Birch Pollen Research Articles (Page 1)

Analysis of 1175 Korean adults in the 2019 KNHANES study found that sensitization to house dust mites and birch pollen significantly increased glaucoma risk, while oak pollen sensitization showed a protective effect. The relationship between allergen sensitization and glaucoma remains poorly understood. This study investigated the association between specific allergen sensitization patterns and glaucoma risk using data from the 2019 Korea National Health and Nutrition Examination Survey. In this population-based cross-sectional study, we analyzed 1175 adult participants (≥19y) who completed ophthalmologic examinations and allergen sensitization assessments. Glaucoma diagnosis was based on International Society of Geographical and Epidemiological Ophthalmology criteria. Specific IgE antibodies against 7 common allergens were measured using ImmunoCAP assays, with significant sensitization defined as IgE ≥3.5kU/L. We employed the Synthetic Minority Over-sampling Technique to address class imbalance. Multiple logistic regression models were employed to evaluate associations between allergen sensitization and glaucoma, adjusting for demographic and clinical factors. Among the participants, 50 (4.3%) were diagnosed with glaucoma. Analysis of allergen sensitization patterns revealed house dust mites as the most prevalent allergen (11.7% overall), with comparable rates between the glaucoma (12.0%) and non-glaucoma groups (11.7%). Birch pollen sensitization followed at 4.1% and 4.0% in the glaucoma and non-glaucoma groups, respectively. Multivariate logistic regression analysis, after adjusting for confounders, identified house dust mite sensitization as having the strongest positive association with glaucoma (OR: 3.08, 95% CI: 1.40-6.77, P =0.005), followed by birch pollen (OR: 2.69, 95% CI: 1.02-7.12, P =0.046). Interestingly, oak pollen sensitization demonstrated a protective effect (OR: 0.24, 95% CI: 0.07-0.81, P =0.022). Our findings suggest a complex relationship between allergen sensitization and glaucoma, with different allergens showing varying associations with disease risk.

Different urban environments shape the allergenicity and immunotoxicity of birch pollen.

Component-resolved diagnostics study on nut sensitization and cross-reactivity in China.

Comparing alder, birch and grass pollen concentrations derived from spatiotemporal statistical and dispersion models across Switzerland

Until now, no study has investigated the impact of allergen immunotherapy (AIT) on genome-wide DNA methylation in a longitudinal set-up. Herein, we investigated whether differences in DNA methylation occur in birch pollen allergic patients undergoing 6 months of birch pollen AIT, assessed alterations in methylation-based blood cell type composition, and correlated DNA methylation to serological AIT biomarkers. We performed genome-wide DNA-methylation analysis on bisulfite-converted DNA derived from whole blood samples of 16 birch pollen-allergic patients (pre-/post-birch pollen AIT) and 15 placebo (pre-/post-placebo treatment). Our analysis identified cg22187251, located within a regulatory region upstream of the glucosaminyl (N-acetyl) transferase 2 (GCNT2) gene and cg22336863 upstream of the transcription start site of actin binding rho activating protein (ABRA), as hypermethylated. Functional assays revealed that these regions exhibit methylation-dependent promoter and enhancer activities. We identified differentially methylated positions within the HLA gene complex, and an AIT-specific increase of CD8+ T cell populations accompanied by a decrease in natural killer (NK) cell proportion. Strong to moderate correlations with clinical biomarkers (such as specific IgG4) were observed for 42% of the top 100 differentially methylated positions. GCNT2 and ABRA are implicated in Rho-signaling, a pathway involved in Th2 differentiation. GCNT2 modulates the SMAD-dependent TGF-β pathway, indicating a role in mediating AIT-induced immunotolerance. This is the first longitudinal study investigating DNA methylation changes induced by birch pollen AIT.

