Grass Pollen Season Research Articles

Nasal allergen-neutralizing IgG4 antibodies block IgE-mediated responses: Novel biomarker of subcutaneous grass pollen immunotherapy

Grass pollen subcutaneous immunotherapy (SCIT) is associated with induction of serum IgG4-associated inhibitory antibodies that prevent IgE-facilitated allergen binding to B cells. We sought to determine whether SCIT induces nasal allergen-specific IgG4 antibodies with inhibitory activity that correlates closely with clinical response. In a cross-sectional controlled study, nasal fluid and sera were collected during the grass pollen season from 10 SCIT-treated patients, 13 untreated allergic patients (with seasonal allergic rhinitis [SAR]), and 12 nonatopic control subjects. Nasal and serum IgE and IgG4 levels to Phleum pratense components were measured by using the Immuno Solid Allergen Chip microarray. Inhibitory activity was measured by IgE-facilitated allergen binding assay. IL-10+ regulatory B cells were quantified in peripheral blood by using flow cytometry. Nasal and serum Phl p 1- and Phl p 5-specific IgE levels were increased in patients with SAR compared to nonatopic control subjects (all, P<.001) and SCIT-treated patients (nasal, P < .001; serum Phl p 5, P = .073). Nasal IgG4 levels were increased in the SCIT group compared to those in the SAR group (P<.001) during the pollen season compared to out of season. IgG-associated inhibitory activity in nasal fluid and serum was significantly increased in the SCIT group compared to that in the SAR (both, P<.01). The magnitude of the inhibitory activity was 93% (P < .001) in nasal fluid compared to 66% (P < .001) in serum and was reversed after depletion of IgG. Both nasal fluid (r=-0.69, P=.0005) and serum (r=-0.552, P=.0095) blocking activity correlated with global symptom improvement. IL-10+ regulatory B cells were increased in season compared to out of season in the SCIT group (P<.01). For the first time, we show that nasal IgG4-associated inhibitory activity correlates closely with the clinical response to allergen immunotherapy in patients with allergic rhinitis with or without asthma.

LATE SUMMER/FALL GRASS POLLEN SEASON: RETROSPECTIVE ANALYSIS OVER A 6 YEAR PERIOD

Introduction Retrospective analysis of cumulative grass pollen data was performed to confirm a grass pollen season in late summer/fall in metropolitan Philadelphia. Methods A review of pollen data collected over 6 years from Burkard air samplers was done at 2 sites. Qualitative and quantitative pollen analysis was performed according to National Allergy Bureau standards. Grass counts were reported in grains per cubic meter per 24 hours (gr/m3/24hr). Results In addition to spring grass pollination, a second grass pollen season was identified yearly at 2 locations, Philadelphia/urban and Mount Laurel, New Jersey/suburban. Combined station data revealed that the second grass season started mid-late August (range August 15th- 28th), peaked September 9th (range August 19th -September 15th) and ended mid September/early October (range September 17th to October 6th). The mean peak grass count was 28.93 gr/m3/24hr in Philadelphia/urban and 30.93 gr/m3/24hr in Mount Laurel/suburban. There was no statistically significant difference in mean peak counts (mean difference 2.0, CI -16.29 to 20.29). Conclusions Our results confirm a second, clinically relevant grass pollen season in both Philadelphia and southern New Jersey. This later season may reflect growth of warm season grasses (big bluestem and indian grass), native to Pennsylvania and southern New Jersey. Pollen levels were sufficient to provoke a significant allergic response in sensitive individuals. Knowledge of this late summer/fall grass season may help identify individuals who may benefit from grass immunotherapy for those with late summer/fall grass pollinosis. Figure. Composite average grass pollen values 2012–2017

Human exposure to airborne pollen and relationships with symptoms and immune responses: Indoors versus outdoors, circadian patterns and meteorological effects in alpine and urban environments

