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Atopic, allergic, and especially asthmatic subjects might be particularly susceptible to sensory irritation induced by airborne chemicals compared to healthy individuals. Therefore, a good characterization of subjects is essential in inhalation exposure studies on sensory irritants. A total of 105 volunteers, 87% of whom reported to be non-allergic, participated in a medical examination that included skin prick test (SPT), measurements of total IgE, specific IgE (sIgE) to an ubiquitous allergen mix (sx1), and fractionated exhaled nitric oxide (FeNO), as well as pulmonary function and methacholine test. The median value of sIgE to sx1 was 0.20 kU/L (0.07-91.3 kU/L) and correlated significantly with total IgE (28.8 kU/L (2-756 kU/L)) and FeNO (14 ppb (5-100 ppb)). Forty-three subjects (41%) had sIgE to sx1 ≥ 0.35 kU/L and were classified as atopic. Thirty-five subjects, all also sx1-positive, were positive in SPT. Obstruction, small airway disease, and/or bronchial hyperreactivity were diagnosed in 18 subjects. Receiver operating characteristics (ROC) were performed to check whether signs of sensitization are useful to discriminate subjects with and without airway diseases. However, sx1, total IgE, FeNO, and SPT reached only low areas under the curve (AUC: 0.57-0.66). Although predominantly young and, according to their own statements, mostly non-allergic subjects participated in the study, almost half of them were atopic, and 10% had airway disease or bronchial hyperreactivity. This indicates that the validity of self-reported data might be inaccurate. In summary, diversified investigations of the allergy-related health status appear necessary for a thorough characterization of subjects for exposure studies on sensory irritants.

Background: Diagnosis of mould allergy is complicated due to the heterogeneity of the test material and the decrease in the number of commercial mould skin test solutions that are currently available., Objectives: The aim of this study was to compare skin prick tests (SPT) from different manufacturers to one another and concurrently with sIgE tests for Aspergillus fumigatus (Asp f), Cladosporium herbarum (Cla h), Penicillium chrysogenum (Pen ch), Alternaria alternata (Alt a) and Aspergillus versicolor (Asp v) to ascertain a feasible diagnostic procedure for mould sensitization., Methods: In this multi-centre study, 168 patients with mould exposure and/or mould-induced respiratory symptoms were included. Mould SPT solutions were analysed biochemically and tested in duplicate on patients' arms. Specific IgE (sIgE) concentrations to corresponding mould species and mould mix (mx1) were measured by ImmunoCAP. SPTs in accordance with one another and with sIgE were further considered. The test efficiency was calculated using receiver-operating characteristic (ROC) analysis., Results: Mould sensitization was more frequently detected by the SPT (90 of 168) than by the sIgE tests (56 of 168). Concordances of double SPT positives were only sufficient (≥ 80%) for environmental allergens, two Asp f and three Alt a SPT solutions, whereas all other mould solutions revealed concordances < 80%. The antigen content of SPT solutions was positively associated with concordant SPT double values as well as with sIgE. Taking sIgE as the 'positive standard', all mould SPT solutions revealed test efficiencies > 80%, but varied up to 20% in sensitivity and positive predictive value with the exception of Alt a., Conclusions: SPT solutions are sensitive and essential diagnostic tools for the detection of mould sensitization. Our recommendation for diagnosis would be to test at least Alt a, Asp f and Pen ch using SPT and additional sIgE test to mx1., (© 2016 John Wiley & Sons Ltd.)

