A temporally and spatially explicit, data-driven estimation of airborne ragweed pollen concentrations across Europe.

Ongoing and future climate change driven expansion of aeroallergen-producing plant species comprise a major human health problem across Europe and elsewhere. There is an urgent need to produce accurate, temporally dynamic maps at the continental level, especially in the context of climate uncertainty. This study aimed to restore missing daily ragweed pollen data sets for Europe, to produce phenological maps of ragweed pollen, resulting in the most complete and detailed high-resolution ragweed pollen concentration maps to date. To achieve this, we have developed two statistical procedures, a Gaussian method (GM) and deep learning (DL) for restoring missing daily ragweed pollen data sets, based on the plant's reproductive and growth (phenological, pollen production and frost-related) characteristics. DL model performances were consistently better for estimating seasonal pollen integrals than those of the GM approach. These are the first published modelled maps using altitude correction and flowering phenology to recover missing pollen information. We created a web page (http://euragweedpollen.gmf.u-szeged.hu/), including daily ragweed pollen concentration data sets of the stations examined and their restored daily data, allowing one to upload newly measured or recovered daily data. Generation of these maps provides a means to track pollen impacts in the context of climatic shifts, identify geographical regions with high pollen exposure, determine areas of future vulnerability, apply spatially-explicit mitigation measures and prioritize management interventions.

Biologicals in the treatment of chronic rhinosinusitis with nasal polyps ­ position of the Polish Society of Otorhinolaryngologists ­Head and Neck Surgeons and the Polish Society of Allergology experts

Chronic rhinosinusitis with nasal polyps (CRSwNP) has a significant impact on the well-being and social functions of the patient. The generalized inflammatory process with the formation of nasal polyps and excess eosinophils in the mucosa of the paranasal sinuses is called type 2 inflammation, which is mediated by Th2 lymphocytes ­ cells of the immune system responsible for chronic inflammatory processes. Today, we also know the key pro-inflammatory mediators against which new drugs have been developed, the so-called biological drugs, are produced in cell lines. In this document, we present currently available biologicals approved for the treatment of patients with T2-related chronic rhinosinusitis.

The impact of data assimilation into the meteorological WRF model on birch pollen modelling.

We analyse the impact of ground-based data assimilation to the Weather Research and Forecasting (WRF) meteorological model on parameters relevant for birch pollen emission calculations. Then, we use two different emission databases (BASE - no data assimilation, OBSNUD - data assimilation for the meteorological model) in the chemical transport model and evaluate birch pollen concentrations. Finally, we apply a scaling factor for the emissions (BASE and OBSNUD), based on the ratio between simulated and observed seasonal pollen integral (SPIn) to analyse its impact on birch concentrations over Central Europe. Assimilation of observational data significantly reduces model overestimation of air temperature, which is the main parameter responsible for the start of pollen emission and amount of released pollen. The results also show that a relatively small bias in air temperature from the model can lead to significant differences in heating degree days (HDD) value. This may cause the HDD threshold to be attained several days earlier/later than indicated from observational data which has further impact on the start of pollen emission. Even though the bias for air temperature was reduced for OBSNUD, the model indicates a start for the birch pollen season that is too early compared to observations. The start date of the season was improved at two of the 11 stations in Poland. Data assimilation does not have a significant impact on the season's end or SPIn value. The application of the SPIn factor for the emissions results in a much closer birch pollen concentration level to observations even though the factor does not improve the start or end of the pollen season. The post-processing of modelled meteorological fields, such as the application of bias correction, can be considered as a way to further improve the pollen emission modelling.

Drug-induced diseases in otolaryngology - causes, clinical signs, treatment.

In the daily practice of an otolaryngologist, we encounter cases where the symptoms are not the result of disease but result from pharmacotherapy. In the case of symptoms such as hearing loss, tinnitus, or dizziness, polytherapy may be used as the basis for their occurrence, which, due to the lack of rationality in combining drugs, leads to symptoms that the patient and the doctor very often interpret as a new disease syndrome. The aim of the study is to show and to raise awareness of the fact that the symptoms of hearing organ impairment are frequently drug-related and only a modification of the currently used pharmacotherapy is a rational procedure in such cases. This paper describes 30 cases who developed side effects of polypharmacy in the form of hearing disorders, dizziness, and tinnitus. The causes of drug-related complications were discussed, as well as effective methods of their prevention.

Drug-induced diseases in otolaryngology - causes, clinical signs, treatment.