Pollen exposure is a major cause of respiratory allergies worldwide. However, it is unclear how everyday exposure is related to symptoms and how allergic patients may be affected spatially and temporally. Hence, we investigated the relationship of pollen, symptoms and immune responses under a controlled regime of ‘high-low-moderate’ pollen exposure in urban versus alpine environment.The research was conducted in 2016 in two locations in Germany: urban Augsburg (494 m) and Schneefernerhaus (UFS) on Zugspitze mountain (2656 m). Monitoring of airborne pollen took place using Hirst-type volumetric traps. On UFS, both indoor and outdoor samples were taken. Grass pollen allergic human volunteers were monitored daily during the peak of the grass pollen season, in Augsburg, on UFS, then again in Augsburg. Nasal biosamples were obtained throughout the study to investigate immune responses.All symptoms decreased significantly during the stay on UFS and remained low even after the return to Augsburg. The same was observed for nasal total IgE and IgM levels and for nasal type 2 cytokines and chemokines. Augsburg showed higher pollen concentrations than those on UFS. At all sites, pollen were present throughout each day, but were more abundant in Augsburg during morning. On UFS, outdoor pollen levels were up to 6-fold higher than those indoors. Nasal, ocular and pulmonary symptoms correlated with current and previous days' pollen concentrations and relative humidity.Stays in low-exposure environments during the peak pollen season can be an efficient means of reducing allergic symptoms and immune responses. However, in alpine environments, even occasional pollen exposure during short intervals may still trigger symptoms because of the additional environmental stress posed onto allergics. This highlights the need for the consideration of additional environmental factors, apart from symptom diaries and immune responses, so as to efficiently predict high-risk allergy periods.

Persistent regulatory T-cell response 2 years after 3 years of grass tablet SLIT: Links to reduced eosinophil counts, sIgE levels, and clinical benefit.

BackgroundIn the first 2 years of grass tablet sublingual immunotherapy treatment, we have previously demonstrated a progressive development of a regulatory T‐cell response, which was preceded by an early decrease in the frequency of both IL‐4+ cells and sIgE levels. A progressive increase in sIgG 4 levels and FAB blockage were also found.MethodsBy monitoring immunological kinetics during 3 years of active treatment + 2 years of follow‐up, we aimed to identify key immunological parameters that could explain sustained clinical benefit of grass tablet sublingual immunotherapy.ResultsThirty patients completed the 5‐year clinical trial protocol. Although individual responses were heterogeneous, reduction in both sIgE and circulating IL‐4+ cells compared to the initial 1‐ to 4‐month peak was maintained throughout the 3‐year treatment period and for 2 years after discontinuation. Meanwhile, after a 2‐year increase in sIgG4, the levels were stabilized during the third year and decreased post‐therapy. FAB inhibition remained significantly inhibited throughout the study compared to preimmunotherapy in 83% of patients. A sustained regulatory T‐cell response, after IT cessation, occurs in two‐thirds of the patients. There was a statistical association between this regulatory response, the maintenance of lower eosinophil counts during grass pollen seasons, and sIgE titers lower than before immunotherapy treatment, and the latter were significantly associated with clinical response.ConclusionOur results suggest that the immunological mechanisms underlying the sustained response after 2 years of cessation of immunotherapy (3‐year treatment period) are linked to the acquisition and maintenance of a regulatory T‐cell response.

Google Trends reflect allergic rhinitis symptoms related to birch and grass pollen seasons

Google Trends (GT) describes the variation of the relevant interest of internet searches toward medical conditions and related symptoms. Allergic rhinitis symptom levels result from the intensity of exposure to aeroallergens in combination with relevant medication use. We analyze data from Germany to examine the relationship between hay fever-related Google search terms, symptom levels, medication use, and pollen count levels. For doing so, we also employ the new definitions on pollen season and peak pollen period start and end as proposed by the European Academy of Allergy and Clinical Immunology in a recently published position paper. We extract GT data for a number of search terms related to allergic rhinitis for Germany. We use total nasal symptom and mediation scores as reported by patients via a patient hay fever diary in the Berlin and Brandenburg areas in Germany for 3 years (2014–2016), accompanied by pollen data. Then a Pearson and Spearman correlation analysis is performed between symptom data and GT data. A graphical analysis is conducted, and the identification of pollen season and peak pollen periods is done based on the EAACI criteria. The analysis reveals that GT data are highly correlated with symptom levels and follow peak pollen period start–end, concerning grass and birch pollen-induced allergic rhinitis symptoms. GT data can be used as a proxy for the identification of the onset and variation of nasal symptom and medication score for allergic rhinitis sufferers.

