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Background Methods Results Conclusions Subcutaneous immunotherapy has emerged as an effective option for treating allergic diseases. Here, we assessed the clinical impact of the mannan‐conjugated birch pollen polymerized allergoid T502 in birch pollen‐induced allergic rhinoconjunctivitis.In this prospective, randomized, double‐blind placebo‐controlled phase III trial, 298 birch pollen–allergic adult patients were treated across 28 trial sites in Germany. Patients received either placebo or 23,000 mTU T502 subcutaneously over five pre‐seasonal visits. Efficacy was assessed by comparing the combined symptom and medication score (CSMS) between placebo and T502 during the peak birch pollen season 2022. Safety, tolerability and immunologic effects were also analyzed.During the peak birch pollen season, the median CSMS of the T502 group was reduced by 33% (p = 0.002) compared to placebo. The median daily symptom score and daily medication score were reduced by 30.4% (p < 0.001) and 56.3% (p = 0.045), respectively. Health related quality of life improved as reflected by reduction of RQLQ values by 31.5% (p < 0.0001). Production of Bet v 1 sIgG4 and Bet v 1 sIgG increased up to 6.2‐fold and 3‐fold respectively in the T502 group (p < 0.0001). The sIgE/sIgG4 ratio was strongly reduced in the T502 group at V7 (−62.9%, p < 0.0001).No fatalities nor serious adverse events were reported. In total, 16 systemic allergic reactions occurred (Grade I/II).Treatment with T502 significantly reduced symptoms and medication need in rhinoconjunctivitis patients. The treatment is well tolerated and safe. [ABSTRACT FROM AUTHOR]

Pollen, in addition to allergens, comprise low molecular weight components (LMC) smaller than 3 kDa. Emerging evidence indicates the relevance of LMC in allergic immune responses. However, the interaction of birch pollen (BP)-derived LMC and epithelial cells has not been extensively studied. We investigated epithelial barrier modifications induced by exposure to BP LMC, using the human bronchial epithelial cell line 16HBE14o-. Epithelial cell monolayers were apically exposed to the major BP allergen Bet v 1, aqueous BP extract or BP-derived LMC. Barrier integrity after the treatments was monitored by measuring transepithelial electrical resistance at regular intervals and by using the xCELLigence Real-Time Cell Analysis system. The polarized release of cytokines 24 h following treatment was measured using a multiplex immunoassay. Epithelial barrier integrity was significantly enhanced upon exposure to BP LMC. Moreover, BP LMC induced the repair of papain-mediated epithelial barrier damage. The apical release of CCL5 and TNF-α was significantly reduced after exposure to BP LMC, while the basolateral release of IL-6 significantly increased. In conclusion, the results of our study demonstrate that BP-derived LMC modify the physical and immunological properties of bronchial epithelial cells and thus regulate airway epithelial barrier responses. [ABSTRACT FROM AUTHOR]

Pollen traps, the current gold standard to determine pollen load and thereby the allergy season, are not sufficient to determine the allergenic risk. Therefore, the establishment of highly sensitive assays for allergen measurement is of highest interest. Herein, a graphene field-effect transistor (GFET) was constructed on an interdigitated electrodes chip to develop an immersible biosensor, which was used to detect the major birch pollen allergen Bet v 1. Graphene was wet-transferred on interdigitated electrodes that contain a reference electrode used as a liquid gate in the GFET. Using a standard ELISA protocol, two different anti-Bet v 1 antibodies were chosen and immobilized on graphene for the specific capture of the target allergen. The sensitivity of the GFET biosensor was evaluated using a standard Ag/AgCl liquid gate electrode and a reference electrode when the chip was immersed in Bet v 1-containing solutions. The results showed a higher performance and sensitivity for Bet v 1 detection compared to a mediator release method, one of the most sensitive assays for allergen detection. Compared with conventional methods of allergen detection, these immersible biosensors significantly improved the speed and level of detection providing the foundation of a point-of-need platform for in-field application. Furthermore, the proposed technique provides both a new biosensor for allergen detection and a strategy for designing low-cost integrated biosensors.

Background: Nasal allergen challenge (NAC) is used to investigate the effects of allergen exposure and assess treatment efficacy in allergic rhinitis (AR). This study aims to establish dose‐responses to NAC using licensed silver birch (SB) pollen and house dust mite (HDM) sublingual tablets as sources of the allergen extracts in participants with AR. Methods: Sixteen volunteers with HDM‐induced perennial AR and 15 volunteers with SB pollen‐induced seasonal rhinitis underwent a graded up‐dosing NAC with extracts derived from HDM allergen (Acarizax®) and SB (Itulazax®) tablets, respectively. Total nasal symptom score (TNSS, range 0–12) and peak nasal inspiratory flow (PNIF) were recorded before, at 10 min and at the end of the NAC. The dose of each allergen that provoked a TNSS of at least 7 ("provoking dose 7") in most allergic participants was identified. NACs using the "provoking dose 7" were performed on 5 non‐allergic individuals to test for irritant effects. The "provoking dose 7" of HDM extract was used in a subgroup of two SB allergic, non‐HDM allergic, volunteers, and vice versa for SB extract, to test for allergen specificity of the responses. Results: Most patients experienced a TNSS of at least 7/12 at a median concentration of 1500 AU/mL for both SB pollen and HDM. The average decline in PNIF at this dose was 63.15% for SB and 63.99% for HDM. NACs using the 1500 AU/mL concentrations were performed on 5 non‐allergic individuals with no symptomatic or PNIF response. 1500 AU/mL of HDM extract produced no symptoms in SB allergics nor 1500 AU/mL SB extract in HDM allergics. Conclusion: For both SB and HDM extracts, the optimal allergen dose for NAC to cause a moderate‐severity response ("provoking dose 7/12") was 1500 AU/mL. Licensed sublingual allergen tablets provide a readily available and inexpensive source of SB and HDM extracts for use in future interventional studies in AR. [ABSTRACT FROM AUTHOR]

Background: There is still great need to develop new strategies to improve the efficacy of allergen immunotherapies with optimal safety standards for patients. A new promising approach is to couple allergoids to mannan. The objective of this phase IIa/IIb study was to identify the optimal dose of mannan‐conjugated birch pollen allergoids for the short‐course treatment of birch pollen–induced allergic rhinoconjunctivitis. Methods: For this prospective, randomized, double‐blind, placebo‐controlled, dose‐finding study, 246 birch pollen–allergic adults received 0.5 mL placebo or 1000, 3000 or 10,000 mTU/mL of mannan‐conjugated birch pollen allergoids at five pre‐seasonal visits. Efficacy was assessed by comparing allergic rhinoconjunctivitis symptoms and use of anti‐allergic medication during the peak of the birch pollen season 2020. Immunologic, tolerability and safety effects were also analysed. Results: The highest dose of mannan‐conjugated birch pollen allergoids reduced the combined symptom and medication score during the peak birch pollen season by a median of 24.7% compared to placebo. The production of Bet v 1 specific IgG4 significantly increased in a dose‐dependent manner (3.6‐ and 4.5‐fold) in the 3000 and 10,000 mTU/mL groups. The Bet v 1 specific IgE/IgG4 ratio was also strongly reduced (up to −70%). No fatalities nor serious adverse events were reported, and no adrenaline was used. In total, four systemic reactions occurred (two grade I and two grade II). Conclusion: All doses of mannan‐conjugated birch pollen allergoids can be considered as safe. Since the application of 10,000 mTU/mL resulted in the highest efficacy, this dose qualifies for further investigation. [ABSTRACT FROM AUTHOR]

Abstract Background Nasal allergen challenge (NAC) is used to investigate the effects of allergen exposure and assess treatment efficacy in allergic rhinitis (AR). This study aims to establish dose‐responses to NAC using licensed silver birch (SB) pollen and house dust mite (HDM) sublingual tablets as sources of the allergen extracts in participants with AR. Methods Sixteen volunteers with HDM‐induced perennial AR and 15 volunteers with SB pollen‐induced seasonal rhinitis underwent a graded up‐dosing NAC with extracts derived from HDM allergen (Acarizax®) and SB (Itulazax®) tablets, respectively. Total nasal symptom score (TNSS, range 0–12) and peak nasal inspiratory flow (PNIF) were recorded before, at 10 min and at the end of the NAC. The dose of each allergen that provoked a TNSS of at least 7 (“provoking dose 7”) in most allergic participants was identified. NACs using the “provoking dose 7” were performed on 5 non‐allergic individuals to test for irritant effects. The “provoking dose 7” of HDM extract was used in a subgroup of two SB allergic, non‐HDM allergic, volunteers, and vice versa for SB extract, to test for allergen specificity of the responses. Results Most patients experienced a TNSS of at least 7/12 at a median concentration of 1500 AU/mL for both SB pollen and HDM. The average decline in PNIF at this dose was 63.15% for SB and 63.99% for HDM. NACs using the 1500 AU/mL concentrations were performed on 5 non‐allergic individuals with no symptomatic or PNIF response. 1500 AU/mL of HDM extract produced no symptoms in SB allergics nor 1500 AU/mL SB extract in HDM allergics. Conclusion For both SB and HDM extracts, the optimal allergen dose for NAC to cause a moderate‐severity response (“provoking dose 7/12”) was 1500 AU/mL. Licensed sublingual allergen tablets provide a readily available and inexpensive source of SB and HDM extracts for use in future interventional studies in AR.

