level of venom allergen 5 in the laboratory populations was elevated as the levels of deltamethrin resistance increased. Full-length cDNAs of the venom allergen 5 gene were cloned from Cx. pipiens pallens, and contained an open reading frame of 765 bp, encoding a protein with 254 amino acids. The deduced amino acid sequence shared 100% identity with the ortholog in Culex quinquefasciatus Say. The overexpression of venom allergen 5 decreased the susceptibility of mosquito cells to deltamethrin, while knockdown of this gene by RNAi increased the susceptibility of mosquitoes to deltamethrin. This study provides the first evidence of the association between the venom allergen 5 gene and deltamethrin resistance in mosquitoes.

Trends and threshold exceedances analysis of airborne pollen concentrations in Metropolitan Santiago Chile

Pollen is one of the primary causes of allergic rhinoconjunctivitis in urban centers. In the present study, the concentrations of 39 different pollens in the Santiago de Chile metropolitan area over the period 2009–2013 are characterized. The pollen was monitored daily using Burkard volumetric equipment. The contribution of each type of pollen and the corresponding time trends are evaluated. The concentrations of the pollens are compared with the established threshold levels for the protection of human health. The results show that the total amount of pollen grains originating from trees, grasses, weeds and indeterminate sources throughout the period of the study was 258,496 grains m-3, with an annual average of 51,699 ± 3,906 grains m-3 year-1. The primary source of pollen is Platanus orientalis, which produces 61.8% of the analyzed pollen. Grass pollen is the third primary component of the analyzed pollen, with a contribution of 5.82%. Among the weeds, the presence of Urticacea (3.74%) is remarkable. The pollination pattern of the trees is monophasic, and the grasses have a biphasic pattern. The trends indicate that the total pollen and tree pollen do not present a time trend that is statistically significant throughout the period of the study, whereas the grass pollen and weed pollen concentrations in the environment present a statistically significant decreasing trend. The cause of this decrease is unclear. The pollen load has doubled over the past decade. When the observed concentrations of the pollens were compared with the corresponding threshold levels, the results indicated that over the period of the study, the pollen concentrations were at moderate, high and very high levels for an average of 293 days per year. Systematic counts of the pollen grains are an essential method for diagnosing and treating patients with pollinosis and for developing forestation and urban planning strategies.

Seasonal variations of allergenic pollen in a Mediterranean region - Alexandroupolis, north-east Greece

OBJECTIVES

The aim of this study was to describe the aerobiological characteristics of NE Greece, identify the most prevalent taxa, define the duration of the main pollen season and correlate allergen records with meteorological parameters.

MATERIALS AND METHOD

A 7-day volumetric trap, running continuously throughout the year, was used to collect circulating pollen. Pollen taxa were characterized by standard protocols and counted as grains/m(3) . The main pollen season was deduced from these data and running means (10-day averages) were plotted against time. Correlations with climatic factors (temperature, rain, humidity, wind velocity) were assessed by single linear regression analysis.

RESULTS

In total, 11 pollen families were identified, including 6 arboreal and 5 non-arboreal taxa. The 5 most prevalent taxa were Oleaceae, Fagaceae, Poaceae, Cupressaceae and Pinaceae. Peak pollen concentrations were detected in April and May, with daily averages exceeding 410 grains/m(3) . Compositeae had the longest pollen season of 135 days and Oleaceae the shortest, extending to only 27 days. Correlations with meteorological parameters showed variable associations among different taxa, with mean temperature (p<0.001), relative humidity (p=0.015), and wind speed (p=0.042) emerging as the most significant determinants as regards total pollen counts.

CONCLUSIONS

Describing the aerobiological characteristics of NE Greece enabled the identification of allergenic risks that are specific for this region. Records generated in this study can be used to alert sensitized individuals of prevailing seasonal patterns, in order to take necessary precautions against imminent exposures. The monitoring system established here can serve as a reference guide for future epidemiological research focusing on allergic asthma and rhinitis.

