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.

Tolerability and immunological effect of short up-dosing immunotherapy with 2 standardized native allergen extracts derived from the pollen of Salsola kali and Cupressus arizonica

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Validation of Recipes for Double-Blind Placebo-Controlled Challenges With Milk, Egg White, and Hazelnut.

BACKGROUND: The double-blind, placebo-controlled food challenge (DBPCFC) is considered the definitive diagnostic test for food allergy. Nevertheless, validated recipes for masking the foods are scarce, have not been standardized, and differ between centers. Sensory evaluation techniques such as the triangle test are necessary to validate the recipes used for DBPCFC. METHODS: We developed 3 recipes for use in DBPCFC with milk, egg white, and hazelnut and used the triangle test to validate them in a 2-phase study in which 197 volunteers participated. In each phase, participants tried 3 samples (2 active-1 placebo or 2 placebo-1 active) and had to identify the odd one. In phase 1, the 3 samples were given simultaneously, whereas in phase 2, the 3 samples of foods that failed validation in phase 1 were given sequentially. A visual analog scale (VAS) ranging from 1 to 10 was used to evaluate how much participants liked the recipes. RESULTS: In phase 1, the egg white recipe was validated (n=89 volunteers, 38.9% found the odd sample, P=.16). Milk and hazelnut recipes were validated in phase 2 (for both foods, n=30 participants, 36.7% found the odd sample, P=.36). Median VAS scores for the 3 recipes ranged from 6.6 to 9.7. CONCLUSIONS: We used sensory testing to validate milk, egg white, and hazelnut recipes for use in DBPCFC. The validated recipes are easy to prepare in a clinical setting, provide the equivalent of 1 serving dose, and were liked by most participants.

IgE recognition patterns in peanut allergy are age dependent: perspectives of the EuroPrevall study.

BACKGROUND: We tested the hypothesis that specific molecular sensitization patterns correlate with the clinical data/manifestation in a European peanut-allergic population characterized under a common protocol. METHODS: Sixty-eight peanut-allergic subjects and 82 tolerant controls from 11 European countries were included. Allergy to peanut and lowest symptom-eliciting dose was established by double-blind placebo-controlled food challenge in all but anaphylactic subjects. Information of early or late (before or after 14 years of age) onset of peanut allergy was obtained from standardized questionnaires. IgE to peanut allergens rAra h 1-3, 6, 8-9, profilin and CCD was determined using ImmunoCAP. RESULTS: Seventy-eight percent of peanut allergics were sensitized to peanut extract and 90% to at least one peanut component. rAra h 2 was the sole major allergen for the peanut-allergic population. Geographical differences were observed for rAra h 8 and rAra h 9, which were major allergens for central/western and southern Europeans, respectively. Sensitization to rAra h 1 and 2 was exclusively observed in early-onset peanut allergy. Peanut-tolerant subjects were frequently sensitized to rAra h 8 or 9 but not to storage proteins. Sensitization to Ara h 2 ≥ 1.0 kUA /l conferred a 97% probability for a systemic reaction (P = 0.0002). Logistic regression revealed a significant influence of peanut extract sensitization and region on the occurrence of systemic reactions (P = 0.0185 and P = 0.0436, respectively). CONCLUSION: Sensitization to Ara h 1, 2 and 3 is usually acquired in childhood. IgE to Ara h 2 ≥ 1.0 kUA /l is significantly associated with the development of systemic reactions to peanut.

Validation of the Spanish Version of the Food Allergy Quality of Life Questionnaire–adult form (S-FAQLQ-AF)