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

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

Environmental grass pollen levels in utero and at birth and cord blood IgE: Analysis of three birth cohorts

BackgroundEarly life factors are associated with allergic respiratory diseases, but the role of high grass pollen concentrations during pregnancy and shortly after birth is not known. ObjectiveTo assess outdoor levels of grass pollen during the intrauterine period and at birth during peak pollen season on cord blood IgE in birth cohorts. MethodsThree birth cohorts were included: MACS (n = 429), Australia; COPSAC2000 (n = 200), Denmark; and LISA (n = 1968), Germany. Cord blood IgE was categorized (<0.5 kU/L, 0.5–1 kU/L, >1 kU/L) and dichotomized (high IgE ≥ 0.5 kU/L). Birth during the grass pollen season months and cumulative exposure to outdoor grass pollen counts during pregnancy with cord blood IgE were analysed using multinomial regression and analysed in meta-analysis using binomial regression adjusted for potential confounders. ResultsBirth during the grass pollen season had higher pooled odds of cord blood IgE >0.5 kU/L 1.37 (95% CI 1.06, 1.77) in a meta-analysis with little heterogeneity between the three cohorts. Cumulative exposure to outdoor grass pollen counts during the entire pregnancy was associated with slightly lower pooled odds but significant (OR = 0.98, 95% CI: 0.96 to 0.99). ConclusionsBirth during grass pollen seasons were associated with increased risk of high cord blood IgE in cities from both hemispheres, but high pollen loads in the environment during the entire pregnancy appeared protective. As IgE responses develop during the first months of life, our study findings provide new insights into the mechanisms of grass pollen exposure at birth and shortly after on possible allergic respiratory diseases.

Sublingual grass allergen specific immunotherapy: a retrospective study of clinical outcome and discontinuation

BackgroundSublingual immunotherapy (SLIT) is effective, tolerable, and convenient for many allergic patients. Still, real-world evidence is scarce and the aim of this study is to assess the patient reported outcome of treatment with SLIT against grass pollen allergy in a consecutive patient population.MethodsPatients (n = 329) who were confirmed to be allergic to timothy grass and had been prescribed SLIT were consecutively enrolled in the study and completed a questionnaire online or in hard copy.Results207 (62.9%) patients responded to the questionnaire. The female/male ratio was 105/102 with a mean age of 39 ± 11 years (range 19–70 years). 113 (55%) patients reported they had completed the full 3-year treatment period, 49 (24%) were still on treatment, and 45 (22%) had discontinued treatment prematurely. Respondents who had completed the full treatment period reported that their allergy symptoms in the most recent grass pollen season had improved to a larger extent than subjects still on treatment or discontinuing the treatment prematurely. Improvement of asthma was twice as common among patients who completed compared to discontinued treatment (42 vs. 20%). Younger age (37 ± 12 vs. 41 ± 11 years, p < 0.001) and a higher prevalence of reported oral and/or gastrointestinal side effects (49 vs. 24%, p = 0.02) characterised the group that terminated SLIT. Forgetfulness was the most commonly reported specific reason.ConclusionTreatment perseverance resulted in improved patient reported outcome. Forgetfulness was the most frequently reported reason for discontinuing SLIT treatment against grass pollen allergy.

Intra-Seasonal Initiation of the SQ-Standardised Grass Allergy Immunotherapy Tablet Routinely Applied by Allergy Specialists and General Practitioners with Experience in Treatment of Allergy: A Non-Interventional Observational Study.

