Mugwort Pollen Research Articles

Mugwort Pollen-Related Food Allergy: Lipid Transfer Protein Sensitization and Correlation With the Severity of Allergic Reactions in a Chinese Population.

PurposeLittle is known about the importance of lipid transfer protein (LTP) sensitization in China. In this study, we investigated the relationship between LTP sensitization and the severity of clinical symptoms in a population of patients with mugwort pollen-related food allergy.MethodsFood-induced symptoms were evaluated in 148 patients with mugwort pollen allergy by a standardized questionnaire. Specific immunoglobulin E (IgE) to Art v 1, Art v 3, Pru p 3, Ara h 9 and Cor a 8 were quantified by ImmunoCAP. Immunoblotting of peach extracts were performed with sera from peach-allergic patients.ResultsIn total, 72% (107/148) of the study population experienced food allergy. Forty-eight percent (51/107) of patients with mugwort pollen-related food allergy experienced at least 1 episode of food-induced anaphylaxis. Food allergy correlated with IgE reactivity to Art v 3, but not to Art v 1. Sensitization to Pru p 3, Ara h 9 or Cor a 8 was prevalent (80%, 69 or 63%, respectively) among individuals with food allergy. Food allergic patients with systemic reactions (SR) had higher values for Pru p 3, Ara h 9 and Cor a 8 than patients with oral allergy syndrome (OAS). Furthermore, the strong IgE reactivity detected in immunoblots of peach extracts indicated that Pru p 3 was the major allergen and was more prevalent in patients with SR than in patients with OAS (100% vs. 55%).ConclusionsLTPs are major food allergens for mugwort pollen-related food allergy in China, and may contribute to SR.

Clinical utility of basophil activation test in diagnosis and predicting severity of mugwort pollen-related peach allergy

BackgroundCross-reactivity between pollen and plant foods results in low specificity of food-IgE and skin prick testing, which may cause over-diagnosis. A test that can accurately diagnose pollen-related food allergy and identify patients at risk of developing severe reactions is needed. This study evaluates basophil CD63 expression as a biomarker for diagnosis and predicting severity of mugwort pollen-related peach allergy. MethodsBased on their allergic reactions to peach, an oral allergy symptom group (OAS, n ​= ​15), a systemic reaction group (SR, n ​= ​23), a peach-sensitized but tolerant group (PST, n ​= ​21) and a non-peach-sensitized nonallergic group (NSE, n ​= ​10) were identified among mugwort pollen allergic patients. Measurements of specific IgE to peach and its components, and basophil activation test (BAT) were performed. ResultsUpon stimulation with peach extract, BAT in peach-allergic patients (OAS and SR groups) showed a significant dose-dependent upregulation of CD63 compared with PST patients, but showed no difference between SR and OAS groups. BAT to Pru p 3 could discriminate not only between sensitization and clinical allergy, but also between OAS and systemic reactions. BAT to Pru p 3 revealed 92% sensitivity, 95% specificity, 92% positive predictive value, and 92% negative predictive value. Receiver operating characteristic curves showed that BAT to Pru p 3 had the largest area under the curve. ConclusionsIn the diagnosis of mugwort pollen-related peach allergy, BAT to Pru p 3 is superior to testing for IgE specific for peach and its components. Additionally, basophil activation can predict clinical severity.

Analysis of mugwort (Artemisia) pollen seasons in selected cities in Poland in 2018

The aim of the present study was to compare the mugwort pollen season in 2018 in Bialystok, Bydgoszcz, Cracow, Drawsko-Pomorskie, Lublin, Olsztyn, Opole, Sosnowiec, Szczecin, Warsaw, Wroclaw, and Zielona Gora. Pollen concentration measurements were made by the volumetric method using Burkard or Lanzoni pollen samplers. The pollen season was considered as the period during which 98% of the total annual pollen count occurred. The Seasonal Pollen Index (SPI) was calculated as the sum of the average daily pollen concentrations throughout the season determined for the individual cities. The mugwort pollen season started earliest in Bialystok (June 21st) and Bydgoszcz (June 25th), while in the other cities its onset occurred in the first 10 days of July. Significant differences were found in season duration (68–110 days), SPI, and peak value. The longest season occurred in Zielona Gora and Bydgoszcz, while the shortest one in Wroclaw. The highest SPI and maximum concentration values were observed in Lublin and Zielona Gora. In most of the cities, the peak value was recorded in the first 10 days of August. The highest risk of allergy in people sensitive to the pollen of this taxon was found in Zielona Gora, Lublin, and Warsaw.