Introducción: Se evalúa el impacto de la alergia alimentaria sobre la calidad de vida, mediante cuestionarios específicos integrado en el proyecto EuroPrevall. Validar y adaptar a lengua castellana el cuestionario FAQLQ-AF. Material y métodos: La traducción y adaptación cultural del cuestionario original se realizó siguiendo recomendaciones de la OMS. Los autores del cuestionario original aceptaron la versión en lengua castellana del FAQLQ-AF (S-FAQLQ-AF). Los pacientes fueron incluidos siguiendo los siguientes criterios: (1) Síntomas alérgicos tras ingesta de un alimento y prick test positivos o IgE frente al alimento implicado, (2) Un médico evaluó la capacidad de los pacientes para completar los cuestionarios (S-FAQLQ-AF y el genérico SF-12). Para explorar la fiabilidad de las respuestas entre 10 y 14 días después de rellenar el primer cuestionario, los pacientes rellenaban de nuevo el S-FAQLQ-AF con preguntas en distinto orden. Resultados: Ochenta y dos pacientes (≥18 años) fueron incluidos. La validez de constructo fue evaluada a partir de la correlación entre el S-FAQLQ-AF y el FAIM (Medida Independiente de la Alergia a Alimentos (rho =0.83, p<.0001). El cuestionario S-FAQLQ-AF (Cronbach-alpha =0.95) y sus diferentes dominios mostraron excelente consistencia interna: Evitación de alérgenos (alpha=0.93); impacto emocional (alpha=0.83), riesgo de exposición accidental (alpha=0.85) y salud relacionada con alergia alimentaria (alpha=0.66). No se halló correlación entre el S-FAQLQ-AF y el cuestionario SF-12. Conclusión: La versión Española del cuestionario de adultos FAQLQ-AF es una herramienta válida, fiable, fácil de usar, rápida de completar y sensible al cambio, discriminando pacientes con diferentes fenotipos atópicos, para evaluar el impacto de la alergia alimentaria en la calidad de vida (AU)

Introduction: Specific food allergy quality of life questionnaires have been developed within the context of the EuroPrevall project. We aimed to adapt and validate the Food Allergy Quality of Life Questionnaire-Adult Form (FAQLQ-AF) in the Spanish language. Methods: The original English questionnaire was translated and culturally adapted into Spanish following World Health Organization guidelines. The final Spanish version of the FAQLQ-AF (S-FAQLQ-AF) was approved by the original authors. Consecutive patients (≥18 years old) who fulfilled the following criteria were recruited: 1) diagnosis of food allergy defined as immediate allergic symptoms and a positive prick test or IgE against the culprit food(s) and 2) physician-assessed ability to complete the questionnaires. Patients completed the S-FAQLQ-AF and a Spanish version of the SF-12 questionnaire. Reliability was assessed 10 to 14 days after completion of the first questionnaire. Results: Eighty-two consecutive outpatients were recruited and cross-sectional validity was assessed based on the correlation between the S-FAQLQ-AF and the Food Allergy Independent Measure (FAIM) in this population (rho=0.83, P<.0001). The S-FAQLQ-AF showed excellent internal consistency (Cronbach alpha, 0.95). S-FAQLQ-AF domains also had excellent internal consistency: alpha=0.93 for allergen avoidance-dietary restrictions; alpha=0.83 for emotional impact; alpha=0.85 for risk of accidental exposure, and alpha=0.66 for food allergy related health. Limited correlation was found between the S-FAQLQ-AF and the SF-12. Conclusion: The S-FAQLQ-AF is a valid, short, easy-to-use, and reliable instrument that discriminates between patients with different atopic phenotypes and is suitable for assessing the impact of IgE-mediated food allergy on patient quality of life (AU)

Lentil (Lens culinaris) lipid transfer protein Len c 3: a novel legume allergen.

