Allergen Profile of London Plane Tree Pollen: Clinical and Molecular Pattern in Central Spain.

BACKGROUND AND OBJECTIVES: Platanus acerifolia (London plane tree) is a deciduous tree of the Platanaceae family. Sensitization to this plant varies with geography. Madrid, located in central Spain, has one of the highest London plane tree pollen concentration levels on the Iberian Peninsula. We evaluated both the clinical characteristics and the molecular sensitization pattern of patients with allergy to London plane tree pollen in the region of Madrid. METHODS: Thirty-eight patients allergic to London plane tree pollen were selected according to their clinical symptoms and positive results in skin prick testing and/or specific IgE determination. Serum was collected, and allergen components were evaluated using immunodetection techniques as well as ImmunoCAP. The IgE-binding proteins detected were identified and characterized using mass spectrometry. RESULTS: Analysis of serum samples from allergic patients revealed 9 IgE-binding bands in London plane tree pollen extract. Among these, the 45-kDa protein, which corresponded to Pla a 2, was detected in 76.3% of patients. However, the 18-kDa (Pla a 1) and 9-kDa (Pla a 3) bands were detected in 44.7% and 23.7% of sera, respectively. These results were confirmed using purified proteins. Characterization of the allergen revealed the 27-kDa protein to be glutathione-S-transferase. CONCLUSIONS: The molecular profile of patients sensitized to London plane tree pollen differs from that reported in studies from other locations. In the population we studied, the prevalence of Pla a 2 was higher than that of Pla a 1 and Pla a 3. In addition, the minor allergen previously referred to as Pla a 4 was characterized as glutathione-S-transferase.

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.

Quality of life improvement with allergen immunotherapy treatment in patients with rhinoconjunctivitis in real life conditions. Results of an observational prospective study (ÍCARA).

Summary: Objectives. Evaluate the changes in quality of life of patients with allergic rhinoconjunctivitis (AR), with or without asthma, after one-year treatment with allergen immunotherapy. Methods. This was an observational prospective multicenter study. RQLQ questionnaire and VAS scale to assess treatment satisfaction were used. Impact on AR and asthma was also analyzed. Any adverse reaction was recorded. Results. 127 patients were recruited. Mean values in RQLQ decreased from 2.61 to 1.34 points, reflecting a statistically and clinically significant improvement (p minor 0.01). The percentage of asthmatic patients decreased significantly (p minor 0.01). Mean value of patients' satisfaction was 7.24 (SD = 1.90). Only 11 patients presented systemic reactions (9.17%), none of them serious. Conclusions. One-year AIT treatment significantly increases QoL in patients with AR. Moreover, high patients' satisfaction values were reported, together with an adequate safety profile.

Lettuce Allergy Is a Lipid Transfer Syndrome-Related Food Allergy With a High Risk of Severe Reactions.

BACKGROUND AND OBJECTIVE: Lipid transfer protein (LTP) sensitization is the most common cause of food allergy in the Mediterranean area, with peach allergy acting as the primary sensitizer in most cases. Lettuce has been described as a common offending food in patients with LTP syndrome. The aim of the study was to investigate the frequency and clinical expression of LTP syndrome in a sample of lettuceallergic patients. METHODS: We determined specific IgE to Pru p 3 and lettuce in a sample of 30 patients with a diagnosis of lettuce allergy. Symptoms elicited by other LTP-containing plant-derived foods and the presence of cofactors were assessed. RESULTS: The clinical symptoms of lettuce allergy were frequently severe, with 18 of the 30 patients experiencing anaphylaxis. All the patients had allergic reactions to other plant foods. Cofactors were involved in the clinical reactions of 13 of the 30 patients. Sensitization to pollens was found in 90% of patients. CONCLUSIONS: Lettuce allergy is found not as an isolated condition but in the context of LTP syndrome and it is characterized by severe reactions and frequent cofactor association.