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.MethodsTwo 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.ResultsThe 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.ConclusionsComponent‐resolved diagnosis of Chinese Artemisia pollen‐allergic patients helps assess the potential risk of mugwort‐associated allergic asthma.

Prevention of allergy by virus-like nanoparticles (VNP) delivering shielded versions of major allergens in a humanized murine allergy model.

BackgroundIn high‐risk populations, allergen‐specific prophylaxis could protect from sensitization and subsequent development of allergic disease. However, such treatment might itself induce sensitization and allergies, thus requiring hypoallergenic vaccine formulations. We here characterized the preventive potential of virus‐like nanoparticles (VNP) expressing surface‐exposed or shielded allergens.MethodsFull‐length major mugwort pollen allergen Art v 1 was selectively targeted either to the surface or to the inner side of the lipid bilayer envelope of VNP. Upon biochemical and immunological analysis, their preventive potential was determined in a humanized mouse model of mugwort pollen allergy.ResultsVirus‐like nanoparticles expressing shielded version of Art v 1, in contrast to those expressing surface‐exposed Art v 1, were hypoallergenic as they hardly induced degranulation of rat basophil leukemia cells sensitized with Art v 1‐specific mouse or human IgE. Both VNP versions induced proliferation and cytokine production of allergen‐specific T cells in vitro. Upon intranasal application in mice, VNP expressing surface‐exposed but not shielded allergen induced allergen‐specific antibodies, including IgE. Notably, preventive treatment with VNP expressing shielded allergen‐protected mice from subsequent sensitization with mugwort pollen extract. Protection was associated with a Th1/Treg‐dominated cytokine response, increased Foxp3+ Treg numbers in lungs, and reduced lung resistance when compared to mice treated with empty particles.ConclusionVirus‐like nanoparticles represent a novel and versatile platform for the in vivo delivery of allergens to selectively target T cells and prevent allergies without inducing allergic reactions or allergic sensitization.

SERUM IGE REACTIVITY TO CROSS-REACTING MOLECULES IN POLLEN ALLERGIC PATIENTS FROM NORTH EASTERN POLAND

Introduction Presence of IgE which cross-react with allergen components such as profilins, polcalcins and cross-reacting carbohydrate determinants (CCD) creates a problem in selection of patients for allergen immunotherapy. This study assesses the prevalence of sensitization to profilins, polcalcins and CCDs in seasonal allergic rhinitis patients (ARs). Methods 112 allergic rhinitis (AR) patients age 14 to 55 years with sensitization to at least one seasonal allergen (IgE>0.7 KU/l) were studied. IgE sensitization to recombinant(r) Bet v 2, rPhl p 12, rBet v 4, rPhl p 7 and CCDs in addition to rBet v 1, rPhl p 1, rPhl p 5 was evaluated using a multiplex immunoblot (Euroimmun, Germany). Results 64.3%, 80.4% and 41.1% of AR patients were sensitized to birch, timothy grass and mugwort pollen, respectively. Sensitization to rBet v 2/Phl p 12 occured in 26.8%, to Bet v 4/Phl p 7 in 8.9%, and to CCDs in 25%. In 29.3% of AR patients serum IgE reactivity to any of the cross-reactive component could be demonstrated. Serum IgE reactivity to rBet v 2 was always accompanied by reactivity to rPhl p 12 and reactivity to rBet v 4 was always accompanied by reactivity to rPhl p 7. Conclusions Evaluation of serum IgE reactivity to cross-reactive components may be useful in assessment of AR patients qualified for allergen immunotherapy.