BACKGROUND: Lentils are increasingly consumed in many parts of the world.Two allergens, Len c 1 and 2, have been reported previously. Recently, peanut and green bean lipid transfer proteins (LTPs) have been identified as the first two members of an important group of allergens that might be associated with severe food allergies. OBJECTIVE: To investigate lentil LTP as a potential new allergen. METHODS: Efficacy of LTP extraction was monitored at different acidic pH values, using immunoblotting with cross-reactive anti-peach LTP antiserum. Natural LTP was purified from lentil extract and expressed as recombinant allergen in Escherichia coli. Sera from 10 lentil-allergic and/or -sensitized patients (Spain: 6, Italy: 1 and the Netherlands: 3) were used to further characterize lentil LTP. RESULTS: Natural lentil LTP, purified from the homogenized germinated seeds and optimally extracted at pH 3, was identified and designated as allergen Len c 3. By CAP, 9/10 sera showed specific IgE to Len c 3. Recombinant (r) Len c 3 was successfully purified. The natural (n) Len c 3 CAP was completely inhibited by rLen c 3/rPru p 3. IgE binding to lentil pH 3 extract blot was completely inhibited by rLen c 3. CONCLUSION: The availability of immunochemically active nLen/rLen c 3 as a novel legume allergen facilitates further development and implementation of a third (next to peanut and green bean) legume LTP in component-resolved diagnosis strategies and contributes to evaluate the clinical importance of legume LTPs. Preferential extraction of Len c 3 (pH 3) will affect the production of sensitive extract-based diagnostic tests.

Sublingual immunotherapy in peach allergy: monitoring molecular sensitizations and reactivity to apple fruit and Platanus pollen.

BACKGROUND: Peach allergy is prevalent, persistent, and potentially severe and as such is a target for immunotherapy. Our aims were to evaluate the profile of sensitization to Rosaceae allergens and the effects of sublingual peach immunotherapy on immunoglobulin (Ig) E levels to these allergens, to monitor for neosensitizations, and to check if this treatment modified other Rosaceae fruit and pollen-related sensitizations. METHODS: A double-blind placebo-controlled trial was conducted on 56 peach-allergic patients who received, sublingually, a standardized peach extract quantified in mass units of Pru p 3, or placebo for 6 months. IgE to recombinant (r) Mal d 1, rMal d 4, rPru p 3, and natural (n) Art v 3 and skin prick test (SPT) reactivity to Platanus pollen and apple extracts evaluated before treatment (T0), after 1 month (T1) and after and 6 months (T6) were recorded. RESULTS: In total, 18.5% of patients recognized rMal d 1, 83.3%, rPru p 3, 24.1%, rMal d 4, and 25.9% nArt v 3. IgE to Pru p 3 rose from T0 to T1 in both the active group (P = .003) and the placebo group (P = .022), and remained elevated at T6 in the active group (P = .001). IgE to other purified allergens did not change significantly and no relevant neosensitizations were detected. SPT reactions to peach decreased from T0 to T6 in the active group (P < 0.05). Reactivity to peach (T1 and T6) and apple (T6) was lower in the active group than in the control group. CONCLUSIONS: The main allergen was Pru p 3. Changes in rPru p 3 IgE levels and in peach and apple extract SPT were induced by sublingual immunotherapy.

Peach profilin: cloning, heterologous expression and cross-reactivity with Bet v 2.

BACKGROUND: Peach is among the main foods causing allergic reactions in the Mediterranean adult population. Only a single peach allergen, named Pru p 3, has been characterized. However, a potential role of profilin has also been suggested in grass pollen-associated allergy to peach. METHODS: Complementary DNA clones for two different peach profilin isoforms were obtained by reverse transcriptase polymerase chain reaction using non-degenerated primers. Expression of recombinant peach profilin was performed in Escherichia coli, and confirmed using rabbit polyclonal antibodies to sunflower pollen profilin. Twenty-nine individual sera from patients with peach allergy proved by double-blind, placebo-controlled food challenges (DBPCFC), either with (n = 15) or without (n = 14) specific IgE to Bet v 2, were used in immunodetection assays to test recombinant peach profilin reactivity. RESULTS: Each peach profilin cDNA included an open reading frame coding for a 131 amino acid protein. The peach profilin isoforms, designated Pru p 4.01 and Pru p 4.02, showed 80% of amino acid sequence identity, and were very similar (>70% identity) to allergenic profilins from plant foods and pollens. Recombinant Pru p 4.01 was expressed in E. coli as a nonfusion protein, displaying the expected molecular size and reacting with anti-profilin antibodies. rPru p 4.01 was recognized by all sera (15 of 15) with specific IgE to Bet v 2, whereas no sera (zero of 14) without IgE to this birch allergen reacted with rPru p 4.01. CONCLUSIONS: Peach profilin Pru p 4 is very closed to other allergenic profilins from plant foods and pollens. A complete correlation between reactivity to rPru p 4 and rBet v 2 has been found in sera from peach allergic patients.

