Quantification of airborne birch (Betula sp.) pollen grains and allergens in Krakow

INTRODUCTION: Birch (Betula sp.) pollen grains are the main cause of seasonal allergies in northern and central Europe. The allergen particles released from the grains are often well distributed in the air. Due to their size, airborne protein particles can easily penetrate into the lower parts of the respiratory airways and may lead to symptoms of asthma. The purpose of this paper was to quantify both Betula sp. pollen grains and allergens in the air. MATERIAL/METHODS: Materials for the investigation were collected in the spring of 2003 with two Hirst-type pollen volumetric traps. Tapes from one trap served for routine birch pollen grain counts, while those from the second for the immunodetection of birch allergens. As birch pollen allergen concentration is seen as dark spots on X-ray films densitometric measurements of the spots were used to quantify birch-pollen antigen concentrations in the air. RESULTS: In most instances, birch pollen counts corresponded with birch pollen allergen levels. However, on several occasions outside the pollen season, only grains or only allergens were detected. Apart from sampling variability, this could be due to faulty/dead pollen grains or submicronic airborne allergen particles. CONCLUSIONS: Counting intact pollen grains and antibody-based detection of allergen molecules are efficient tools in controlled allergen avoidance.     

Concentrations of major grass group 5 allergens in pollen grains and atmospheric particles: implications for hay fever and allergic asthma sufferers sensitized to grass pollen allergens

BACKGROUND: Grass pollen allergens are the most important cause of hay fever and allergic asthma during summer in cool temperate climates. Pollen counts provide a guide to hay fever sufferers. However, grass pollen, because of its size, has a low probability of entering the lower airways to trigger asthma. Yet, grass pollen allergens are known to be associated with atmospheric respirable particles. OBJECTIVE: We aimed (1) to determine the concentration of group 5 major allergens in (a) pollen grains of clinically important grass species and (b) atmospheric particles (respirable and nonrespirable) and (2) to compare the atmospheric allergen load with clinical data to assess different risk factors for asthma and hay fever. METHODS: We have performed a continuous 24 h sampling of atmospheric particles greater and lower than 7.2 microm in diameter during the grass pollen season of 1996 and 1997 (17 October 1996-16 January 1997) by means of a high volume cascade impactor at a height of about 15 m above ground in Melbourne. Using Western analysis, we assessed the reactivity of major timothy grass allergen Phl p 5 specific monoclonal antibody (MoAb) against selected pollen extracts. A MoAb-based ELISA was then employed to quantify Phl p 5 and cross-reactive allergens in pollen extracts and atmospheric particles larger and smaller than 7.2 microm. RESULTS: Phl p 5-specific MoAb detected group 5 allergens in tested grass pollen extracts, indicating that the ELISA employed here determines total group 5 allergen concentrations. On average, 0.05 ng of group 5 allergens were detectable per grass pollen grain. Atmospheric group 5 allergen concentrations in particles > 7.2 microm were significantly correlated with grass pollen counts (rs = 0.842, P < 0. 001). On dry days, 37% of the total group 5 allergen load, whereas upon rainfall, 57% of the total load was detected in respirable particles. After rainfall, the number of starch granule equivalents increased up to 10-fold; starch granule equivalent is defined as a hypothetical potential number of airborne starch granules based on known pollen count data. This indicates that rainfall tended to wash out large particles and contributed to an increase in respirable particles containing group 5 allergens by bursting of pollen grains. Four day running means of group 5 allergens in respirable particles and of asthma attendances (delayed by 2 days) were shown to be significantly correlated (P < 0.001). CONCLUSION: Here we present, for the first time, an estimation of the total group 5 allergen content in respirable and nonrespirable particles in the atmosphere of Melbourne. These results highlight the different environmental risk factors for hay fever and allergic asthma in patients, as on days of rainfall following high grass pollen count, the risk for asthma sufferers is far greater than on days of high pollen count with no associated rainfall. Moreover, rainfall may also contribute to the release of allergens from fungal spores and, along with the release of free allergen molecules from pollen grains, may be able to interact with other particles such as pollutants (i.e. diesel exhaust carbon particles) to trigger allergic asthma.     