IntroductionIntra-seasonal start of treatment with the SQ® grass sublingual immunotherapy (SLIT) tablet (GRAZAX®, ALK, Denmark) has been previously demonstrated to be well-tolerated. The objective of our study was to investigate the tolerability of intra-seasonal start of treatment comparing patients treated by allergists and general practitioners experienced in treatment of allergy (GPs).MethodsIn a non-interventional, open-label, observational study, data on intra-seasonal start with the SQ® grass SLIT tablet were recorded in patients treated by allergists and GPs in Germany. Adverse events (AEs) were recorded by the physicians at first administration and during the 1–3-month observation period. The tablets taken and any AEs were recorded by the patients in diaries for the first 14 days.ResultsTreatment with the SQ® grass SLIT tablet was started in 198 patients, and in 179 intra-seasonal (allergists: 140, GPs: 39) and 19 post-seasonal; average treatment period was 47 days. AEs related to intra-seasonal start were reported in 43.6% of patients; no relevant differences between allergists and GPs were observed. In the subgroup of GPs, patients were younger (p = 0.0191), had more frequently asthma (p = 0.0043), more patients used symptomatic medication in the previous pollen season (p = 0.0198) and were more frequently treated for other diseases (p = 0.0467). In the allergists subgroup, more diagnostic allergy tests were applied (p < 0.0001) with less anti-allergic premedication at first administration (p = 0.0026).ConclusionThe intra-seasonal start of treatment with the SQ® grass SLIT tablet in patients routinely treated by allergists or GPs with experience in treatment of allergy was well-tolerated, although patient characteristics were different with respect to age, frequency of asthma and concomitant allergies, use of symptomatic medication in the previous grass pollen season and concomitant treatment of other diseases. The safety profile from a previous placebo-controlled clinical trial and data from a previous real-life study on intra-seasonal start performed by allergists were confirmed.

Adherence and quality of life in adults and children during 3-years of SLIT treatment with Grazax\u2014a real life study

Respiratory allergic disease represents a global health problem, 30% of the population suffers from allergic rhinoconjunctivitis and 20% suffer from asthma. Allergy immunotherapy induce immunological tolerance and thereby modify the response to allergens and sublingual immunotherapy (SLIT) offers the possibility of home administration of allergen therapy, but adherence is more uncertain. The aim of the study was to investigate the adherence with GRAZAX in adults and children ≥ 5 years during three consecutive years of treatment. This was a non-interventional, prospective, observational, multi-center, open-label study to investigate adherence, quality of life, safety and tolerability of GRAZAX in adult and pediatric patients in a real-life setting. During the 3-years study period estimation of adherence was done regularly. Quality of life as well as symptom score was also assessed. In total, 399 patients (236 adults and 163 children) were included in the study. At baseline, 100% suffered from moderate-severe eyes and nose symptoms, and 31% had asthma in the grass pollen season. Overall, 55% completed a 3-years treatment period, whereas 37% stopped before end of study and 8% were lost to follow up. After 3 years, the adherence rate decreased from 98.2% (first month), 93.7% (first year), 93.2% (second year) and 88.9% (third year) and adverse events were the main reason for pre-term termination. The study suggests a good adherence to treatment in a real life setting among the patients finalizing 3-years SLIT therapy. The treatment was effective both on symptoms and HRQL.

Biphasic activation of complement and fibrinolysis during the human nasal allergic response

Biphasic activation of complement and fibrinolysis during the human nasal allergic response

Clinical Efficacy of a Recombinant Grass Pollen Vaccine One Year after a 4 Month Treatment Course