[Cross-reactivity between fruit and vegetables]. / Reactividad cruzada en frutas y vegetales.

Vegetable foods are the most frequent cause of food allergy after the age of 5 years. The most commonly implicated foods are fruit and dried fruits, followed in Spain by legumes and fresh garden produce. In patients allergic to fruit and garden produce, multiple sensitizations to other vegetable products, whether from the same family or taxonomically unrelated, are frequent, although they do not always share the same clinical expression. Furthermore, more than 75 % of these patients are allergic to pollen, the type of pollen varying in relation to the aerobiology of the area. The basis of these associations among vegetable foods and with pollens lies in the existence of IgE antibodies against "panallergens", which determines cross-reactivity. Panallergens are proteins that are spread throughout the vegetable kingdom and are implicated in important biological functions (generally defense) and consequently their sequences and structures are highly conserved. The three best-known groups are allergens homologous to Bet v 1, profilins, and lipid transfer proteins (LTP). Allergens homologous to Bet v 1 (major birch pollen allergen) constitute a group of defense proteins (PR-10), with a molecular weight of 17 kDa, which behave as major allergens in patients from northern and central Europe with allergy to vegetables associated with birch pollen allergy. In these patients, the primary sensitization seems to be produced through the inhalation route on exposure to birch pollen. The symptomatology characteristically associated with sensitization to this family of allergens is oral allergy syndrome (OAS). Profilins are highly conserved proteins in all eukaryotic organisms and are present in pollen and a wide variety of vegetable foods. They have a molecular weight of 14 kDa and present a high degree of structural homology as well as marked cross-reactivity among one another. The presence of anti-profilin IgE broadens the spectrum of sensitizations to vegetable foods detected through skin tests and/or in vitro tests but whether it correlates with the clinical expression of food allergy is unclear.LTPs are the most commonly implicated allergens in allergy to Rosaceae fruits in patients from the Mediterranean area without birch pollen sensitization. LTPs are a family of 9kDA polypeptides, widely found in the vegetable kingdom and implicated in cuticle formation and defense against pathogens (PR-14). They are thermostable and resistant to pepsin digestion, which makes them potent food allergens and explains the frequent development of systemic symptoms (urticaria, anaphylaxis) in patients allergic to Rosaceae fruits in Spain. LTPs have also been identified in other vegetable foods and in pollens and a marked degree of cross-reactivity among them has been demonstrated, which may explain (together with profilin) the frequency of individuals sensitized to vegetable foods in the Mediterranean area.

Reactividad cruzada en frutas y vegetales / Cross-reactivity between fruit and vegetables