The effect of anti-IgE treatment on in vitro leukotriene release in children with seasonal allergic rhinitis

BACKGROUND: Binding of allergens with IgE to the IgE receptors on mast cells and basophils results in the release of inflammatory mediators as sulfidoleukotrienes (SLTs), triggering allergic cascades that result in allergic symptoms, such as asthma and rhinitis. OBJECTIVE: We sought to investigate whether anti-IgE (Oma-lizumab), a humanized monoclonal anti-IgE antibody, in addition to specific immunotherapy (SIT) affects the leukotriene pathway. METHODS: Ninety-two children (age range, 6-17 years) with sensitization to birch and grass pollens and with seasonal allergic rhinitis were included in a phase III, placebo- controlled, multicenter clinical study. All subjects were randomized to one of 4 treatment groups. Two groups subcutaneously received birch SIT and 2 groups received grass SIT for at least 14 weeks before the start of the birch pollen season. After 12 weeks of SIT titration, placebo or anti-IgE was added for 24 weeks. The primary clinical efficacy variable was symptom load (ie, the sum of daily symptom severity score and rescue medication score during pollen season). Blood samples taken at baseline and at the end of study treatment after the grass pollen season were used for separation of leukocytes in this substudy. After in vitro stimulation of the blood cells with grass and birch pollen allergens, SLT release (LTC4, LTD4, and LTE4) was quantified by using the ELISA technique. RESULTS: Before the study treatment, SLT release to birch and grass pollen exposure did not differ significantly among the 4 groups. Under treatment with anti-IgE + SIT-grass (n = 23), a lower symptom load occurred during the pollen season compared to placebo + SIT-grass (n = 24, P =.012). The same applied to both groups receiving birch SIT (n = 23 and n = 22, respectively; P =.03). At the end of treatment, the combination of anti-IgE plus grass SIT, as well as anti-IgE plus birch SIT, resulted in significantly lower SLT release after stimulation with the corresponding allergen (416 ng/L [5th-95th percentile, 1-1168] and 207 ng/L [1-860 ng/L], respectively) compared with placebo plus SIT (2490 ng/L [384-6587 ng/L], P =.001; 2489 ng/L [1-5670 ng/L], P =.001). In addition, treatment with anti-IgE was also followed by significantly lower SLT releases to the allergens unrelated to SIT (grass SIT: 300 ng/L [1-2432 ng/L] in response to birch allergen; birch SIT: 1478 ng/L [1-4593 ng/L] in response to grass pollen) in comparison with placebo (grass SIT: 1850 ng/L [1-5499 ng/L], P =.001; birch SIT: 2792 ng/L [154-5839 ng/L], P =.04]. CONCLUSION: Anti-IgE therapy reduces leukotriene release of peripheral leukocytes stimulated with allergen in children with allergic rhinitis undergoing allergen immunotherapy independent of the type of SIT allergen used.     

Trisetum paniceum (wild oats) pollen counts and aeroallergens in the ambient air of Madrid,Spain

BACKGROUND: Madrid has a short but intensive grass pollen season, in which 79% of the total grass pollen load is released from the middle of May to the middle of June. The main objectives of this study were to quantify Trisetum paniceum (wild oats) aeroallergen in the atmosphere in Madrid from February to December 1996 and to correlate the aeroallergen concentrations with grass pollen counts. METHODS: Two different samplers were used to assess allergen exposure; a Burkard spore trap was used to collect pollen grains and a high-volume air sampler to collect airborne particles. A total of 182 air filters were collected and extracted in 1 ml of PBS and analysed by ELISA inhibition, using pooled sera from highly allergic individuals. RESULTS: T. paniceum aeroallergens were detected not only during the grass pollen season, but also before and after. Wild oat allergens had two main peaks of 1 and 1.9 microg/m(3), occurring in late May and July, respectively. The time series analysis established the existence of lags between the two main variables pollen counts and aeroallergen activity. Analysis of the data by the Spearman rank test and linear regression showed a weak correlation between grass allergenic activity and grass pollen counts (Spearman's rho = 0.29). Data obtained from time series analysis demonstrated that grass allergenic activity correlated strongly with current and 5-week-old grass pollen grain counts (r(2) = 0.73). CONCLUSIONS: Wild oats allergenic activity was detected during the entire year and not only during the pollen season. This fact is an important aspect to be considered in the clinical follow-up and treatment of grass pollen-sensitised patients in Madrid.     