The dynamics of pollen seasons of the most allergenic plants - 15-year observations in Warsaw.

Allergic rhinitis concerns nearly 25% of the Polish population. Among pollen allergens, the most common reasons for allergic rhinitis are: grass, birch and mugwort. Knowledge of the characteristics of pollen seasons is necessary in diagnostics, monitoring of therapy and prevention of allergic rhinitis. P urpose: This work aims to analyze pollen seasons of the most allergenic plants in the Polish population; grass, birch and mugwort in the years 2003-2017 in Warsaw. M aterial and methods: Measurements of pollen concentration were carried out using Burkard volumetric spore trap operating in continuous mode. Analysis of pollen seasons was conducted based on the following characteristics: beginning, end, and length of season, the seasonal pollen index (SPI), defined as the sum of average daily pollen concentrations over the year, maximum daily concentration, number of days with maximum and threshold concentration. Linear regression together with the Pearson correlation coefficient were used in statistical analysis to study the relationship between variables; furthermore, descriptive characteristics of distributions studied were determined. R esults: The average beginning of the birch pollen season in the analyzed period is April 10th, and it belongs to seasons of average length (47 days on average). Birch pollen count above 75 grains/m3, when most allergic people develop symptoms, was recorded for an average of 18 days. The highest daily birch pollen count reaching 6321 grains/m3 (2012) exceeded the lowest value of the maximum concentration by almost 20 times (2015). Among the taxa analyzed, the highest values of daily counts and annual sums were recorded for birch pollen. The average date for the beginning of grass pollination season is on May 13th. It is the longest pollen season (on average 134 days), and the period when concentration exceeded 50 grains/m3 covered an average of 26 days. The highest daily grass pollen counts reaching 496 grains/m3 (2007) exceeded the lowest value of maximum concentration by 3.5 times (2016). The average date of the beginning of mugwort pollen season is July 16th. The season lasts 65 days on average, when concentration exceeding 30 grains /m3 was registered for an average of 12 days. The highest daily mugwort pollen count reaching 154 grains/m3 (2007) exceeded the lowest value of maximum concentration by 4 times (2013). For all analyzed taxa, the strongest correlated variables are the sum of average daily pollen concentrations over the year (SPI ) and daily maximum concentration (correlation for birch pollen = 0.92, for grass pollen = 0.88, and for mugwort pollen = 0.91). Periods of pollen in the air show certain variation in the analyzed 15-year period. The maximum concentration in the pollen season for the analyzed taxa and the the sum of average daily pollen concentrations over the year show the highest variability, particularly strongly expressed in the case of birch pollen. There is a linear relationship between the sum of average daily pollen concentrations over the year and the maximum concentration value as well as the number of days with the threshold concentration for all analyzed taxa. Variability of parameters describing the dynamics of pollen seasons indicates the need to monitor, both by patients with hay fever and physicians, the current information on the concentration of pollen in the air during the pollen season.

PD-1 has a unique capacity to inhibit allergen-specific human CD4+ T cell responses

T lymphocytes have a crucial role in initiating and promoting type I allergies. Their responses are tightly regulated by numerous activating and inhibitory signals provided by APCs. Here we have addressed the role of the major coinhibitory receptors PD-1, CTLA-4, BTLA and LAG-3 in allergen-specific CD4+ T cell responses. PBMCs of healthy individuals and 41 patients allergic to house dust mites, birch, grass or mugwort pollen were stimulated with allergenic extracts and expression of coinhibitory receptors on responding CD4+ T cells was assessed. Blocking antibodies to PD-1, CTLA-4, BTLA and LAG-3 were used to evaluate the role of coinhibitory pathways. Allergen-specific CD4+ T cells showed strong upregulation of PD-1, LAG-3 and CTLA-4 upon stimulation, whereas BTLA was downregulated. Blockade of PD-1 strongly enhanced proliferation and cytokine production (IL-10; TH1 cytokines IFN-γ, TNF-α; TH2 cytokines IL-5, IL-13) of allergen-specific CD4+ T cells derived from allergic as well as non-allergic individuals. BTLA blockade enhanced proliferation but not cytokine production in response to house dust mite extract. Blocking LAG-3 was ineffective and surprisingly, we observed reduced proliferation and cytokine production in presence of a CTLA-4 antibody. Our results point to a unique potency of PD-1 pathways to dampen allergen-specific human T cells.