Xiaoyan Wang,1,2 Lijia Chen,1 Jiaqi Ding,3 Hongtian Wang,1 Xueyan Wang1,2 1Department of Allergy, Beijing Shijitan Hospital, Capital Medical University, Beijing, 100038, People’s Republic of China; 2Beijing Laboratory of Allergic Diseases, Beijing Municipal Education Commission, Beijing, 100038, People’s Republic of China; 3Department of Otolaryngology, Qingdao Women and Children’s Hospital Affiliated to Qingdao University, Qingdao, Shandong, 0355729, People’s Republic of ChinaCorrespondence: Xueyan Wang, Hongtian Wang, Tieyi Road, No. 10th, Haidian District, Beijing, 100038, People’s Republic of China, Tel +86 13810570961 ; +86 13391836668, Email allergy_wxy@126.com; wht301@263.netPurpose: To investigate the major allergen components associated with birch pollen allergy in northern China and elucidate clinical relevance to pollen food allergy syndrome (PFAS).Methods: Fifty-eight patients were recruited for a cross-sectional study and categorized into two groups: PFAS group and non-PFAS group, as well as apple allergy group and non-apple allergy group. The sIgE levels of birch pollen and its components, namely Bet v 1, Bet v 2, Bet v 4, and Bet v 6, were analyzed.Results: Among 58 participants, 44 individuals (75.9%) reported PFAS. 32 out of 44 (72.7%) participants reported apple allergy. Bet v 1 exhibited the highest sensitization rate at 82.8%, followed by Bet v 2 (29.3%) and Bet v 6 (1.7%). The combined sensitization rate for Bet v 1 and/or Bet v 2 was 93.1%. A total of 77.6% of the subjects demonstrated sensitization to single component, while 19.0% exhibited sensitization to two components. The sIgE levels of birch pollen and Bet v 1 were significantly elevated in PFAS group compared to non-PFAS group (p=0.001, p< 0.001, respectively), as well as in apple-allergic and non-apple-allergic group (p< 0.001, p< 0.001, respectively). The optimal cut-off values for birch pollen and Bet v 1 sIgE were determined to be 7.09 kUA/L (with a sensitivity of 84.1% and specificity of 78.6%) and 5.11 kUA/L (with a sensitivity of 75.0% and specificity of 85.7%) when diagnosing PFAS. In terms of apple allergy, the optimal cut-off value were 9.40 kUA/L (with a sensitivity of 81.3% and specificity of 76.9%) and 6.53 kUA/L (with a sensitivity of 84.4% and specificity of 84.6%), respectively.Conclusion: The predominant sensitization pattern is mono-sensitization to Bet v 1, but when considering immunotherapy, Bet v 2 should also be taken into account. Bet v 1 serves as a valuable biomarker for diagnosing PFAS and apple allergy.Keywords: birch pollen, allergen component, Bet v 1, pollen food allergy syndrome, apple allergy

The intensity of birch pollen season is expressed by seasonal pollen integral (SPIn, the sum of the mean daily pollen concentration during the birch pollination period) and the amount of Bet v 1 allergen released per birch pollen grain expressed by pollen allergen potency (PAP). Betula pollen and Bet v 1 allergen were simultaneously measured in the air of Bratislava from 2019 to 2022 by using two Burkard traps (Hirst-type and cyclone) in order to evaluate the causes of the seasonal variation in the SPIn and PAP levels. The highest SPIn (19,975 pollen/m3) was observed in 2022 and the lowest one (1484 pollen/m3) in 2021. The average daily PAP level (4.0 pg Bet v 1/pollen) was highest in 2019 and lowest (2.5 pg Bet v 1/pollen) in 2020. We found that seasonal variation in SPIn was associated mainly with the changes in environmental conditions during the pre-season period, whereas the year-to-year variation in PAP levels was attributed to environmental conditions during both pre- and in-season periods. Our results indicate that rainy weather in June 2020 and cold overcast weather in January‒February 2021 resulted in low SPIn in 2021. On the other hand, dry weather in June 2021 and warm weather in January‒February 2022 resulted in high SPIn in 2022. The low average daily PAP level in 2020 was associated with (1) low levels of gaseous air pollutants in March, when the ripening of pollen takes place; (2) an earlier start of the birch main pollen season (MPS); and (3) dry weather during the MPS. On the other hand, high PAP level in 2019 was associated with higher levels of air pollutants in March and during the MPS. [ABSTRACT FROM AUTHOR]

Experimental seasonal forecasts using the INM-CM5 climate model have been applied as the input data for the temperature–time phenological model of birch pollination. A test method has been developed within the framework of the joint model for the seasonal forecasting of the time of the beginning of birch pollen dispersion in the European territory of Russia. Verification of this method on seasonal retrospective forecasts of the INM-CM5 model (in 1991–2019) has shown an adequate reproduction of the days of the beginning of birch pollen season simulated for the same period based on ERA5 reanalysis. The mean systematic errors are ±2 days, and the spatial correlation coefficients exceed +0.84. The forecasts of the date of pollen dispersion beginning in 2022 simulated from the experimental operational seasonal forecasts using the INM-CM5 model with a monthly lead time and with a zero lead time are also evaluated. It is shown that the errors in forecasting the onset of pollen dispersion are ±5–10 days, with smaller errors of forecasts with a 1-month lead time. The results allow us to conclude that the seasonal forecast of the surface temperature based on the INM-CM5 model can be used as input information for the temperature–time phenological model for the operational forecast of the start time of birch pollen dispersion in the European territory of Russia. [ABSTRACT FROM AUTHOR]

Dupilumab reduces symptom burden in allergic rhinitis and suppresses allergen-specific IgE production Keywords: allergen-specific; allergy; birch pollen; dupilumab; grass pollen EN allergen-specific allergy birch pollen dupilumab grass pollen 1687 1691 5 06/02/23 20230601 NES 230601 To the Editor, Type 2 immune responses underlie many respiratory diseases including allergy and chronic rhinosinusitis. In some patients, allergen-specific IgE levels in nMLF dropped even below the detection limit (e.g. patient #1, 2 and #3 for selected allergens). Male patients experienced on average a larger reduction in total IgE in nMLF but not in serum and the percentage reduction in serum IgE levels correlated negatively with the number of allergens a patient was sensitised to (Tables S2 and S3). [Extracted from the article]

Background: Pollen variation can affect field study data quality. Nasal allergen challenge (NAC) is considered the gold standard for evaluating allergic rhinitis, while environmental exposure chambers (EECs) are mainly used in phase 2 drug development studies. We aimed to study birch-induced allergic rhinitis under 3 different conditions. Methods: This study included 30 participants allergic to birch pollen, based on birch skin prick test, specific immunoglobulin E (IgE), and positive NAC. Participants were exposed to placebo twice, followed by 2 consecutive 4-h birch airborne exposures, repeated on 2 occasions to evaluate reproducibility and priming effect. Nasal response was defined as total corrected nasal symptom score (ΔTNSS) ≥ 5 during NAC and EEC. The primary end-point was to measure TNSS during the last 2 h of first allergen exposure. TNSS was also analyzed during natural exposure. Results: The dose most commonly yielding positive TNSS during NAC was 175.2 ng/200 μL. Eighteen participants experienced ΔTNSS ≥5 during the last 2 h of the first exposure, whereas 21 had positive responses at all 4 exposures. Mean ΔTNSS was 1 with placebo versus 6 with birch. Exposures were reproducible, with no observed priming effect. Airborne Bet v 1 was 25 ng/m3, while the pollen measurement was 279/m3 during pollen season. TNSS reached 5 in 67.9% of participants during peak pollen season. Conclusion: EEC outcomes were similar to those obtained with NAC and natural exposure, suggesting the usefulness of EEC in allergic rhinitis studies. The primary end-point was reached, as 60% of participants experienced nasal responses.