Do levels of airborne grass pollen influence asthma hospital admissions?

Background The effects of environmental factors and ambient concentrations of grass pollen on allergic asthma are yet to be established.
Objective We sought to estimate the independent effects of grass pollen concentrations in the air over Melbourne on asthma hospital admissions for the 1992–1993 pollen season.
Methods Daily grass pollen concentrations were monitored over a 24-h period at three stations in Melbourne. The outcome variable was defined as all-age asthma hospital admissions with ICD9-493 codes. The ambient air pollutants were average daily measures of ozone, nitrogen dioxide and sulphur dioxide, and the airborne particle index representing fine particulate pollution. Semi-parametric Poisson regression models were used to estimate these effects, adjusted for air temperature, humidity, wind speed, rainfall, day-of-the-week effects and seasonal variation.
Results Grass pollen was a strong independent non-linear predictor of asthma hospital admissions in a multi-pollutant model ( P =0.01). Our data suggest that grass pollen had an increasing effect on asthma hospital admissions up to a threshold of 30 grains/m³, and that the effect remains stable thereafter.
Conclusion Our findings suggest that grass pollen levels influence asthma hospital admissions. High grass pollen days, currently defined as more than 50 grains/m³, are days when most sensitive individuals will experience allergic symptoms. However, some asthmatic patients may be at a significant risk even when airborne grass pollen levels are below this level. Patients with pollen allergies and asthma would be advised to take additional preventive medication at lower ambient concentrations.     

Birch and ragweed pollinosis north of Milan: a model to investigate the effects of exposure to "new" airborne allergens

BACKGROUND: The effects of sudden and massive exposure of the general population to novel airborne allergens are not known. This study aimed to investigate the clinical effects of two "new" allergens, ragweed and birch, in an area north of Milan during the last 15 years. METHODS: We reviewed the records of 2571 monosensitized patients seen during the last 10 years in two allergy units north of Milan. Data included age at onset of allergic symptoms, and family history of allergic diseases. In this sample, 500 were allergic to grass, mite, birch, and ragweed; 293 to pellitory; 167 to mugwort; 100 to Alternaria; and 11 to plantain. RESULTS: Birch pollen-allergic patients and ragweed pollen-allergic patients showed a similar mean age at onset (35.3 years vs. 35.1 years; P = NS), but were significantly older than all other groups of patients (P < 0.001). Patients allergic to ragweed and birch pollen, 304 and 323 respectively, were >30 years at the onset of allergic symptoms. A family history of allergic disorders among first degree relatives was far less frequent among patients allergic to birch pollen (29%) or ragweed pollen (27%) than among patients sensitive to all other airborne allergens, except those allergic to mugwort pollen (P < 0.001). In both ragweed and birch groups, a positive family history was significantly more common among subjects < 30 years than in those > 30 years at onset of respiratory allergy (81/196 (41%) vs. 54/304 (18%), P < 0.001 for the ragweed group; 80/177 [45%]vs. 65/323 (20%), P < 0.001 for the birch group). CONCLUSION: Exposure of the general population of this area to two new airborne allergens resulted in the onset of respiratory allergy in many older people who lacked any relevant predisposing factor. Although we cannot exclude the possibility that those who became allergic had been exposed to birch or ragweed pollen elsewhere, a more likely explanation is a specific susceptibility that remains viable until the subject encounters the "right" allergen.     

