Localization of Four Allergens in Artemisia Pollen by Immunofluorescent Antibodies.

BACKGROUND: Artemisia pollens have a high potential to induce allergic symptoms. Seven allergen components have been identified, but only Art v 7 has been localized in the pollen grain. This study aimed to localize the allergens in the pollen grains of 4 Artemisia spp. METHODS: Pollen extracts from 2 Chinese Artemisia spp., A. argyi and A. annua, were used to immunize BALB/c mice. Recombinant Art v 1 and Art v 3 allergens were used to select specific monoclonal antibodies (mAbs). Three mAbs were used to purify the natural allergens and were then analyzed by mass spectrometry. As reported previously, polyclonal antibodies were obtained from rabbits immunized with 3 synthesized peptides of Art an 7. Using conventional histology procedures with pollens from 4 Artemisia spp. (A. argyi, A. annua, A. capilaris, and A. sieversiana), allergen images were observed and recorded by fluorescence and confocal laser microscopy. RESULTS: We obtained 2 specific mAbs against Art v 1, 1 against Art v 2, and 4 against Art v 3 homologs. The Art v 1 and Art v 3 homologs were mainly located on the pollen walls, and the Art v 7 homologous protein was localized intracellularly around nuclei. The location of the Art v 2 homologous protein varied across species, being intracellular around nuclei for A. annua and A. argyi, and in both the pollen wall and around nuclei for A. capilaris and A. sieversiana. CONCLUSIONS: Four mugwort allergens were localized in the pollen, and the major Art v 1 and Art v 3 allergens were located mainly in the pollen wall.

Artemisia pollen allergy in China: Component-resolved diagnosis reveals allergic asthma patients have significant multiple allergen sensitization.

BACKGROUND: Artemisia pollen allergy is a major cause of asthma in Northern China. Possible associations between IgE responses to Artemisia allergen components and clinical phenotypes have not yet been evaluated. This study was to establish sensitization patterns of four Artemisia allergens and possible associations with demographic characteristics and clinical phenotypes in three areas of China. METHODS: Two hundred and forty patients allergic to Artemisia pollen were examined, 178 from Shanxi and 30 from Shandong Provinces in Northern China, and 32 from Yunnan Province in Southwestern China. Allergic asthma, rhinitis, conjunctivitis, and eczema symptoms were diagnosed. All patients' sera were tested by ImmunoCAP with mugwort pollen extract and the natural components nArt v 1, nArt ar 2, nArt v 3, and nArt an 7. RESULTS: The frequency of sensitization and the IgE levels of the four components in Artemisia allergic patients from Southwestern China were significantly lower than in those from the North. Art v 1 and Art an 7 were the most frequently recognized allergens (84% and 87%, respectively), followed by Art v 3 (66%) and Art ar 2 (48%). Patients from Northern China were more likely to have allergic asthma (50%) than patients from Southwestern China (3%), and being sensitized to more than two allergens increased the risk of allergic asthma, in which co-sensitization to three major allergens Art v 1, Art v 3, and Art an 7 is prominent. CONCLUSIONS: Component-resolved diagnosis of Chinese Artemisia pollen-allergic patients helps assess the potential risk of mugwort-associated allergic asthma.

[Food allergy:definitions, prevalence, diagnosis and therapy].

Food allergy is phenotypically an extremely heterogeneous group of diseases affecting multiple organs, sometimes in an isolated way, sometimes simultaneously, with the severity of reactions ranging from mild and local to full-blown anaphylaxis. Mechanistically, it is defined as a Th2-driven immune disorder in which food-specific IgE antibodies are at the basis of immediate-type adverse reactions. The sites of sensitization and symptoms do not necessarily overlap. Food allergy, which is the theme of this paper, is often confused with other adverse reactions to food of both animmune (e.g., celiac disease) and non-immune (e.g., lactose intolerance) nature. To reliably diagnose food allergy, a careful history (immediate-type reactions) needs to be complemented with demonstration of specific IgE (immune mechanism) and confirmed by an oral challenge. Co-factors such as exercise, medication, and alcohol may help trigger food allergy and further complicate accurate diagnosis. Where food extract-based diagnostic tests are poorly correlated to symptom severity, new generation molecular diagnostics that measure IgE against individual food allergens provide clinicians and patients with more reliable symptom severity risk profiles. Molecular diagnostics also support establishing whether food sensitization originates directly from exposure to food or indirectly (cross-reactivity) from pollen sensitization. Epidemiological surveys have indicated that allergy to peach primarily originates from peach consumption in Europe, whereas in China it is the result of primary sensitization to mugwort pollen, in both cases mediated by an allergen molecule from the same family. Epidemiological surveys give insight into the etiology of food allergy, the size of the problem (prevalence), and the risk factors involved, which together support evidence-based strategies for prevention. Over the past decade, food allergy has increased in the affluent world. Economic growth and urbanization in upcoming economies are likewise expected to lead to increased prevalence of food allergies, sometimes to different foods due to dietary habits. Molecular allergology and biotechnology now offer the possibility to combat the increasing burden of food allergy by developing safe immunotherapies for food allergy, using hypoallergenic mutant recombinant molecules. The first clinical trials to evaluate such approaches are underway. Last but not least, the identification and clinical risk characterization of a more and more complete list of food allergens additionally provides the allergenicity risk assessment of genetically modified foods a firmer basis.