Background: Sensitization to wheat flour plays an important role in the development and diagnosis of baker's asthma., Objectives: We evaluated wheat allergen components as sensitizers for bakers with work-related complaints, with consideration of cross-reactivity to grass pollen., Methods: Nineteen recombinant wheat flour proteins and 2 cross-reactive carbohydrate determinants were tested by using CAP-FEIA in sera of 101 bakers with wheat flour allergy (40 German, 37 Dutch, and 24 Spanish) and 29 pollen-sensitized control subjects with wheat-specific IgE but without occupational exposure. IgE binding to the single components was inhibited with wheat flour, rye flour, and grass pollen. The diagnostic efficiencies of IgE tests with single allergens and combinations were evaluated by assessing their ability to discriminate between patients with baker's allergy and control subjects based on receiver operating characteristic analyses., Results: Eighty percent of bakers had specific IgE levels of 0.35 kUA/L or greater and 91% had specific IgE levels of 0.1 kUA/L or greater to at least one of the 21 allergens. The highest frequencies of IgE binding were found for thiol reductase (Tri a 27) and the wheat dimeric α-amylase inhibitor 0.19 (Tri a 28). Cross-reactivity to grass pollen was proved for 9 components, and cross-reactivity to rye flour was proved for 18 components. A combination of IgE tests to 5 components, Tri a 27, Tri a 28, tetrameric α-amylase inhibitor CM2 (Tri a 29.02), serine protease inhibitor-like allergen (Tri a 39), and 1-cys-peroxiredoxin (Tri a 32), produced the maximal area under the curve (AUC = 0.84) in receiver operating characteristic analyses, but this was still lower than the AUC for wheat- or rye flour-specific IgE (AUC = 0.89 or 0.88, respectively)., Conclusions: Component-resolved diagnostics help to distinguish between sensitization caused by occupational flour exposure and wheat seropositivity based on cross-reactivity to grass pollen. For routine diagnosis of baker's allergy, however, allergen-specific IgE tests with whole wheat and rye flour extracts remain mandatory because of superior diagnostic sensitivity., (Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Exposures to molds and bacteria (especially actinomycetes) at workplaces are common in garbage workers, but allergic respiratory diseases due to these microorganisms have been described rarely. The aim of our study was a detailed analysis of mold or bacteria-associated occupational respiratory diseases in garbage workers. From 2002 to 2011 four cases of occupational respiratory diseases related to garbage handling were identified in our institute (IPA). Hypersensitivity pneumonitis (HP) was diagnosed in three subjects (cases 1-3, one smoker, two non-smokers), occupational asthma (OA) was diagnosed in one subject (case 4, smoker), but could not be excluded completely in case 2. Cases 1 and 2 worked in composting sites, while cases 3 and 4 worked in packaging recycling plants. Exposure periods were 2-4 years. Molds and actinomycetes were identified as allergens in all cases. Specific IgE antibodies to Aspergillus fumigatus were detected exclusively in case 4. Diagnoses of HP were essentially based on symptoms and the detection of specific IgG serum antibodies to molds and actinomycetes. OA was confirmed by bronchial provocation test with Aspergillus fumigatus in case 4. In conclusion, occupational HP and OA due to molds occur rarely in garbage workers. Technical prevention measures are insufficient and the diagnosis of HP is often inconclusive. Therefore, it is recommended to implement the full repertoire of diagnostic tools including bronchoalveolar lavage and high resolution computed tomography in the baseline examination.

It is common that the inhalation of occupational allergens induces occupational airway diseases, but the inducers are diverse and complex, and the pathomechanism of the disease is not clear in every case. Only few allergens have been studied in detail (e.g., wheat flour and natural rubber latex), and most of the occupational airway sensitizers have only been documented as case reports. This review describes occupational type I aeroallergens according to their source (plant, animal, microbial, and chemical) and workplace application area. New aspects on the diagnosis and legal preventive regulations for occupational allergic airway diseases are described.

Objective: Cross-reactivity between grass pollen and grain flour allergens is well known, but their significance in apprentice bakers with primary sensitization to grass pollen is not known., Methods: Twenty-five subjects with mild asthma (most of them with hay fever), but without prior occupational flour exposure, underwent standardized experimental inhalation challenges with placebo and wheat and rye flours in randomized order on three consecutive days. Sensitization to flours and environmental allergens was assessed by skin prick tests and specific IgE antibodies in sera. IgE inhibition experiments were performed with wheat and rye flours as solid phases, and grass and tree pollen as inhibitors., Results: Five subjects experienced a positive reaction after flour inhalation (responders), whereas 20 subjects did not show such a reaction (non-responders). All responders showed sensitizations to flours, whereas only 25% of the non-responders demonstrated the same sensitization. Specific IgE concentrations to flours, but also to grass and tree pollen, were higher in responders. Inhibition experiments demonstrated cross-reactivity between flours and grass or tree pollen, with higher inhibition rates in responders., Conclusions: Subjects with pronounced sensitizations to grass or tree pollen, but without prior occupational exposure to flours, may experience both sensitization and allergic asthmatic reactions to flours due to cross-reactive grass and tree pollen allergens.