Type I respiratory allergies to birch pollen and pollen from related trees of the order Fagales are increasing in industrialized countries, especially in the temperate zone of the Northern hemisphere, but the reasons for this increase are still debated and seem to be multifaceted. While the most important allergenic molecules of birch pollen have been identified and characterized, the contribution of other pollen components, such as lipids, non-allergenic immunomodulatory proteins, or the pollen microbiome, to the development of allergic reactions are sparsely known. Furthermore, what also needs to be considered is that pollen is exposed to external influences which can alter its allergenicity. These external influences include environmental factors such as gaseous pollutants like ozone or nitrogen oxides or particulate air pollutants, but also meteorological events like changes in temperature, humidity, or precipitation. In this review, we look at the birch pollen from different angles and summarize current knowledge on internal and external influences that have an impact on the allergenicity of birch pollen and its interactions with the epithelial barrier. We focus on epithelial cells since these cells are the first line of defense in respiratory disease and are increasingly considered to be a regulatory tissue for the protection against the development of respiratory allergies.

Bet v 1 is the major allergen in birch pollen to which up to 95% of patients sensitized to birch respond. As a member of the pathogenesis-related PR 10 family, its natural function is implicated in plant defense, with a member of the PR10 family being reported to be upregulated under iron deficiency. As such, we assessed the function of Bet v 1 to sequester iron and its immunomodulatory properties on human immune cells. Binding of Bet v 1 to iron quercetin complexes FeQ2 was determined in docking calculations and by spectroscopy. Serum IgE-binding to Bet v 1 with (holoBet v1) and without ligands (apoBet v 1) were assessed by ELISA, blocking experiments and Western Blot. Crosslinking-capacity of apo/holoBet v 1 were assessed on human mast cells and Arylhydrocarbon receptor (AhR) activation with the human reporter cellline AZ-AHR. Human PBMCs were stimulated and assessed for labile iron and phenotypic changes by flow cytometry. Bet v 1 bound to FeQ2 strongly with calculated Kd values of 1 nm surpassing affinities to quercetin alone nearly by a factor of 1000. Binding to FeQ2 masked IgE epitopes and decreased IgE binding up to 80% and impaired degranulation of sensitized human mast cells. Bet v 1 facilitated the shuttling of quercetin, which activated the anti-inflammatory AhR pathway and increased the labile iron pool of human monocytic cells. The increase of labile iron was associated with an anti-inflammatory phenotype in CD14+monocytes and downregulation of HLADR. To summarize, we reveal for the first time that FeQ2 binding reduces the allergenicity of Bet v 1 due to ligand masking, but also actively contributes anti-inflammatory stimuli to human monocytes, thereby fostering tolerance. Nourishing immune cells with complex iron may thus represent a promising antigen-independent immunotherapeutic approach to improve efficacy in allergen immunotherapy. [ABSTRACT FROM AUTHOR]

Background: Inflammasomes are large protein complexes that assemble in the cytosol in response to danger such as tissue damage or infection. Following activation, inflammasomes trigger cell death and the release of biologically active forms of pro‐inflammatory cytokines interleukin (IL)‐1β and IL‐18. NOD‐like receptor family pyrin domain containing 6 (NLRP6) inflammasome is required for IL‐18 secretion by intestinal epithelial cells, macrophages, and T cells, contributing to homeostasis and self‐defense against pathogenic microbes. However, the involvement of NLRP6 in type 2 lung inflammation remains elusive. Methods: Wild‐type (WT) and Nlrp6−/− mice were used. Birch pollen extract (BPE)‐induced allergic lung inflammation, eosinophil recruitment, Th2‐related cytokine and chemokine production, airway hyperresponsiveness, and lung histopathology, Th2 cell differentiation, GATA3, and Th2 cytokines expression, were determined. Nippostrongylus brasiliensis (Nb) infection, worm count in intestine, type 2 innate lymphoid cell (ILC2), and Th2 cells in lungs were evaluated. Results: We demonstrate in Nlrp6−/− mice that a mixed Th2/Th17 immune responses prevailed following birch pollen challenge with increased eosinophils, ILC2, Th2, and Th17 cell induction and reduced IL‐18 production. Nippostrongylus brasiliensis infected Nlrp6−/− mice featured enhanced early expulsion of the parasite due to enhanced type 2 immune responses compared to WT hosts. In vitro, NLRP6 repressed Th2 polarization, as shown by increased Th2 cytokines and higher expression of the transcription factor GATA3 in the absence of NLRP6. Exogenous IL‐18 administration partially reduced the enhanced airways inflammation in Nlrp6−/− mice. Conclusions: In summary, our data identify NLRP6 as a negative regulator of type 2 immune responses. [ABSTRACT FROM AUTHOR]

Background: Allergen immunotherapy (AIT) is an approved treatment for seasonal respiratory allergic diseases. A depigmented polymerized birch pollen extract for subcutaneous allergen immunotherapy (SCIT) has been demonstrated to be efficacious and safe in patients allergic to birch pollen and its homologous group. Objective: To determine whether SCIT with a birch pollen formulation (5000 depigmented polymerized (DPP) units/mL) shows sustained and long‐term efficacy in adults and adolescents with birch‐pollen induced allergic rhinitis with or without intermittent asthma. Methods: A multicentre (n = 66), double‐blind, placebo‐controlled Phase III clinical trial was performed in the Czech Republic, Finland, Germany, Latvia, Lithuania, Poland and Russia. Participants were randomized 2:1 to active treatment (birch 5000 DPP/ml) or placebo for three years of SCIT and followed up for two treatment‐free years. The primary efficacy endpoint was the EAACI's combined symptom and medication score for rhinoconjunctivitis (CSMSEAACI). Results: A total of 973 participants were screened and 649 were randomized (active treatment: n = 434; placebo: n = 215). The intention‐to‐treat analysis of the CSMSEAACI in the overall study population did not demonstrate statistically significant differences in years 1, 2 and 3. In a post‐hoc analysis, among the subgroup of patients monosensitized to birch pollen allergen only (n = 200), we observed a statistically significant difference (active treatment vs. placebo) in the CSMSEAACI in year 2, 3 and 5. The AIT's safety profile was good. Conclusions: SCIT with a depigmented polymerized birch pollen extract was safe. Sustained and long‐term efficacy in years 2, 3 and 5 in monosensitized patients, but not in polysensitized patients was demonstrated. (EudraCT 2012‐000414‐11) [ABSTRACT FROM AUTHOR]

The properties of biogenic aerosol strongly depend on the particle's proteinaceous compounds. Proteins from primary biological aerosol particles (PBAPs) can cause allergic reactions in the human respiratory system or act as ice and condensation nuclei in clouds. Consequently, these particles have high impact on human health and climate. The detection of biogenic aerosol is commonly performed with fluorescence-based techniques. However, many PBAPs (i.e., pollen of birch, mugwort, or ragweed) show weak or rather low fluorescence signals in the particular protein region (λex ~ 255–280 nm, λem ~ 280–350 nm). We hypothesize that the fluorescence signal of proteins present in birch pollen is being distorted within its native matrix. In this study, we conducted in vitro quenching experiments and employed UV/Vis spectroscopy, capillary zone electrophoresis (CZE), liquid chromatography (LC), electrospray ionization mass spectrometry (ESI–MS), and multistage MS (MS2 and MS3) to target major components in birch pollen washing water (BPWW) possibly quenching the fluorescence activity of proteins and thus explaining the lack of corresponding protein fluorescent signals. We identified quercetin-3-O-sophoroside (Q3OS, MW 626 g mol−1) to be the main UV/Vis absorbing component in BPWW. Our results point out that Q3OS suppresses the fluorescence of proteins in our samples predominantly due to inner filter effects. In general, when applying fluorescence spectroscopy to analyze and detect PBAPs in the laboratory or the atmosphere, it is important to critically scrutinize the obtained spectra. [ABSTRACT FROM AUTHOR]