European guidelines recommend using a standardized baseline series of skin prick test (SPT) allergens for the diagnosis of airway allergies. In addition, local adaptation and/or extension of test panels according to regional exposure and sensitization patterns are increasingly being discussed. Regional sensitization rates according to SPTs based on the most recent GA2LEN baseline series in Central Germany were retrospectively analyzed for 960 consecutive patients with respiratory symptoms at our university outpatient clinic. Additional SPT allergens of interest were further analyzed. High sensitization rates to the baseline SPT series were observed in our highly selected study cohort. The positivity rates were particularly high for olive pollen (30.8%) and plantain pollen (33.4%). Positive olive and birch pollen SPTs were found in 98.5% of olive-ash-birch pollen tested patients. High SPT positivity rates (98.1%) for plane tree and olive tree pollen were found, whereas only six patients (1.9%) were diagnosed with exclusive cypress pollen sensitization. Subgroup analysis of SPTs for palm tree pollen revealed that 92% of patients with palm tree positivity showed polysensitization, and all but one patient had concomitant grass pollen sensitization. Regular evaluations of SPT series may be necessary because of climate change, extract production, and increasing population mobility. Ash and cypress pollen extracts could currently be removed from the baseline SPT panel without significantly decreasing diagnostic accuracy. Positive SPTs to non-native palm tree pollen may indicate the presence of IgE to cross-reacting panallergens, which may help to differentiate primary sensitization from cross-reactivity directly. Limitations include the retrospective monocentric design and lack of molecular IgE confirmation.

<b>Introduction:</b> Exposure to pollen allergens is one of the key environmental factors determining the occurrence of allergic rhinitis. In Central Europe, tree pollen plays a significant role in triggering symptoms of inhalant allergy in the spring months.Aim: This study evaluated the deposition of tree pollen grains in a 3D anatomical model of the adult nasal cavity under varying flow rates (5 L/min, 7.5 L/min, and 20 L/min per nostril).<b>Material and methods:</b> Original methods of analysis were developed, including macroscopic analysis of photographs reflecting tree pollen deposits on the surface of the lateral wall of a printed 3D anatomical model of the nasal cavity and nasal septum, and microscopic evaluation of pollen collected from selected parts of the nasal geometry. The macroscopic analysis was supplemented with original software for the quantitative determination of areas covered with pollen deposits.<b>Results:</b> The results showed statistically significant differences in the regional deposition of pollen grains of different sizes in the nasal cavity, depending on the flow conditions. The deposition of birch, alder, and hazel pollen grains in the nasal cavity exhibits similar characteristics, with significant differences between the individual segments of the lateral wall and the nasal septum. While the middle segment of the lateral wall accounted for the largest segment share of the total lateral wall deposition, the highest relative pollen deposition in relation to the segment area was found in the front segment. The posterior segment of the lateral wall showed a marginal contribution to the deposition process. The most significant percentage of the segment area of the nasal septum covered with pollen was recorded in the anterior segment. However, the posterior segment accounted for a larger share of the total septal deposition due to its larger surface area. Consistent findings describe deposits of large pollen grains from pine and spruce trees. The values of segmental pollen deposition in the anterior segment were significantly higher than in the other segments. The deposition on the nasal septum was significantly greater in the anterior than in the posterior segment. Lateral wall share % and septal share % tended to increase with increasing airflow through the nasal cavity, reaching their highest values at 20 L/min. The intensification of airflow led to a shift in the location of maximum pollen deposition towards the anterior sections of the nose, with a simultaneous reduction in pollen penetration into the posterior segments.<b>Conclusions:</b> The study confirms the role of inertial effects in the flow and deposition of aerosols in the nasal cavity, indicating that the large size of pollen grains and higher airflow rates promote pollen deposition mainly in the anterior regions of the lateral wall and nasal septum. However, it also shows that other deposition mechanisms, such as direct interception in the case of grain aggregates, and differences in effective particle density, may influence the spatial distribution of deposited pollen in the nasal cavity. The results obtained should facilitate the control of allergen exposure and the use of topical treatment.

Conformational plasticity of β-rich proteins: Molecular insights into stability, dynamics, and functional adaptation of Bet v 1-like proteins.