Los alimentos vegetales son la causa más frecuente de alergia a alimentos a partir de los 5 años de edad. Los más frecuentemente implicados son las frutas y frutos secos, seguidos en nuestro país de las legumbres y hortalizas frescas. En los pacientes alérgicos a frutas y hortalizas es muy frecuente encontrar sensibilizaciones múltiples a otros alimentos vegetales, de la misma familia o taxonómicamente no relacionados, aunque no todas ellas tienen expresión clínica. Además, más del 75 por ciento de estos pacientes son alérgicos a pólenes, variando el tipo de polen en relación con la aerobiología de la zona. La base de estas asociaciones de alimentos vegetales entre sí y con pólenes reside en que existen anticuerpos IgE frente a "panalergenos", lo que determina la reactividad cruzada. Los panalergenos son proteínas ampliamente extendidas en el reino vegetal, implicadas en funciones biológicas importantes (generalmente de defensa), por lo cual sus secuencias y estructuras están altamente conservadas. Los tres grupos mejor conocidos son los alergenos homólogos de Bet v 1, las profilinas y las proteínas transportadoras de lípidos (PTL).Los alergenos homólogos de Bet v 1 (alergeno mayor del polen de abedul) son un grupo de proteínas de defensa (PRP-10) de 17 kDa de peso molecular, que se comportan como alergenos mayores en los pacientes del Norte y Centro de Europa que presentan alergia a alimentos vegetales asociada con polinosis al abedul. En estos pacientes la sensibilización primaria parece producirse por vía inhalatoria al exponerse al polen de abedul. La sintomatología característica asociada con la sensibilización a esta familia de alergenos es el Síndrome de Alergia Oral (SAO).Las profilinas son proteínas altamente conservadas en todos los organismos eucarióticos, presentes en pólenes y en una gran variedad de alimentos vegetales. Tienen un peso molecular de 14 kDa, y presentan una alta homología en sus estructuras y una importante reactividad cruzada entre ellas. La presencia de IgE anti-profilina amplía el espectro de sensibilizaciones a alimentos vegetales detectadas mediante pruebas cutáneas y/o test in vitro, pero no está claro que se correlacione con la expresión clínica de la alergia a alimentos. Las PTLs son los alergenos mayores implicados en la alergia a frutas rosáceas en pacientes del área mediterránea no sensibilizados a polen de abedul. Las PTLs son una familia de polipéptidos de 9kDA de peso molecular, ampliamente distribuidos en el reino vegetal, e implicados en la formación de la cutícula y en la defensa frente a patógenos (PRP-14). Son termoestables y resistentes a la digestión con pepsina, lo que las convierte en potentes alergenos alimentarios y explica la frecuente aparición de clínica sistémica (urticaria, anafilaxia) en los pacientes alérgicos a rosáceas de nuestro área. Se han identificado también PTLs en otros alimentos vegetales y en pólenes, y se ha demostrado un notable grado de reactividad cruzada entre ellas, lo que puede explicar (junto a la profilina) la frecuencia de personas sensibilizadas a alimentos vegetales en el área mediterránea (AU)

Vegetable foods are the most frequent cause of food allergy after the age of 5 years. The most commonly implicated foods are fruit and dried fruits, followed in Spain by legumes and fresh garden produce. In patients allergic to fruit and garden produce, multiple sensitizations to other vegetable products, whether from the same family or taxonomically unrelated, are frequent, although they do not always share the same clinical expression. Furthermore, more than 75 % of these patients are allergic to pollen, the type of pollen varying in relation to the aerobiology of the area. The basis of these associations among vegetable foods and with pollens lies in the existence of IgE antibodies against "panallergens", which determines cross-reactivity. Panallergens are proteins that are spread throughout the vegetable kingdom and are implicated in important biological functions (generally defense) and consequently their sequences and structures are highly conserved. The three best-known groups are allergens homologous to Bet v 1, profilins, and lipid transfer proteins (LTP). Allergens homologous to Bet v 1 (major birch pollen allergen) constitute a group of defense proteins (PR-10), with a molecular weight of 17 kDa, which behave as major allergens in patients from northern and central Europe with allergy to vegetables associated with birch pollen allergy. In these patients, the primary sensitization seems to be produced through the inhalation route on exposure to birch pollen. The symptomatology characteristically associated with sensitization to this family of allergens is oral allergy syndrome (OAS). Profilins are highly conserved proteins in all eukaryotic organisms and are present in pollen and a wide variety of vegetable foods. They have a molecular weight of 14 kDa and present a high degree of structural homology as well as marked cross-reactivity among one another. The presence of anti-profilin IgE broadens the spectrum of sensitizations to vegetable foods detected through skin tests and/or in vitro tests but whether it correlates with the clinical expression of food allergy is unclear. LTPs are the most commonly implicated allergens in allergy to Rosaceae fruits in patients from the Mediterranean area without birch pollen sensitization. LTPs are a family of 9kDA polypeptides, widely found in the vegetable kingdom and implicated in cuticle formation and defense against pathogens (PR-14). They are thermostable and resistant to pepsin digestion, which makes them potent food allergens and explains the frequent development of systemic symptoms (urticaria, anaphylaxis) in patients allergic to Rosaceae fruits in Spain. LTPs have also been identified in other vegetable foods and in pollens and a marked degree of cross-reactivity among them has been demonstrated, which may explain (together with profilin) the frequency of individuals sensitized to vegetable foods in the Mediterranean area (AU)

Tolerance of a cluster schedule on the treatment of seasonal allergic respiratory disease with pollen extracts quantified in mass units.