The lipid interaction capacity of Sin a 2 and Ara h 1, major mustard and peanut allergens of the cupin superfamily, endorses allergenicity.

BACKGROUND: Sin a 2 (11S globulin) and Ara h 1 (7S globulin) are major allergens from yellow mustard seeds and peanut, respectively. The ability of these two allergens to interact with lipid components remains unknown. OBJECTIVE: To study the capacity of Sin a 2 and Ara h 1 to interact with lipid components and the potential effects of such interaction in their allergenic capacity. METHODS: Spectroscopic and SDS-PAGE binding assays of Sin a 2 and Ara h 1 with different phospholipid vesicles and gastrointestinal and endolysosomal digestions in the presence or absence of lipids were performed. The capacity of human monocyte-derived dendritic cells (hmoDCs) to capture food allergens in the presence or absence of lipids, the induced cytokine signature, and the effect of allergens and lipids to regulate TLR2-L-induced NF-kB/AP-1 activation in THP1 cells were analyzed. RESULTS: Sin a 2 and Ara h 1 bind phosphatidylglycerol (PG) acid but not phosphatidylcholine (PC) vesicles in a pH-dependent manner. The interaction of these two allergens with lipid components confers resistance to gastrointestinal digestion, reduces their uptake by hmoDCs, and enhances their stability to microsomal degradation. Mustard and peanut lipids favor a proinflammatory environment by increasing the IL-4/IL-10 ratio and IL-1ß production by hmoDCs. The presence of mustard lipids and PG vesicles inhibits TLR2-L-induced NF-kB/AP-1 activation in THP1 cells. CONCLUSION: Sin a 2 and Ara h 1 interact with lipid components, which might well contribute to explain the potent allergenic capacity of these two clinically relevant allergens belonging to the cupin superfamily.

Sensitive detection of major food allergens in breast milk: first gateway for allergenic contact during breastfeeding.

Food allergy is recognized as a major public health issue, especially in early childhood. It has been hypothesized that early sensitization to food allergens maybe due to their ingestion as components dissolved in the milk during the breastfeeding, explaining reaction to a food, which has never been taken before. Thus, the aim of this work has been to detect the presence of the food allergens in breast milk by microarray technology. We produced a homemade microarray with antibodies produced against major food allergens. The antibody microarray was incubated with breast milk from 14 women collected from Fundación Jiménez Díaz Hospital. In this way, we demonstrated the presence of major foods allergens in breast milk. The analysis of allergens presented in breast milk could be a useful tool in allergy prevention and could provide us a key data on the role of this feeding in tolerance induction or sensitization in children.

Impact of glutathione on the allergenicity of the peach lipid transfer protein Pru p 3.

BACKGROUND AND OBJECTIVE: The allergenic potential of proteins can be altered under various physicochemical conditions. Glutathione (GSH) is a reducing agent that is used as an antioxidant in food products. We aimed to characterize the natural folding of peach proteins and test the allergenicity of reduced and natural Pru p 3, the major peach allergen. METHODS: Pru p 3 was purified from peach, and its conformation was analyzed by means of circular dichroism. Using a thiol fluorescent probe, reduced proteins were detected in fresh peach. GSH-reduced Pru p 3 was tested in vitro for T-cell proliferation and in vivo using skin prick testing. RESULTS: GSH-reduced Pru p 3 produced variable skin prick reactions in peach-allergic patients. The proliferative response of peripheral blood mononuclear cells from allergic patients to reduced Pru p 3 tended to be less intense, whereas secretion of the cytokines IFN-γ, IL-5, and IL-10 was comparable. In a pool of sera from peach-allergic patients, reduction hardly impaired IgE-binding. Moreover, the stability of reduced Pru p 3 to gastrointestinal digestion was similar to that of the natural form. CONCLUSIONS: GSH can at least transiently reduce Pru p 3. We found that the effect of reduction on the allergenicity of Pru p 3 varied. Therefore, as an additive, GSH does not seem to eliminate the risk of reactions for peach-allergic patients.