P060A MICA typing by NGS revealed the association of MICA GENE polymorphism with specific IgE production in cedar pollen allergy

Aim We have found the association of Japanese Cedar Pollinosis (JCPsis) with SNPs near MICA gene by SNPs typing in HLA gene region. In this study, the association was clarified by MICA gene typing using amplicon sequenceing method by NGS. Methods DNAs from 178 JCPsis patients, 185 healthy controls were tested allele types of MICA and HLA by HLA and KIR typing Kit (Scisco Genetics Inc) on MiSeq (Illumina Inc,). Serum samples from them were titrated for the presence of specific IgE antibodies to Japanese cedar pollen(JCP), orchard grass pollen, mugwort pollen, & house dust mite by radioallergosorbent test. Results Though all controls were selected not to have any symptom of pollinosis, only 101 in 185 individuals were specific IgE negative to all allergens tested, and 84 individuals were positive to one or more allergens including JCP. Therefore, the control group was divided into two groups, specific IgE negative and positive to allergens. The significant association of MICA with JCPsis was found only in analysis using IgE negative control group. IgE positive control group showed no association. MICA*008((P = 0.0036, odds = 0.5) & MICA*027 (P = 0.016, odds = 0.55) showed strong reverse association. Conclusions MICA*008 is lacked a part of trans-membrane region and produce soluble protein. Furthermore, 008 and 027 has the haplotype of 175Gly, 213 Ile, 251Arg which are reported to relate with MICA shedding. This haplotype associate with JCPsis strongly (P = 0.0000399, Odds = 0.46). It is speculated that soluble MICA may suppress IgE production by binding NKG2D and inactivating NK cell, and suppress pollinosis. This speculation is also supported by the report that NKG2D is critical for allergy.

Artemisia pollen is the main vector for airborne endotoxin

Endotoxin (LPS) released from gram-negative bacteria causes strong immunologic and inflammatory effects and, when airborne, can contribute to respiratory conditions, such as allergic asthma. We sought to identify the source of airborne endotoxin and the effect of this endotoxin on allergic sensitization. We determined LPS levels in outdoor air on a daily basis for 4 consecutive years in Munich (Germany) and Davos (Switzerland). Air was sampled as particulate matter (PM) greater than 10μm (PM>10) and PM between 2.5 and 10μm. LPS levels were determined by using the recombinant Factor C assay. More than 60% of the annual endotoxin exposure was detected in the PM>10 fraction, showing that bacteria do not aerosolize as independent units or aggregates but adhered to large particles. In Munich 70% of annual exposure was detected between June 12th and August 28th. Multivariate modeling showed that endotoxin levels could be explained by phenological parameters (ie, plant growth). Indeed, days with high airborne endotoxin levels correlated well with the amount of Artemisia pollen in the air. Pollen collected from plants across Europe (100 locations) showed that the highest levels of endotoxin were detected on Artemisia vulgaris (mugwort) pollen, with little on other pollen. Microbiome analysis showed that LPS concentrations on mugwort pollen were related to the presence of Pseudomonas species and Pantoea species communities. In a mouse model of allergic disease, the presence of LPS on mugwort pollen was needed for allergic sensitization. The majority of airborne endotoxin stems from bacteria dispersed with pollen of only one plant: mugwort. ThisLPS was essential for inducing inflammation of the lung and allergic sensitization.