Celery can trigger severe food allergies and is often associated with birch pollen allergies. Although celery must be declared on food labeling in the European Union, few studies have investigated its allergen content. This study introduces a simultaneous quantitative method to determine the actual content of two isoallergens of Api g 1 in fresh and processed celery, by using mass spectrometry. Excellent analytical performance was achieved, with limits of detection and quantification of 0.06 μg/g and 0.13 μg/g, respectively, with recovery range of 95.0-80.4%, and intra- and inter-day precision relative standard deviation values of 8.0-2.0% and 11.0-5.1%, respectively. Furthermore, the calculated content of the total Api g 1 isoallergens in raw celery ranged from 3.24-91.25 μg/g. Therefore, this method is useful for providing reliable data to the food industry and people with food allergy.

Modelling of airborne birch pollen over Central Europe - model evaluation and sensitivity analysis.

ABSTRACTAllergen immunotherapy (AIT) of patients with IgE‐mediated allergy results in the synthesis of blocking IgG antibodies mediating allergen tolerance. However, as antibody concentrations wane after stopping AIT, tolerance may be lost. The impact of a single booster allergen application on B‐cellular memory in AIT‐treated birch pollen (BP)‐allergic patients was investigated. Twenty‐five patients with BP allergy who finished AIT 3–12 years ago received one allergen injection approximately 4 months prior to the next BP season. We determined peripheral Bet v 1‐specific IgG‐secreting cells (ASC) by ELISPOT analysis and BP‐specific IgG, IgG4, and IgE serum antibodies by ImmunoCAP, and the allergen‐blocking capacity of IgG/IgG4 antibodies by ELIFAB assay. Clinical responses were assessed by visual analog scales. Immunological findings were compared with the primary B cell response of 12 BP‐allergic patients receiving conventional AIT. Bet v 1‐specific ASC significantly increased 2–4 weeks after BP‐injection, accompanied by enhanced levels of both BP‐specific IgG/IgG4 antibodies and allergen‐blocking serum activity. Compared with conventional up‐dosing, a single booster vaccination led to a markedly stronger B cell response after 4 weeks. Allergen booster injection activates B‐cellular memory associated with blocking IgG/IgG4 antibodies, pointing to reinforcement of allergen tolerance after completion of AIT.

A novel device, Skin Prick Automated Test (SPAT), previously showed reduced variability and more consistent test results compared to conventional skin prick test (SPT) to identify allergic sensitisation. This study aimed to clinically validate the adjusted SPAT cut-off in patients with confirmed birch or house dust mite (HDM) allergy. Seventy-five adults were included: 25 non-allergic subjects (confirmed by lack of allergy history and negative SPT), 25 birch and 25 HDM allergic rhinitis patients (both confirmed by positive SPT and nasal allergen challenge [NAC]). All subjects received a conventional SPT and an automated SPT for B ver, D pter, D far and control solutions. A cut-off of 4.2 and 4.1 mm, respectively, resulted in the highest accuracy to detect birch or HDM allergy using SPAT. Referring to previous study results suggesting a reliable cut-off value of 4.5 mm, it was decided to maintain 4.5 mm as SPAT cut-off indicating allergic sensitisation. Accuracy did not significantly differ between SPAT (96% using 4.5 mm) and conventional SPT (98% using 3.0 mm) to detect HDM allergy or to detect birch pollen allergy (100% for SPAT and SPT). SPAT wheal measurements performed through a ruler on the forearm or through digital measurement on a composite image did not significantly differ for any of the patient groups analysed. SPAT showed an equivalent accuracy to detect birch pollen or HDM allergy compared to conventional SPT, using the adjusted 4.5 mm SPAT cut-off in patients with confirmed allergic rhinitis. The SPAT web viewer can be used easily and effectively for digital wheal measurement on a composite image.

Structured Fresh Apple Consumption for Birch Pollen Food Allergy Syndrome in an Uncontrolled Phase II/III Trial.

