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Background: Polcalcins are pollen-specific allergens with two EF-hand calcium-binding sites that exhibit strong cross-reactivity. Our objective was to isolate and express the cDNA coding of the EF-hand calcium-binding allergen from lilac pollen and to study cross-reactivity with other polcalcins from related and nonrelated pollen sources with different specific antibodies and sera from two different populations. Methods: Specific cDNA was amplified by PCR, cloned and expressed in Escherichia coli. Purification was achieved by gel permeation and ion exchange chromatographies. ELISA titration and inhibition assays were performed using the recombinant forms of Syr v 3, Ole e 3, Che a 3 and Phl p 7 with sera from two Spanish regions with different sensitization profiles, as well as Phl p 7- and Ole e 3-specific polyclonal rabbit antisera, and an Ole e 3-specific monoclonal antibody. Results: Syr v 3 displays two EF-hand consensus sites and 8863 Da of theoretical molecular mass. The allergen consists of 80 residues with identities ranging from 66 to 87% with polcalcins included in this study. Syr v 3, Ole e 3, Che a 3 and Phl p 7 showed a similar IgG- and IgE-binding capacity although differences at quantitative level were observed depending on the population of patients’ sera. Conclusion: Syr v 3 is a polcalcin with structural and antigenic similarities to the members of this family. Diagnosis of polcalcin-sensitized patients could be performed whatever polcalcin used, whereas for immunotherapy, primary sensitization to a particular allergenic source should be considered.

Background: Several studies have shown that allergy to natural rubber latex is associated with cross-reactivity to certain foods such as tomato and potato. The objective was to investigate the clinical and immunologic differences between a group of patients with clinical allergy to tomato and latex and another which had only clinical allergy to tomato. We also aimed to assess, in vitro, the relationship of tomato and latex allergens, which could explain the cross-reactivity. Methods: Forty patients with histories of adverse reactions to tomato and IgE-mediated hypersensitivity were enrolled in the study. Tomato, latex, and potato components were analyzed by SDS–PAGE immunoblotting. CAP and immunoblot inhibition were used to study allergen cross-reactivity. Results: Patients from group A had a mean age of 13.2 years, and in group B the mean age was 21.7 years. In group B, 9/10 patients belonged to the latex-fruits syndrome. All patients of both groups tolerated potato. Immunoblotting patterns obtained with patients' sera from pool A showed IgE-binding bands to tomato ranging from 44 to 46 kDa and a triple band at 67 kDa. For latex, there was a strong binding at 44 kDa, and potato showed a strong band of 44 kDa and a 67-kDa triple band. In pool B, the binding to the band of 44 kDa in latex and tomato was more intense than in pool A. In pool A, immunoblot inhibition with potato allergen showed an intense inhibition of the three allergens (potato, latex, and tomato); with latex, inhibition was partial and with tomato, a complete inhibition of tomato and latex was observed, and a partial inhibition of potato. In pool B, the inhibition pattern followed a similar tendency to pool A. The CAP inhibition confirmed the high rate of cross-reactivity between tomato, potato, and latex. Conclusions: In our study, tomato, potato, and latex showed a common band of 44–46 kDa probably corresponding to patatin. This protein could be implicated in the high cross-reactivity between tomato, latex, and potato observed in the immunoblot and CAP inhibition.

We report a case of occupational bronchial asthma and rhinoconjunctivitis caused by Phoenix canariensis (PC) pollen. The canary palm is a type of palm tree, belonging to the Arecaceae family, which is widely distributed in frost-free regions as an ornamental tree. Our patient was referred because he suffered symptoms of bronchial asthma, rhinoconjunctivitis, and contact urticaria when pruning dried leaves from PC during the pollination months. The skin prick test (SPT) with a PC pollen extract was positive, as was the specific IgE to PC pollen determined by Phadezym RAST, indicating an IgE-mediated sensitization. The nonspecific bronchial provocation test (BPT) performed with methacholine disclosed a mild bronchial hyperreactivity, and specific BPT with PC pollen elicited an immediate fall of 25% in FEV1 with respect to baseline. On RAST inhibition studies, a significant cross-reactivity was found between PC pollen and date palm (P. dactylifera) pollen. These results suggest that PC pollen could be a potential allergen in PC-growing areas.

Background: ThiomucaseH is a mucopolysaccharidase obtained from ovine tissues mainly used to facilitate the diffusion of local anaesthetics and in the treatment of cellulitis. A patient with an anaphylaxis in relation to the intramuscular administration of ThiomucaseH is reported. Objective: To investigate ThiomucaseH allergens and their possible relationship with dander allergens and animal albumins. Material and methods: Skin prick tests (SPT) and serum-specific IgE were performed with ThiomucaseH and danders. ThiomucaseH SDS-PAGE immunoblotting was performed in order to study allergens. RAST/CAP inhibition and SDS-PAGE immunoblotting inhibition were carried out to study the crossreactivity. Results: Skin prick tests (SPT) were positive to ThiomucaseH, animal dander (cat, dog, sheep, other), bovine serum albumin (BSA), and echinococcus. Specific IgE was also positive to ThiomucaseH, animal dander (cat, dog, sheep, other), BSA and echinococcus. In the RAST-CAP inhibition assays BSA was nearly completely inhibited by ThiomucaseH, ThiomucaseH was partially inhibited by BSA and cat and Echinococcus granulosus was partially inhibited by sheep and ThiomucaseH. In the ThiomucaseH SDS-PAGE immunoblotting several proteins fixed IgE, ranging from 20 kDa to > 94 kDa, the strongest with 43 kDa. The IgE fixation to BSA, cat and sheep in the SDS-PAGE immunoblotting was completely inhibited by the preincubation of the serum with ThiomucaseH. Conclusions: An IgE-mediated anaphylaxis to ThiomucaseH is documented. Multiple allergens are recognized in ThiomucaseH by the patient serum, the main with 43 kDa. Partial cross-reactivity with BSA, cat dander and sheep dander is documented.