Allergy to cypress and olive pollen: Clinical phenotypes and allergen recognition.

BACKGROUND AND OBJECTIVES: Cypress and olive pollen are the most prevalent sensitizer trees in the Mediterranean area. Some patients exhibit a dual sensitization which has not been well documented yet. To identify the allergens involved in the dual cypress and olive allergy (C+O) and study the relationship between phenotype and allergen sensitization. METHODS: C+O patients were selected. Monosensitized subjects to olive or cypress were used as reference. Specific IgE to whole extracts and purified allergens from olive and cypress were performed. Immunoblotting was done to analyze IgG and IgE-binding using olive polyclonal antibodies and patients' sera, respectively. Mutual immunoblotting inhibition of olive and cypress extracts, and inhibition of cypress extract immunoblotting with olive allergens were performed. Multiple correspondence analysis and hierarchical cluster classifications were conducted to analyze the relationships between C+O clinical presentation (symptoms, seasonality) and allergen profile. RESULTS: C+O patients were clustered in 4 phenotypes. The most frequent one (58.4%) was rhinoconjunctivitis in winter (February) and spring (May), with asthma in 38% of subjects. Ole e 1 and Cup s 1 were the major allergens. Homologous proteins to Ole e 1, Ole e 9 and Ole e 11 in cypress pollen were identified and these olive allergens inhibit IgE-binding to cypress extract. CONCLUSIONS: The exclusive C+O allergy results from co-sensitization to Cup s 1 and Ole e 1, and to cross-reactivity due to Ole e 1-like, Ole e 9-like and Ole e 11-like allergens not described previously, and translates into 4 clinical phenotypes of winter and/or spring or perennial rhinoconjunctivitis with and without asthma.

Association Between the Seed Storage Proteins 2S Albumin and 11S Globulin and Severe Allergic Reaction After Flaxseed Intake.

BACKGROUND: Given the increased popularity of flaxseed in meals, several cases of allergy to these seeds have been reported. Little is known about the allergens implicated in hypersensitivity reactions to flaxseed. The present study aimed to identify the allergens involved in IgE-mediated reactions in 5 patients with a clinical history of severe systemic symptoms after flaxseed consumption. METHODS: Proteins that were potential allergens with IgE-binding capacity were purified from flaxseed extract using chromatography and identified via MALDI-TOF mass spectrometry. Immunoassays were performed using the 5 allergic patients' sera tested individually and as a pool. RESULTS: Immunoblotting of the flaxseed extract revealed a low-molecular-mass protein (around 13 kDa) in 4 of the 5 patients, while a protein of approximately 55 kDa was detected in 2 patients. The proteins were identified by mass spectrometry as flaxseed 2S albumin, which is included in the WHO/IUIS allergen nomenclature as Lin u 1, and 11S globulin. Inhibition assays revealed in vitro IgE-mediated cross-reactivity between Lin u 1 and peanut and cashew nut proteins, while IgE-mediated recognition of 11S globulin by patients' sera was partially inhibited by several plant-derived sources. CONCLUSIONS: Seed storage proteins from flaxseed were involved in the development of severe symptoms in the 5 patients studied and exhibited cross-reactivity with other allergenic sources. Besides the severity of flaxseed allergy in patients sensitized to 2S albumin, this is the first time that 11S globulin has been identified as a potential allergen. Taking these data into account should ensure a more accurate diagnosis.