[About Minimization of Expenses on Allergy Diagnosis in Children: Analysis of Consistency of in Vitro- and in Vivo-Allergic Examinations Results]

High morbidity rate of atopic diseases among children, including high importance of grass pollen as a sensitizing agent, determine the relevance ofstudies on diagnostic examination systems for appointment of adequate therapy. The research of the most relevant allergens for patients to excludeof duplicating and uninformative tests became urgent after development of a new type of diagnostic tests that does not require expensive equipment. The objective of this research was to evaluate the results of in vitro- and in vivo-diagnostic examinations of children with various forms of atopic disease caused by pollen of meadow grasses, and to choose the most significant prognostic parameters for the diagnosis.

METHODS

277 children aged 4-16 years with various forms of atopic disease were included in the study. There were performed skin prick tests and determination of IgE-antibodies levels to allergen extracts of cocksfoot (g3), meadow fescue (g4), timothy grass (g6).

RESULTS

In the studied group of patients 32-50% of children have antibodies to grass allergens. There was a close correlation of antibody response on the investigated allergens, quantitative coincidence of IgE-antibodies to g3 andg4 allergens levels. IgE (g6) concentration was close to the IgE(g3) and IgE(g4) levels (85.0 ± 21.6%). Analysis of the skin tests results showed that 44% of patients have a positive response to grass allergens, and in vivo-tests results coincide with serologicaltests results, mostly in a qualitative sense. The most significant relationship was noted between in vivo and in vitro-tests in the results of testing the response to meadow fescue pollen.

CONCLUSION

Based on these data IgE concentration index to meadow fescue allergens can be used as a prognostic marker to determine the sensitization of patients with different nosology forms of allergy and can help to improve allergic diagnostics.

Subcutaneous immunotherapy in Northern Israel: efficacy and safety

BACKGROUND

The efficacy of subcutaneous immunotherapy for the treatment of allergic rhinitis, allergic conjunctivitis, allergic asthma and stinging insect hypersensitivity has been demonstrated in several studies.

OBJECTIVES

To investigate the effectiveness and side effects of immunotherapy in Israel and the relationship between local and systemic side effects.

METHODS

This retrospective study was based on patient records and a computerized database for drug dispensing over a 5 year period. Success was rated as partial or complete. Side effects were classified as local or systemic. Systemic side effects were further classified according to severity, as mild (cutaneous), moderate (respiratory symptoms), or severe (cardiovascular).

RESULTS

Of the 135 patients on aero-allergen immunotherapy who reached maintenance, 120 (88.9%) exhibited complete or partial improvement and 15 (11.1%) did not improve. All of the 44 patients on hymenoptera immunotherapy reached effective maintenance doses. The mean percent side effects calculated per treatment (injection) were 2.49 for local and 1.58 for a systemic reaction during the build-up phase, and 1.13 and 1.12 during the maintenance phase, respectively. Rates of systemic reactions were 1.3% for cutaneous, 1.14% for respiratory and 0.97% for cardiovascular reactions during the build-up phase, and 1.11%, 0.53%, and 0.51% during the maintenance phase, respectively. The odds of systemic reactions were significantly higher in patients with local reactions both in the build-up phase (P = 0.03) and in the maintenance phase (P = 0.0003). The number of annual medications dispensed per patient decreased from 31.5 to 26.0 during the first year after reaching maintenance, and to 22.5 in the second year. Pharmaceutical costs were 67% lower 1 year after the start of the maintenance phase, compared to the year before the start of immunotherapy, and 63% lower in the second year (P = NS).

CONCLUSIONS

Immunotherapy was effective and safe. Recognizing the benefits and safety of immunotherapy by physicians and health authorities is necessary to provide better care for allergic patients.

Weighted road density and allergic disease in children at high risk of developing asthma

Background

Evidence for an association between traffic-related air pollution and allergic disease is inconsistent, possibly because the adverse effects may be limited to susceptible subgroups and these have not been identified. This study examined children in the Childhood Asthma Prevention Study (CAPS), potentially susceptible to air pollution effects because of a family history of asthma.

Methods

We examined cross-sectional associations at age eight years between road density within 75 m and 50 m of home address weighted by road type (traffic density), as a proxy for traffic-related air pollution, on the following allergic and respiratory outcomes: skin prick tests (SPTs), total and specific serum IgE, pre- and post-bronchodilator lung function, airway hyperresponsiveness, exhaled NO, and reported asthma and rhinitis.