Introduction and Aim of the Study: During the birch pollen season, cross-reactions between the allergen Bet v 1 and the Mal d 1 allergen from apples can induce pollen-related food allergy (prFA), particularly after apple consumption. The aim of this study is to investigate the molecular mechanisms of this allergy and present effective treatment and prevention methods, which could significantly improve the quality of life for allergy sufferers. Review Methods: The PubMed database was used for the literature review. English search terms included: “allergy,” “apple varieties,” “birch pollinosis,” “allergen-specific immunotherapy,” “birch pollen-associated food allergy syndrome,” and “Mal d 1.” Overview of Current Knowledge: Birch pollen allergy is one of the most common pollen allergies, with the Bet v 1 protein responsible for cross-reactive allergic responses following apple consumption. In apples, the Mal d 1 allergen triggers these reactions, which is particularly significant in Central and Northern Europe. Apples with red flesh are considered hypoallergenic due to their low Mal d 1 content and are a beneficial choice for allergic individuals. Various immunotherapy approaches, including sublingual immunotherapy, are utilized effectively to alleviate symptoms and support allergen tolerance. Conclusion: Pollen-related food allergy associated with birch pollen significantly affects the daily lives of allergy sufferers, especially during the birch pollen season. Advances in molecular mechanism research have allowed the identification of apple varieties with lower allergenic potential, enabling their use in immunotherapy and offering hope for improving patients' quality of life.

Background: Pollen-Food Allergy Syndrome (PFAS) typically presents as mild oral symptoms but can rarely progress to systemic reactions. Pathogenesis-related proteins group 10 (PR-10) are proteins usually associated with oral allergy syndrome due to their thermolabile and gastrolabile properties. Case Presentation: We report a 12-year-old boy with birch pollen allergy who developed anaphylaxis after raw carrot consumption without identified cofactors. Previously, he experienced only oral allergy syndrome with raw carrot and fennel. Molecular diagnostics confirmed isolated PR-10 sensitization. The reaction occurred during birch pollen season, and the patient tolerated cooked carrot, consistent with PR-10's thermal instability. Conclusions: This case highlights how PFAS, typically characterized by mild and localized symptoms, can occasionally manifest with systemic reactions. High levels of specific IgE for Bet v 1 and pollen season may represent risk factors for systemic reactions in PFAS patients. Clinicians must be aware that allergies due to pollen cross-reactive allergens can be associated with systemic reactions.

Hypoallergenic recombinant fold-variants of major allergens have been suggested as safer and more effective AIT candidates. The Bet v 1-fold variant BM41, with confirmed preclinical hypoallergenicity and increased immunogenicity, was proposed for the treatment of birch pollen allergy. We performed a 6-month randomized, double-blind, placebo-controlled first-in-human clinical trial with BM41, a licensed birch pollen extract-based treatment, as the active comparator (AC), and placebo (n = 16, n = 16, and n = 15, respectively). The primary endpoint was safety. Secondary outcomes were Bet v 1-specific (s)IgE, IgG, IgG1, and IgG4 responses measured by ImmunoCAP, and sIgE-blocking activity using mediator release and facilitated antigen binding assays. Despite SPT-confirmed hypoallergenicity (~50% compared to natural Bet v 1), more adverse events occurred in response to BM41. Although similar sIgG and sIgG1 levels were induced, sIgG4 levels increased 3-fold more in AC compared to the BM41 group. In AC, the sIgG4/sIgG1 ratio tripled over time, whereas for BM41 it stagnated. BM41 induced efficient serum inhibitory activity for sIgE compared to placebo but was 12%-32% less efficient than AC. Both sIgG4 and sIgG1 contributed to the blocking effect in AC, while in BM41 both sIgG subclasses showed a lowered functional capacity. Preclinically established hypoallergenicity of BM41 did not result in a lower number of adverse events. The reduced induction of sIgG4 by the fold variant in the course of the treatment was less efficient in blocking sIgE-mediated responses. This is the first study providing evidence that, instead of a Th1-favored IgG1-dominated response, "modified Th2"-skewed IgG4-dominated humoral responses are beneficial in AIT vaccine design.

