nCup a 1 as a marker of allergy to cypress pollen

The increase in polysensitisations among allergic patients has led us to search for suitable means of diagnosis for identifying true sensitisation, and distinguishing true sensitisation from cross-reactivity. Cross-reactive carbohydrate determinants (CCDs) present in glycoproteins from cypress pollen extracts have been linked with such cross-reactivity, particularly in in vitro assays. The application of component-resolved diagnosis using recombinant allergens makes it possible to identify true allergens. The problem arises when the allergen available for the usual diagnostic methods, which are used as a reference for the diagnosis of allergy to cypress pollen nCup a 1, is a native allergen. The aim of the study was to validate the native allergen nCup a as a marker of true sensitisation to cypress pollen. The sera of 96 subjects with a proven allergy to cypress pollen were analysed. We then quantified IgE specific to Cupressus arizonica and to nCup a 1 and also analysed the CCDs in subjects sensitised to several tree pollen allergens, presenting with MUXF3-specific IgE. Results revealed that there is a statistically significant correlation between conventional diagnostic techniques used to determine allergy to cypress pollen (SPT and IgE Cupressus arizonica) and sensitisation to nCup a 1. CCD quantification in subjects sensitised to several tree pollen antigens showed that these did not interfere with our results. We validated the native Cupressus arizonica allergen, nCup a 1, as a marker of allergy to cypress pollen in our population.