In order to evaluate the tolerance of a cluster schedule on specific immunotherapy (SIT), 306 patients were included in a multicenter study. The patients were suffering from rhinoconjunctivitis with/without asthma, caused by sensitization to olive and/or grass pollen. SIT was administered subcutaneously according to a cluster schedule in which the maintenance dose is reached after four visits (3 weeks). The extracts were biologically standardized with major allergens quantified in mass units. Local reactions appeared in 7.2% of the patients and 1.3% of the doses. Systemic reactions (SR) were recorded in 1.2% of the doses administered to 9.5% of the patients. No anaphylactic shock was registered, and all the SR responded fully and rapidly to treatment. There was no difference in SR according to diagnosis or allergen extract used. The majority of SR occurred with the administration of vial of higher concentration (Vial 2: 7 SR (22%), Vial 3: 32 SR (78%), p < 0.05). Of the 32 SR recorded with Vial 3, 13 (41%) were immediate, with no existing association between dose administered and appearance of SR. However, of the 18 delayed SR (56%), 14 occurred after the administration of the first two doses of Vial 3 and four occurred after administration of the second two doses (78% vs 22%, p < 0.05). On the other hand, this regime realized an important saving in cost and time compared to the conventional schedule (1581 fewer doses and 2754 fewer visits were necessary to reach the optimal dose). Considering all these factors, the clinical profile of the proposed regime may be qualified as good. However, future studies are necessary in order to better adjust the schedule to avoid the delayed SR that occurred after the administration of the first two doses of Vial 3.

Lipid-transfer proteins as potential plant panallergens: cross-reactivity among proteins of Artemisia pollen, Castanea nut and Rosaceae fruits, with different IgE-binding capacities.

BACKGROUND: Lipid-transfer proteins (LTPs), but not Bet v 1 homologues, have been identified as major allergens of apple and peach in the Rosaceae fruit-allergic population in the Mediterranean area. Many of these patients show cosensitization to mugwort pollen. LTPs have an ubiquitous distribution in tissues of many plant species, and have been proposed as a novel type of plant panallergens. OBJECTIVE: We sought to isolate LTPs from Artemisia pollen and from a plant food not belonging to the Rosaceae family, such as chestnut nut, and to compare their amino acid sequences and IgE-binding capacities with those of apple and peach LTPs. METHODS: Allergens (LTPs) were isolated by different chromatographic methods (gel-filtration, ion exchange and/or reverse-phase HPLC), and characterized by N-terminal amino acid sequencing and MALDI analysis. Specific IgE-quantification and immunodetection, as well as immunoblot and ELISA inhibition assays, were carried out using sera from patients allergic to both apple and peach. RESULTS: Purified LTPs from Artemisia pollen and from chestnut seed showed molecular masses about 9 700d, and 43-50% sequence identity with the equivalent allergens of apple and peach in the first 30 N-terminal residues, which comprise about one third of the total amino acid sequence. A similar degree of sequence identity (50%) was found between the Artemisia and chestnut proteins. Both isolated LTPs bound specific IgE of sera from Rosaceae fruits allergic patients. However, substantially lower values of specific IgE-binding and maximum ELISA inhibition percentages were obtained for Artemisia and chestnut LTPs when compared to those from apple and peach. CONCLUSION: LTPs from Artemisia pollen and chestnut crossreact with allergens (LTPs) of Rosaceae fruits, but significant differences in specific IgE-binding capacities were observed among members of the plant LTP family. Thus, further studies are needed to evaluate the clinical significance of the observed cross-reactivities of plant LTPs.

Peels of Rosaceae fruits have a higher allergenicity than pulps.

