Barbara Ballmer-weber - Academia.edu (original) (raw)

Papers by Barbara Ballmer-weber

Research paper thumbnail of Food allergy in adolescence and adulthood

Chemical immunology and allergy, 2015

In young children, food allergy is usually acquired via the gastrointestinal tract and directed t... more In young children, food allergy is usually acquired via the gastrointestinal tract and directed toward egg and milk. Adolescent and adult patients, however, mainly acquire food allergy via primary sensitization to inhalant allergens on the basis of cross-reactivity between proteins in inhalant sources and in food. This type of food allergy is frequently mediated by sensitization to broadly represented allergens, or so-called panallergens. Food allergic reactions in adult patients - similar to those in children - range in severity from very mild and local symptoms, as in contact urticaria of the oral mucosa, to systemic symptoms involving distal organs, to a fatal outcome. Plant foods, such as fruits, nuts, and vegetables, are the most prevalent allergenic foods in this age group. © 2015 S. Karger AG, Basel.

Research paper thumbnail of Recombinant food allergens in the diagnosis of pollen-related food allergy

Arbeiten aus dem Paul-Ehrlich-Institut (Bundesamt für Sera und Impfstoffe) zu Frankfurt a.M, 2003

Research paper thumbnail of Heterogeneity of banana allergy: characterization of allergens in banana-allergic patients

Research paper thumbnail of A novel approach for investigation of specific and cross-reactive IgE epitopes on Bet v 1 and homologous food allergens in individual patients

Research paper thumbnail of The serum bank of EuroPrevall – The prevalence, cost and basis of food allergy across Europe

Research paper thumbnail of Hazelnut allergy across Europe dissected molecularly: A EuroPrevall outpatient clinic survey

Journal of Allergy and Clinical Immunology, 2015

Hazelnut allergy is birch pollen-driven in Northern/Western Europe and lipid transfer protein-dri... more Hazelnut allergy is birch pollen-driven in Northern/Western Europe and lipid transfer protein-driven in Spain and Italy. Little is known about other regions and other allergens. Establishing a molecular map of hazelnut allergy across Europe. In 12 European cities, subjects reporting reactions to hazelnut (n = 731) were evaluated and sensitization to 24 foods, 12 respiratory allergen sources, and latex was tested by using skin prick test and ImmunoCAP. A subset (124 of 731) underwent a double-blind placebo-controlled food challenge to hazelnut. Sera of 423 of 731 subjects were analyzed for IgE against 7 hazelnut allergens and cross-reactive carbohydrate determinants by ImmunoCAP. Hazelnut allergy was confirmed in 70% of those undergoing double-blind placebo-controlled food challenges. Birch pollen-driven hazelnut sensitization (Cor a 1) dominated in most cities, except in Reykjavik, Sofia, Athens, and Madrid, where reporting of hazelnut allergy was less frequent anyhow. In Athens, IgE against Cor a 8 dominated and strongly correlated with IgE against walnut, peach, and apple and against Chenopodium, plane tree, and mugwort pollen. Sensitization to seed storage proteins was observed in less than 10%, mainly in children, and correlated with IgE to nuts, seeds, and legumes. IgE to Cor a 12, observed in all cities (10% to 25%), correlated with IgE to nuts, seeds, and pollen. In adulthood, the importance of hazelnut sensitization to storage proteins, oleosin (Cor a 12), and Cor a 8 is diluted by the increased role of birch pollen cross-reactivity with Cor a 1. Cor a 8 sensitization in the Mediterranean is probably driven by diet in combination with pollen exposure. Hazelnut oleosin sensitization is prevalent across Europe; however, the clinical relevance remains to be established.