<b>Introduction:</b> In the daily practice of an otolaryngologist, we encounter cases where the symptoms are not the result of disease but result from pharmacotherapy. In the case of symptoms such as hearing loss, tinnitus, or dizziness, polytherapy may be used as the basis for their occurrence, which, due to the lack of rationality in combining drugs, leads to symptoms that the patient and the doctor very often interpret as a new disease syndrome. <br><b>Aim:</b> The aim of the study is to show and to raise awareness of the fact that the symptoms of hearing organ impairment are frequently drug-related and only a modification of the currently used pharmacotherapy is a rational procedure in such cases. <br><b>Material:</b> This paper describes 30 cases who developed side effects of polypharmacy in the form of hearing disorders, dizziness, and tinnitus. The causes of drug-related complications were discussed, as well as effective methods of their prevention.

New treatment options for acute rhinosinusitis according to EPOS 2020.

Acute rhinosinusitis (ARS) is a very common condition and mostly of viral origin. About 0.5-2% of the viral ARS are complicated by a bacterial infection. Due to viral etiology and inflammatory mechanisms of rhinitis and rhinosinusitis, symptomatic treatment including phytotherapy have been used for their treatment for decades. Scientific societies and expert groups recommend the use of herbal medicines in acute viral and acute post-viral rhinosinusitis. In 2021, Polish patients gained access to a new therapeutic option for acute sinusitis in the form of a drug containing a distillate of a mixture of rectified essential oils of eucalyptus, sweet orange, myrtle and lemon common.

Extension of WRF-Chem for birch pollen modelling-a case study for Poland.

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.

Prevalence of allergic rhinitis and asthma in Poland in relation to pollen counts.

INTRODUCTION: Despite the known role of pollen allergens in causing allergy symptoms in sensitized individuals, there are few publications investigating the relationship between pollen exposure in different regions and the prevalence of inhalant allergy. AIM: To assess the association between the prevalence of allergic rhinitis and asthma and the degree of exposure to pollen in various regions of Poland. MATERIAL AND METHODS: Completed questionnaires of 9,443 subjects living in four urban centres (Wroclaw, Katowice, Warsaw, Bialystok), collected within part of the ECAP project, were analyzed. Children aged 6-7 (n = 2,278), adolescents aged 13-14 (n = 2,418), and adults aged 20-44 (n = 4,747) constituted 24.2%, 25.6% and 50.3% of the respondents, respectively. The clinical part (including skin prick tests, an assay of Timothy grass-specific IgE), was attended by 24% of the respondents. Data from 6-year pollen monitoring served to characterize birch and grass pollen seasons. RESULTS: We found insignificant negative associations between the duration of birch pollen season and the prevalence of declared allergic rhinitis and asthma during the season across all age groups. There were insignificant inverse associations between the number of days with above-threshold and high grass pollen concentrations, total grass pollen count and the prevalence of declared allergic rhinitis and asthma during the season across all age groups. Associations noted in the clinical part were also non-significant; however, these trends were not uniform across the age groups. CONCLUSIONS: Our findings do not confirm the hypothesis of a positive association between pollen exposure and the prevalence of allergic rhinitis and asthma.

Intranasal steroid therapy - EPOS 2020.

INTRODUCTION: Due to their strong, multidirectional anti-inflammatory activity, intranasal glucocorticoids are the mainstay of treatment in rhinosinusitis, including acute rhinosinusitis, chronic rhinosinusitis, and chronic rhinosinusitis with nasal polyps, as well as allergic rhinitis. Owing to its high systemic safety and high anti-inflammatory efficacy, mometasone furoate - a new-generation intranasal glucocorticoid - was approved in 2019 as an over-the-counter medication for Polish patients diagnosed with allergic rhinitis. Scientific societies and expert groups recommend the use of intranasal glucocorticoids in a much broader range of indications. In February 2020, an updated version of the European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS 2020) was published. AIM: This article discusses the role of nasal glucocorticoids in regimens used in the treatment of nasal sinusitis as published in EPOS 2020 with Polish country-specific realities being taken into account.

Impact of physicochemical properties of nasal spray products on drug deposition and transport in the pediatric nasal cavity model.