The allergen profile of beech and oak pollen

Background Beech and oak pollen are potential allergen sources with a world‐wide distribution. Objective We aimed to characterize the allergen profile of beech and oak pollen and to study cross‐reactivities with birch and grass pollen allergens. Methods Sera from tree pollen‐allergic patients with evidence for beech and oak pollen sensitization from Basel, Switzerland, (n=23) and sera from birch pollen‐allergic patients from Vienna, Austria, (n=26) were compared in immunoblot experiments for IgE reactivity to birch (Betula pendula syn. verrucosa), beech (Fagus sylvatica) and oak (Quercus alba) pollen allergens. Subsequently, beech and oak pollen allergens were characterized by IgE inhibition experiments with purified recombinant and natural allergens and with allergen‐specific antibody probes. Birch‐, beech‐ and oak pollen‐specific IgE levels were determined by ELISA. Results Beech and oak pollen contain allergens that cross‐react with the birch pollen allergens Bet v 1, Bet v 2 and Bet v 4 and with the berberine bridge enzyme‐like allergen Phl p 4 from timothy grass pollen. Sera from Swiss and Austrian patients exhibited similar IgE reactivity profiles to birch, beech and oak pollen extracts. IgE levels to beech and oak pollen allergens were lower than those to birch pollen allergens. Conclusion IgE reactivity to beech pollen is mainly due to cross‐reactivity with birch pollen allergens, and a Phl p 4‐like molecule represented another predominant IgE‐reactive structure in oak pollen. The characterization of beech and oak pollen allergens and their cross‐reactivity is important for the diagnosis and treatment of beech and oak pollen allergy.     

Responsiveness of eosinophils to aeroallergens may be independent of atopic status

It has been reported that extracts from common aeroallergens directly activate eosinophils from non-allergic individuals, eliciting chemotaxis and degranulation. The aims of this study were to compare the reactivity of eosinophils from non-atopic and atopic individuals to airborne allergens, and to assess if this reactivity was modulated by natural exposure to birch pollen. Blood-derived eosinophils were stimulated with allergen extracts from birch pollen, cat dander, house dust mite and timothy grass, and their capacity to degranulate (eosinophil peroxidase, EPO; major basic protein, MBP) and produce T helper type 1 and 2 cytokines were evaluated as well as their capacity to migrate in vitro , in and out of the birch pollen season. Eosinophils from atopic and non-atopic individuals responded similarly to stimulation with allergen extracts with respect to directed migration, EPO and MBP release, which was independent of the season when the samples were collected. Interestingly, eosinophils from both study groups were incapable of producing tumour necrosis factor-α (TNF-α) during the birch pollen season, but could generate interleukin-4. Innate responsiveness of eosinophils to aeroallergens is independent of the atopic status of the individual. In vivo exposure to birch allergen as seen during the birch pollen season downregulates the capacity of eosinophils to produce the cytokine TNF-α.     

Immunologic significance of respirable atmospheric starch granules containing major birch allergen Bet v 1

BACKGROUND: Birch-pollen allergens are an important cause of early spring hay fever and allergic asthma. Recently, we reported a mechanism for the release of respirable allergenic particles from birch pollen containing the major allergen Bet v 1. In this study, we aimed to assess the immunologic significance of the released Bet v 1-containing starch granules in the environment. METHODS: A two-site monoclonal antibody-based assay (ELISA) was employed to quantitate Bet v 1 in high-volume air sampler filter extracts, and immunogold-labelling was used on sections of these extracts to localize Bet v 1. Immunoblot analyses were performed with pooled sera from patients sensitive to birch pollen. RESULTS: Atmospheric starch granules contained Bet v 1, and the concentration increased upon light rainfall. Sera from patients allergic to birch allergens recognized extracts from isolated starch granules. CONCLUSIONS: The clinical implications of these findings are that starch granules released from birch pollen are potentially able to trigger allergic asthmatic reactions to Bet v 1, since the allergen occurs in respirable particles. Thus, clinicians can advise asthma patients to remain indoors on days of light rainfall during the birch-pollen season to avoid high levels of allergen exposure.     

Comparison of direct immunostaining and electroimmunoassay for analysis of airborne grass-pollen antigens