Background: Several wheat flour allergens relevant to baker's asthma have been identified in the last 25 years. The aim of this study was to determine the frequency of sensitization to these allergens in German bakers., Methods: Using recombinant DNA technology, the following wheat flour allergens were cloned, expressed in Escherichia coli and purified: five subunits of the wheat α-amylase inhibitors (WTAI-CM1, WTAI-CM2, WTAI-CM3, WDAI-0.19 and WMAI-0.28), thioredoxin, thiol reductase or 1-cys-peroxiredoxin homologues, triosephosphate-isomerase, αβ-gliadin, serpin, glyceraldehyde-3-phosphate-dehydrogenase, a nonspecific lipid transfer protein (nsLTP), dehydrin, profilin and peroxidase. In addition, ImmunoCAPs with the recombinant allergen ω-5-gliadin and two cross-reactive carbohydrate determinants (CCDs), horse radish peroxidase (HRP) and the N-glycan of bromelain (MUXF), were used. Specific IgE was measured in wheat flour-positive sera from 40 German bakers with work-related asthma/rhinitis and 10 controls with pollinosis., Results: Thirty bakers (75%) had IgE to at least one of the 19 single allergens. Most frequent was IgE to WDAI-0.19, HRP and MUXF (25% each), followed by WTAI-CM1 (20%), thiol reductase (16%), WTAI-CM3 (15%), WTAI-CM2 and thioredoxin (12.5%), WMAI-28, triosephosphate-isomerase, αβ-gliadin (10%), 1-cys-peroxiredoxin (7.5%), dehydrin, serpin, glyceraldehyde-3-phosphate-dehydrogenase (5%), ω-5-gliadin, nsLTP and profilin (2.5%). Fifteen bakers (38%) had IgE to any α-amylase inhibitor and 12 (30%) to at least one CCD. The controls reacted exclusively to CCDs (80%), profilin (60%), thioredoxin (30%), triosephosphate isomerase and nsLTP (10%)., Conclusions: The single allergen sensitization profiles obtained with 17 recombinant wheat flour allergens and two CCDs revealed no major allergen for German bakers. The highest frequencies were found for α-amylase inhibitors and CCDs., (© 2011 John Wiley & Sons A/S.)

Background: Natural rubber latex (NRL) products are complex mixtures consisting of different allergenic components. Among them, Hev b 1 belongs to the important and well-characterized ones. To quantify the relevant allergen Hev b 1 in NRL products, a two-site monoclonal antibody (mAb)-based assay was developed., Methods: Two Hev b 1-specific mAbs with different epitope recognition and ability to bind simultaneously to an Hev b 1 molecule were used in the study. Both mAbs (II4F9 and II4G9) were enriched by in vitro production in a modular minifermenter and affinity purified. Wells of micro-ELISA plates coated with captured mAb II4G9 were incubated with samples containing Hev b 1. Bound Hev b 1 was detected by a combination of biotinylated mAb II4F9 as detection antibody and peroxidase-labeled avidin., Results: The optimized sandwich ELISA was highly reproducible in the linear range of the standard curve and Hev b 1 concentrations ranging from 12.5 to 400 ng/100 microl could be detected. The assay was suitable for the detection of Hev b 1 concentrations in latex sap and latex products, e.g. gloves, with a detection limit of 1.25 microg of Hev b 1/g of rubber. In a preliminary study with five different brands of latex gloves, Hev b 1 concentrations were found to be in the range of 18-40 microg per gram of rubber material, corresponding to 2-4% of the total extractable protein content in latex glove extracts., Conclusions: A sensitive sandwich assay was developed to quantify the latex allergen Hev b 1. This assay can be used to standardize latex extracts with regard to the content of the major allergen Hev b 1., (Copyright 2000 S. Karger AG, Basel)

Background: The rubber elongation factor in Hevea rubber (Hev b 1) is one of the most important latex allergen and is leading cause of latex type 1 hypersensitivity in children with spina bifida., Objective: The aim of this study was to define the allergenic and antigenic epitopes of Hev b 1., Methods: The immunoglobulin- (Ig)E and IgG antibody binding sites on Hev b 1 allergen were delineated by enzyme linked immunosorbent assay (ELISA) using synthetic overlapping peptides covering the whole Hev b 1 sequence. In order to improve the binding capacity and specificity all peptides were biotinylated at the N-terminal end via a 6-aminohexanoic acid as spacer and then adsorbed to streptavidin pre-coated microtitre plates. Fine mapping to define the essential amino acid residues for the antibody binding was achieved by using overlapping peptides with one amino acid offset., Results: It was demonstrated that the IgE epitopes were located in different regions of Hev b 1 including the C-terminal segment (121-137) and the segments with amino acid residues of 30-49 and 46-64. Two monoclonal antibodies (MoAbs) II2F3 and II4G9 raised against purified Hev b 1 recognized the C-terminal segment only. The results of epitope mapping with three rabbit antisera revealed that five positive peptides, including the epitope peptides 31-49, 46-64 and 121-137, were involved in the antibody-binding sites. Fine mapping on the segments 46-64 and 121-137 showed that the two MoAbs reacted with the peptide 125-134 in the C-terminal region, whereas the peptide with amino acids 124-134 was essential for recognition by human IgE antibodies. Epitopes to rabbit polyclonal IgG and human IgE were also found to be involved in the amino acid residues of 47-59., Conclusion: Our results indicate that the most allergenic/antigenic portions of Hev b 1 allergen are the C-terminal region and the region with amino acid residues of 31-64. In both regions, the minimal IgE-binding epitope is almost identical with the IgG-binding epitope.