The study is focused on the analysis of physicochemical properties of selected nasal sprays of mometasone furoate, and the influence of these properties on aerosol quality and penetration in the pediatric nose. After the determination of drugs surface tension and viscosity, spray geometry and size distribution of aerosol droplets, the topical delivery of each drug to different parts of the pediatric model of the nose with the flexible vestibule was evaluated by colorimetric visualization. All tested drugs are pseudo-plastic liquids, showing some differences in flow consistency constant k (range 714-1422) and flow behavior index n (range 0.16-0.31). At no-flow conditions, all sprays are deposited mainly in the anterior of the nasal cavity and the septum (2-3 cm from the nostril), as a result of inertial impaction of large droplets. The deposition range is slightly influenced by the geometry of the aerosol cloud, which, in turn, depends both on drug properties and the type of the spraying nozzle. Deposition experiments accompanied by the airflow show an enhancement of drug transport to deeper parts of the nasal cavity (up 4-6 cm from the vestibule), and this effect can be attributed to the secondary effects of spreading of the deposited liquid layer along the narrow air passages in the nose. Plume geometry, dose volume and rheological properties of the drug were shown to be important factors in the spray penetration pattern in the pediatric nose. The deepest delivery can be expected for drugs of low viscosity and short aerosol plumes.

A study on the spatial and temporal variability in airborne Betula pollen concentration in five cities in Poland using multivariate analyses.

During the spring period, Betula pollen is the main cause of inhalant allergies in Poland and therefore it is important to monitor and forecast airborne pollen concentrations of this taxon. This study conducted a comparative analysis of the basic characteristics of Betula pollen seasons at the regional scale. The study was carried out from 2001 to 2016 in five cities in Poland: Lublin, Warsaw, Cracow, Sosnowiec, and Szczecin. To find the attributes of birch pollen seasons that mostly differentiated the individual cities, a general discriminant analysis (GDA) was performed, while a principal component analysis (PCA) allowed us to reduce the data space and present a scatterplot of PCA scores in order to compare pollen seasons in the individual cities. The contingency table was also analyzed to check whether there was a significant relationship between pollen counts in the studied years and cities. At most of the sites, biennial cycles of low and high pollen concentrations can be observed. Due to the high variation in seasons in each of these cities, two data groups were distinguished: Group 1 was composed of seasons with high pollen deposition (2001, 2003, 2006, 2008, 2010, 2012, 2014, 2016), and Group 2 comprising the other seasons. Multivariate analyses were performed on both these groups as well as in the entire dataset. End98, Peak Value, and Annual Total had the highest discriminant power. In Group 1, Warsaw and Sosnowiec differed the most in the investigated parameters, while Cracow and Szczecin differed the least. In both groups, most seasons with the highest pollen birch concentration were observed in Lublin, followed by Warsaw, while in Cracow, the number of such seasons was the smallest.

Treatment strategy of allergic rhinitis in the face of modern world threats.

Allergic rhinitis (AR) is the most common form of allergy, which - as epidemiological research has shown - applies to nearly 25% of the population. AR significantly affects the quality of life of the patient, and the more severe the disease, the greater the risk of developing bronchial asthma. One of the factors affecting the severity of symptoms and the degree of their control is air pollution. In some patients, despite proper treatment, persistence or only partial remission of symptoms (uncontrolled allergic rhinitis) is observed. This can lead to an increase in comorbidities - inflammation of the paranasal sinuses, otitis media and asthma - both in children and in adults. The treatment of allergic rhinitis, in accordance with the standards, consists in: education of the patient, elimination of the allergen from the environment and factors intensifying the course of the disease, selection of proper pharmacotherapy and specific allergen immunotherapy. Many factors influence the selection of the antihistamine used, e.g., the opportunity of safe increase of the dosage.

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

INTRODUCTION: 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). CONCLUSIONS: 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.

A six-month analysis of frontal sinus drainage pathway in patients with frontal sinusitis after balloon sinuplasty.

BACKGROUND: The balloon catheter has been used for a decade to dilate paranasal sinus outflow tracts. The question is: how wide and how durable is the dilation of drainage pathways in patients in long-term observations after this procedure? OBJECTIVE: The objective of our study was to observe the changes occurring in the frontal sinus drainage pathway (FSDP) in patients with frontal sinusitis at least 6 months after surgery using balloon catheters in an isolated procedure. MATERIALS AND METHODS: We analyzed and measured the FSDP width on computed tomography (CT) of 23 images before and after the use of balloon catheters. We also assessed mucosal changes using Zinreich's scale, and symptom improvements with the Sino-Nasal Outcome Test (SNOT-20). RESULTS: A statistically significant difference in the width of the FSDP was found before and after sinuplasty in the study group (p ≤ .0016). On average, the FSDP increased by 24.1%. Clinically meaningful and statistically significant (p ≤ .0002) symptom improvement as indicated by the mean SNOT-20 score was observed. Mucosal changes were also statistically significant (p ≤ .0018) after surgery. CONCLUSION: The findings at least 6 months after follow-up indicated that the use of balloon catheters in an isolated procedure allowed durable modeling of FSDP and was associated with radiological and clinical improvements.