Pollen traps, the current gold standard to determine pollen load and thereby the allergy season, are not sufficient to determine the allergenic risk. Therefore, the establishment of highly sensitive assays for allergen measurement is of highest interest. Herein, a graphene field-effect transistor (GFET) was constructed on an interdigitated electrodes chip to develop an immersible biosensor, which was used to detect the major birch pollen allergen Bet v 1. Graphene was wet-transferred on interdigitated electrodes that contain a reference electrode used as a liquid gate in the GFET. Using a standard ELISA protocol, two different anti-Bet v 1 antibodies were chosen and immobilized on graphene for the specific capture of the target allergen. The sensitivity of the GFET biosensor was evaluated using a standard Ag/AgCl liquid gate electrode and a reference electrode when the chip was immersed in Bet v 1-containing solutions. The results showed a higher performance and sensitivity for Bet v 1 detection compared to a mediator release method, one of the most sensitive assays for allergen detection. Compared with conventional methods of allergen detection, these immersible biosensors significantly improved the speed and level of detection providing the foundation of a point-of-need platform for in-field application. Furthermore, the proposed technique provides both a new biosensor for allergen detection and a strategy for designing low-cost integrated biosensors., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Abstract Background Allergen immunotherapy (AIT) is an approved treatment for seasonal respiratory allergic diseases. A depigmented polymerized birch pollen extract for subcutaneous allergen immunotherapy (SCIT) has been demonstrated to be efficacious and safe in patients allergic to birch pollen and its homologous group. Objective To determine whether SCIT with a birch pollen formulation (5000 depigmented polymerized (DPP) units/mL) shows sustained and long‐term efficacy in adults and adolescents with birch‐pollen induced allergic rhinitis with or without intermittent asthma. Methods A multicentre (n = 66), double‐blind, placebo‐controlled Phase III clinical trial was performed in the Czech Republic, Finland, Germany, Latvia, Lithuania, Poland and Russia. Participants were randomized 2:1 to active treatment (birch 5000 DPP/ml) or placebo for three years of SCIT and followed up for two treatment‐free years. The primary efficacy endpoint was the EAACI's combined symptom and medication score for rhinoconjunctivitis (CSMSEAACI). Results A total of 973 participants were screened and 649 were randomized (active treatment: n = 434; placebo: n = 215). The intention‐to‐treat analysis of the CSMSEAACI in the overall study population did not demonstrate statistically significant differences in years 1, 2 and 3. In a post‐hoc analysis, among the subgroup of patients monosensitized to birch pollen allergen only (n = 200), we observed a statistically significant difference (active treatment vs. placebo) in the CSMSEAACI in year 2, 3 and 5. The AIT's safety profile was good. Conclusions SCIT with a depigmented polymerized birch pollen extract was safe. Sustained and long‐term efficacy in years 2, 3 and 5 in monosensitized patients, but not in polysensitized patients was demonstrated. (EudraCT 2012‐000414‐11)

Abstract Background A cost-minimization analysis (CMA) was performed to evaluate the economic implications of introducing the SQ Tree sublingual immunotherapy (SLIT)-tablets marketed as ITULATEK® (Health Canada regulatory approval in April 2020) for the treatment of pollen-induced (birch, alder and/or hazel) seasonal allergic rhinitis in Canada (Ontario and Quebec), where Tree Pollen subcutaneous immunotherapy (SCIT) is already an available treatment option. Methods A CMA was deemed appropriate and was based on the assumption that the SQ Tree SLIT-tablets have comparable efficacy to Tree Pollen SCIT. A societal perspective was adopted in the model, including relevant costs of medications, costs of health care services, and productivity losses. The time horizon in the model was three years, which corresponds to a minimal treatment course of allergy immunotherapy. Resource use and costs were based on published sources, where available, and validated by Canadian specialist clinicians (allergists) in active practice in Ontario and in Quebec, where applicable. A discount rate of 1.5% was applied in accordance with the Canadian Agency for Drugs and Technologies in Health (CADTH) guidelines. To assess the robustness of the results, scenario analyses were performed by testing alternative assumptions for selected parameters (e.g., Tree Pollen SCIT resource use, discount rates, number of injections, annual SCIT dosing with maintenance injections, and nurse time support), to evaluate their impact on the results of the analysis. Results The direct costs, including the drug costs, and physician services costs, for three years of treatment, were similar for both SQ Tree SLIT-tablets vs. Tree Pollen SCIT in both Ontario and Quebec ($2799.01 and $2838.70 vs. $2233.76 and $2266.05 respectively). However, when the indirect costs (including patient’s travel expenses and lost working hours) are included in the model, total savings for the treatment with SQ Tree SLIT-tablets of $1111.79 for Ontario and $1199.87 for Quebec were observed. Scenario analyses were conducted and showed that changes in assumptions continue to result in the savings of SQ Tree SLIT- tablets over Tree Pollen SCIT. Conclusions The CMA indicates that SQ Tree SLIT-tablets are a cost-minimizing alternative to Tree Pollen SCIT when considered from a societal perspective in Ontario and Quebec.

[Display omitted] Celery root is known to cause severe allergic reactions in patients sensitized to mugwort pollen. We studied clinically well-characterized patients with celery allergy by IgE testing with a comprehensive panel of celery allergens to disentangle the molecular basis of what is known as the celery–mugwort syndrome. Patients with suspected food allergy to celery underwent a standardized interview. Main inclusion criteria were a positive food challenge with celery or an unambiguous case history of severe anaphylaxis. IgE to celery allergens (rApi g 1.01, rApi g 1.02, rApi g 2, rApi g 4, nApi g 5, rApi g 6, rApi g 7) and to mugwort allergens (rArt v 1, rArt v 3, rArt v 4) were determined. IgE levels ≥0.35 kU A /L were regarded positive. Seventy-nine patients with allergy to celery were included. Thirty patients had mild oral or rhinoconjunctival symptoms, and 49 had systemic reactions. Sixty-eight percent had IgE to celery extract, 80% to birch pollen, and 77% to mugwort pollen. A combination of Api g 1.01, 1.02, 4, 5, and 7 increased the diagnostic sensitivity for celery allergy to 92%. The lipid transfer proteins Api g 2 and Api g 6 were not relevant in our celery-allergic population. IgE to Api g 7, detected in 52% of patients, correlated closely (r = 0.86) to Art v 1 from mugwort pollen. Eleven of 12 patients with monosensitization to Api g 7 were IgE negative to celery extract. The odds ratio for developing a severe anaphylactic reaction rather than only mild oral symptoms was about 6 times greater (odds ratio, 5.87; 95% confidence interval, 1.08-32.0; P =.0410) for Api g 7–sensitized versus –nonsensitized subjects. There is an urgent need for routine diagnostic tests to assess sensitization to Api g 7, not only to increase test sensitivity but also to identify patients at risk of a severe allergic reaction to celery. [ABSTRACT FROM AUTHOR]

Keywords: allergen extract; allergen-specific immunotherapy; Bet v 1; birch pollen; extraction method; minor allergens EN allergen extract allergen-specific immunotherapy Bet v 1 birch pollen extraction method minor allergens 784 787 4 06/01/22 20220601 NES 220601 Key Messages Direct comparison of extraction methods used in commercial manufacturing of allergen products reveals distinct differences. To the Editor, All marketed birch pollen allergen products used in allergen-specific immunotherapy (AIT) are based on aqueous extracts prepared from large batches of pollen collected from hundreds of birch trees. [Extracted from the article]

The study's main objective was to specify the extent to which weather conditions were related to the course of birch pollen seasons in the years 1997–2020. The impact of atmospheric conditions on the daily concentrations of birch pollen grains, the Annual pollen integral (APIn), and the length of pollen seasons were studied. The dependency between each meteorological condition and various features of the birch pollen season was determined using Spearman's rho correlation, the Kruskal–Wallis test, and cluster analysis with the k-means method. It has been shown that the duration of sunshine and average air temperature occurring within 14 days preceding the season has the most significant influence on the beginning of a birch pollen season. The value of daily birch pollen concentrations in Sosnowiec showed a statistically significant positive correlation with the duration of sunlight and the average and maximum wind speed. The daily concentration also depended on the synoptic situation: the mass airflow direction, the type of air mass inflow, and the type of weather front. The near-ground temperature influenced the APIn of birch pollen grains during the period of 14 days before the beginning of the season and the meteorological conditions occurring in the summer of the preceding year such as the maximum temperature, duration of sunlight, the maximum and average wind speed, and the relative air humidity. It was concluded that the length of birch pollen seasons decreased year by year. [ABSTRACT FROM AUTHOR]

Allergic asthma is a highly prevalent inflammatory disease of the lower airways, clinically characterized by airway hyperreactivity and deterioration of airway function. Immunomodulatory probiotic bacteria are increasingly being explored to prevent asthma development, alone or in combination with other treatments. In this study, wild-type and recombinant probiotic Lactobacillus rhamnosus GR-1 were tested as preventive treatment of experimental allergic asthma in mice. Recombinant L. rhamnosus GR-1 was designed to produce the major birch pollen allergen Bet v 1, to promote allergen-specific immunomodulation. Administration of wild-type and recombinant L. rhamnosus GR-1 prevented the development of airway hyperreactivity. Recombinant L. rhamnosus GR-1 also prevented elevation of airway total cell counts, lymphocyte counts and lung IL-1β levels, while wild-type L. rhamnosus GR-1 inhibited airway eosinophilia. Of note, a shift in gut microbiome composition was observed after asthma development, which correlated with the severity of airway inflammation and airway hyperreactivity. In the groups that received L. rhamnosus GR-1, this asthma-associated shift in gut microbiome composition was not observed, indicating microbiome-modulating effects of this probiotic. These data demonstrate that L. rhamnosus GR-1 can prevent airway function deterioration in allergic asthma. Bet v 1 expression by L. rhamnosus GR-1 further contributed to lower airway inflammation, although not solely through the expected reduction in T helper 2-associated responses, suggesting involvement of additional mechanisms. The beneficial effects of L. rhamnosus GR-1 correlate with increased gut microbiome resilience, which in turn is linked to protection of airway function, and thus further adds support to the existence of a gut-lung axis.

