Allergy to Salsola Kali in a Salsola incanescens-rich area: role of extensive cross allergenicity.
ABSTRACT Pollens from the Salsola spp. are an important source of respiratory allergy in tropical countries. Our aim was to characterize the IgE binding proteins of S. incanescens pollen extract and study its cross-reactivity with S. kali pollen allergens.
Prick tests with S. kali and S. incanescens pollen extracts were performed on eight respiratory allergy patients from Mashhad, Northeast Iran. The antigenic profiles and IgE-binding patterns of S. kali and S. incanescens pollen extracts were compared by SDS-PAGE and Western blotting, using individual sera from the salsola pollen-sensitive patients. Cross-reactivity of proteins in the two weeds was assessed by IgE- immunoblotting inhibition.
S. kali and S. incanescens pollen extracts showed similar IgE-binding profiles in Western blotting. The IgE binding components of 39, 45, 66 and 85 kDa were detected in both pollen extracts. Furthermore, inhibition of the immunoblots revealed extensive inhibition of IgE binding to proteins and a close relationship between these two weeds allergens.
S. incanescens pollen is a potent allergen source with several IgE binding components that shows a close allergenic relationship with S. kali. Our results suggest that in S. incanescens-rich areas, S. kali pollen extracts could be used as a diagnostic reagent for allergic patients to S. incanescens pollen.
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ABSTRACT: IgE-mediated allergy affects >25% of the population in industrialized countries. Repeated contact with the disease-eliciting allergens induces rises of allergen-specific IgE Abs and progression of the disease to more severe manifestations. Our study uses a type of vaccine that is based on genetically modified allergen derivatives to treat allergic patients. We developed hypoallergenic derivatives of the major birch pollen allergen, Bet v 1, by genetic engineering and vaccinated birch pollen-allergic patients (n = 124) in a double-blind, placebo-controlled study. Active treatment induced protective IgG Abs that inhibited allergen-induced release of inflammatory mediators. We also observed a reduction of cutaneous sensitivity as well as an improvement of symptoms in actively treated patients. Most important, rises of allergen-specific IgE induced by seasonal birch pollen exposure were significantly reduced in vaccinated patients. Vaccination with genetically engineered allergen derivatives is a therapy for allergy that not only ameliorates allergic reactions but also reduces the IgE production underlying the disease.Proceedings of the National Academy of Sciences 11/2004; 101 Suppl 2:14677-82. · 9.74 Impact Factor
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ABSTRACT: Knowledge of patterns of pollen cross-reactivity is crucial for diagnostics and especially for formulation of immunotherapy vaccines in times of diminishing availability of pollen extract constituents. As phylogenetic relationships have become better clarified, it becomes apparent that cross-reactivity does reflect taxonomy in the very great majority of cases. Contradictory observations of unexpected cross-reactivity between unrelated plants, sometimes remarkably distant ones, require explanation. There are many proteins, presumably performing vital functions, that are tightly preserved throughout the evolutionary tree from plants to animals, such as profilins, lipid transfer proteins, and pathogenesis-related proteins. These might function as panallergens. The small differences that exist between these ubiquitous proteins explain why these are frequently minor allergens not reacting in the majority of allergic sera. This review summarizes cross-reactivity studies with both crude pollen extracts and purified or recombinant allergenic proteins. The patterns of cross-allergenicity that emerge should be helpful in guiding both diagnostic and therapeutic decisions.Journal of Allergy and Clinical Immunology 09/2003; 112(2):229-39; quiz 240. · 12.05 Impact Factor
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ABSTRACT: Salsola kali (Russian thistle) is a weed which belongs to the Chaenopodiacea family. It is widely distributed along the coasts of Europe, North Africa, USA and Australia. The objectives of this study were to study the allergenic composition of S. kali pollen and to purify an important allergen from the pollen extracts of this plant. A population of 66 individuals with specific IgE-mediated allergic symptoms and positive skin tests to S. kali were included in the study. Specific IgE to S. kali was determined by direct enzyme-linked immunosorbent assay (ELISA). The antigenic and allergenic profile of S. kali was evaluated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), isoelectric focussing (IEF) and immunoblot. Allergen purification was conducted by preparative SDS-PAGE. The allergenicity of the protein was evaluated by skin testing, direct ELISA, ELISA inhibition and immunoblots. Specific IgE to S. kali was detected in 39 of the 66 individuals (59%). An allergen with a molecular weight of approximately 43 kDa was purified. This allergen was termed Sal k 1. A partial sequencing was obtained and no homology was found with other known proteins/allergens. The allergenicity of Sal k 1 was tested in vitro and in vivo. Of the 39 individuals with a positive specific IgE determination to S. kali, 26 (66.6%) had detectable specific IgE to Sal k 1. Twenty of these 39 individuals were skin-prick tested with the purified allergen (0.5 mg/ml) and all of them had a positive skin test to the purified allergen. Ten additional individuals, used as negative controls, had a negative response. Sal k 1, an important allergen of S. kali, is recognized, in vitro, by approximately 67% of the patients sensitized to S. kali. Twenty patients with a positive skin test to a standardized S. kali extract had a positive reaction to the purified allergen.Allergy 12/2003; 58(11):1152-6. · 5.88 Impact Factor