Immediate and sustained clinical efficacy of a recombinant grass pollen vaccine (BM32) consisting of IgE epitope peptides of Phl p 1, 2, 5 and 6 was evaluated in terms of optimized treatment schedule of a 4 month pre- seasonal treatment in grass pollen allergic patients (NCT02643641). Four treatment schedules (3, 4, 5 times active vs. Placebo) of BM32 were evaluated during grass pollen seasons 2016 and 2017. Symptom Scores (SS), Medication Scores (MS) and Combined Scores (SMS) of actively treated subjects were compared to placebo. In 2016 scores were correlated with symptoms (TNSS) in the challenge chamber. Symptoms and medication intake were reported daily during entire grass pollen season. SS was reported on a four point scale comprising 4 nasal symptoms (runny nose, blocked nose, sneezing, itchy nose) and 2 ocular symptoms (itchy/red eyes, and watery eyes). It was calculated as the sum of scores divided by 6. In the MS score values were assigned to categories of medication and calculated as predefined in the protocol. 124 subjects were included in the full analysis set. The mean daily SMS during the pollen peak immediately after treatment with 3, 4 or 5 injections of BM32 improved by 15%, 3% and 25 % vs. Placebo. During the grass pollen peak 2017 no further treatment effect could be demonstrated. Correlation coefficient of TNSS in the challenge chamber and SS during season 2016 was .5. Five active injections demonstrated the best immediate clinical efficacy, but no sustained effect. BM32 was safe and well tolerated.

Safety and efficacy of immunotherapy with the recombinant B-cell epitope–based grass pollen vaccine BM32

BackgroundBM32 is a grass pollen allergy vaccine based on recombinant fusion proteins consisting of nonallergenic peptides from the IgE-binding sites of the 4 major grass pollen allergens and the hepatitis B preS protein.ObjectiveWe sought to study the safety and clinical efficacy of immunotherapy (allergen immunotherapy) with BM32 in patients with grass pollen–induced rhinitis and controlled asthma.MethodsA double-blind, placebo-controlled, multicenter allergen immunotherapy field study was conducted for 2 grass pollen seasons. After a baseline season, subjects (n = 181) were randomized and received 3 preseasonal injections of either placebo (n = 58) or a low dose (80 μg, n = 60) or high dose (160 μg, n = 63) of BM32 in year 1, respectively, followed by a booster injection in autumn. In the second year, all actively treated subjects received 3 preseasonal injections of the BM32 low dose, and placebo-treated subjects continued with placebo. Clinical efficacy was assessed by using combined symptom medication scores, visual analog scales, Rhinoconjunctivitis Quality of Life Questionnaires, and asthma symptom scores. Adverse events were graded according to the European Academy of Allergy and Clinical Immunology. Allergen-specific antibodies were determined by using ELISA, ImmunoCAP, and ImmunoCAP ISAC.ResultsAlthough statistical significance regarding the primary end point was not reached, BM32-treated subjects, when compared with placebo-treated subjects, showed an improvement regarding symptom medication, visual analog scale, Rhinoconjunctivitis Quality of Life Questionnaire, and asthma symptom scores in both treatment years. This was accompanied by an induction of allergen-specific IgG without induction of allergen-specific IgE and a reduction in the seasonally induced increase in allergen-specific IgE levels in year 2. In the first year, more grade 2 reactions were observed in the active (n = 6) versus placebo (n = 1) groups, whereas there was almost no difference in the second year.ConclusionsInjections of BM32 induced allergen-specific IgG, improved clinical symptoms of seasonal grass pollen allergy, and were well tolerated.

The analysis of grass pollen season in northern Poland in 2017

This paper presents the course of the pollen season of grass (Poaceae) in Szczecin, Drawsko Pomorskie, Olsztyn, Bydgoszcz, Warsaw and Bialystok in 2017. Grass are typical wind-pollinated plants and the most important agent causing pollinosis in Europe. Seasonal Pollen Index (SPI) was estimated as the annual sum of daily average pollen concentrations. The highest, recorded airborne concentration of 132 pollen grains/m3 was noted in Warsaw on the 24th of June. The maximum values of seasonal pollen count occurred between of 9th June and 8th of July in all cities. The highest grass pollen allergen hazard occurred in 2017 in Warsaw, Szczecin, Drawsko Pomorskie and Olsztyn.