Meteorological parameters and air pollen count in association with self-reported peripartum depressive symptoms

BackgroundMeteorological parameters and air pollen count have been associated with affective disorders and suicide. Regarding peripartum depression, the literature is restricted and inconclusive. MethodsThis cross-sectional study included women (pregnant, n = 3843; postpartum, n = 3757) who participated in the BASIC (Biology, Affect, Stress, Imaging, and Cognition) study 2010–2015 and the UPPSAT (Uppsala-Athens) study (postpartum, n = 1565) in 2006–2007. Cases were defined according to presence of depressive symptoms during pregnancy (gestational week 32) and 6 weeks postpartum, using the Edinburgh Postnatal Depression Scale (EPDS). Exposure of sunshine, temperature, precipitation, snow coverage, and air pollen counts of durations of 1, 7, and 42 days prior to the outcome were studied for associations with depressive symptoms, using negative binomial regression. ResultsPrior to Bonferroni correction, the concentration of mugwort pollen, both one week and six weeks before the EPDS assessment at gestational week 32, was inversely associated with depressive symptoms in pregnancy, both before and after adjustment for season. No associations were found between the exposure to meteorological parameters and pollen and depressive symptoms, at the same day of depressive symptoms’ assessment, the previous week, or the six weeks prior to assessment, either during pregnancy or postpartum after Bonferroni correction. ConclusionsThere was no evidence that neither short-term nor long-term exposure to meteorological parameters or air pollen counts were associated with self-reported peripartum depressive symptoms in Uppsala, Sweden.

Spatial distribution of pollen-induced symptoms within a large metropolitan area—Berlin, Germany

Large spatial differences in the distribution of three allergologically relevant pollen types for Central Europe—birch, grass, and mugwort—are revealed within a large metropolitan area—Berlin, Germany. The purpose of the study is an examination of the hypothesis that these different pollen exposure conditions can cause different degrees of pollen-induced symptoms within the city. Pollen data from 14 gravimetric traps and one volumetric trap in Berlin and anonymously reported pollen-induced symptom data from the online-based self-documentation tool “Patient’s Hayfever Diary” (PHD) are used for the analysis of temporal and spatial variations of the severity of the overall total symptoms. Geographically localised symptom data are linked to the nearest pollen trap. Statistical analysis is performed using Kendall’s Tau-b. Higher amounts of monitored birch and grass pollen in the peripheral areas of Berlin induce stronger symptoms in PHD users located within suburbs than those located in the city centre. There is no statistical relationship between the varying presence of mugwort pollen in the air and the severity of symptoms. Spatial differences in the pollen-induced symptom severity within a large city coinciding with spatial differences in birch and grass pollen depositions are shown for the first time. Therefore, pollen data from a single trap may not provide an appropriate explanation for differences in pollen-induced symptoms across the city. More detailed and reliable information about the exposure to allergenic pollen can be addressed by installing further traps in order to improve the knowledge about pollen exposure within cities.

Efficacy of indoor air purification in treating Artemisia (mugwort) pollen allergic rhinitis: study protocol for a randomised controlled trial

BackgroundAllergic rhinitis (AR) is a worldwide health problem. Allergen avoidance is strongly recommended for AR patients. Air purification can reduce concentrations of particles in indoor air, including those of allergens. Air purifiers have been recommended by clinicians for AR patients, but few studies have focused on the removal of airborne allergens from home environments. Such studies have been limited by a lack of blinding, small samples, or a failure to measure allergen levels, disease activity, or a combination of these factors. This study investigates the efficacy of a high-efficiency air purifier in reducing disease activity in the homes of AR patients sensitive to the allergens produced by Artemisia (mugwort) pollen.MethodsThis is a randomized, double-blind, clinical controlled trial that will test active and inactive versions of an air purifier (Atmosphere®; Amway China). Sixty AR patients sensitive to the allergens produced by Artemisia pollen will be assigned randomly to two groups of equal numbers. All patients will undergo a 4-week treatment period and a 4-week observation period. Evaluation will be conducted at baseline (day 0) and on days 7, 14, 21, 28, and 56. The primary outcome measure will be the difference in visual analog scale scores from baseline. Secondary outcomes will be changes from baseline in nasal symptoms, allergy symptom scores, responses to the Rhinoconjunctivitis Quality of Life Questionnaire, Epworth Sleepiness Scale scores, and tolerability scores for the air purifier. Side effects of treatment will be recorded.DiscussionReducing exposure to allergens can reduce the risk of conditions such as AR. We hypothesise that AR patients sensitive to the allergens produced by Artemisia pollen will not suffer symptoms in a pollen-free environment. AR patients can remove pollen from their homes using air purifiers, decreasing the risk of symptoms. We expect that our study results will provide reliable evidence for determining the effects of air-purification therapy.Trial registrationChiCTR-INR-17012481. (Retrospectively registered 26 August 2017).