The hemoglobins of the midge Chironomus thummi thummi (Chi t I) are known to cause immediate-type hypersensitivity reactions in humans. Further knowledge of the antigenic sites of such allergens will provide new therapeutic approaches. The aim of our study was to identify and characterize linear B-cell epitopes of the hemoglobin component III of Chi t I (136 amino acid residues). Using the antigenic index algorithm of Jameson and Wolf (Jameson and Wolf (1988) Comput. Appl. Biosci. 4, 181-186), three linear binding sequences of this allergen molecule were predicted. Two mouse monoclonal antibodies (mAbs 3 and 6) raised against purified Chi t I component III were investigated by ELISA for their binding to nine synthetic peptides 19-21 residues in length, covering nearly the whole sequence of component III. MAb 6 recognized only one peptide (11-30) while mAb 3 bound to both N-terminal peptides (1-19 and 11-30), suggesting that the antibody binding site is located in the overlapping region. This assumption could be confirmed in ELISA with solid phase-bound recombinant peptides (RP) as well as in inhibition studies with free tryptic peptides indicating that identification of these linear B-cell epitopes is neither influenced by the method of peptide production nor by the kind of used immunoassay. To define the essential amino acid residues we investigated mAbs with solid phase-bound overlapping octamers. In the case of mAb 3, amino acids experimentally identified as essential for antibody binding (aa 13-17) are identical with those residues predicted as a B-cell epitope with the antigenic index of Jameson and Wolf.

Hemoglobins of the Diptera (insect) family Chironomidae have been identified as causative allergens in asthmatic patients. In this study, 229 Japanese, 17 Taiwanese, and 92 Swedish sera from atopic patients were tested for antibodies against Chi t I, the hemoglobin from the European midge species Chironomus thummi, and against crude extracts from the Japanese midges Tokunagayusurika akamusi (T. akamusi) and Cricotopus sylvestris (Cr. sylvestris). Nearly 40% of patients showed a positive reaction to Cr. sylvestris extract, which contains no hemoglobin. This result is probably due to the presence of other partially cross-reacting allergens than hemoglobin. Nearly all tested Japanese serum samples showed cross-reactivity between Chi t I and Cr. sylvestris, a finding which is evidence for common epitopes in both midge species. Furthermore, an overall good correlation between the amounts of IgE antibodies against Chi t I and Chi t I component III was found in sera from Swedish, Japanese, and German patients.

Background The rubber elongation factor in Hevea rubber (Hey b 1) is one of the most important latex allergen and is leading cause of latex type I hypersensitivity in children with spina bifida. Objective The aim of this study was to define the allergenic and antigenic epitopes of Hey b 1. Methods The immunoglobulin- (Ig)E and IgG antibody binding rites on Hey b I allergen were delineated by enzyme linked immunosorbent assay (ELISA) using synthetic overlapping peptides covering the whole Hey b 1 sequence. In order to improve the binding capacity and specificity all peptides were biotinylated at the N-terminal end via a 6-aminohexanoic acid as spacer and then adsorbed to streptavidin pre-coated microtitre plates. Fine mapping to define the essential amino acid residues for the antibody binding was achieved by using overlapping peptides with one amino acid offset. Results It was demonstrated that the IgE epitopes were located in different regions of Hey b I including the C-terminal segment (121–137) and the segments with amino acid residues of 30–49 and 46–64. Two monoclonal antibodies (MoAbs) II2F3 and II4G9 raised against purified Hey b 1 recognized the C-terminal segment only. The results of epitope mapping with three rabbit antisera revealed that five positive peptides, including the epitope peptides 31–49, 46–64 and 121–137, were involved in the antibody-binding sites. Fine mapping on the scgments 46–64 and 121–137 showed that the two MoAbs reacted with the peptide 125–134 in the C-terminal region, whereas the peptide with amino acids 124–134 was essential for recognition by human IgE antibodies. Epitopes to rabbit polyclonal IgG and human IgE were also found to be involved in the amino acid residues of 47–59. Conclusion Our results indicate that the most allergenic/antigenic portions of Hey b 1 allergen are the C-terminal region and the region with amino acid residues of 31–64. In both regions, the minimal IgE-binding epitope is almost identical with the IgG-binding epitope. [ABSTRACT FROM AUTHOR]