Symptomatic Treatment of Pollen-Related Allergic Rhinoconjunctivitis in Children: Randomized Controlled Trial

This study aimed to compare the efficacy of daily intranasal corticosteroid, on-demand intranasal corticosteroid, and daily oral antihistamine in decreasing symptoms from grass-pollen allergic rhinoconjunctivitis.This study examined patients who were 6–18 years of age in the Netherlands and had a diagnosis of allergic rhinitis and evidence of grass-pollen sensitization.This was a 3-armed, single-blind, randomized controlled trial occurring for 3 months during the grass-pollen season. Patients were randomized to daily intranasal corticosteroid (INCS) (fluticasone 100 µg per day if <12 years of age; 200 µg per day if >12 years of age), on-demand intranasal corticosteroid (same dosing but only used when needed), or on-demand oral antihistamine (5 mg levocetirizine). Patients recorded their symptoms by using a daily online symptom diary that included questions about nose and eye symptoms.One hundred and fifty children were randomized. There were no statistically significant differences between groups in symptom-free days, although the trend favored on-demand INCS (30% symptom-free days compared with 22% for daily INCS and 15% for on-demand oral antihistamine). Patients randomized to on-demand INCS received 61% less nasal steroid than those randomized to daily INCS.The authors conceded that the study was underpowered to detect significant differences but noted that the on-demand INCS group performed slightly better than the daily INCS group, supporting that on-demand INCS was not inferior to daily INCS and allowed for lower overall corticosteroid exposure.Traditionally, providers have taught that daily intranasal corticosteroids are necessary to keep allergic rhinoconjunctivitis symptoms at bay, and current guidelines recommend daily use. In reality, many patients’ families do not adhere to this approach. Furthermore, some studies of on-demand inhaled corticosteroids for asthma exacerbations do not demonstrate inferiority, leading researchers to wonder if this approach might also have some efficacy in children with allergic conjunctivitis. In this study, researchers attempt to evaluate a strategy of on-demand INCS versus daily INCS versus oral on-demand antihistamine. Unfortunately, due to low recruitment, the study was underpowered to detect a statistically significant difference, although it is unlikely that daily INCS was superior to on-demand INCS given that the data demonstrated that on-demand INCS users had a higher proportion of symptom-free days than daily INCS users. This provides support for the suggestion that there may be a role for on-demand INCS among children with allergic rhinoconjunctivitis. Further research into this dosing strategy should be done, perhaps with a greater diversity of allergic rhinoconjunctivitis triggers.

Thirty-four years of pollen monitoring: an evaluation of the temporal variation of pollen seasons in Belgium

For the first time in Belgium, fluctuations in airborne pollen quantities over a 34 years period have been analyzed. Seven pollen types have been selected comprising the most clinically relevant in Belgium nowadays (birch, alder, hazel and grasses) and others that are known to be allergenic in other European countries and frequently found in Belgium (plane, ash and mugwort). Pollen monitoring was performed with a seven-day recording volumetric spore trap placed in Brussels. We measured increasing airborne pollen for four trees, namely alder, hazel, ash and plane. Although the total pollen index for birch has not increased significantly, an increasing trend in the annual amount of days above the concentration threshold of 80 pollen grains/m3 was clearly observed. Concerning temporal variations, the pollen season has tended to end earlier for birch, ash and plane and the peak concentration of the pollen of plane has been appearing earlier in the year. In the investigated period, the pollen seasons of grasses and mugwort have tended to become less severe. Furthermore, we reported a temporal shift of the grass pollen season, beginning and ending earlier, together with an advance of the annual peak date.

Specific immunotherapy in local allergic rhinitis: A randomized, double-blind placebo-controlled trial with Phleum pratense subcutaneous allergen immunotherapy.

