Background: A considerable number of pollen-allergic patients develops allergy to plant foods, which has been attributed to cross-reactivity between food and pollen allergens. The aim of this study was to analyze the differences among pollen-allergic patients with and without plant food allergy. Methods: Eight hundred and six patients were recruited from 8 different hospitals. Each clinical research group included 100 patients (50 plant food-allergic patients and 50 pollen-allergic patients). Diagnosis of pollen allergy was based on typical case history of pollen allergy and positive skin prick tests. Diagnosis of plant-food allergy was based on clear history of plant-food allergy, skin prick tests and/or plant-food challenge tests. A panel of 28 purified allergens from pollens and/or plant foods was used to quantify specific IgE (ADVIA-Centaur® platform). Results: Six hundred and sixty eight patients (83%) of the 806 evaluated had pollen allergy: 396 patients with pollen allergy alone and 272 patients with associated food and pollen allergies. A comparison of both groups showed a statistically significant increase in the food and pollen allergy subgroup in frequency of: (1) asthma (47 vs. 59%; p < 0.001); (2) positive skin test results to several pollens: Plantago,Platanus,Artemisia,Betula,Parietaria and Salsola (p < 0.001); (3) sensitization to purified allergens: Pru p 3, profilin, Pla a 1 – Pla a 2, Sal k 1, PR-10 proteins and Len c 1. Conclusion: Results showed relevant and significant differences between both groups of pollen-allergic patients depending on whether or not they suffered from plant-derived food allergy.

Background: Olea europaea pollen is an important cause of seasonal allergic rhinitis and bronchial asthma in southern Spain. For patients allergic to grass pol– len the critical concentration of airborn pollen is 50 grains/m³, but in the case of Olea pollinosis no data is available. Methods: Fifty–six seasonal allergic rhinitis patients (29 in 1994 and 27 in 1995) were included in this study, all of whom lived in Jaen. Daily symptom card were filled in and pollen counts during May and June were performed in both years. A linear regression model was used for analysis of the airborne pollen concentration and the symptom score. Results: Significant correlations among daily counts of Olea pollen and rhinitis symptoms were obtained. Most of our monosensitized patients needed a high Olea pollen concentration in the atmosphere (around 400 grains/m³) to suffer at least from mild allergic rhinitis symptoms. Conclusion: Local conditions with a wide area dedicated to olive tree cultivars result in a high concentration of this pollen in the atmosphere. Monosensitized Olea patients in our area seem to need exceptionally high levels to suffer from allergic symptoms.

Our data suggest an association of Ole e 2 and Ole e 10 with bronchial asthma. Also, we found a genetic control of Ole e 2 and Ole e 10 IgE-specific responses that could be relevant to clinical disease in olive pollen allergy.

β-conglutin has been identified as a major allergen for Lupinus angustifolius seeds. The aim of this study was to evaluate the binding of IgE to five recombinant β-conglutin isoforms (rβ) that we overexpressed and purified and to their natural counterparts in different lupin species and cultivars. Western blotting suggested β-conglutins were the main proteins responsible for the IgE reactivity of the lupin species and cultivars. Newly identified polypeptides from "sweet lupin" may constitute a potential new source of primary or cross-reactive sensitization to lupin, particularly to L. albus and L. angustifolius seed proteins. Several of them exhibited qualitative and quantitative differences in IgE-binding among these species and cultivars, mainly in sera from atopic patients that react to lupin rather than peanut. IgE-binding was more consistent to recombinant β2 than to any of the other isoforms, making this protein a potential candidate for diagnosis and immunotherapy.

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Background: Recombinant allergens have potential advantages over conventional allergenic extracts. However, these recombinant allergens should be evaluated for their antigenic activity and compared with their natural counterparts before being used for clinical purposes. Methods: We studied 33 patients with seasonal rhinitis and/or bronchial asthma and a positive skin prick test to Olea europaea pollen extract, 10 atopic patients with no history of pollinosis and a negative skin prick test to O. europaea extract and 10 healthy controls. Skin prick tests and determination by ELISA of specific IgE to natural Ole e 1 (nOle e 1) and recombinant Ole e 1 (rOle e 1) expressed in Pichia pastoris were performed in all patients and controls. Inhibition assays were performed between nOle e 1 and rOle e 1 by ELISA. Results: All patients with O. europaea pollinosis had positive skin test responses to both commercial O. europaea extract and nOle e 1 allergen, and all reacted to rOle e 1 on the skin prick test. The nonatopic and atopic control subjects with negative olive pollen skin test results did not react to rOle e 1 on the skin prick test, even at the highest concentrations, confirming the specificity of this test. We found a weak correlation between the wheal surface area produced by the prick test with nOle e 1 and the wheal surface area produced by rOle e 1 at 10 μg/ml (r = 0.42, p < 0.05). Comparison of specific IgE against both nOle e 1 and rOle e 1 in the patients did not reveal any significant difference. There was a strong correlation between the amount of specific IgE against nOle e 1 and rOle e 1 (r = 0.99, p < 0.01). The two proteins displayed the same extent of binding inhibition to IgE antibodies in ELISA inhibition experiments. Conclusions: These results confirm the immunological activity of rOle e 1 expressed in P. pastoris and indicate that Ole e 1 is one of the major allergens in O. europaea pollinosis as evaluated by skin prick test and serological methods. The correlation between rOle e 1 and nOle e 1 in skin test results and serologic data indicates the potential of recombinant allergens for clinical applications and diagnosis of O. europaea pollen allergy.

Olive seeds, which are a raw material of interest, have been reported to contain 11S seed storage proteins (SSPs). However, the presence of SSPs such as 7S vicilins has not been studied. In this study, following a search in the olive seed transcriptome, 58 sequences corresponding to 7S vicilins were retrieved. A partial sequence was amplified by PCR from olive seed cDNA and subjected to phylogenetic analysis with other sequences. Structural analysis showed that olive 7S vicilin contains 9 α-helixes and 22 β-sheets. Additionally, 3D structural analysis displayed good superimposition with vicilin models generated from Pistacia and Sesamum. In order to assess potential allergenicity, T and B epitopes present in these proteins were identified by bioinformatic approaches. Different motifs were observed among the species, as well as some species-specific motifs. Finally, expression analysis of vicilins was carried out in protein extracts obtained from seeds of different species, including the olive. Noticeable bands were observed for all species in the 15–75 kDa MW interval, which were compatible with vicilins. The reactivity of the extracts to sera from patients allergic to nuts was also analysed. The findings with regard to the potential use of olive seed as food are discussed.

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