Allergen cross-reactions among three strongly sensitizing Euphorbiaceae species, i.e., the rubber tree (Hevea brasiliensis), castor bean (Ricinus communis), and the Mediterranean weed Mercurialis annua were studied in Finnish patients (n = 25) allergic to natural rubber latex (NRL), but with no known exposure to castor bean or M. annua, and French patients allergic to castor bean (n = 26) or to M. annua (n = 9), but not to NRL. In immunoglobulin E (IgE)-immunoblotting, 28% of NRL-allergic patient sera recognized castor bean seed and 48% reacted to castor bean pollen proteins. Likewise, 35% of the NRL-allergic patient sera bound to M. annua pollen allergens. Nineteen percent of castor bean-allergic patients showed IgE to NRL and 8% to M. annua proteins. Sera from patients allergic to M. annua reacted in 44% to NRL, in 56% to castor bean seed, and in 78% to castor bean pollen proteins. In immunoblotting, castor bean seed extract inhibited the binding of NRL-reactive IgE to 20 kDa, 30 kDa of NRL, and 55 kDa of proteins; NRL extract, in turn, inhibited the binding of castor bean-reactive IgE to 14, 21-22, 29, and 32-34 kDa of castor bean proteins. In ELISA inhibition, NRL extract inhibited 33% of the binding of M. annua--reactive IgE of pooled sera to M. annua pollen. In conclusion, allergen cross-reactivity in vitro was observed among three botanically related Euphorbiaceae members, H. brasiliensis, R. communis, and M. annua, but the molecular specificity of the observed cross-reactions as well as their clinical significance remains to be elucidated. Allergen cross-reactivity should be taken into account in diagnostic work.
BACKGROUND: A study was performed to compare the effects of immunization with ragweed pollen (RW) in two different adjuvants on the characteristics of a previously described model of experimental immune-mediated blepharoconjunctivitis (EC) in rats. METHODS: Lewis or Brown Norway (BN) rats were immunized with 100 microg of RW in emulsion with aluminum hydroxide [Al(OH)3] or complete Freund's adjuvant (CFA). Three weeks later, the animals were challenged with eye drops containing RW in PBS. Twenty-four hours after topical challenge, eyes, blood, and lymph nodes were obtained for histology, measurement of antigen-specific antibodies, and proliferation or cytokine assays, respectively. In addition to active immunization, recipients of RW-primed lymph node cells were challenged and evaluated as above. RESULTS: RW in both adjuvants induced infiltration with predominantly mononuclear cells in Lewis rats and eosinophils in BN rats. As well as active immunization, eosinophils were detected only in BN rats by adoptive transfer of cells. Lymphocyte proliferative responses to RW were high in immunized Lewis rats when CFA was used as an adjuvant. In contrast, proliferative responses in BN rats were higher when Al(OH)3 was used. RW-specific IgE was detected only in BN rats. There were no significant differences in RW-specific IgG1/IgG2a ratio among the four groups. Lewis rats had higher level of RW-specific interferon-gamma in the culture supernatant. CONCLUSIONS: The characteristics of EC are different in Lewis and BN rats, dependent on the genetic background of the rat strains. The response to RW was similar to other previously used antigens, such as ovalbumin.
Allergic response to pollen is increasing worldwide, leading to high medical and social costs. However, the effect of pollen exposure on lung function has rarely been investigated. Over 1800 children in the Swedish birth cohort BAMSE were lung-function- and IgE-tested at the age of 8 and 16 years old. Daily concentrations for 9 pollen types together with measurements for ozone, NO2 , PM10 , PM2.5 were estimated for the index day as well as up to 6 days before the testing. Exposure to grass pollen during the preceding day was associated with a reduced forced expiratory volume in 8-yr-olds; -32.4 ml; 95% CI: -50.6 to -14.2, for an increase in three pollen counts/m³. Associations appeared stronger in children sensitized to pollen allergens. As the grass species flower late in the pollen season, the allergy care routines might be weakened during this period. Therefore, allergy information may need to be updated to increase awareness among grass pollen-sensitized individuals.
The EC-funded EuroPrevall project examined the prevalence of food allergy across Europe. A well-established factor in the occurrence of food allergy is primary sensitization to pollen.
