Prevalence of self-perceived allergic diseases and risk factors in Italian adolescents.

The aim of the study was to assess the symptoms prevalence of allergic diseases in a population of 11-15 yr old schoolchildren, to evaluate the associations between asthma and other symptoms and identify risk factors for asthma, rhinitis and eczema syndromes. A sample of 481 students was studied using an International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Prevalence of different kind of self-reported symptoms was calculated. Using a logistic regression approach, we tried to identify risk factors for three syndromes - rhinitis, eczema and asthma. The highest and the lowest prevalence rates of self-reported symptoms were recorded for rhinitis (43.6%) and for eczema (8.1%), respectively. The prevalence of asthma was 15.7%. Univariate analysis showed a mutual association between wheeze and rhinitis symptoms. Multivariate logistic regression model for eczema syndrome revealed female gender as a significant risk factor. The polytomic logistic multivariate regression revealed female gender and family history of allergy as significant risk factors for rhinitis syndrome only, and maternal smoking and familial allergy for rhinitis and asthma together. In particular, familial allergy yields a 400% higher chance of developing asthma and rhinitis together. The synergistic effect of familial allergy on rhinitis and asthma syndromes suggests the implementation of preventive measures in children with family history of these diseases.

Differences in the presence of allergens among several types of indoor environments.

Exposure to indoor allergens can occur both at home and in public places such as schools and workplaces. To investigate and compare the presence of indoor allergens in different kind of environments (schools, offices and homes), dust samples were collected from furniture, desks, mattresses and floors with a standardized procedure. Samples were analyzed for Der p 1, Der f 1, Mite group 2 (mites) and Fel d 1(cat) by monoclonal antibody ELISA assay. Mite allergens were detected with low frequencies in schools and workplaces and with high frequency in homes. Fel d 1 was found with high frequency in every examined environment. Homes rather than public places can represent the environment where people can easier incur in mite allergy. All environments could be at risk for cat allergen exposure.

Exposure to indoor allergens and association with allergy symptoms of employees in a work environment.

Exposure to indoor allergens is an important risk factor for sensitisation and respiratory allergy. The aim of this paper was to evaluate the levels of mite, cat and latex allergens in dust collected from an indoor workplace and to assess whether the exposure to these allergens was associated with the allergy symptoms reported by employees. Sixty dust samples were collected. Allergen concentrations were measured with antibody based ELISAs. All 144 participants compiled a questionnaire exploring possible symptoms of allergy. No association between latex allergen exposure and symptoms was found in spite of the high frequency of latex allergens. Mite allergens were detected in a minority of rooms. Cat allergen was the most important indoor allergen in the sampled workplace and exposure to this allergen could represent a risk for employees.

The ISS Sensitizing Agents Data Bank (BDS).

The Istituto Superiore Sanità has developed a data bank on sensitizing substances (Banca Dati Sensibilizzanti, BDS), available on website (www.iss.it/bdse/), sharing complete, controlled and updated information coming from different sources, such as scientific publications, international agencies and governmental or non governmental organizations. It is worthwhile that the main objective of the BDS is not the classification of sensitizing or potentially sensitizing agents within specific risk classes, but it is essentially to provide concise and non confidential information related to this endpoint. At present, the BDS includes: all the substances officially classified by European Union, (Annex I to Directive 67/548/EEC), some substances listed in I (Directive 67/548/EEC) for endpoints different than "sensitization" but indicated as sensitizers by other relevant institutions, all the substances indicated as sensitizers by relevant agencies or institutions (ACGIH, DFG), some substances indicted as sensitizers by industry and other non-governmental organizations (ETAD and HERA), all the substances regarded as "potentially sensitizing dyes" by the Commission of the European Community for the award of the eco-label to textile products, some substances for which, even in the absence of any categorization by Union, ACGIH or DFG, it is not possible to exclude a sensitizing potential on the basis of reliable documents.

Cloning and Expression of the Olea europaea allergen Ole e 5, the pollen Cu/Zn superoxide dismutase.

BACKGROUND: Recombinant DNA technology does provide pure, well-defined and reproducible products to be used for clinical purposes, by cloning and expressing the cDNA of allergens present in a specific extract. Ole e 5 is a pollen allergen of Olea europaea with an IgE-binding frequency of about 35%, which has been identified as a superoxide dismutase (SOD). The aim of this study was to clone the cDNA of Ole e 5, to express Ole e 5 in Escherichia coli and to characterize its immunoreactivity. METHODS: cDNA of Ole e 5 was amplified by nested 3'-RACE PCR and cloned in pGEX vector 6P expression vector. After sequencing of some clones and homology analysis, the rOle e 5 was produced in an E. coli strain as a fusion protein with GST and purified. Then, the protein immunoreactivity was evaluated by patients' IgE binding (ELISA, ELISA inhibition, and immunoblotting) and by rabbit anti-rOle e 5 binding (immunoblotting and immunoblotting inhibition). RESULTS: The sequence analysis of Ole e 5 cDNA confirmed that Ole e 5 is a Cu/Zn SOD, with an identity from 90 to 80% with SOD from other species. rOle e 5 was recognized by IgE from 39% of olive pollen-allergic patients tested; moreover, this binding was inhibited by the olive pollen extract. An anti-rOle e 5 antiserum raised in rabbit strongly reacted with a natural component of about 16-kDa molecular weight present in the olive pollen extract; moreover, this binding was inhibited by the recombinant protein. CONCLUSIONS: Ole e 5 is the first Cu/Zn SOD identified as an allergen in a pollen source. Due to the widespread presence of this enzyme, rOle e 5 allergen, cloned and expressed in a complete form in E. coli, could represent a good tool to investigate the allergen cross-reactivity between O. europaea pollen and other allergenic sources, such as plant foods and other pollens.

Refolding of the Cupressus arizonica major pollen allergen Cup a1.02 overexpressed in Escherichia coli.

The cDNA encoding an isoform of the cypress major pollen allergen, Cup a1.02, has been cloned and expressed in Escherichia coli as a N-terminal 6x His-tagged protein. To increase recovery, Cup a1.02 was expressed at high levels exploiting the T5 strong promoter and led to accumulate as inclusion bodies. The insoluble purified aggregates were solubilized in 6 M guanidine hydrochloride, immobilized using nickel-chelating affinity chromatography, and successfully refolded by controlled removal of the chaotropic reagent. Enhanced protein refolding was observed by reducing the protein concentration at 0.6-0.8 mg/ml. SDS-PAGE and gel filtration chromatography indicated an apparent molecular mass of approximately 40 kDa and the occurrence of the protein as monomers. The reconstituted fusion protein displayed the same immunological properties of the native Cup a1.02 protein as proven by IgE immunoreactivity. Immunoblotting, ELISA, and histamine release test showed that the tag did not preclude the protein functionality hence validating its correct three-dimensional folding. The protein fold was also assessed by CD spectroscopy and deconvolution of the spectrum allowed to estimate the secondary structure as a prevalence of beta structures (higher than 60%) and a small contribution from alpha helices (less than 12%). The reported procedure has proven to be useful for the production of multi-milligrams of recombinant Cup a1.02 allergen suitable for structural biology studies and for the molecular and functional characterization of the IgE binding sites.