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Notes: A 29-year-old female bakery shop assistant was occupationally sensitized to flour allergens and Aspergillusα-amylase (Asp o 2). The latter represents a strongly allergenic component of routinely used baking additives. The patient had repeatedly responded to the consumption of white bread with rhinitis, conjunctivitis, and, occasionally, wheal and flare reactions. She underwent allergologic investigations including oral challenge tests with commercially available bread loaves. Elevated specific IgE antibodies against bread extracts, Asp o 2, and flour allergens were detectable in her serum. The provocation test with bread resulted in a running nose together with a strong increase in nasal resistance. All symptoms subsided about 3 h after the challenge. None of the above symptoms could be observed when bread free of Aspergillusα-amylase was administered. This outcome provides evidence of a clinically relevant persistent allergenicity to Asp o 2 in bread.

Notes: Polyclonal human IgE antibodies of patients sensitized to one species of the Diptera family Chironomidae as well as polyclonal rabbit anti-Chi t I hyperimmune serum recognize antigenic sites present in nearly all of the 33 species of this insect family. Evolutionary distantly related genera usually show weaker antibody binding. According to the pattern of reactivity of rabbit anti-Chi t I-component III, expression of the epitopes of this molecule varies considerably in the genera Chironomus and Glyptotendipes; it appears to be almost totally absent in all other species. Of five monoclonal antibodies raised against Chi t I-component III, two recognize an epitope which is expressed in nearly all closely related species. Three monoclonal antibodies recognize epitopes which are expressed in only a few species of the same genus. Our results demonstrate the presence of common as well as species-specific epitopes in chironomid hemoglobins which behave as potent inhalant allergens.

Notes: Recent studies have demonstrated that allergy to natural rubber latex (NRL) is associated with cross-reactivity to certain foods. The aim of this study was to investigate the prevalence of NRL sensitization and allergy in children with atopic dermatitis (n=74). We also examined cross-reactions between latex and foods, and compared the frequency of suspected latex cross-reacting fruits in children with and without NRL-specific immunoglobulin E (IgE). Twelve of the 74 atopic children studied (16.2%; 95% confidence interval (CI), 8.7–26.6%) had circulating IgE antibodies to latex. These NRL-sensitized children were older and they showed significantly higher total IgE values (p〈0.003) when compared with the group of children without NRL sensitization. Of the specific food IgE evaluations, 18.4% (93 out of 505) were positive, and 69.9% were observed in the group of children with latex-specific IgE, most frequently to potato, tomato, sweet pepper, and avocado. An isolated latex-specific IgE response without food-specific IgE was never observed. Exclusively in the latex-positive group, conformity with the report of allergic symptoms after ingestion of food and increased food-specific IgE was found. Twenty children without proven latex sensitization showed increased food-specific IgE, most frequently to potato, banana, and chestnut. Avocado-specific IgE was never determined in this patient group. No significant differences were detected concerning the sensitization to potato, banana, and kiwi between NRL-sensitized children and the group of 20 children without latex-specific IgE. The competitive CAP inhibition using sera from children with specific IgE to both latex and food showed different cross-reactivities between latex and the specific food. A close relationship existed between latex and avocado (median inhibition: 100%), whereas sensitization to latex and kiwi seemed to be independent in our study group (inhibition: 〈25%). In particular, for potato, cross-reactivity and co-sensitization existed. Our study demonstrated that children with atopic dermatitis are a high-risk group for latex sensitization. Increasing age, additional sensitization to ubiquitous inhaled allergens, and enhanced total serum IgE values seemed to be important variables for latex sensitization and further sensitization to the latex-associated foods. Cross-reactivity and, in some cases, co-sensitization to specific fruits and vegetables, were observed.

Notes: A 58-year-old pharmaceutical worker regularly developed asthma and rhinitis when handling bromelain, a purified protease of pineapple (Ananas comosus), at her workplace, where she had been employed for about 10 years. RAST and prick test showed strong positive reactions to bromelain. Both inhalation test with 0.03 mg bromelain and peroral challenge by ingestion of 190 g pineapple resulted in asthmatic reactions; the latter challenge was accompanied by gastrointestinal symptoms. Five of six workers sensitized to papain, showed positive RAST and skin test results to bromelain, two of them also showed immediate asthmatic reactions after bronchial challenge with bromelain. Out of sixty asthmatics not exposed to airborne proteases but probably to these as constituents of foods, two had positive skin test results and eight had positive RAST results to bromelain; but in no case was there clear evidence for clinical sensitization.The presented data prove conclusively that bromelain is capable of inducing IgE mediated respiratory and gastrointestinal allergic reactions. Furthermore, there is evidence for immunological cross-reaction between the two plant proteases bromelain and papain in human subjects.

Notes: The sera of seven patients clinically hypersensitive to papain—in one case also to bromelain—and the sera of sixty asthmatic patients with allergies to other inhalant and food allergens were investigated for IgE antibody activity to the plant proteases papain and bromelain and to common allergens by RAST, confirmed in some sera by RAST inhibition.There seems to be a relation between the antibody reactions to papain and bromelain, in several cases also between the reactions to these proteases and to grass pollen and flour. Studies by RAST inhibition showed that papain, bromelain, wheat flour, rye flour, grass pollen and birch pollen mutually inhibit IgE antibody to each antigen; but the degree of inhibition varies among the different sera and allergens.Our results suggest that these allergens from various plants, besides having specific antigenic determinants, also possess similar or even identical antigenically active regions, leading to immunological cross-reactivity.

Notes: Seven out of eleven workers occupationally exposed to airborne papain developed immediate hypersensitive reactions, predominantly asthma and rhinitis. Skin tests and RAST with papain were positive in all symptomatic workers, but not in the four asymptomatic workers. Furthermore, out of forty non-exposed asthmatics, thirty-eight had negative RAST results and all had negative skin test results. Bronchial provocation tests with 0.15–0.5 mg papain performed in five patients with a positive case history showed in each case an immediate asthmatic reaction; in addition to that, one patient developed signs of a dual asthmatic reaction.Our results suggest that airborne papain is a highly immunogenic agent in humans, which induces type I allergic reactions in a large percentage of the exposed subjects.

Notes: Background The rubber elongation factor in Hevea rubber (Hev b 1) is one of the most important latex allergen and is leading cause oflatex 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. Eine 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.