Results

Weighted road density was positively associated with allergic sensitisation and allergic rhinitis. Adjusted relative risk (RR) for house dust mite (HDM) positive SPT was 1.25 (95% CI: 1.06–1.48), for detectable house dust mite-specific IgE was 1.19 (95% CI: 1.01–1.41) and for allergic rhinitis was 1.30 (95% CI: 1.03–1.63) per 100 m local road or 33.3 m motorway within 50 m of home. Associations were also seen with small decrements of peak and mid-expiratory flows and increased risk of asthma, current wheeze and rhinitis in atopic children.

Conclusion

Associations between road density and allergic disease were found in a potentially susceptible subgroup of children at high risk of developing atopy and asthma.

[The study of profile of hypersensitivity to pollen and fungal allergens in the Moscow region]

The profile of hypersensitivity to pollen and fungal allergens is an important element of common pattern of immune diseases needed for development of effective pharmaceuticals. The purpose of the study was to analyze the rate of detection of combined forms of hypersensitivity to pollen and fungal allergens (pollen of birch, hazel, cocksfoot, wormwood, fungi A. alternata, C. herbarum, R. nigricans, P. notatum, C. albicans, A. fumigatus) in the Moscow region on the basis of data of scarification skin samples. The mono-sensibilization was established in 23.36% of all cases of hypersensitivity. At that, among leading allergens turned out A. alternata and cocksfoot pollen (6.54% and 4.67%), followed by allergens of wormwood pollen, P. notatum, R. nigricans, birch pollen and C. albicans (3.74%, 3.74%, 1.87%, 1.87% and 0.93% correspondingly). The polysensibilization was established in 51.40% of cases. Besides, the combined hypersensitivity to pollen allergens of plants (20.26%) and to pollen and fungal allergens (20.56%) occurred more frequently In the group of patients with polysensibilization predominated combined allergic reactions to pollen allergens and A. alternata allergens (36.36%). On the whole, most frequently occurred sensitization to allergens of birch, hazel, cocksfoot, wormwood and A. alternata allergen (76.14%, 69.32%, 57.95%, 55.68%, 39.77% and 56.82% correspondingly). In the Moscow region predominate combined forms of hypersensitivity to two and more pollen and fungal allergens. The polysensitization to pollen allergens and A. alternata allergen occurs more frequently.

[Clinical features of atopic asthma and their relation to the T-regulatory cells and total immunoglobulin E]

Allergic diseases are among the most popular in the world. Scientific hypothesis formation and multifactorial pathogenesis of atopic asthma (AA) is constantly updated. Our purpose of this study was to investigate the relationship of humoral and cellular immunity with features clinical and anamnestic data in patients AA. Found that AA is genetically determined disorders, mainly transmitted through the maternal line, characterized polisensibilization, most of household allergens. AA is often associated with other allergic nosology (62.2%) and gastrointestinal diseases (44.4%). In the absence of clinical evidence of disease at CD4+/CD25+/Foxp3+, IgE and IL-4 in patients with AA is higher than in healthy individuals. When polyvalent allergy has been a significant increase in IgE (199.3 +/- 22.2) and IL-4 (79.2 +/- 16.5) and reduced expression of molecules CD4+/CD25+/Foxp3+ compared with sensitization to one or two allergens.

[The analysis of the allergens in 576 patients with allergic rhinitis in Qingyang of Gansu Province]

OBJECTIVE

To investigate the allergens distribution of 576 allergic rhinitis patients in Qingyang, and to provide basic epidemiologic information for the prevention and treatment of allergic rhinitis.

METHOD

Skin prick test was done to all the 576 patients with allergic rhinitis with 28 kinds of allergens.

RESULT

Four hundred and eighty cases (83.3%) showed positive reaction to at least one allergen of 28 allergens. The most common allergens were Magwort (73.3%), Giant Ragweed (55.0%) Tree II (51.7%), Tree I (48.3%) Dermatophagoides farinae (43.3%) and Dermatophagoides pteronyssinus (36.7%). Moreover. the positivity decreased with age. There was no difference between male and female.