Seasonal exposure to birch pollen (BP) is a major cause of pollinosis. The specific role of Toll-like receptor 4 (TLR4) in BP-induced allergic inflammation and the identification of key factors in birch pollen extracts (BPE) initiating this process remain to be explored. This study aimed to examine (i) the importance of TLR4 for dendritic cell (DC) activation by BPE, (ii) the extent of the contribution of BPE-derived lipopolysaccharide (LPS) and other potential TLR4 adjuvant(s) in BPE, and (iii) the relevance of the TLR4-dependent activation of BPE-stimulated DCs in the initiation of an adaptive immune response. In vitro, activation of murine bone marrow-derived DCs (BMDCs) and human monocyte-derived DCs by BPE or the equivalent LPS (nLPS) was analyzed by flow cytometry. Polymyxin B (PMB), a TLR4 antagonist and TLR4-deficient BMDCs were used to investigate the TLR4 signaling in DC activation. The immunostimulatory activity of BPE was compared to protein-/lipid-depleted BPE-fractions. In co-cultures of BPE-pulsed BMDCs and Bet v 1-specific hybridoma T cells, the influence of the TLR4-dependent DC activation on T cell activation was analyzed. In vivo immunization of IL-4 reporter mice was conducted to study BPE-induced Th2 polarization upon PMB pre-treatment. Murine and human DC activation induced by either BPE or nLPS was inhibited by the TLR4 antagonist or by PMB, and abrogated in TLR4-deficient BMDCs compared to wild-type BMDCs. The lipid-free but not the protein-free fraction showed a reduced capacity to activate the TLR4 signaling and murine DCs. In human DCs, nLPS only partially reproduced the BPE-induced activation intensity. BPE-primed BMDCs efficiently stimulated T cell activation, which was repressed by the TLR4 antagonist or PMB, and the addition of nLPS to Bet v 1 did not reproduce the effect of BPE. In vivo, immunization with BPE induced a significant Th2 polarization, whereas administration of BPE pre-incubated with PMB showed a decreased tendency. These findings suggest that TLR4 is a major pathway by which BPE triggers DC activation that is involved in the initiation of adaptive immune responses. Further characterization of these BP-derived TLR4 adjuvants could provide new candidates for therapeutic strategies targeting specific mechanisms in BP-induced allergic inflammation.

Birch (Betula pendula) pollen causes inhalant allergy in about 20% of human population in Europe, most of which is sensitive to the main birch allergen, Bet v1. The aim of the study was to find out (i) whether and how the analysed birch individuals differ in regard to composition of individual subunits of pollen proteins and to protein content in these subunits; (ii) whether the level of particulate matter relates to concentration of Bet v1 allergen. Study was performed in Southern Poland, in 2017–2019. Pollen material was collected at 20 sites, of highly or less polluted areas. Protein composition was analysed by SDS-PAGE, while the concentration of Bet v1 was evaluated by ELISA. The obtained results were estimated at the background of the particulate matter (PM10) level and the birch pollen seasons in Kraków. The electrophoregrams of pollen samples collected at different sites showed huge differences in staining intensities of individual protein subunits, also among important birch allergens: Bet v1, Bet v2, Bet v6 and Bet v7. The level of Bet v1 was significantly higher in the pollen samples collected at the more polluted sites. While the birch pollen allergenic potential is determined, the both pollen exposure and the content of the main allergenic components should be considered, as factors causing immunological response and clinical symptoms manifestation in sensitive individuals. [ABSTRACT FROM AUTHOR]

Background: A cost-minimization analysis (CMA) was performed to evaluate the economic implications of introducing the SQ Tree sublingual immunotherapy (SLIT)-tablets marketed as ITULATEK® (Health Canada regulatory approval in April 2020) for the treatment of pollen-induced (birch, alder and/or hazel) seasonal allergic rhinitis in Canada (Ontario and Quebec), where Tree Pollen subcutaneous immunotherapy (SCIT) is already an available treatment option. Methods: A CMA was deemed appropriate and was based on the assumption that the SQ Tree SLIT-tablets have comparable efficacy to Tree Pollen SCIT. A societal perspective was adopted in the model, including relevant costs of medications, costs of health care services, and productivity losses. The time horizon in the model was three years, which corresponds to a minimal treatment course of allergy immunotherapy. Resource use and costs were based on published sources, where available, and validated by Canadian specialist clinicians (allergists) in active practice in Ontario and in Quebec, where applicable. A discount rate of 1.5% was applied in accordance with the Canadian Agency for Drugs and Technologies in Health (CADTH) guidelines. To assess the robustness of the results, scenario analyses were performed by testing alternative assumptions for selected parameters (e.g., Tree Pollen SCIT resource use, discount rates, number of injections, annual SCIT dosing with maintenance injections, and nurse time support), to evaluate their impact on the results of the analysis. Results: The direct costs, including the drug costs, and physician services costs, for three years of treatment, were similar for both SQ Tree SLIT-tablets vs. Tree Pollen SCIT in both Ontario and Quebec ($2799.01 and $2838.70 vs. $2233.76 and $2266.05 respectively). However, when the indirect costs (including patient's travel expenses and lost working hours) are included in the model, total savings for the treatment with SQ Tree SLIT-tablets of $1111.79 for Ontario and $1199.87 for Quebec were observed. Scenario analyses were conducted and showed that changes in assumptions continue to result in the savings of SQ Tree SLIT- tablets over Tree Pollen SCIT. Conclusions: The CMA indicates that SQ Tree SLIT-tablets are a cost-minimizing alternative to Tree Pollen SCIT when considered from a societal perspective in Ontario and Quebec. [ABSTRACT FROM AUTHOR]

Birch and hazel pollen are the most common causes of allergic diseases that occur during the spring season. For decades, the method of quantitative determination of specific IgE (sIgE) against allergen extracts has been used in the laboratory diagnosis of allergies. In recent years, there has been the possibility of determining sIgE by individual allergenic molecules, either native or recombinant. This method, known as Component Resolved Diagnosis (CRD), has made it possible to identify major and cross-reactive allergenic molecules. Genuine allergenic molecules in birch (Bet v 1), hazel (Cor a 1) and hazelnut (Cor a 8, 9, 11, 14) are responsible for allergic reactions in most patients. Moreover, they cause a severe clinical picture in patients with hypersensitivity, in contrast to cross-reactive molecules, eg. Bet v 1 homologues in vegetables (celery, soy) and fruits (apple, cherry, pear), or Bet v 2 homologues in vegetables (celery, carrot) and fruits (muskmelon, peach, banana), that cause milder symptoms. In the diagnostic context, future research will make it possible to determine the diagnostic significance of the detection of individual allergen molecules responsible for allergy symptoms in each individual patient. The application of bioinformatics will certainly help in the interpretation of the findings, especially in cases when multiplex assays are applied. Particular progress is also expected in the application of allergen molecules to allergen-specific immunotherapy. [ABSTRACT FROM AUTHOR]

In recent years, allergies due to airborne pollen allergens have shown an increasing trend, along with the severity of allergic symptoms in most industrialized countries, while synergism with other common atmospheric pollutants has also been identified as affecting the overall quality of citizenly life. In this study, we propose the state-of-the-art WRF-Chem model, which is a complex Eulerian meteorological model integrated on-line with atmospheric chemistry. We used a combination of the WRF-Chem extended towards birch pollen, and the emission module based on heating degree days, which has not been tested before. The simulations were run for the moderate season in terms of birch pollen concentrations (year 2015) and high season (year 2016) over Central Europe, which were validated against 11 observational stations located in Poland. The results show that there is a big difference in the model's performance for the two modelled years. In general, the model overestimates birch pollen concentrations for the moderate season and highly underestimates birch pollen concentrations for the year 2016. The model was able to predict birch pollen concentrations for first allergy symptoms (above 20 pollen m−3) as well as for severe symptoms (above 90 pollen m−3) with probability of detection at 0.78 and 0.68 and success ratio at 0.75 and 0.57, respectively for the year 2015. However, the model failed to reproduce these parameters for the year 2016. The results indicate the potential role of correcting the total seasonal pollen emission in improving the model's performance, especially for specific years in terms of pollen productivity. The application of chemical transport models such as WRF-Chem for pollen modelling provides a great opportunity for simultaneous simulations of chemical air pollution and allergic pollen with one goal, which is a step forward for studying and understanding the co-exposure of these particles in the air. [ABSTRACT FROM AUTHOR]