Yli-Panula E, Takahashi Y, Rantio-Lehtimäki A. Comparison of direct immunostaining and electroimmunoassay for analysis of airborne grass-pollen antigens.
Sensitive pollen-allergic patients have been reported to show allergic symptoms not only during the pollen release of allergenic plants but also both before and after the pollen season. Symptoms before the season are evidently provoked by small-sized particles originating partly from developing pollen grains, partly from other plant parts. After the pollen season, antigenic material settles on various surfaces, which thus form a new source of allergenic material. Measuring the allergen concentrations in indoor and outdoor environments demands an effective sampling method and a rapid and sensitive immunochemical analysis, especially for particles of small-sized fractions which are not detected in microscopic analyses. The efficiency of an ELISA and an immunochemical staining method was tested with monoclonal IgG against Phl p 5, the main grass allergen. The Burkard trap and MPC impactor 'Marple personal cascade impactor with six-stage particle size fractionation' were compared. The sampling was carried out in southwestern Finland in the summer of 1994. The number of grass-pollen antigen spots greatly exceeded the simultaneous pollen count, indicating considerable antigen activity outside the pollen grains. The counts were especially high in small-sized fractions after the pollen season, when hardly any airborne pollen was found. Spots and pollen divided according to size were highly intercorrelated, indicating that the threshold values used were appropriate.     

Preseasonal local allergoid immunotherapy to grass pollen in children: a double-blind, placebo-controlled, randomized trial

BACKGROUND: We assessed the efficacy of preseasonal local allergoid immunotherapy in a group of children with asthma and/or rhinitis and/or rhinoconjunctivitis due to grass pollen. METHODS: We randomly assigned 24 children allergic to grass pollen to receive local allergoid immunotherapy for 3 months before the pollen season and 24 such patients to receive identically appearing placebo. The immunotherapy consisted of tablets of monomeric allergoid grass pollen allergens held in the mouth until they dissolved and then swallowed. The study was double-blind. Symptoms and medications were scored on diary cards during the pollen season. Nasal eosinophil cationic protein levels were measured by the monoclonal antibodies EG1 and EG2 outside the pollen season and at low and at high pollen concentration during the pollen season. RESULTS: The active-treatment group had a statistically significant reduction of total symptoms (P<0.05), especially bronchial symptoms (P<0.05), in comparison with the placebo group. Immunotherapy was well tolerated and compliance was good. Nasal levels of EG2 and EG1 increased significantly during the pollen season, but there was no difference between groups. EG2/EG1 increased significantly only in the placebo group during natural allergen exposure (P<0.01). CONCLUSIONS: Our results suggest that this immunotherapy is effective for the treatment of asthma due to grass pollen in children.     

Effects of sublingual immunotherapy for multiple or single allergens in polysensitized patients.

BACKGROUND: Sublingual immunotherapy (SLIT) has proven efficacy in treating respiratory allergy. OBJECTIVE: To compare the clinical and functional effects and the effect on nasal eosinophils of SLIT with either single or combination allergens. METHODS: We performed an open-labeled, controlled, 4 parallel-group randomized study with 58 patients sensitized to birch and grasses only who had rhinitis and bronchial hyperreactivity in both pollen seasons. Patients were recruited for the study from January 1, 1999, to June 30, 2001. The patients received SLIT for birch, SLIT for grass, SLIT for birch and grass, or drugs only. Symptom and medication scores, forced expiratory volume in 1 second, bronchial hyperreactivity, and nasal eosinophil counts were evaluated in both pollen seasons at baseline and after 2 and 4 years. RESULTS: Ten patients dropped out and 48 completed the study. No change in all the considered parameters vs baseline was seen in patients treated with drugs only. Those patients receiving SLIT for grass or birch had a significant clinical improvement and nasal eosinophil reduction vs baseline and vs patients who did not receive SLIT in the target season (P < .01) but also in the unrelated pollen season (P < .05). The patients receiving SLIT for grass and birch improved as well, and their improvement in clinical symptoms and inflammation was significantly greater than in patients treated with SLIT for the single allergens. Minor changes were seen in the forced expiratory volume in 1 second, since it remained within the reference range in the whole population. CONCLUSION: In patients sensitized to grass and birch, SLIT with the 2 allergens provided the best clinical results. Nevertheless, SLIT with birch only or grass only also provided a measurable improvement in the grass season and birch season, respectively.     