Do Plantago lanceolata Skin Prick Test-Positive Patients Display IgE to Genuine Plantain Pollen Allergens? Investigation of Pollen Allergic Patients from the North-East of France

Background: English plantain (Plantago lanceolata) is an important weed pollen allergen source triggering allergic symptoms during summer. To elucidate genuine versus cross-reactive sensitization, we investigated IgE reactivity patterns and inhibition capacities of plantain-sensitized patients. Methods: Sera of 35 rhinoconjunctivitis patients from the north-east of France with positive skin prick tests (SPT) to Plantago lanceolata pollen were tested with clinically relevant allergen sources using ELISA, ImmunoCAP, and immunoblot inhibition. Results: The patients were multisensitized with additional reactivity to grass (94.3%), ash (74.3%), birch (71.4%), and mugwort (55.2%) pollen in SPT. Sensitization prevalence to allergen molecules was 34.3% (Pla l 1), 94.3% (Phl p 1/5), 60.0% (Ole e 1), 65.7% (Bet v 1), 37.1% (profilin), and 40.0% (CCD). In immunoblot, IgE reactivity to plantain pollen was inhibited with relevant pollen extracts and purified rPla l 1. Two sera did not reveal any IgE cross-reactivity, while reactivity to plantain was efficiently inhibited by grass pollen in the sera of 10 patients. The sera from 17 different patients could be inhibited by grass, birch, or ash pollen to varying degrees. Thus, only 37.1% of our patients demonstrated true plantain pollen sensitization, while 62.9% were solely positive due to IgE cross-reactive molecules from other clinically relevant pollen. Conclusions: Plantain pollen-sensitized patients are multi-reactors demonstrating varying and complex IgE-reactivity profiles. In vivo and in vitro tests using extracts are typically blurred due to the presence of homologous allergens or CCD in grass, birch, or ash pollen. So far, Pla l 1 represents the only indicative marker allergen for the diagnosis of genuine plantain pollen sensitization.

Genetic restriction of antigen-presentation dictates allergic sensitization and disease in humanized mice

BackgroundImmunoglobulin(Ig)E-associated allergies result from misguided immune responses against innocuous antigens. CD4+ T lymphocytes are critical for initiating and perpetuating that process, yet the crucial factors determining whether an individual becomes sensitized towards a given allergen remain largely unknown. ObjectiveTo determine the key factors for sensitization and allergy towards a given allergen. MethodsWe here created a novel human T cell receptor(TCR) and human leucocyte antigen (HLA)-DR1 (TCR-DR1) transgenic mouse model of asthma, based on the human-relevant major mugwort (Artemisia vulgaris) pollen allergen Art v 1 to examine the critical factors for sensitization and allergy upon natural allergen exposure via the airways in the absence of systemic priming and adjuvants. ResultsAcute allergen exposure led to IgE-independent airway hyperreactivity (AHR) and T helper(Th)2-prone lung inflammation in TCR-DR1, but not DR1, TCR or wildtype (WT) control mice, that was alleviated by prophylactic interleukin(IL)-2-αIL-2 mAb complex-induced expansion of Tregs. Chronic allergen exposure sensitized one third of single DR1 transgenic mice, however, without impacting on lung function. Similar treatment led to AHR and Th2-driven lung pathology in >90% of TCR-DR1 mice. Prophylactic and therapeutic expansion of Tregs with IL-2-αIL-2 mAb complexes blocked the generation and boosting of allergen-specific IgE associated with chronic allergen exposure. ConclusionsWe identify genetic restriction of allergen presentation as primary factor dictating allergic sensitization and disease against the major pollen allergen from the weed mugwort, which frequently causes sensitization and disease in humans. Furthermore, we demonstrate the importance of the balance between allergen-specific T effector and Treg cells for modulating allergic immune responses.