Allergic sensitization to the major allergen Bet v 1 represents the dominating factor inducing a vast variety of allergic symptoms in birch pollen allergic patients worldwide, including the pollen food allergy syndrome. In order to overcome the huge socio-economic burden associated with allergic diseases, allergen-specific immunotherapy (AIT) as a curative strategy to manage the disease was introduced. Still, many hurdles related to this treatment exist making AIT not the patients’ first choice. To improve the current situation, the development of hypoallergen-based drug products has raised attention in the last decade. Herein, we investigated the efficacy of the novel AIT candidate BM4, a hypoallergenic variant of Bet v 1, to induce treatment-relevant cross-reactive Bet v 1-specific IgG antibodies in two different mammals, Wistar rats and New Zealand White rabbits. We further analyzed the cross-reactivity of BM4-induced Wistar rat antibodies with the birch pollen-associated food allergens Mal d 1 and Cor a 1, and the functional capability of the induced antibodies to act as IgE-blocking IgG antibodies. Enzyme-linked immunosorbent assay (ELISA) was used to determine the titers of rat IgG1, IgG2a, IgG2b, and IgE, as well as rabbit IgG and IgE antibodies. To address the functional relevance of the induced IgG antibodies, the capacity of rat sera to suppress binding of human IgE to Bet v 1 was investigated by using an inhibition ELISA and an IgE-facilitated allergen-binding inhibition assay. We found that the treatment with BM4 induced elevated Bet v 1-specific IgG antibody titers in both mammalian species. In Wistar rats, high BM4-specific IgG1, IgG2a, and IgG2b titers (104 to 106) were induced, which cross-reacted with wild-type Bet v 1, and the homologous allergens Mal d 1 and Cor a 1. Rat allergen-specific IgG antibodies sustained upon treatment discontinuation. Sera of rats immunized with BM4 were able to significantly suppress binding of human IgE to the wild-type allergens and CD23-mediated human IgE-facilitated Bet v 1 binding on B cells. By contrast, treatment-induced IgE antibody levels were low or undetectable. In summary, BM4 induced a robust IgG immune response that efficiently blocked human IgE-binding to wild-type allergens, underscoring its potential therapeutic value in AIT.

Background: Birch pollen allergy affects pregnant women, and such allergy may affect the development of allergic diseases in their children. Using nationwide birth cohort data, this study aimed to investigate the prevalence of birch pollen IgE positivity and to identify correlating factors in pregnant women in Hokkaido, Japan, a high-latitude island. Methods: Participants included 6856 pregnant women. Participants responded to questionnaires regarding lifestyle factors and history of allergies. Data regarding parity, height, and pre-pregnancy weight were collected from medical records. Blood samples were obtained from participants during the first trimester of pregnancy, and serum allergen-specific IgE titers were determined. Results: The serum of 30.2% participants was positive for birch pollen IgE (≥0.35 UA/mL). Such positivity significantly correlated with a history of other allergic diseases, particularly food allergy and allergic rhinitis/hay fever. In multivariate logistic regression analysis, pre-pregnancy high body mass index (BMI ≥ 25) significantly correlated with birch pollen IgE positivity [odds ratio (OR), 1.24; 95% CI, 1.05–1.47; reference BMI, 18.5–24.9] and higher income (≥10 million yen per year; OR,0.55; 95% CI, 0.37–0.81; reference, household income

Abstract Background The clinical benefit of allergen-specific immunotherapy (AIT) involves induction of blocking antibodies. It is not clear if these antibodies function via steric hindrance alone or a combination of levels, avidities, and epitope specificities, and clinical outcome cannot be predicted. We aim to in-depth characterize serum antibody profiles during birch pollen AIT, investigate therapy-induced antibodies for their capacity to block IgE binding to Bet v 1 and correlate data with clinical outcomes. Methods Immune responses of five birch pollen allergic patients were monitored during the first year of AIT by nasal provocation tests (NPTs), ImmunoCAP, immunoblots, direct and avidity enzyme-linked immunosorbent assays, mediator release assays, facilitated antigen binding (FAB) assays, and inhibition mediator release assays. Results There was no correlation between NPT results and therapy-induced changes in levels (IgE, IgG, IgA, IgM), avidities, or mediator release potency of Bet v 1-specific antibodies. In FAB assays, blocking antibodies initiated upon AIT were shown to prevent formation of Bet v 1-IgE complexes of an indicator serum pool and significantly correlated with clinical readout. Inhibition mediator release assays using patient-specific IgE for passive sensitization revealed therapy-induced blocking capacities with very good correlation to NPT results. Notably, this assay was the only one to detect a non-responder during treatment in this pilot study. Conclusions Clinical outcome of AIT depends on induction of blocking antibodies able to prevent the patient’s own IgE from allergen binding. Monitoring of clinical efficacy seems to be best achieved using the inhibition mediator release assay, as development of relevant blocking antibodies can be verified in a patient-tailored manner.

Allergic sensitization to the major allergen Bet v 1 represents the dominating factor inducing a vast variety of allergic symptoms in birch pollen allergic patients worldwide, including the pollen food allergy syndrome. In order to overcome the huge socio-economic burden associated with allergic diseases, allergen-specific immunotherapy (AIT) as a curative strategy to manage the disease was introduced. Still, many hurdles related to this treatment exist making AIT not the patients' first choice. To improve the current situation, the development of hypoallergen-based drug products has raised attention in the last decade. Herein, we investigated the efficacy of the novel AIT candidate BM4, a hypoallergenic variant of Bet v 1, to induce treatment-relevant cross-reactive Bet v 1-specific IgG antibodies in two different mammals, Wistar rats and New Zealand White rabbits. We further analyzed the cross-reactivity of BM4-induced Wistar rat antibodies with the birch pollen-associated food allergens Mal d 1 and Cor a 1, and the functional capability of the induced antibodies to act as IgE-blocking IgG antibodies. Enzyme-linked immunosorbent assay (ELISA) was used to determine the titers of rat IgG1, IgG2a, IgG2b, and IgE, as well as rabbit IgG and IgE antibodies. To address the functional relevance of the induced IgG antibodies, the capacity of rat sera to suppress binding of human IgE to Bet v 1 was investigated by using an inhibition ELISA and an IgE-facilitated allergen-binding inhibition assay. We found that the treatment with BM4 induced elevated Bet v 1-specific IgG antibody titers in both mammalian species. In Wistar rats, high BM4-specific IgG1, IgG2a, and IgG2b titers (104 to 106) were induced, which cross-reacted with wild-type Bet v 1, and the homologous allergens Mal d 1 and Cor a 1. Rat allergen-specific IgG antibodies sustained upon treatment discontinuation. Sera of rats immunized with BM4 were able to significantly suppress binding of human IgE to the wild-type allergens and CD23-mediated human IgE-facilitated Bet v 1 binding on B cells. By contrast, treatment-induced IgE antibody levels were low or undetectable. In summary, BM4 induced a robust IgG immune response that efficiently blocked human IgE-binding to wild-type allergens, underscoring its potential therapeutic value in AIT. [ABSTRACT FROM AUTHOR]