Birch pollen rupture and the release of aerosols of respirable allergens

BACKGROUND: Birch pollen allergens have been implicated as asthma triggers; however, pollen grains are too large to reach the lower airways where asthmatic reactions occur. Respirable-sized particles containing birch pollen allergens have been detected in air filters, especially after rainfall but the source of these particles has remained speculative. OBJECTIVE: To determine the processes by which birch pollen allergens become airborne particles of respirable size with the potential to contribute to airways inflammation. METHODS: Branches with attached male catkins were harvested and placed in a controlled emission chamber. Filtered dry air was passed through the chamber until the anthers opened, then they were humidified for 5 h and air-dried again. Flowers were disturbed by wind generated from a small electric fan. Released particles were counted, measured and collected for immuno-labelling and high-resolution microscopy. RESULTS: Birch pollen remains on the dehisced anther and can rupture in high humidity and moisture. Fresh pollen takes as long as 3 h to rupture in water. Drying winds released an aerosol of particles from catkins. These were fragments of pollen cytoplasm that ranged in size from 30 nm to 4 microm and contained Bet v 1 allergens. CONCLUSION: When highly allergenic birch trees are flowering and exposed to moisture followed by drying winds they can produce particulate aerosols containing pollen allergens. These particles are small enough to deposit in the peripheral airways and have the potential to induce an inflammatory response.     

The allergen profile of ash (Fraxinus excelsior) pollen: cross-reactivity with allergens from various plant species

BACKGROUND: Ash, a wind-pollinated tree belonging to the family Oleaceae, is distributed world-wide and has been suggested as a potent allergen source in spring time. OBJECTIVE: The aim of this study was to determine the profile of allergen components in ash pollen in order to refine diagnosis and therapy for patients with sensitivity to ash pollen METHODS: The IgE reactivity profile of 40 ash pollen-allergic patients was determined by immunoblotting. Antibodies raised to purified pollen allergens from tree and grass pollens were used to identify cross-reactive structures in ash pollen extract. IgE immunoblot inhibition studies were performed with recombinant and natural pollen allergens to characterize ash pollen allergens and to determine the degree of cross-reactivity between pollen allergens from ash, olive, birch, grasses and weeds. RESULTS: The allergen profile of ash pollen comprises Fra e 1, a major allergen related to the major olive allergen, Ole e 1, and to group 11 grass pollen allergens, the panallergen profilin, a two EF-hand calcium-binding protein, a pectinesterase-like molecule and an allergen sharing epitopes with group 4 grass pollen allergens. Thus, the relevant allergens of ash are primarily allergens that share epitopes with pollen allergens from other tree, grass and weed species. CONCLUSIONS: Allergic symptoms to ash pollen can be the consequence of sensitization to cross-reactive allergens from other sources. The fact that ash pollen-allergic patients can be discriminated on the basis of their specific IgE reactivity profile to highly or moderately cross-reactive allergens has implications for the selection of appropriate forms of treatment.     

Traffic-related air pollutants induce the release of allergen-containing cytoplasmic granules from grass pollen

BACKGROUND/AIM: Pollen cytoplasmic granules (PCG) are loaded with allergens. They are released from grass pollen grains following contact with water and can form a respirable allergenic aerosol. On the other hand, the traffic-related air pollutants NO2 and O3 are known to be involved in the current increase in the prevalence of allergic diseases via their adjuvant effects. Our objective was to determine the effects of air pollutants on the release of PCG from Phleum pratense (timothy grass) pollen. METHODS: P. pratense pollen was exposed to several concentrations of NO2 and O3. The induced morphological damages were observed by environmental scanning electron microscopy, and the amount of PCG released from the pollen upon contact with water was measured. RESULTS: The percentages of damaged grain were 6.4% in air-treated controls, 15% after treatment with the highest NO2 dose (50 ppm) and 13.5% after exposure to 0.5 ppm O3. In treated samples, a fraction of the grains spontaneously released their PCG. Upon subsequent contact with water, the remaining intact grains released more PCG than pollen exposed to air only. CONCLUSIONS: Traffic-related pollutants can trigger the release of allergen-containing granules from grass pollen, and increase the bioavailability of airborne pollen allergens. This is a new mechanism by which air pollution concurs with the current increase in the prevalence of allergic diseases.     