CONCLUSION

The study shows that Magwort. Giant ragweed and tree II are the most important allergens on Qingyang district.

[Analysis of allergen variation for 3292 patients with allergic rhinitis]

OBJECTIVE

To investigate the variation of common allergens in patients with allergic rhinitis in recent 4 years in Tianjin First Center Hospital.

METHODS

The medical records of skin prick test on 3292 patients with allergic rhinitis between 2009 and 2012 were restrospectively analyzed. The changing trend of various allergens in 4 years and distribution differences were compared. The differences of the top 5 allergens in under age group, adult group and different gender group were further analyzed by SPSS 19.0 software.

RESULTS

The positive rate of dermatophagoides farinae was increasing year by year, from 45.1% in 2009 to 66.3% in 2012, and the positive rate of dermatophagoides pteronyssinus increased from 42.0% in 2009 to 58.6% in 2012, the difference was statistically significant (χ(2) value was 68.70, 41.55, all P < 0.01). The positive rate of dermatophagoides farinae and dermatophagoides pteronyssinus in adult group and male group showed significant upward trend year by year (χ(2) value was 75.85, 69.93, 274.25, 42.62, all P < 0.01), but not in adult group and female group. The positive rate of quinoa, mugwort and humulus scandens decreased year by year between 2009 and 2011(χ(2) value was 22.08, 11.64, 203.19, all P < 0.01), but increased again in 2012(χ(2) value was 21.55, 29.38, 12.40, all P < 0.01).

CONCLUSIONS

There is a tendency of change of allergens in patients with AR. This phenominon may be helpful for doctors to choose the type of skin prick liquid.

Multiplex PCR for identifying common dust mites species (Dermatophagoides pteronyssinus, Dermatophagoides farinae and Blomia tropicalis)

INTRODUCTION

Dust mites are known to be an important source of inhalant allergens causing allergic rhinitis and asthma worldwide. The sizes of dust mite populations in patients' houses are useful to monitor the risk of allergen exposure. However, mite identification using the conventional microscopic technique requires specific expertise and is time consuming; therefore a molecular technique has been developed in order to solve these drawbacks.

OBJECTIVE

To develop a multiplex PCR assay for identifying the three common dust mite species in Thailand, namely Dermatophagoides pteronyssinus (Dp), D. farinae (Df) and Blomia tropicalis (Bt), and to evaluate the efficacy of the technique.

METHODS

Pairs of primers were designed and tested in either singleplex PCR or multiplex PCR. The multiplex PCR technique was also optimized in order to obtain specific products. The reaction mixture contained 5 pmole of individual primers, 10 mM dNTP, 5 units Taq DNA polymerase and genomic DNA (gDNA). The reaction was run for 25 cycles at 94 degrees C for 20 seconds, 58 degrees C for 20 seconds and 72 degrees C for 30 seconds. The PCR products were analyzed by 1.5% agarose gel electrophoresis with GelRed fluorescence dye. The optimized multiplex technique was also tested with 30 house dust samples and dust samples spiked with DNA from other insect and mite species.

RESULTS

Three PCR products were obtained with the relevant gDNA templates as expected; 143 bp for DF, 221 bp for DP and 318 bp for BT, respectively. The detection limit of the tests was found to be as low 1 ng of gDNA, whereas mixed gDNA species confirmed the 100% specificity of this assay. The total duration from the preparation of the PCR reaction mixture until the analysis by agarose gel electrophoresis was approximately 2 hours. No amplified product was obtained from mites and insects of other species.

CONCLUSION

The multiplex PCR was successfully developed for identifying 3 common dust mite species. This technique can be helpful, not only for non-acarologist personnel for dust mite identification, but also for patients who are allergic to dust mites.