To analyse geographic and temporal variations in pollen exposure, allowing the investigation of how these variations influence the prevalence and incidence of food allergies across Europe.
Airborne pollen data for two decades (1990-2009) were obtained from 13 monitoring sites located as close as possible to the EuroPrevall survey centres. Start dates, intensity and duration of Betulaceae, Oleaceae, Poaceae and Asteraceae pollen seasons were examined. Mean, slope of the regression, probability level (P) and dominant taxa (%) were calculated. Trends were considered significant at P 10% of total pollen exposure only in Siauliai (Artemisia) and Legnano (Ambrosia). Consistent trends towards changing intensity or duration of exposure were not observed, possibly with the exception of (not significant) decreased exposure to Artemisia and increased exposure to Ambrosia.
This is the first comprehensive study quantifying exposure to the major allergenic pollen families Betulaceae, Oleaceae, Poaceae and Asteraceae across Europe. These data can now be used for studies into patterns of sensitization and allergy to pollen and foods.
BACKGROUND: Few studies have investigated the use of specific immunotherapy (SIT) for childhood seasonal allergic asthma. OBJECTIVE: We sought to examine the efficacy and safety of SIT with Alutard SQ grass pollen (Phleum pratense Alutard SQ; ALK-Abelló, Hørsholm, Denmark) in children with seasonal allergic asthma. METHODS: A randomized, double-blind, placebo-controlled study assessing the efficacy of grass pollen SIT over 2 pollen seasons was performed. Children (3-16 years) with a history of seasonal allergic asthma sensitized to grass pollen (P pratense) and requiring at least 200 microg of inhaled beclomethasone equivalent per day were enrolled. Subjects with symptomatic asthma or rhinoconjunctivitis outside the grass pollen season were excluded. The primary outcome measure was a combined asthma symptom-medication score during the second pollen season. Secondary outcome measures included end-point titration skin prick testing and conjunctival and bronchial provocation testing to allergen, sputum eosinophilia, exhaled nitric oxide, and adverse events. RESULTS: Thirty-nine subjects were enrolled. Thirty-five subjects provided data for analysis. The use of SIT was associated with a substantial reduction in asthma symptom-medication score compared with that after placebo (P = .04). There were also significant reductions in cutaneous (P = .002), conjunctival (P = .02), and bronchial (P = .01) reactivity to allergen after SIT compared with that after placebo. The 2 groups had similar levels of airway inflammation, despite a trend toward less inhaled steroid use in the active group. No serious adverse events were reported, and no subjects withdrew because of adverse events. CONCLUSION: The study has shown that SIT is effective and well tolerated in children with seasonal allergic asthma to grass pollen.
Asymptomatic skin sensitization (AS) is a risk factor for the development of allergic symptoms. A meticulous definition of this condition requires a systematic assessment of clinical symptoms before inclusion.
To examine the concordance between retrospective assessment of seasonal allergic symptoms and prospective seasonal symptom registration among subjects with AS.
On the basis of a population survey, autumn 2002, including skin prick tests (positive if > or =3 mm) and a screening questionnaire, 87 subjects with AS to birch and/or grass pollen, birch and/or grass pollen allergic symptomatic subjects (n = 63) and healthy controls (n = 40) were included in January to March 2003, completed diary cards on symptom and medication use during the relevant seasons 2003, and were examined at follow up in autumn 2003. Allergy: positive SPT and symptoms > or = seven diary days.
Eleven AS subjects (birch: n = 10) subsequently developed allergic symptoms, yet nine admitted, at follow up, to have had symptoms before inclusion, or even denied pollen-related symptoms despite a significant diary. Compared with AS subjects sensitized to grass pollen, AS subjects sensitized to birch pollen had significantly larger skin prick reactions and more often and severe pollen symptoms.
In the context of double-sensitization, retrospective symptom assessment is not a reliable method for ensuring that subjects classified, as asymptomatically skin sensitized, are truly, asymptomatic. This matter should be considered in studies on allergy development.