BACKGROUND: It is not uncommon that patients allergic to fruits such as apple, pear, and peach, refer adverse reactions after the ingestion of the whole fruit, but subsequently tolerate the pulp. OBJECTIVE: This study aimed to compare the allergenicity of peels and pulps of apple, peach, and pear in 33 patients allergic to these fruits. METHODS: Clinical reactivity to the ingestion of whole fruit (peel + pulp) and pulp was established by medical history. Peels and pulps were tested separately in skin prick tests (SPTs), histamine release tests (HRTs) and RASTs. Cross-allergenicity between peel and pulp of apple and peach was studied by RAST inhibition. RESULTS: Adverse reactions appeared more frequently and were more severe when the whole fruit was eaten. More than 40% of patients allergic to apple and pear tolerated the ingestion of the pulp of these fruits, and reactions were only elicited by the intake of the whole fruit. Peels induced higher SPTs, HRTs and RASTs than pulps. An important cross-allergenicity was found between the peel and pulp of apple and peach, although the amount of the shared allergenic epitopes seemed to be higher in peels. CONCLUSION: Our results suggest that peels of Rosaceae fruits such as apple, peach, and pear, have a higher allergenicity than pulps, which is clinically relevant. This aspect should be considered in the evaluation of patients allergic to Rosaceae fruits, and in the production of diagnostic materials.

Improvement of fruit allergenic extracts for immunoblotting experiments.

A method based on ion-exchange column chromatography to enhance the protein content of fruit allergenic extracts was found to help make the subsequent SDS-PAGE immunoblotting assays possible; otherwise, they were difficult to achieve due to the high carbohydrate content. Fractionated extracts of apple, pear, and peach (peel and pulp) were obtained by anion-exchange chromatography (Q-Sepharose column), providing clear electrophoretic patterns which allowed IgE detection by enzymatic assays of the transferred membranes. This chromatographic method produced in one single step an enriched extract directly from the standard crude aqueous one, with an increment in the protein content of more than sixfold, on average; thus, it proved to be more suitable than the usual chemical fractionation procedures.

Pollen-related allergy to peach and apple: an important role for profilin.

BACKGROUND: Birch pollinosis is often accompanied by allergy to fruits such as peach and apple. Bet v I is of major importance as cross-reactive allergen for this combined allergy. We studied a group of patients with combined grass pollinosis and fruit allergy from an area virtually without birch trees. OBJECTIVE: The aim of this study was to investigate the possible involvement of profilin and carbohydrate groups as cross-reactive structures in pollen and fruits. METHODS: RAST inhibition was performed to measure cross-reactive IgE to pollen and fruits. The presence of IgE against profilin was determined in a RAST with purified grass profilin, and IgE against carbohydrate structures was determined in a RAST with proteinase K-digested grass pollen extract. The biologic activity of IgE in response to profilin was tested by in vitro histamine release and skin prick tests. RESULTS: IgE against fruits was shown to be largely cross-reactive with grass pollen. The majority of the patients had IgE against profilin (12 of 16) and carbohydrate structures (9 of 10). Profilin was shown to have biologic activity, in both histamine release and skin prick tests. CONCLUSION: Profilin is an important allergen for patients with combined grass pollen/fruit allergy in areas without birch trees.

Swiss chard hypersensitivity: clinical and immunologic study.

Allergy to vegetables and fruits seems to be more prevalent in atopics, especially in birch pollen-sensitized individuals. We report a case of a grass pollen-sensitized woman, in whom the inhalation of vapor from boiling Swiss chard precipitated rhinoconjunctivitis and asthma. Type I hypersensitivity to Swiss chard was demonstrated by means of immediate skin test reactivity, specific IgE determination by RAST, basophil degranulation, histamine release test, and an immediate bronchial provocation test response to Swiss chard extract. The controls did not react to any of these tests. RAST inhibition assays suggest the presence of some cross-reactivity among Swiss chard and grass pollen antigens, as well as cross-reactivity between vegetables and weed pollens of the chenopod family.