Introduction: Sublingual immunotherapy (SLIT) with birch pollen extract has been shown to be an efficacious treatment of allergic rhinitis (AR). An as-yet unanswered question is whether and how clinical benefit translates into patient benefit, i.e. what benefit patients derive from this treatment.Methods: This 1-year, open, prospective, multicenter, non-interventional study conducted in 75 German centers measured patient-relevant benefit of birch pollen SLIT (Staloral® Birch) using the questionnaire "Patient Benefit Index for Allergic Rhinitis (PBI-AR)". At treatment onset, patients rated the importance of 25 treatment needs; after the first birch pollen season on treatment, goal achievement was evaluated. A preference-weighted benefit index was calculated and its association with gender, asthma, allergy status, and severity of AR symptoms was determined.Results: Mean age of the 291 adult patients was 38.8 years; 58.4% were female. The most important treatment goals were to "be able to stay outdoors without symptoms" (87.3% quite or very important), "no longer have a runny or stuffed-up nose" (86.9%), and "be able to breathe through your nose more freely" (86.9%). The treatment goals with the highest benefit ratings (referring to those patients to whom the respective goal applied) were to "have confidence in the therapy" (60.5% has helped "quite" or "very much"), "have an easily applicable treatment" (55.6%), and "be able to breathe through my nose more freely" (51.7%). The average PBI-AR global score was 2.19 (SD 1.04) (0-4; with 4 indicating maximum benefit). No significant differences in PBI-AR global score or subscales were found between men and women, poly- and monoallergic patients, or patients with severe versus mild rhinoconjunctivitis. Patients with asthma reported relevant but lower benefit than patients without asthma.Conclusion: After 1 year of birch pollen SLIT treatment, patients reported considerable benefit, mainly due to a reduction of physical symptoms and treatment burden. [ABSTRACT FROM AUTHOR]

Pollen concentrations on Alpine mountain tops are poorly known due to few observations and few modeling studies. We present two case studies from the Alps that provide insights into the spatial and temporal distribution of birch pollen. The numerical pollen dispersion model COSMO-ART (COnsortium for Small-scale MOdelling-Aerosols and Reactive Trace gases) was used to simulate the birch pollen transport during the 2017 pollen season. The model configuration included 1.1-km horizontal grid spacing and 80 vertical levels. The simulations were compared with daily pollen concentrations from two mountain tops in the Alps (Weissfluhjoch near Davos, Switzerland, at 2692 m and Schneefernerhaus, Germany, at 2650 m a.s.l.). In addition, the Swiss pollen stations at Davos (1587 m a.s.l.) and Buchs (446 m a.s.l.) were used. COSMO-ART simulations agreed well with the observations at Davos and Weissfluhjoch. At the Environmental Research Station Schneefernerhaus, the pollen concentrations were generally overestimated. We analyzed the pollen transport episode of 9 April 2017 at Weissfluhjoch in more detail using vertical cross sections of the COSMO-ART simulations. The results suggest that pollen can be lifted up to 3000 m in the morning hours and are subsequently transported by large-scale winds leading to higher birch pollen concentrations at Weissfluhjoch than at Davos. This suggests that the actual situation regarding sources, topography and wind determines the pollen distribution and not only altitude. Still, pollen levels at Weissfluhjoch are more than one order of magnitude lower than typical pollen levels at lowland Swiss stations such as Buchs. [ABSTRACT FROM AUTHOR]

We investigated the prophylactic and therapeutic effects of the oral administration of transgenic rice seeds expressing a hypoallergenic Bet v 1 derivative of allergic birch pollen conjunctivitis in mice. Transgenic rice seed depositing a chimeric molecule called TPC7 (tree pollen chimera 7) created by DNA shuffling of Bet v 1 family sequences from birch, alder and hazel in protein bodies of endosperm was generated. BALB/c mice were sensitized to birch pollen in alum and challenged with pollen in eyedrops. They were fed TPC7 transgenic or non-transgenic (control) rice seeds for 14 d before sensitization (prophylactic protocol) or 17 d after sensitization (therapeutic protocol). The clinical score and number of conjunctival eosinophils were significantly lower in TPC7-fed mice than in the control mice based on both the prophylactic and therapeutic protocols. Serum concentration of allergen-specific IgE did not differ between TPC7-fed and control groups in either protocol. Prophylactic administration of TPC7 downregulated the production of IL-4 and IFN-γ, whereas therapeutic administration of TPC7 upregulated the production of IFN-γ by allergen-stimulated splenocytes. Prophylactic or therapeutic oral administration of transgenic rice expressing TPC7 suppressed birch pollen-induced allergic conjunctivitis in mice. Feeding transgenic rice is a potentially effective approach as an allergen-specific immunotherapy for allergic conjunctivitis.

Background: The efficacy of epinastine 0.05% ophthalmic solution for pollen allergic conjunctivitis has already been shown in a conjunctival allergen challenge (CAC) test using cedar pollen as a challenge. The present study investigated the efficacy of this solution against birch pollen conjunctivitis in a CAC test. Methods: Ten adult subjects (eight males and two females) with asymptomatic birch pollen conjunctivitis were enrolled in this study. The average age of the subjects was 41.1 years. This study was conducted during a period without birch pollen dispersion. In each subject, the epinastine 0.05% ophthalmic solution was instilled in one eye, and an artificial tear fluid was instilled in the fellow eye in a double-blind manner. Five minutes or 4 h after the drug instillation, both eyes were challenged with an optimal concentration of birch pollen, and ocular itching and conjunctival hyperemia were then graded. Tears were collected before the drug instillation and 20 min after the pollen challenge, and the histamine level was measured. Results: The ocular itching scores and palpebral conjunctival hyperemia scores of the epinastine-treated eyes were significantly lower than those of the contralateral control eyes when the eyes were pretreated with the drug 4 h before the CAC. There was a significant correlation between the tear histamine level and mean ocular itching score of three time points (3, 5 and 10 min) following the CAC in the control eyes but not the epinastine-treated eyes. Conclusions: Epinastine is effective in suppressing ocular itching and conjunctival hyperemia in birch pollen conjunctivitis.

Purpose: Evaluation of a new individual wearable air purifier (Respiray Wear A+) for birch pollen, house dust mite (HDM), and cat-allergic rhinoconjunctivitis (ARC) patients in a standardized allergen exposure chamber (AEC)., Materials and Methods: Eligible allergic patients were exposed to birch pollen, HDM raw material, and cat allergen in an AEC for 60 minutes without (V1) and with (V3) the use of the Respiray device. Nasal, ocular, bronchial, and other symptoms were rated by the patients every 10 minutes, and their wellbeing, peak nasal inspiratory flow (PNIF), and lung function parameters were assessed every 30 minutes. The primary endpoint was the change in the median of the total symptom score (TSS) at V3 compared to V1 at 60 minutes of exposure. The secondary endpoints consisted of the total nasal symptom score (TNSS) and total eye symptom score (TESS)., Results: 23 patients with birch pollen allergy, 37 patients with HDM allergy, and 41 patients with cat allergy were included in the analysis. Significant reduced symptom scores of ~ 49% were observed when using Respiray Wea A+ under birch pollen exposure (p < 0.05) in the primary endpoint TSS (V3 2.43 compared to V1 4.78). An 48% reduction of symptoms was seen in TSS in case of HDM exposure (V3 3.59; V1 6.92, (t-test: p < 0.01)) and the highest reduction of TSS (60%) under Respiray A+ using cat allergens (V3 2.95, V1 7.44, (t-test p < 0.01) after 60 minutes of exposure. The personal wellbeing revealed clinically meaningful improvements over time in all three studies which manifested in a lower symptom increase during the final allergen exposures., Conclusion: The individual wearable air purifier Respiray Wear A+ protects significantly against airborne pollen, HDM, and cat allergens and may be a very useful device for avoiding indoor allergens in a new way., Competing Interests: The authors declare no conflict of interest. Table 1.Characteristics of probands at the studies with birch pollen, house dust mite, and cat allergens. Subject dataBirch pollen (n = 23)Dust mites (n = 37)Cat allergens (n = 41)Age (years), mean (SD)39.4 (12.5)40.4 (13.6)35.4 (11.8)Female, n (%)17 (73.9)31 (83.8)32 (78)Male, n (%)6 (26.1)6 (16.2)9 (22)Weight (kg), mean (SD)74.7 (27.8)76.4 (20.4)71,7 (13.6)Prick test (mm), mean (SD)9.3 (3.5)7.5 (2.7)6.4 (1.8) Table 2.Flow chart of the entire study. At least 7 days prior to V1Day 1Day 2Day 7Day 8Screening V0Baseline exposure without Respiray V1Safety call V2Exposure with Respiray V3Safety call V4 Figure 1.Components of Respiray Wear A+. 1 = Air is drawn into the device through the intake grille. 2 = Large particles are filtered using the pre-filter. 3 = The body of the device houses fans, battery, and electronics. 4 = The HEPA filter blocks allergens and allows only clean air to pass through. 5 = Clean air is blown out from the output grilles. 6 = The device is worn on the user’s chest using straps.Figure 2.Capture from a CFD simulation depicting the streamlines exiting the device. Table 3.Total symptom score values V1 and V3 at the 60-minute time point are used as base of operation to determine the improvement rate in percentage. The p-value was calculated applying a t-test. „Improvement“ in the table means fewer symptoms using Respiray Wear A+ in comparison to symptom severity without a filter. AllergenMean value baseline (V1)Mean value – with filter (V3)Improvement rate (%)p-valueBirch4.782.43490.01149House dust mite6.923.59480.00236Cat7.442.95600.00308 Figure 3.Mean values of the sums of total symptom score (TSS) for V1 (without Respiray) and V3 (with Respiray) during exposure to birch, house dust mite, and cat allergens.Figure 4.Mean values of the sums of total eye symptom score (TESS) for V1 (without Respiray) and V3 (with Respiray) during exposure to birch, house dust mite, and cat allergens.Figure 5.Mean values of the sums of total nose symptom score (TNSS) for V1 (without Respiray) and V3 (with Respiray) during exposure to birch, house dust mite, and cat allergens. Table 4.Total eye symptom scores for V1 and V3 at the 60-minute time point are used as base of operation to determine the improvement rate in percent. The p-value was calculated applying a t-test. „Improvement“ in the table means fewer symptoms using Respiray Wear A+ in comparison to symptom severity without a filter. AllergenMean value – baseline (V1)Mean value – with filter (V3)Improvement rate (%)p-valueBirch2.481.35460.03390House dust mite3.732.00460.00519Cat4.001.66590.00308 Table 5.Total nasal symptom scores for V1 and V3 at the 60-minute time point are used as base of operation to determine the improvement rate in percent. The p-value was calculated applying a t-test. „Improvement“ in the table means fewer symptoms using Respiray in comparison to symptom severity without a filter. AllergenMean value – baseline (V1)Mean value – with filter (V3)Improvement rate (%)p-valueBirch2.301.09530.00307HDM3.191.59500.00098Cat3.441.29620.00311 Table 6.Visual analog scale well-being values for V1 and V3 at the 60-minute time point are used as base of operation to determine the improvement rate in percent. The p-value was calculated applying a t-test. „Improvement“ in the table means fewer symptoms using Respiray Wear A+ in comparison to symptom severity without a filter. AllergenMean value – baseline (V1)Mean value – with filter (V3)Improvement rate (%)p-valueBirch2114310.5192House dust mite3118400.2556Cat3116460.2565 Figure 6.Mean values of the visual analog scale scores at minutes 0, 30, and 60 at baseline and final exposure to all different allergens without Respiray (V1) and with Respiray (V3). Table 7.Total symptom score values for V1 and V3 over the measured time frame. The mean value of all investigated subjects as well as the standard deviation are depicted. AllergenMoment0 minutes10 minutes20 minutes30 minutes40 minutes50 minutes60 minutesMeanSDMeanSDMeanSDMeanSDMeanSDMeanSDMeanSDBirchBaseline (V1)1.742.801.351.072.701.493.522.003.962.314.302.844.783.22BirchWith filter (V3)1.041.021.571.242.091.472.131.222.221.382.351.612.431.56House dust miteBaseline (V1)1.651.773.382.304.782.656.243.156.703.136.733.176.923.23House dust miteWith filter (V3)1.411.382.051.842.971.643.382.143.272.293.572.573.592.67CatBaseline (V1)1.241.483.201.854.932.606.202.856.712.877.393.537.443.65CatWith filter (V3)1.001.181.801.472.561.663.001.973.122.143.222.662.952.48, (© Dustri-Verlag Dr. K. Feistle.)