Research paper thumbnail of Component-resolved diagnosis with recombinant allergens in patients with cherry allergy

The Journal of allergy and clinical immunology, 2002

In pollen-related food allergy, extracts for skin prick tests (SPTs) are often not standardized, ... more In pollen-related food allergy, extracts for skin prick tests (SPTs) are often not standardized, and the test reliability is affected by false-negative reactions. We sought to evaluate a panel of recombinant allergens (RAs) derived from one allergenic food for use in component-resolved in vivo diagnosis, taking cherry as a model food. Seventy-nine subjects were included in the study: 24 Swiss patients (group 1) with a positive double-blind placebo-controlled food challenge result to cherries, 23 patients with birch pollen allergy but without cherry allergy (group 2), 23 nonatopic subjects (group 3), and 9 Spanish patients with a history of a cherry allergy (group 4). SPTs were performed in duplicate by using recombinant cherry allergens (Bet v 1-related allergen: recombinant (r) Pru av 1; profilin: rPru av 4; and lipid transfer protein: rPru av 3) in concentrations of 10, 50, and 100 microg/mL. Furthermore, IgE reactivity to rPru av 1, rPru av 4, and rPru av 3 was assessed by means ...

Research paper thumbnail of Enlarging the Toolbox for Allergen Epitope Definition with an Allergen-Type Model Protein

Research paper thumbnail of Low preparedness for food allergy as perceived by school staff: a EuroPrevall survey across Europe

The journal of allergy and clinical immunology. In practice

Research paper thumbnail of Neurodermitis

Therapeutische Umschau, 2010

Atopic eczema (AE) is a multifaktoriell skin disease caused by a variety of factors such as genet... more Atopic eczema (AE) is a multifaktoriell skin disease caused by a variety of factors such as genetic conditions, alterated skin structure, immunologic deviations, psychological and environmental factors, among others. There are two main subtypes of AE, i.e. the IgE-associated ("extrinsic atopic eczema") and the non-IgE-associated type ("intrinsic atopic eczema") with different prognosis concerning the development of respiratory diseases ("atopy march"). The role of allergens varies: while in early childhood food allergens may play a role, mites and microbial antigens may become more relevant in adolescence and adulthood. Recently, it was demonstrated that Filaggrin is a major gene for atopic eczema. The altered skin structure and a deficiency in antimicrobial peptides favour colonization with Staphylococcus aureus; their enterotoxins with superantigenic activity stimulate activation of T cells and macrophages. Also sensitization to the yeast Malassezia spp. occurs almost exclusively in AE patients. So far, AE skin lesions are orchestrated by the local tissue expression of proinflammatory cytokines and chemokines with activation of T lymphocytes, dendritic cells, macrophages, keratinocytes, mast cells, and eosinophils which lead to the skin inflammatory responses. From the therapeutic point of view, a step wise approach using emollients as a basic treatment is recommended. Modern topical corticosteroids of moderate to medium potency applied once per day and only on several days per week offer an efficient anti-inflammatory treatment with moderate side effects. Topic immunomodulatory drugs (tacrolimus and pimecrolimus) have in addition substantially improved the treatment of AE. Proactive treatment approaches also in disease-free intervals may reduce exacerbations and total drug use. Phototherapy and wet dressings are both efficient and safe additional tools in more severe forms. For generalized severe forms systemic drugs such as Cyclosporin A are very helpful. Various Biologicals and antipruriginous substances are under clinical investigation and may add to an improved therapy in the future.

Research paper thumbnail of Food allergy in the Netherlands: differences in clinical severity, causative foods, sensitization and DBPCFC between community and outpatients

Clinical and Translational Allergy, 2015

Research paper thumbnail of Urtikaria – die häufigste dermatologische Erkrankung

Therapeutische Umschau, 2010

Urticaria is a very frequent disease. The life time risk to experience at least one episode of ur... more Urticaria is a very frequent disease. The life time risk to experience at least one episode of urticaria is around 15 - 25 %. This article summarizes the most important definitions, classifications and diagnostic procedures in urticaria, as well as the evidence based management of urticaria. The recommendations given in this article are in accordance with two recent position papers by the European Academy of Allergology and Clinical Immunology (EAACI), the Global Allergy and Asthma European Network (GA2LEN), the European Dermatology Forum (EDF), and the World Allergy Organization (WAO).