High-throughput NMR assessment of the tertiary structure of food allergens

Background

In vitro component-resolved diagnosis of food allergy requires purified allergens that have to meet high standards of quality. These include the authentication of their conformation, which is relevant for the recognition by specific IgE antibodies from allergic patients. Therefore, highly sensitive and reliable screening methods for the analysis of proteins/allergens are required to assess their structural integrity. In the present study one-dimensional 1H Nuclear Magnetic Resonance (1D 1H-NMR) analysis was adopted for the assessment of overall structural and dynamic properties and authentication of a set of relevant food allergens, including non-specific lipid transfer proteins from apple, peach and hazelnut, 7/8S seed storage globulins from hazelnut and peanut, 11S seed storage globulins from hazelnut and peanut, caseins from cows' and goats' milk and tropomyosin from shrimp.

Methodology/Principal Findings

Two sets of 1D 1H-NMR experiments, using 700 MHz and 600 MHz instruments at 298 K were carried out to determine the presence and the extent of tertiary structure. Structural similarity among members of the individual allergen families was also assessed and changes under thermal stress investigated. The nuclear magnetic resonance (NMR) results were compared with structural information available either from the literature, Protein Data Bank entries, or derived from molecular models.

Conclusions/Significance

1D ¹H-NMR analysis of food allergens allowed their classification into molecules with rigid, extended and ordered tertiary structures, molecules without a rigid tertiary structure and molecules which displayed both features. Differences in thermal stability were also detected. In summary, 1D ¹H-NMR gives insights into molecular fold of proteins and offers an independent method for assessing structural properties of proteins.

[Molecular aspects of allergy to plant products. Part I. Class I and II allergens and crossreactivity of IgE antibodies]

Food allergies are adverse immunologic reactions that might be due to IgE--or none IgE-mediated immune mechanisms or mixed. One of the more common and typically most mild forms of IgE- mediated food allergy is the so-called oral allergy syndrome (OAS), although systemic symptoms after ingesting a particular fruit or vegetable can occur. Pollen food syndrome is the most common food allergy in adolescents and adults. It develops as a consequence of shared epitopes in the primary and tertiary structures of pollen and food allergens. The authors describe class I and class II allergens, as well as molecularly determined IgE-crossreactivity phenomenon. Also the problem of symptom-free consumed pollen-related food allergens, which might cause T cell-mediated late-phase skin reactions in patients with pollen allergy and atopic dermatitis, is taken up.

Effect of asthma, aeroallergen category, and gender on the psychological status of patients with allergic rhinitis

BACKGROUND

Despite increasing evidence for an association between allergy and psychological disorders in patients with allergic rhinitis (AR), the relationship between comorbid AR and asthma is not clear. The objective of this study was to investigate the effect of concomitant asthma, gender, and sensitization to a particular aeroallergen category on the psychological status of AR patients.

METHODS

We analyzed 524 AR patients (311 males/213 females) aged 16 to 60 years using the Symptom Checklist-90 (SCL-90) and found that 34.2% had persistent AR and 65.8% intermittent AR. Overall, 61 patients (11.6%) had concomitant asthma.

RESULTS

The SCL-90 scores of AR patients were significantly higher for the somatization, obsessive-compulsive, hostility, and psychoticism dimensions than those of the healthy controls. In contrast, the SCL-90 scores for persistent AR and intermittent AR patients were significantly different. Concomitant asthma significantly impacted theAR individuals' SCL-90 dimension scores for the obsessive-compulsive, interpersonal sensitivity, depression, and paranoid ideation subscales. Gender and sensitization to a particular aeroallergen category did not affect the SCL-90 scores of AR patients individually, but led to significant differences in SCL-90 scores for the phobic anxiety and psychoticism subscales when considered in combination.

CONCLUSION

Our results suggest that comorbid asthma exerts an independent main effect on the psychological status of AR patients.

