Mould and grass pollen allergy as risk factors for childhood asthma in Zaragoza, Spain.

OBJECTIVE: Examine the prevalence of asthma and associated predictive factors in a group of 468 students. PATIENTS AND METHODS: A descriptive, cross-sectional observational study in a randomly selected population of 468 children aged 10-12, in the city of Zaragoza. We used the ISAAC questionnaire on asthma completed by children under supervision of the investigators. We assessed the genetic risk (family history of asthma) and environmental risks. The risk for atopy was assessed by the presence of positive skin prick tests. RESULTS: 25.3% of the children had symptoms consistent with asthma in the city of Zaragoza. Among them 33.1% reported a history of asthma in close relatives (OR=1.78, p<0.001). The history of hospitalisations for lower respiratory tract illness was strongly associated with the presence of asthma (OR=6.72, p<0.0001). Positive skin tests to Alternaria (OR=2.00, p<0.0001) and grass pollen (OR=1.76, p<0.001) were predictors of asthma. 63.6% of asthmatic children had presented clinical rhinitis in the previous 12 months, compared with 32% of non-asthmatics, and this difference was statistically significant (OR=3.89, p<0.0001). 47% of asthmatics presented with or previously had eczema, whereas only 26.9% of non-asthmatics presented with or previously had these types of lesions (p<0.0001). CONCLUSION: The following are predictors of asthma: History of hospital admissions for lower respiratory tract illness, presence of rhinitis and/or eczema, positive prick test for certain aeroallergens, especially Alternaria and grass pollen, and family history of asthma.

Correlation between Chenopodiacea/Amaranthacea pollen counts and allergic symptoms in Salsola kali monosensitized patients.

UNLABELLED: We performed a prospective observational study to establish a relationship between pollen counts of Chenopodiacea/Amaranthacea and clinical symptoms of rhinoconjunctivitis and asthma in a group of monosensitised patients. MATERIAL AND METHODS: A total of 60 patients (19 with asthma) were included in the study. All patients collected daily symptom scores during the summer months of 1999, 2000 and 2001. The questionnaire included ocular, nasal and pulmonary symptoms. Pollen counts were expressed as pollen grains/m3. Symptom scores and pollen counts were correlated using correlation coefficients and Log transformed variables. RESULTS: In the 3 seasons studied we identified a peak of pollen and clinical symptoms in the second half of August and first half of September. In 1999, there was a significant positive correlation between total symptoms and daily pollen grains/m3 (p<0.005, r = 0.347). This correlation was not significant for the summers of 2000 and 2001. After further analysis, and by displacing one of both variables between 11 to 17 days, the correlation coefficients for total symptoms, improved for 1999 (r = 0. 744; p < 0.0001) and became significant for 2000 (r = 0. 521; p < 0.0001) and 2001 (r = 0.635; p < 0.0001). CONCLUSION: We identified a significant time lag between pollen counts and symptom scores in S. kali monosensitized patients.

Immunochemical characterization of Russian thistle (Salsola kali) pollen extracts. Purification of the allergen Sal k 1.

BACKGROUND: Salsola kali (Russian thistle) is a weed which belongs to the Chaenopodiacea family. It is widely distributed along the coasts of Europe, North Africa, USA and Australia. The objectives of this study were to study the allergenic composition of S. kali pollen and to purify an important allergen from the pollen extracts of this plant. METHODS: A population of 66 individuals with specific IgE-mediated allergic symptoms and positive skin tests to S. kali were included in the study. Specific IgE to S. kali was determined by direct enzyme-linked immunosorbent assay (ELISA). The antigenic and allergenic profile of S. kali was evaluated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), isoelectric focussing (IEF) and immunoblot. Allergen purification was conducted by preparative SDS-PAGE. The allergenicity of the protein was evaluated by skin testing, direct ELISA, ELISA inhibition and immunoblots. RESULTS: Specific IgE to S. kali was detected in 39 of the 66 individuals (59%). An allergen with a molecular weight of approximately 43 kDa was purified. This allergen was termed Sal k 1. A partial sequencing was obtained and no homology was found with other known proteins/allergens. The allergenicity of Sal k 1 was tested in vitro and in vivo. Of the 39 individuals with a positive specific IgE determination to S. kali, 26 (66.6%) had detectable specific IgE to Sal k 1. Twenty of these 39 individuals were skin-prick tested with the purified allergen (0.5 mg/ml) and all of them had a positive skin test to the purified allergen. Ten additional individuals, used as negative controls, had a negative response. CONCLUSIONS: Sal k 1, an important allergen of S. kali, is recognized, in vitro, by approximately 67% of the patients sensitized to S. kali. Twenty patients with a positive skin test to a standardized S. kali extract had a positive reaction to the purified allergen.

Pistachio nut hypersensitivity: identification of pistachio nut allergens.

Type I hypersensitivity to pistachio nut antigens was demonstrated in three patients by means of immediate skin-test reactivity, specific IgE determination by a fluoroimmunoassay (CAP), CAP-inhibition and leucocyte histamine release. Sensitization to other dried fruits and pollens was observed in the patients. The CAP-inhibition studies revealed significant crossreactivity between pistachio and cashew nut belonging to the Anacardiaceae family, and between pistachio nut and other dried fruits belonging to taxonomically unrelated botanical families. No relevant crossallergenicity was observed between pistachio nut and Lolium and Olea pollens. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of a pistachio nut extract followed by immunoblotting analysis identified four IgE-binding bands with molecular weights of 34, 41, 52 and 60 kD.

Bronchial asthma caused by two unrelated vegetables.

Vegetable-induced asthma is an uncommon hazard. We report an atopic housewife, in whom rhinoconjunctivitis and acute asthma were associated with two vegetables of taxonomically unrelated botanical families (Swiss chard/Chenopodiaceae family and green beans/legume family). Type I hypersensitivity to the antigens in Swiss chard and green beans was demonstrated by means of skin tests, histamine release test, and specific IgE determination by RAST. Bronchial responses after specific bronchial challenges indicated that Swiss chard and green beans might be the causative factor for the acute asthma.

Monoclonal antibodies against Olea europaea major allergen: allergenic activity of affinity-purified allergen and depleted extract and development of a radioimmunoassay for the quantitation of the allergen.

Several monoclonal antibodies (MAbs) were raised against Olea europaea pollen-extract components. Two of these antibodies, named OL 2 and OL 7, recognize two nonoverlapping, nonrepeating epitopes on the olive-allergen Ole e I, as demonstrated by different techniques. The allergen was purified in a single step by MAb-based affinity chromatography, and the allergen revealed a band at molecular weight 20 kd as well as a minor band at 18 kd on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The contribution of allergen Ole e I to the allergenic activity of O. europaea pollen extracts was determined from the effect of allergen depletion by affinity chromatography on skin reactivity and a histamine-release test. The removal of allergen caused a large reduction in the activity of the preparation in 25 monospecific olive-allergic patients. In agreement, the affinity-purified allergen demonstrated a similar response when it was compared with the whole extract in these assays. The results indicated that Ole e I is by far the most important olive-pollen allergen. A two-site solid-phase radioimmunoassay was developed for the quantitation of the allergen Ole e I in mass units. The assay was based on the MAbs, OL 2 and OL 7, and had a detection limit in the nanogram range. A good correlation was found between allergenic activity, as determined by RAST inhibition, and allergen content in 18 olive-pollen extracts. This result indicates that the assay can be a good alternative to RAST inhibition for the standardization of O. europaea extracts.