Allergen immunotherapy has been shown to be an effective treatment for local allergic rhinitis (LAR) to house dust mites. Studies with pollen allergen immunotherapy are limited to observational studies. The aim of this study was to evaluate the clinical efficacy and safety of Phleum pratense subcutaneous immunotherapy (Phl-SCIT) in LAR. In a randomized double-blind placebo-controlled study, 56 patients with moderate-severe LAR to grass pollen received Phl-SCIT with a depigmented polymerized pollen vaccine or placebo for the first year, and Phl-SCIT the second one. The blind was maintained throughout the study. Primary outcome was combined symptom medication score (CSMS) during grass pollen season (GPS). Secondary clinical outcomes included organ-specific symptoms, medication-free days, rhinitis severity and asthma control. Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), nasal allergen provocation test (NAPT), skin testing, serum levels of specific IgG4 and specific IgE and safety were also evaluated. Subcutaneous immunotherapy (SCIT) had a short-term and sustained effect with significant improvements of all primary and secondary clinical outcomes and RQLQ score. SCIT significantly increased serum sIgG4 levels and allergen tolerance, from the 6th to 24th months of treatment. At the end of the study, 83% of patients treated with ≥6months of SCIT tolerated a concentration of P. pratense over 50 times higher than baseline, and 56% gave a negative NAPT. SCIT was well tolerated; six mild local reactions occurred, and there were no serious adverse events related to the study medication. Subcutaneous immunotherapy with depigmented polymerized allergen extracts is a safe and clinically effective treatment for LAR to P.pratense.

Who's at risk of thunderstorm asthma? The ryegrass pollen trifecta and lessons learnt from the Melbourne thunderstorm epidemic.

The Melbourne thunderstorm asthma epidemic in November 2016 was unprecedented in scale and impact. We systematically reviewed our hospital's patients with thunderstorm asthma to identify key risk factors. Of 85 adult patients assessed, the majority (60%) had no prior diagnosis of asthma. However, allergic rhinitis during the grass pollen season was almost universal (99%), as were ryegrass pollen sensitization (100%) and exposure to the outdoor environment during the thunderstorm (94%). Airborne pollen levels on the thunderstorm day were extreme. We conclude that ryegrass pollen sensitization, clinical allergic rhinitis, and acute allergen exposure constitute a risk-factor 'trifecta' for thunderstorm asthma.

Allergen-specific immunotherapy modulates the balance of circulating Tfh and Tfr cells

Abstract Follicular helper T cells (Tfh cells) are a CD4 T cell subset essential for germinal center formation and B cell responses, although their role in allergy and allergen-specific immunotherapy (AIT) is unclear. Here, we show that AIT-treated patients have a higher ratio of regulatory Tfh cells (Tfr) to follicular T cells (Tfh) and hypothesize an IL-2 dependent mechanism.

Evaluation of Pollen Apps Forecasts: The Need for Quality Control in an eHealth Service.

BackgroundPollen forecasts are highly valuable for allergen avoidance and thus raising the quality of life of persons concerned by pollen allergies. They are considered as valuable free services for the public. Careful scientific evaluation of pollen forecasts in terms of accurateness and reliability has not been available till date.ObjectiveThe aim of this study was to analyze 9 mobile apps, which deliver pollen information and pollen forecasts, with a focus on their accurateness regarding the prediction of the pollen load in the grass pollen season 2016 to assess their usefulness for pollen allergy sufferers.MethodsThe following number of apps was evaluated for each location: 3 apps for Vienna (Austria), 4 apps for Berlin (Germany), and 1 app each for Basel (Switzerland) and London (United Kingdom). All mobile apps were freely available. Today’s grass pollen forecast was compared throughout the defined grass pollen season at each respective location with measured grass pollen concentrations. Hit rates were calculated for the exact performance and for a tolerance in a range of ±2 and ±4 pollen per cubic meter.ResultsIn general, for most apps, hit rates score around 50% (6 apps). It was found that 1 app showed better results, whereas 3 apps performed less well. Hit rates increased when calculated with tolerances for most apps. In contrast, the forecast for the “readiness to flower” for grasses was performed at a sufficiently accurate level, although only two apps provided such a forecast. The last of those forecasts coincided with the first moderate grass pollen load on the predicted day or 3 days after and performed even from about a month before well within the range of 3 days. Advertisement was present in 3 of the 9 analyzed apps, whereas an imprint mentioning institutions with experience in pollen forecasting was present in only three other apps.ConclusionsThe quality of pollen forecasts is in need of improvement, and quality control for pollen forecasts is recommended to avoid potential harm to pollen allergy sufferers due to inadequate forecasts. The inclusion of information on reliability of provided forecasts and a similar handling regarding probabilistic weather forecasts should be considered.