Validation study of the new criteria for sensitizer using German sensitizers of Deutschen forschungsgemeinschaft (DFG)

The globally harmonized system of classification and labeling of chemicals (GHS) was recommended by United Nations (UN) and became available in 2008 all over the world. The classification criteria for skin and airway sensitizers in GHS include evidences from animal studies, for example, OECD Guideline 406 (guinea pig maximization test, GPMT and Buhler guinea pig test) and Guideline 429 (local lymph node assay, LLNA). According to Deutschen Forschungsgemeinschaft (DFG) in Germany and European Chemical Bureau (ECB), the criteria for sensitizers also include evidences from validated animal studies. At present recognized and validated animal models for the testing of respiratory hypersensitivity are not available. In Japan, the criteria from the Japan Society for Occupational Health (JSOH) for sensitizers do not include evidences from animal studies. We revised the criteria for sensitizers of JSOH and adopted evidences of animal studies. We organized the research group for sensitizer in 2005 and reviewed the criteria of Germany, EU, GHS and so on (19 experts). The meetings were held twelve times and made the revised criteria for sensitizer which adopted animal studies. We tried to validate the criteria using 28 German sensitizers of DFG, which were not sensitizers in JSOH. We could correctly classify 24 sensitizers by our revised criteria, however, 4 sensitizers could not be classified at first. Therefore, we visited the secretariat of the committee of DFG in Freising, Germany to investigate the evidenced papers of these 4 sensitizers in October, 2008. We could find out the evidenced papers of 2, however, 2 sensitizers could not be classified at last. We could correctly classify 24 of 26 sensitizers. We concluded that our revised criteria were appropriate and that this validation study was successful.

Contact allergy in eczema patients in Thammasat University Hospital

Many patients with eczematous dermatitis need continued care in case of a recurrent or persistent skin condition and potential adverse effect of medications. Allergic contact dermatitis should be considered in the differential diagnosis of eczematous dermatitis especially in a patient whose dermatitis is persistent despite appropriate therapies. Patch testing is an essential investigation in patients with persistent eczematous eruption when contact allergy cannot be ruled out. The purpose of this study was to determine the frequency of contact allergy in patients with eczematous dermatitis in Thammasat University Hospital, Prathumthani, Thailand from June 1, 2008 to June 30, 2009 and to identify a possible relationship between sex, age, occupational differences and type of eczema that is associated with positive patch test reactions. A total of 157 patients were patch tested with 23 standard allergens. One or more positive responses were noted in 70 patients (44.6%). The most common allergen was nickel sulfate (26.8%), followed by cobalt chloride (7.6%), p-phenylenediamine (7.0%), fragrance mix (7.0%). Patients who were initially diagnosed with allergic contact dermatitis had significant correlation with positive patch test results to nickel sulfate, cobalt chloride and phenylenediamine (p = 0.00, p = 0.03, p = 0.02, respectively). Patients who were initially diagnosed with endogenous eczema had significant correlation with positive patch test results to colophony (p = 0.04). Contact allergy to fragrance mix was significantly more frequent in patients who had personal history of atopy (p = 0.04). There was no significant correlation between the frequency of contact allergy and sex, age, location of lesion and patient's occupation. In conclusion, this study demonstrated the prevalence in contact allergy in eczema patients in Thammasat University Hospital and compared the results with other region from Thailand. Further study involving many hospitals in various areas in Thailand is needed to provide more insight into contact allergy in Thailand.

Characterization of pollen by vibrational spectroscopy

Classification, discrimination, and biochemical assignment of vibrational spectra of pollen samples belonging to 43 different species of the order Pinales has been made using three different vibrational techniques. The comparative study of transmission (KBr pellet) and attenuated total reflection (ATR) Fourier transform infrared (FT-IR) and FT-Raman spectroscopies was based on substantial variability of pollen grain size, shape, and relative biochemical composition. Depending on the penetration depth of the probe light, vibrational techniques acquire predominant information either on pollen grain walls (FT-Raman and ATR-FT-IR) or intracellular material (transmission FT-IR). Compared with the other two methods, transmission FT-IR obtains more comprehensive information and as a result achieves superior spectral identification and discrimination of pollen. The results strongly indicate that biochemical similarities of pollen grains belonging to the same plant genus or family lead to similar features in corresponding vibrational spectra. The exploitation of that property in aerobiological monitoring was demonstrated by simple and rapid pollen identification based on relatively small spectral libraries, with the same (or better) taxonomic resolution as that provided by optical microscopy. Therefore, the clear correlation between vibrational spectra and pollen grain morphology, biochemistry, and taxonomy is obtained, while successful pollen identification illustrates the practicability of such an approach in environmental studies.

