S. Vieths

Roasted hazelnuts – allergenic activity evaluated by double‐blind, placebo‐controlled food challenge

Background: Allergy to hazelnuts is a common example of birch pollen related food allergy. Symptoms upon ingestion are often confined to the mouth and throat, but severe systemic reactions have been described in some patients. The aim of the study was to evaluate the reduction in allergenicity by roasting of the nuts.

Influence of food processing on the allergenicity of celery: DBPCFC with celery spice and cooked celery in patients with celery allergy

Background: Celery root is often consumed in a processed form as a cooked vegetable or as a spice. So far, however, there has been no information about the allergenicity of processed celery in celery‐allergic patients.

Development of a functional in vitro assay as a novel tool for the standardization of allergen extracts in the human system

Background:  Biochemical and immunochemical methods used for batch control of allergen extracts rely on the binding of IgE molecules to allergens. They do not measure the ability of a protein to induce type I allergic reactions. Therefore, a biological assay was established that is based on the cellular mechanisms of allergies in order to assess the cross‐linking capacity of allergens.

Factors influencing the quality of food extracts for in vitro and in vivo diagnosis.

Food extracts for diagnostic purposes often lack sufficient activity and consistency. Biologically standardized food extracts are not available on the market. Using extracts from plant‐derived foods as examples, we investigated factors which may be important for the quality of such extracts. Divergent allergenic activities were found between strains of apples, but not within varieties of celery tuber (celeriac), hazelnut, and peanut, respectively. Heating of the food remarkably reduced the activity of apple, hazelnut, and celeriac, but had little effect on peanut. By contrast, heating of semipurified protein extracts from celery tuber and apple for 30 min at 100°C did not deplete the immunoreactivity of the major allergens, indicating that this is an inappropriate test for identifying labile food allergens. Due to their high endogenous enzyme activities, apples and other fruits require special extraction procedures applying either low temperature or enzyme inhibitors. Variation of extraction conditions had little effect on the composition and activity of extracts from hazelnut. The storage stability of skin test solutions from plant foods can be improved by avoiding phenol as an additive and by including 50% of glycerol. For model studies considering neoallergens, IgE was raised in mice against native and heated celery tuber, respectively. When extracts from nonthermally and thermally processed celeriac were subjected to an RBL‐cell mediator release assay with these sera, an inverse ranking was obtained with anti‐heated celeriac IgE and anti‐native celeriac IgE, respectively. These data indicated that new epitopes had been formed by the heating process. Since all parameters were tested in model experiments with either human or murine IgE, their relevance has to be proven in further clinical investigations.

The non‐specific lipid transfer protein, Ara h 9, is an important allergen in peanut

Background Plant food allergy in the Mediterranean area is mainly caused by non‐specific lipid transfer proteins (nsLTP). The aim of this study was to characterize peanut nsLTP in comparison with peach nsLTP, Pru p 3, and assess its importance in peanut allergy.

Identification of a plane pollen lipid transfer protein (Pla a 3) and its immunological relation to the peach lipid-transfer protein, Pru p 3

Background An association between plane tree pollen allergy and plant food allergy has been described, but the cross‐reacting allergens have not yet been identified. The aim of this study was the identification of homologous non‐specific lipid‐transfer proteins (nsLTPs) in plane pollen, and to investigate its immunological relationship with the peach LTP, Pru p 3.

Lettuce anaphylaxis : Identification of a lipid transfer protein as the major allergen

Background:  Allergy to plant‐derived foods is associated with birch pollinosis in central and northern Europe. Symptoms elicited are usually limited to the oropharyngeal system. By contrast, in the Mediterranean area, allergy to the same foods manifests more frequently with systemic reactions caused by nonspecific lipid transfer proteins (nsLTP), independently of an associated pollinosis.

Tomato profilin Lyc e 1: IgE cross‐reactivity and allergenic potency

Background:  To date, very little data are available about the nature of tomato allergens. Immunoglobulin E (IgE) cross‐reactive profilins have been suggested to account for allergic symptoms in patients suffering from tomato allergy.

Identification of enolases and aldolases as important fish allergens in cod, salmon and tuna: component resolved diagnosis using parvalbumin and the new allergens.

The majority of fish‐allergic patients are sensitized to parvalbumin, known to be the cause of important IgE cross‐reactivity among fish species. Little is known about the importance of fish allergens other than parvalbumin.

Characterization of Der p 21, a new important allergen derived from the gut of house dust mites.

Background:  The house dust mite (HDM) Dermatophagoides pteronyssinus is a major allergen source eliciting allergic asthma. The aim of the study was to identify new important HDM allergens associated with allergic asthma.