OBJECTIVE: To investigate the health and monetary consequences of treating allergy with specific immunotherapy (SIT) compared with symptomatic treatment/standard care among patients with grass pollen or mite allergy. METHODS: We performed an economic analysis based on 253 grass- and/or mite allergic patients who started SIT from 1.1.1996 to 1.1.2002 at the Allergy Unit, Aarhus University Hospital and at a specialist practice in Aarhus. Relevant data were collected before, during and after SIT treatment from the national health service based on each patient's personal identification number and medical records and from a specifically designed questionnaire. A cost-benefit analysis including direct and indirect costs before, during and after SIT was performed. In addition direct costs were related to the clinical effect (improvement in well-being) in the form of a cost-effectiveness analysis. RESULTS: The direct cost per patient/year before SIT (equivalent to standard care) was DKK 2,580. The investment in SIT was DKK 27,545 (in present values) per patient over a 4-year period. After SIT the cost was reduced to DKK 1,072 per patient/year. In the long term, prospective introduction of SIT incurred additional present-value direct costs of DKK 13,676 per patient treated and DKK 2,784 per patient/year of improved well-being. However, when indirect costs were included in the economic evaluation SIT was shown to be net beneficial. CONCLUSION: This study reveals that SIT is associated with initial resource investments and subsequent resource savings in the long term compared with standard care. When all consequences are measured in monetary terms, and assuming that sick days are associated with a loss of productivity, this analysis suggests that SIT increases societal welfare. This conclusion also holds if there is no loss of productivity.
In 1993 extremely high levels of birch pollen were recorded in Stockholm, Sweden. We investigated the effects of this exposure on sensitization and development of atopic airway disease in children. The aim of this study was to assess the influence of maternal birch sensitization and symptoms of pollen allergy, as well as exposure to birch pollen during pregnancy, on sensitization and development of atopic airway disease in children. A total of 387 children with atopic heredity (70% had atopic mothers) and born in Stockholm 1993 or 1994 were investigated at age 4.5-5 yr. The children were examined and skin prick tested with inhalant and food allergens. IgE-antibodies against birch pollen and recombinant birch pollen allergen were analyzed in serum. The same tests were performed on the mothers. Children of mothers with symptoms of pollen allergy more often showed symptoms of rhinoconjunctivitis at age 4.5-5, after both high dose [Odds ratio (OR) 5.3; 95% confidence interval (CI): 2.0-13.7] and low dose (OR 4.0; 95% CI: 1.5-10.9) exposure to birch pollen during pregnancy. Similar tendencies were noted for children of mothers sensitized to birch, where stronger effects were suggested in boys (OR 3.8; 95% CI: 1.3-11.5) than in girls (OR 1.2; 95% CI: 0.2-5.5) in the high-dose exposed group. For asthma symptoms and sensitization to birch in the children the results were less consistent. It may be concluded that, maternal pollen allergy seems to have a stronger influence on the development of rhinoconjunctivitis in children with a family history of atopy than the degree of allergen exposure during pregnancy.
The influence of microbial quality of drinking water from different sources on the occurrence of atopy has been poorly examined. This study was undertaken to clarify the association between the overall microbial content in drinking water and the occurrence of atopy among schoolchildren from two neighbouring areas with profound differences in living conditions and lifestyles.
Drinking water samples were obtained from kitchens of nine schools in North Karelia, Finland and of nine schools from Pitkäranta, the Republic of Karelia, Russia. The pupils of these schools were participants of the Karelian Allergy Study. Occurrence of atopy, determined by skin prick test positivity (one or more) to 14 common airborne and food allergens, was measured in all 563 children, aged 7-16 years, from these 18 schools. Water samples were analysed using standard methods for drinking water analyses including viable counts for Escherichia coli, intestinal enterococci, coliform bacteria and heterotrophic bacteria. In addition, total cell counts including both viable and nonviable bacteria, algae and protozoans were assessed using epifluorescence microscope with 4'-6-diamidino-2-phenylindole (DAPI) staining.
In Finland, 29% of the children were sensitized to birch when compared with 2% of the Russian children (P 10(6) cells/ml) and intermediate (10(5)-10(6) cells/ml) DAPI values were associated with reduced risk of atopy (odds ratio 0.34, 95% confidence interval 0.20-0.57 and 0.39, 0.23-0.69, respectively), independently from other factors.
High overall content of micro-organisms in drinking water may be associated with reduced risk of atopy, independently from other determinants.