Pollen allergy is rated as a major public health problem, causing significant morbidity and adversely affecting the quality of people's lives. The airway epithelium serves as the first line of defense in the respiratory system, playing a crucial role in orchestrating immune responses to allergens. In this work, we studied the important transport steps in the major alder pollen allergen Aln g 1 through the human airway epithelium in comparison with those of the birch pollen allergen Bet v 1. Using fluorescence spectroscopy, we showed that both allergens can destroy liposomes with a composition modeling the adult human pulmonary surfactant. Using a polarized Calu-3 monolayer, we showed similar efficiencies of Aln g 1 and Bet v 1 transport through the artificial epithelial barrier. Using qPCR, we showed that Aln g 1 upregulates the expression of IL-33, TSLP, IL-1β, CXCL8 in epithelial cells, playing an important role in the sensitization process. The obtained results may improve our understanding of the primary sensitization mechanisms with the involvement of the PR-10 family of lipid-binding allergens.

Introduction: To determine threshold concentrations of pollen inducing symptoms in seasonal allergic rhinitis patients has been a challenge for decades. Allergen challenge chambers (ACC) allow a controlled, reproducible experimental design to address this problem. Hitherto, ACCs were only run with high pollen concentrations. Methods: The Fraunhofer ACC was technically modified to deploy very low pollen concentrations. Then, adults with birch pollen-induced allergic rhinitis were challenged with varying birch pollen concentrations using a patient-blinded, sham challenge-controlled, part-randomized, titrate-to-effect clinical study setting. Mean increase in Total Nasal Symptom Score (TNSS) ≥0.55 compared to sham challenge was regarded as minimal clinically important difference (MCID). Further endpoints were nasal secretion weight, exhaled nitric oxide (FeNO), and inflammatory cells from nasal lavage. Results: Fifteen participants with mild to moderate allergic rhinitis participated in the experimental study part (mean age 45 years [22–64]; 7 females). Mean TNSS was: 1.08 at 0 pollen/m3; 1.05 at 10 pollen/m3; 1.2 at 50 pollen/m3; 1.74 at 100 pollen/m3; 1.61 at 200 pollen/m3; 2.79 at 1,000 pollen/m3. MCID of TNSS was observed at 100, 200, and 1,000 pollen/m3. More than half of the study population showed a lack of response at 10, 50, and 200 pollen/m3. Nasal secretion increased slightly with concentration. No clinically meaningful results could be derived from FeNO and inflammatory cells. Conclusions: The applied technical modification of the Fraunhofer ACC produced stable, low pollen concentrations. Based on mean TNSS data, the threshold concentration for inducing symptoms with birch pollen was 50–100 pollen/m3.

Spice allergies are often under-recognized and under-researched, leading to delays in diagnosis and treatment. Cross-reactivity with other plant allergens further complicates accurate diagnosis. This literature review seeks to systematize and analyze current data on hypersensitivity to spices, including pepper, cumin, oregano, anise, mustard, and other seasonings. The review covers research published from 2010 to 2023 in peer-reviewed journals, books, and conference proceedings, sourced from databases such as PubMed, Scopus, Web of Science, and Google Scholar. The main pepper allergens are PR-10 proteins, profilins and defensins. They can cause cross-allergic reactions with pollen and other plant allergens. Cumin allergens belong to the PR-10 family and can provoke allergic reactions. Cross-reactivity between cumin and other umbelliferae is common. Oregano contains Bet v 1 allergens and profilins, often leading to cross-allergies with other spices and plants. Allergies to anise are less common but can be a serious problem due to cross-reactivity with birch pollen. Mustard is one of the most allergenic spices. These proteins can cause severe reactions even in small amounts. Diagnosis is carried out using skin prick tests and blood tests for specific IgE antibodies. Cross-reactivity among spices and other allergens complicates the diagnosis and management of spice allergies. This review will be useful for the development of personalized dietary recommendations for patients, accounting for cross-reactivity and individual sensitization profiles.

Birch pollen allergen-induced dsDNA release activates cGAS-STING signaling and type 2 immune response in mice.