Seasonal Variation of Asthma and Allergic Rhinitis

The seasonal variation of consultations on account of asthma and allergic rhinitis, and the relationship with air concentrations of pollen, spores, and lead, cadmium, dust, soot and sulfur dioxide was investigated in Danish general practice during a 1-year period 1977-78. A population of about 500,000 was studied. Among about 3000 asthmatics there were less consultations during spring than the rest of the year, but the seasonal variation of consultations with symptoms was rather small. The highest rate of consultations was in week 24, which is close to the peak of the grass pollen period. No relationship was found between asthma symptoms and concentrations of pollution indicators. Among about 5000 patients with allergic rhinitis the rate of consultations with symptoms increased at the start of the tree pollen season, still more at the start of the birch pollen season, and was very high during weeks 21-26 in the grass pollen season. Two thirds of all consultations for symptomatic allergic rhinitis took place within 10 weeks (Nos. 18-27). During the grass pollen season there was a relative preponderance of young patients, while during the birch pollen season older patients dominated. No connection was seen between rhinitis symptoms and pollution indicators. The different seasonal variation of asthma and allergic rhinitis indicates that the two patient categories differ as regards symptom-provoking factors. Allergic rhinitis is mainly precipitated by grass and birch pollen. The precipitating factors of asthma were not disclosed in this study, with the exception perhaps of some influence from pollen, and - among 0-4-year-old children - respiratory infections.     

Quantification of group 5 grass pollen allergens in house dust.

BACKGROUND: It is widely known and accepted that grass pollen is a major outdoor cause of hay fever. However, it is of virtual importance for grass pollen allergic patients with symptoms all the year round to know the concentration of grass pollen allergens in their homes. OBJECTIVE: The main objective of this study was to quantify the amount of grass pollen allergen in mass units (microg Phl p 5) in dust settled indoors and to detect the distribution of allergenic activity in different sampling locations of homes. Furthermore, we studied the seasonal fluctuation of allergen content in dust samples. METHODS: We adapted the two site binding assay for detection of group 5 grass pollen allergens in samples from randomly selected homes in Hamburg (n = 371), Erfurt (n = 396), Hettstedt (n = 353), Zerbst (n = 289) and Bitterfeld (n = 226), Germany. Dust samples were collected from floor of living room (LR), bedroom (BR) or children's room (CR) and mattress (MA) during period of June 1995 to August 1998. The amount of the major grass group 5 allergens was detected in microg/g dust. RESULTS: Phl p 5 was detected in 67% of the samples analysed (n = 4760). The range was between undetectable (< 0.03 microg/g dust) and 81 microg/g dust. Phl p 5 levels were significantly higher in the dust from LR (geometric mean 0.117 microg/g dust) or BR/CR floors (geometric mean 0.098 microg/g dust) than in mattresses (geometric mean 0.043 microg/g dust). We observed seasonal fluctuation of indoor Phl p 5 levels with peak in June but also annual differences. Thus Phl p 5 content indoors reflects also the different quantities of pollen counts of annual courses. During pollination period we found two times higher Phl p 5 levels (0.172 microg/g dust, P < 0.001) than outside of grass pollination season (0.095 microg/g dust). The indoor Phl p 5 levels outside of season seem to be independent of pollination before. We suppose that settled pollen grains or allergenic material from outdoor particles carried indoors via footwear and clothes accumulates in house dust. CONCLUSION: Although we not known how the allergens in settled dust are equilibrated with those in the air, the considerable high level of Phl p 5 in indoor dust even during periods when no grass pollen is present in the atmosphere may be an important cause of pollen-allergy symptoms outside of season.     

Is it important to perform pollen skin prick tests in the season?

BACKGROUND: Seasonal exposure to pollens causes the characteristic symptoms of respiratory allergy as well as an increase in specific IgE levels and inflammatory mediator release. However, little is known about the effect of natural allergen exposure on the skin test reactivity of patients with seasonal allergy. OBJECTIVE: The aim of this study was to investigate the monthly variation in skin test reactions with pollen allergens during pollen season and its relation to pollen counts. METHODS: Fifteen subjects with seasonal allergic rhinitis and/or asthma (4 male, 11 female) between the ages of 13 and 52 (mean 33.9 +/- 2.9) who lived in Ankara, Turkey were selected for this study. Patients were monitored from the beginning of March to the end of September 1997, and skin prick tests were performed using 5 grass, 12 tree, and 5 weed pollen allergen extracts every month. Atmospheric pollen grains were counted in the Ankara area between January and December, 1997. RESULTS: There were small but statistically significant increases in tree pollen-induced wheal sizes in May when compared with other months (P < 0.05). Skin test reactivity was correlated with tree pollen counts (r = 0.978, P < 0.05). There was not a significant difference in skin test reactivity to grass and weed pollens between months. CONCLUSIONS: Although skin test reactivity may be slightly greater to tree pollen during the tree pollen season, the timing of skin testing is not a critical determinant in patients with pollen allergy.     