Lyophilized Cyclamen europaeum tuber extract in the treatment of rhinosinusitis.

Nasal and sinus mucositis is a significant health problem associated with significant organizational and financial burden for the health care system. In recent years, several important guidelines and positions of expert groups and scientific associations have been published with regard to the diagnostics and treatment of rhinosinusitis, including European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS 2012) [1] and Polish Standards for the Treatment of Rhinitis (PoSLeNN 2013) [2]. The management of viral and postviral rhinosinusitis involves systemic treatment including administration of plant origin products. The goal of this article is to present the current knowledge on the use of intranasal preparations containing natural saponin fractions from the rhizomes of Alpine cyclamen (Cyclamen europaeum). Saponins contained in the extract of Alpine cyclamen (Cyclamen europaeum) rhizomes are surface-active compounds that reduce the surface tension on the nasal mucosal cells while simultaneously stimulating the trigeminal nerve receptors leading to increased production of seromucous secretion and extensive drainage of the nasal and sinus cavities. The analysis of published studies on the efficacy and safety of intranasal products containing lyophilized extracts from Cyclamen europaeum tuber warrants the conclusion that these products are useful in the management of nasal and sinus mucositis due to their beneficial impact on the course of the treatment of acute rhinosinusitis. When used in patients with acute rhinosinusitis, an intranasal preparation containing lyophilized extracts from Cyclamen europaeum tuber efficiently reduces the symptoms, particularly the feeling of pressure and pain in the face. According to the authors of PROSINUS study, single-agent treatment using Cyclamen europaeum extracts is more efficient (in terms of the percentage of success) than other monotherapy or combination regimens.

Progress in the Diagnosis and Control of Ebola Disease.

Ebola hemorrhagic fever is one of numerous viral hemorrhagic fevers. It is a severe, often fatal disease in humans and nonhuman primates (gorillas and chimpanzees). This article discusses the history of Ebola disease, already known routes of infection together with defining prevention methods and treatment trials. The importance of increasing awareness of the risk of disease among people who do not inhabit endemic regions is emphasized. This risk is associated especially with the increasing popularity of tourism to African countries, even to those where the virus is endemic. The research conducted over the years shows that three species of frugivorous bats are subjected to contamination by Ebola, but the infection is asymptomatic in them. It is believed that the saliva of these mammals and other body fluids may be a potential source of infection for primates and humans. In the laboratory, infection through small-particle aerosols has been demonstrated in primates, and airborne spread among humans is strongly suspected, although it has not yet been conclusively demonstrated. The importance of this route of transmission remains unclear. Poor hygienic conditions can aid the spread of the virus. These observations suggest approaches to the study of routes of transmission to and among humans.

Compliance with Vaccination Against Influenza Among the Elderly.

Protective vaccination against influenza is one of the most beneficial methods of preventing this viral disease. The use of vaccines brings not only the health benefits but also has positive implications related to diminishing the costs of treatment, prolonged hospitalization or post-influenza complications. Promoting vaccinations against influenza among the elderly is especially important. The article concerns the perception of these vaccinations and evaluation of the general knowledge on influenza among listeners of a university of the third age in Warsaw, Poland. It aims also at assessing the potential to change opinions and decisions regarding vaccinations against influenza and widely understood influenza prevention among this target group. The research tool, apart from the scientific lecture-like presentation rich in examples, was a self-reported questionnaire designed by the authors specifically for this study purpose. This paper presents the results of survey conducted with the questionnaire completed by 29 persons over 60 years of age. We found that the recent vaccination rate against influenza was just was about 20% in the studied sample of the elderly. The study demonstrates that educational training through a professional lecture presentation facilitates the promotion of health and vaccination coverage against influenza in the elderly.

Deposition of intranasal glucocorticoids--preliminary study.