The patient with allergies

Allergic disease affects a sizeable percentage of the general population, has a significant impact on patient quality of life, and exerts a significant financial burden on society. Atopic symptoms from inhalant allergens are among the most frequent complaints in outpatient medical visits. Key history and physical examination findings help to distinguish allergic rhinitis from other forms of chronic rhinosinusitis. Diagnostic testing may not be necessary unless immunotherapy is contemplated.

[Epidemiology of allergic rhinitis in children residing in the city of Tomsk and rural areas of the Tomsk region]

The present paper is designed to report results of a clinico-epidemiological study that had the objective to elucidate the prevalence of allergic rhinitis among 8,311 first- and eighth-grade schoolchildren from the city of Tomsk and rural areas of the Tomsk region. The investigation was undertaken in the framework of the International Study of Asthma and Allergy in Childhood (ISAAC). It has demonstrated that clinical symptoms of allergic rhinitis (AR) in the region of interest occurred in 36.7% of the children including 35.6% and 38.9% of those attending urban and rural schools respectively. Positive skin test response to the selected panel of allergens was documented in 45.41% and 16.09% of the children in these groups. They most frequently reacted to the cat's hair, birch tree pollen, and a mixture of tick allergens and domestic dust. Only urban community-dwelling children proved sensitized to cockroach (15.62%), wormwood (6%), saltbush (8%), and ragweed (10.93%) allergens. It may be hypothesized that epidemiological characteristics of allergic rhinitis are generated not only under the influence of the urban environment but also depend on other endemic ecological factors.

Key nasal symptoms predicting a positive skin test in allergic rhinitis and patient characteristics according to ARIA classification

OBJECTIVE

To find predicting symptom(s) in patients with a positive skin test, and identify patient characteristics according to ARIA classification.

MATERIAL AND METHOD

Four hundred and thirty four rhinologic patients were retrospectively studied. Nasal obstruction, rhinorrhea, itching, sneezing, and smell dysfunction were assessed. Patients were also classified according to the ARIA guideline.

RESULTS

Of 434 patients, 277 (63.8%) were skin prick test positive. There was no statistical difference in sex, but the mean age of the positive skin test group was lower than that in the negative group (p < 0.05). Intermittent or persistent symptoms and total symptom score were not significantly different. Severe nasal itching was more common in the positive group (p = 0.04). The impact of symptoms was similar between the two groups, except for self-reported comorbidity, which was higher in the negative group (p = 0.039).

CONCLUSION

There were no predicting symptoms and no difference in the symptom characteristics for the patients with positive skin test.

[Allergens used in skin tests in Mexico]

BACKGROUND

Immunotherapy is the only recognized causal treatment for allergies. It is prepared on an individual basis, based on the patient's clinical history and the result of the skin prick test (SPT). An adequate composition of the allergens with which to test the patient is crucial for an optimal diagnosis.

OBJECTIVE

To know allergens used in tests in allergy practices in Mexico.

MATERIALS AND METHOD

A national survey among all members of the Colegio Mexicano de Inmunología Clínica y Alergia (CMICA) and of the Colegio Mexicano de Pediatras Especialistas en Inmunología Clínica y Alergia (COMPEDIA) was carried out. In a second phase respondents were asked to send in the composition of a routine SPT in their clinic. The results are presented descriptively and the frequency is calculated by which certain allergen is tested in the interviewed practices.

RESULTS

A survey response rate of 61 (17%) was obtained and 54% showed their SPT content. Weeds' representation in the SPT seems adequate; Atriplex is tested in all allergy practices. Some trees that show cross-reactivity might be eliminated from the SPT, but 20% doesn't test for Cynodon nor Holcus, and 25% doesn't for important allergens as cat, dog and cockroach. House dust and tobacco are still tested with certain frequency.

CONCLUSIONS

The selection of which allergens to test in a SPT is based on multiple data, that change continuously with new investigations and discoveries. Our specialty is the most indicated--and obligated--to adjust constantly to these changes to have the best diagnostic tool to detect specific allergies.