Type I allergy to elderberry (Sambucus nigra) is elicited by a 33.2 kDa allergen with significant homology to ribosomal inactivating proteins

BACKGROUND: Patients suffering from allergic rhinoconjunctivitis and dyspnoea during summer may exhibit these symptoms after contact with flowers or dietary products of the elderberry tree Sambucus nigra. OBJECTIVE: Patients with a history of summer hayfever were tested in a routine setting for sensitization to elderberry. Nine patients having allergic symptoms due to elderberry and specific sensitization were investigated in detail. We studied the responsible allergens in extracts from elderberry pollen, flowers and berries, and investigated cross-reactivity with allergens from birch, grass and mugwort. METHODS: Sera from patients were tested for IgE reactivity to elderberry proteins by one-dimensional (1D) and 2D electrophoresis/immunoblotting. Inhibition studies with defined allergens and elderberry-specific antibodies were used to evaluate cross-reactivity. The main elderberry allergen was purified by gel filtration and reversed-phase HPLC, and subjected to mass spectrometry. The in-gel-digested allergen was analysed by the MS/MS sequence analysis and peptide mapping. The N-terminal sequence of the predominant allergen was analysed. RESULTS: 0.6% of 3668 randomly tested patients showed positive skin prick test and/or RAST to elderberry. IgE in patients' sera detected a predominant allergen of 33.2 kDa in extracts from elderberry pollen, flowers and berries, with an isoelectric point at pH 7.0. Pre-incubation of sera with extracts from birch, mugwort or grass pollen rendered insignificant or no inhibition of IgE binding to blotted elderberry proteins. Specific mouse antisera reacted exclusively with proteins from elderberry. N-terminal sequence analysis, as well as MS/MS spectrometry of the purified elderberry allergen, indicated homology with ribosomal inactivating proteins (RIPs). CONCLUSION: We present evidence that the elderberry plant S. nigra harbours allergenic potency. Independent methodologies argue for a significant homology of the predominant 33.2 kDa elderberry allergen with homology to RIPs. We conclude that this protein is a candidate for a major elderberry allergen with designation Sam n 1.     

Effects of IL-4 and IL-13 on total and allergen specific IgE production by cultured PBMC from allergic patients determined with recombinant pollen allergens

Background: Interleukin (IL)-4 and IL-13 have been shown to be potent switch factors for IgE synthesis in human B cells. Objective: In this study we investigated the effects of recombinant human IL-4 and IL-13 on total and allergen specific IgE synthesis by peripheral blood inononuclear colls (PBMC) from pollen allergic patients and healthy control individuals. Methods: Peripheral blood mononuclear cells (PBMC) from allergic patients were investigated for their capacity to produce allergen specific IgE in vitro. Total protein extracts from birch pollen and timothy grass pollen as well as purified recombinant birch pollen allergens, Bet v I, birch profiling (Bet v II) and recombinant timothy grass pollen allergens. Phi p I, Phi p II, and Phi p V were used to measure specific IgE-antibody synthesis in cell culture supernatants by IgE-immunoblot and ELISA. Reults PBMC obtained from allergic patients spontaneously secreted allergen specific IgE in the culture supernatants. Addition of Interleukin 4, Interleukin 13 and anti-CD40 antibody to the cultures alone or in combinations significantly induced total IgE production whereas allergen specific IgE production was not affected. Conclusion: Our results indicate that the peripheral blood of allergic individuals contains long lived allergen specific B cells which have already switched to IgE production and which are not sensitive to IL-4 and IL-13 treatment. These results may have implications on attempts to use cytokines or cytokine antagonists in therapy of Type I allergy.