INTRODUCTION: Intranasal glucocorticoids are the treatment of choice in the therapy of rhinitis. The differences in efficiency of particular medications proven by therapeutic index may result from differences in composition of particular formulations as well as from diverse deposition in nasal cavities. Intranasal formulations of glucocorticoids differ in volume of a single dose in addition to variety in density, viscosity and dispenser nozzle structure. The aim of this report was to analyze the deposition of most often used intranasal glucocorticoids in the nasal cavity and assessment of the usefulness of a nose model from a 3D printer reflecting anatomical features of a concrete patient. MATERIAL AND METHODS: Three newest and most often used in Poland intranasal glucocorticoids were chosen to analysis; mometasone furoate (MF), fluticasone propionate (FP) and fluticasone furoate (FF). Droplet size distribution obtained from the tested formulations was determined by use of a laser aerosol spectrometer Spraytec (Malvern Instruments, UK). The model of the nasal cavity was obtained using a 3D printer. The printout was based upon a tridimensional reconstruction of nasal cavity created on the basis of digital processing of computed tomography of paranasal sinuses. The deposition of examined medications was established by a method of visualization combined with image analysis using commercial substance which colored itself intensively under the influence of water being the dominant ingredient of all tested preparations. On the basis of obtained results regions of dominating deposition of droplets of intranasal medication on the wall and septum of the nasal cavity were compared. RESULTS: Droplet size of aerosol of tested intranasal medications typically lies within the range of 25-150 µm. All tested medications deposited mainly on the anterior part of inferior turbinate. FP preparation deposited also on the anterior part of the middle nasal turbinate, marginally embracing a fragment of the central part of this turbinate as well together with deposition in the middle and superior nasal meatus reaching the region of nasal ceiling and olfactory field. MF preparation deposited on the anterior part of the inferior turbinate and central part of this turbinate alike. The area of mucous membrane of lateral wall of nasal cavity on which MF deposited was similar to the area achieved after the application of FP preparation but much greater than in the case of FF preparation. FF drug deposition concentrates only on the anterior part of the inferior turbinate. Despite directing the drug to the lateral wall of the nasal cavity a great proportion of examined preparations deposit also on the nasal septum. CONCLUSIONS: The practical application of tridimensional representation (3D printout) of actual geometry of nasal cavity to establish the deposition of inGKS was proven. Droplet size and the geometry of the aerosol cloud introduced into the nostril determine the significant deposition of medication droplets in the anterior part of the nasal cavity. Both physical properties of the drug as well as spraying system applied influence spatial distribution of the drug. The interaction of the air flow with the layer of deposited fluid plays a major role in the deposition of the drug in the nasal cavity, therefore it is so important that the drug does not drain by gravity but remains at the site of deposition which may be reinforced by thixotropic properties of the preparation.

Long-term intense exposure to grass pollen can mask positive effects of allergenic immunotherapy on non-specific bronchial hyperresponsiveness.

INTRODUCTION: There are many potential factors that can modulate bronchial reactivity, including exposure to allergens, viral infections, and medications. The aim of this study was to analyze the effect of grass pollination intensity on the bronchial reactivity in seasonal allergic rhinitis (SAR) patients subjected to subcutaneous allergenic immunotherapy (SCIT). MATERIAL AND METHODS: This study, performed between 2005 and 2008, included 41 patients with confirmed sensitivity to grass pollens and predominating symptoms of SAR, randomly assigned to desensitization by pre-seasonal or maintenance SCIT. Bronchial provocation challenge with histamine was performed before the onset of immunotherapy, and repeated three times after each pollen season covered by this study. Bronchial reactivity was analyzed with regard to grass pollination intensity in 2005-2008 (air concentration of grass pollen grains, seasonal number of days when air concentration of grass pollen reached at least 20 or 50 grains per 1 m(3)). RESULTS: After 3 years of SCIT, a significant decrease in bronchial responsiveness was observed in the analyzed group as confirmed by an increase in PC20 FEV1 histamine values (p = 0.001). An inverse tendency was observed after 2 years of SCIT, however. This second year of SCIT corresponded to the 2007 season, when a significantly higher number of days with at least 50 grains of pollen per 1 m(3) of air was recorded. CONCLUSIONS: FLUCTUATIONS IN POLLINATION INTENSITY OBSERVED DURING CONSECUTIVE YEARS OF IMMUNOTHERAPY CAN INFLUENCE BRONCHIAL REACTIVITY IN PATIENTS SUBJECTED TO SCIT (ISRCTN REGISTER: ISRCTN 86562422).