Identification of a 62-kDa major allergen from Artemisia pollen as a putative galactose oxidase.

Around 20years ago, a 60- to 70-kDa protein was reported as a major allergen of mugwort (Artemisia vulgaris) pollen. This study was to identify and characterize its molecular properties. Sera from 113 Chinese and 20 Dutch Artemisia-allergic/sensitized subjects (and pools thereof) were used to identify the 60- to 70-kDa allergen. Pollen extracts of seven Artemisia species were compared by immunoblotting. Transcriptomics and proteomics (mass spectrometry) of A.annua pollen were used to identify the putative 60- to 70-kDa Artemisia allergen. Both the natural purified and recombinant allergens were evaluated for IgE reactivity by ImmunoCAP. Fourteen Chinese Artemisia-allergic patients were tested intradermally with purified natural allergen. Immunoblots revealed two major bands at 12 and 25kDa, and a weak band at 70kDa for all seven Artemisia species. Using a combined transcriptomic and proteomic approach, the high molecular mass allergen in A.annua pollen was shown to be a 62-kDa putative galactose oxidase, with a putative N-glycosylation site. More than 94% of Artemisia pollen-allergic patients had IgE response to this allergen. Although recognition of a nonglycosylated recombinant version was only confirmed in a minority (16%) and at much lower IgE levels, this discrepancy cannot be explained simply by reactivity to the carbohydrate moiety on the natural allergen. Intradermal testing with the natural allergen was positive in five of nine sensitized patients. The previously reported 60- to 70-kDa allergen of Artemisia pollen is most likely a 62-kDa putative galactose oxidase here designated Art an 7.

Changes in basophil activation during immunotherapy with house dust mite and mugwort in patients with allergic rhinitis.

BackgroundThe basophil activation test (BAT) is a promising tool for monitoring allergen-specific immunotherapy responses.ObjectiveWe aimed to investigate the changes in basophil activation in response to the inhalant allergens of house dust mite (HDM) and mugwort pollen during immunotherapy in patients with allergic rhinitis.MethodsWe enrolled patients with allergic rhinitis who were to receive subcutaneous immunotherapy for the inhalant allergens HDM or mugwort. A BAT was performed to assess CD63 upregulation in response to allergen stimulation using peripheral blood collected from the patients prior to immunotherapy and at 3, 6, 12, and 24 months after beginning immunotherapy. Rhinitis symptoms were evaluated using the rhinitis quality of life questionnaire (RQLQ) at 1-year intervals.ResultsSeventeen patients (10 with HDM sensitivity, 3 with mugwort sensitivity, and 4 with sensitivity to both HDM and mugwort) were enrolled in the study. Basophil reactivity to HDM did not change significantly during 24 months of immunotherapy. However, a significant reduction in basophil reactivity to mugwort was observed at 24-month follow-up. There was no significant association between the change in clinical symptoms by RQLQ and the change in basophil reactivity to either allergen. The change in allergen-specific basophil reactivity to HDM was well correlated with the change in nonspecific basophil activation induced by anti-FcεRI antibody, although basophil reactivity to anti-FcεRI antibody was not significantly reduced during immunotherapy.ConclusionSuppression of CD63 upregulation in the BAT was only observed with mugwort at 2-year follow-up. However, the basophil response did not reflect the clinical response to immunotherapy.