Objective: To explore the allergen components of birch pollen in the Beijing area and interpret its clinical significance. Methods: A total of 58 patients with birch pollen allergy were included in the cross-sectional study and divided into allergic rhinitis（AR） and allergic asthma（AA） groups according to clinical manifestations. Concentration of birch pollen allergen sIgE, as well as Bet v 1, Bet v 2, Bet v 4 and Bet v 6 sIgE were detected by ImmunoCAP immunolinked immunoassay. Differences of sIgE concentration of birch pollen allergen component in AR and AA were analyzed. Results: There were 44（75.9%） cases of AR and 14（24.1%） cases of AA were enrolled. All the 18 patients with spring pollen allergy were AR patients without AA. There were 40 cases with both spring and autumn pollen allergy, of which 26 cases（65%） were AR and 14 cases（35%） were AA. The sIgE of birch pollen allergen was level 2 or above in all subjects. 94.8% were positive for any four allergen components. 77.6% were mono-sensitized to any allergen component while 17.2% were dual-sensitized. The positive rate of Bet v 1 and/or Bet v 2 was 93.1%. The positive rates of four protein components were: Bet v 1（82.8%）, Bet v 2（29.3%）, Bet v 6（1.7%）, Bet v 4（0%）. sIgE of birch pollen was positively correlated with sIgE level of Betv 1（ r =0.898, P <0.001）. The sIgE concentration of Bet v2 in AA group was significantly higher than that in AR group（[4.34±14.35] kUA/L vs [1.56±3.26] kUA/L, P <0.05）. There was no significant difference in other components. Conclusion: Bet v 1 is the main allergen component of birch pollen in the Beijing area, and Bet v 1 plus Bet v 2 can diagnose more than 90% of birch pollen allergy., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.)

Environmental factors such as air pollution are known to exacerbate respiratory illness and increase the overall health risk. However, on a daily or seasonal basis, the relation between air pollutants, weather and a disease such as asthma is not clear. When combined with aeroallergens such as birch pollen and under specific weather conditions, synergistic effects may increase symptoms of respiratory illness and morbidity and then reveal interesting links with environmental factors. Hence, it is important to improve the understanding of pollution-pollen-weather and broaden the public health message. Combined analysis and model simulation of aeroallergens, air pollution and weather as presented here is important to correctly evaluate health burdens and allow a better forecast of the potential health risk. However, analyzing the combined effects of several environmental factors is not well understood and represents a challenging task. This paper shows: (1) the results of data analysis performed in Montreal for asthma hospitalization in relation to complex synergistic environmental factors, and (2) model simulation of birch pollen using a coupled weather-air quality model (GEM-MACH) compared with model-data fusion of classical chemical species (e.g., near-surface ozone, nitrogen dioxide and fine particulate matter) in order to evaluate spatiotemporal vulnerable zone for asthma health risk.

In Belgium, ~ 10% of the people is estimated to suffer from allergies due to pollen emitted by the birch family trees. Timely information on forthcoming pollen exposure episodes using a forecasting system can allow patients to take preventive measures. To date, the only available information on pollen concentrations in Belgium comes from five stations that monitor daily airborne birch pollen concentrations, but real-time and detailed spatial information is lacking. Pollen transport models can both quantify and forecast the spatial and temporal distribution of airborne birch pollen concentrations if accurate and updated maps of birch pollen emission sources are available and if the large inter-seasonal variability of birch pollen is considered. Here we show that the SILAM model driven by ECMWF ERA5 meteorological data is able to determine airborne birch pollen levels using updated maps of areal fractions of birch trees, as compared to the pollen observations of the monitoring stations in Belgium. Forest inventory data of the Flemish and Walloon regions were used to update the default MACCIII birch map. Spaceborne MODIS vegetation activity combined with an updated birch fraction map and updated start and end dates of the birch pollen season were integrated into SILAM. The correlation (R2) between SILAM modelled and observed time series of daily birch pollen levels of 50 birch pollen seasons increased up to ~ 50%. The slopes of the linear correlation increased on average with ~ 60%. Finally, SILAM is able to capture the threshold of 80 pollen grains m−3 exposure from the observations. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the impact of birch pollen (Betula pendula Roth.) on the efficacy of the predatory mite Kampimodromus aberrans (Oudemans) (Acari: Phytoseiidae) as a biological control agent for the two spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) at different predator release ratios. The experiments were conducted on apple cv. Golden Delicious at 1:5, 1:15 and 1:30 predator-prey release ratios in a climate room (25±2°C, 65±10% RH and 16:8 L:D). The predatory mites were also offered pollen grains daily (0.5-0.10 mg/leaf) on the apple seedling during the experiments. One week after the release of K. aberrans, significant reductions in T. urticae density were observed at a ratio of 1:5; and the density remained at low levels thereafter, especially in the pollen experiments. The highest mean numbers of T. urticae in the control group (no predator release) were observed in week 3 with 4067 mites per leaf and 4922 mites per leaf, respectively for the pollen and no pollen application plots. This study demonstrates the potential of K. aberrans to effectively control T. urticae at ratios of 1:5 and 1:15 within three weeks, especially at a ratio of 1:5 when the pollen was added. Furthermore, releasing K. aberrans at the appropriate time and ratio enabled more successful control of T. urticae populations and plant damage, and subsequently kept the mites at low levels. [ABSTRACT FROM AUTHOR]