Protein families: implications for allergen nomenclature, standardisation and specific immunotherapy

Allergens are embedded into the protein universe as members of large families and superfamilies of related proteins which is a direct consequence of their shared evolution. The classification of allergens by protein families offers a valuable frame of reference that allows the design of experiments to study cross-reactivity and allergenic potency of proteins. Information on protein family membership also complements the current official IUIS allergen nomenclature. All presently known allergens belong to one of 140 (1.4%) of the 10,340 protein families currently described by version 23.0 of the Pfam database. This is indicative of a strong bias among allergens towards certain protein architectures that are able to induce an IgE response in an atopic immune system. However, even small variations in the structure of a protein alter its immunological characteristics. Various isoforms of the major birch pollen allergen Bet v 1 were shown to possess highly variant immunogenic and allergenic properties. Ber e 1 and SFA8, two 2S albumins, were revealed to display differential capacities to polarise an immune response. Such data will be exploited in the future for the design of allergy vaccines.

Early identification of atopy in the prediction of persistent asthma in children

The long-term solution to the asthma epidemic is thought to be prevention, and not treatment of established disease. Atopic asthma arises from gene-environment interactions, which mainly take place during a short period in prenatal and postnatal development. These interactions are not completely understood, and hence primary prevention remains an elusive goal. We argue that primary-care physicians, paediatricians, and specialists lack knowledge of the role of atopy in early life in the development of persistent asthma in children. In this review, we discuss how early identification of children at high risk is feasible on the basis of available technology and important for potential benefits to the children. Identification of an asthmatic child's atopic status in early life has practical clinical and prognostic implications, and sets the basis for future preventative strategies.

Comprehensive 3D-modeling of allergenic proteins and amino acid composition of potential conformational IgE epitopes

Similarities in sequences and 3D structures of allergenic proteins provide vital clues to identify clinically relevant immunoglobulin E (IgE) cross-reactivities. However, experimental 3D structures are available in the Protein Data Bank for only 5% (45/829) of all allergens catalogued in the Structural Database of Allergenic Proteins (SDAP, http://fermi.utmb.edu/SDAP). Here, an automated procedure was used to prepare 3D-models of all allergens where there was no experimentally determined 3D structure or high identity (95%) to another protein of known 3D structure. After a final selection by quality criteria, 433 reliable 3D models were retained and are available from our SDAP Website. The new 3D models extensively enhance our knowledge of allergen structures. As an example of their use, experimentally derived "continuous IgE epitopes" were mapped on 3 experimentally determined structures and 13 of our 3D-models of allergenic proteins. Large portions of these continuous sequences are not entirely on the surface and therefore cannot interact with IgE or other proteins. Only the surface exposed residues are constituents of "conformational IgE epitopes" which are not in all cases continuous in sequence. The surface exposed parts of the experimental determined continuous IgE epitopes showed a distinct statistical distribution as compared to their presence in typical protein-protein interfaces. The amino acids Ala, Ser, Asn, Gly and particularly Lys have a high propensity to occur in IgE binding sites. The 3D-models will facilitate further analysis of the common properties of IgE binding sites of allergenic proteins.

Primary prevention of occupational asthma: identifying and controlling exposures to asthma-causing agents

BACKGROUND

Primary prevention of occupational asthma requires timely identification and regulation of asthma-causing agents.

METHODS

We examined 39 substances identified as causing allergic occupational asthma in the US to determine the basis for their identification and their regulatory status. We compared them with occupational asthmagens identified and regulated in the UK and Germany.

RESULTS

US regulatory agencies have not established consistent, evidence-based methods to identify and control exposures to substances that cause occupational asthma. Occupational asthmagens are identified primarily by non-regulatory US organizations, and most are not regulated to prevent asthma.

CONCLUSIONS

Implementing an evidence-based identification and regulatory process for occupational asthmagens will help to ensure primary prevention of occupational asthma in the US. This should include: establishing consistent identification criteria; publishing a list of occupational asthmagens; collecting use, exposure, and health effects information on asthma-causing substances; requiring medical surveillance and medical removal protection in addition to exposure limits; and stimulating development of safer alternatives.