Biodiversity of pollen in indoor air samples as revealed by DNA metabarcoding

We conducted DNA metabarcoding (based on the nuclear ITS2 region) to characterize indoor pollen samples (possibly accompanied by other plant fragments) and to discover whether there are seasonal changes in their taxonomic diversity. It was shown that DNA metabarcoding has potential to allow a good discovery of taxonomic diversity. The number of spermatophyte families and genera varied greatly among sampling sites (pooled results per building) and times, between 9–40 and 10–66, respectively. Comparable Shannon's diversity indices equaled 0.33–2.76 and 0.94–3.16. The total number of spermatophyte genera found during the study was 187, of which 43.9, 39.6, 7.5 and 9.1% represented wild, garden/crop and indoor house plants, and non‐domestic fruit or other plant material, respectively. Comparable proportions of individual sequences equaled 77.4, 18.8, 2.7 and 1.1%, respectively. When comparing plant diversities and taxonomic composition among buildings or between seasons, no obvious pattern was detected, except for the second summer, when pollen coming from outdoors was highly dominant and the proportions of likely allergens, birch, grass, alder and mugwort pollen, were very high. The average pairwise values of SørensenChao indices that were used to compare similarities for taxon composition between samples among the samples from the two university buildings, two nurseries and farmhouse equaled 0.514, 0.109, 0.564, 0.865 and 0.867, respectively, while the mean similarity index for all samples was 0.524. Cleaning frequency may strongly contribute to the observed diversity. The discovery of considerable diversities, including pollen coming from outside, in both winter and summer shows that substantial amounts of pollen produced in summer enter buildings and stay there throughout the year.

Distinct epitope structures of defensin-like proteins linked to proline-rich regions give rise to differences in their allergenic activity.

BackgroundArt v 1, Amb a 4, and Par h 1 are allergenic defensin‐polyproline–linked proteins present in mugwort, ragweed, and feverfew pollen, respectively. We aimed to investigate the physicochemical and immunological features underlying the different allergenic capacities of those allergens.MethodsRecombinant defensin‐polyproline–linked proteins were expressed in E. coli and physicochemically characterized in detail regarding identity, secondary structure, and aggregation status. Allergenic activity was assessed by mediator releases assay, serum IgE reactivity, and IgE inhibition ELISA using sera of patients from Austria, Canada, and Korea. Endolysosomal protein degradation and T‐cell cross‐reactivity were studied in vitro.ResultsDespite variations in the proline‐rich region, similar secondary structure elements were observed in the defensin‐like domains. Seventy‐four percent and 52% of the Austrian and Canadian patients reacted to all three allergens, while Korean patients were almost exclusively sensitized to Art v 1. This was reflected by IgE inhibition assays demonstrating high cross‐reactivity for Austrian, medium for Canadian, and low for Korean sera. In a subgroup of patients, IgE reactivity toward structurally altered Amb a 4 and Par h 1 was not changed suggesting involvement of linear epitopes. Immunologically relevant endolysosomal stability of the defensin‐like domain was limited to Art v 1 and no T‐cell cross‐reactivity with Art v 125‐36 was observed.ConclusionsDespite structural similarity, different IgE‐binding profiles and proteolytic processing impacted the allergenic capacity of defensin‐polyproline–linked molecules. Based on the fact that Amb a 4 demonstrated distinct IgE‐binding epitopes, we suggest inclusion in molecule‐based allergy diagnosis.

Sensitization patterns and minimum screening panels for aeroallergens in self-reported allergic rhinitis in China

Optimization of skin prick test (SPT) panels, especially in view of significant differences in sensitizations patterns within different geographical areas, is an unmet need within China. Our aim was to assess the patterns and clinical relevance of aeroallergen sensitizations in allergic rhinitis (AR) and define the minimal battery of SPT allergens, classified according to the Köppen-Geiger climate map. Overall, 7148 subjects with self-reported AR completed a standard questionnaire and were assessed for sensitization to relevant allergens by SPT. 6340 (88.7%) patients had at least one positive skin prick reaction, and demonstrated unique sensitization patterns by stratification with age, gender, and geographic region. Sensitization to house dust mites (HDM) was highest in south China, whereas the three most prevalent aeroallergens were mugwort, ragweed and dandelion pollen in north-west China. Higher sensitization rates and multiple sensitizations were associated with AR comorbidities. Eight allergens (Der f, mugwort, Blatella, hazel, goosefoot, Penicillium notatum, animal dander and Der p) allowed identification >96% of sensitized subjects in central China. Differences in optimal panels were observed between regions, with five to six allergens being sufficient for north-east, north-west and south China. These SPT panels may provide a cost-effective tool for screening sensitized patients in China.