Research paper thumbnail of How much is too much?: Threshold dose distributions for 5 food allergens

The Journal of allergy and clinical immunology, Jan 18, 2014

Precautionary labeling is used to warn consumers of the presence of unintended allergens, but the... more Precautionary labeling is used to warn consumers of the presence of unintended allergens, but the lack of agreed allergen thresholds can result in confusion and risk taking by patients with food allergy. The lack of data on threshold doses below which subjects are unlikely to react is preventing the development of evidence-based allergen management strategies that are understood by clinician and patient alike. We sought to define threshold dose distributions for 5 major allergenic foods in the European population. Patients with food allergy were drawn from the EuroPrevall birth cohort, community surveys, and outpatient clinic studies and invited to undergo a food challenge. Low-dose, double-blind, placebo-controlled food challenges were undertaken with commercially available food ingredients (peanut, hazelnut, celery, fish, and shrimp) blinded into common matrices. Dose distributions were modeled by using interval-censoring survival analysis with 3 parametric approaches. Of the 5 fo...

Research paper thumbnail of Die hypoallergene Diät

Therapeutische Umschau, 2000

Research paper thumbnail of The Utility of an International Sera Bank for Use in Evaluating the Potential Human Allergenicity of Novel Proteins

Toxicological Sciences, 2007

Research paper thumbnail of Bet v 1 homologous proteins in kiwi fruit- relevant allergens?

World Allergy Organization Journal, 2007

... Background: In Central and Northern Europe birch pollen related food allergy is mainly based ... more ... Background: In Central and Northern Europe birch pollen related food allergy is mainly based upon cross reactive IgE to Bet v 1 and homologues present in various plant derived foods. So far, actinidin, kiwellin and the thaumatin ...

Research paper thumbnail of The EuroPrevall allergen library

World Allergy Organization Journal, 2007

Research paper thumbnail of Analysis of the composition of an immunoglobulin E reactive high molecular weight protein complex of peanut extract containing Ara h 1 and Ara h 3/4

PROTEOMICS, 2005

Peanuts (Arachis hypogaea) contain some of the most potent food allergens. In recent years an inc... more Peanuts (Arachis hypogaea) contain some of the most potent food allergens. In recent years an increasing prevalence of peanut allergies both in children and adults has been observed in the USA and in Europe. In vitro identification and characterization of allergens including those from peanut have been frequently performed by Western blotting. However this method may alter the immunoglobulin E (IgE) antibody reactivity since the proteins are denatured by detergent treatment and/or reduction of disulfide bonds by reducing reagents and does not answer the question how peanut allergens interact with the human digestive apparatus and immune system. Size exclusion chromatography of peanut extract shows that approximately 90% of the total protein content is eluted as one peak in the exclusion volume with a molecular mass of over 200 kDa. The proteins of this fraction were analyzed by blue-native polyacrylamide gel electrophoresis (PAGE), immunoblotting, two-dimensional PAGE and Western blotting. A complex of Ara h 1 (Acc. no. P43237), Ara h 3/4 (AAM46958), Ara h 3 (AAC63045), Ara h 4 (AF086821), Gly 1 (AAG01363) and iso-Ara h 3 (AAT39430) was identified using patients' IgE and allergen-specific monoclonal antibodies; N-terminal sequencing and matrix-assisted laser desorption/ionisation-time of flight analysis verified these findings. A comparison of the peanut allergen sequences of Ara h 3/4, Ara h 3, Ara h 4 and peanut trypsin inhibitor (AF487543) and the proteins Gly 1 and iso-Ara h 3, not yet described as allergens, leads to the conclusion that these proteins are isoallergens of each other. It was shown that these isoallergens are post-translationally cleaved and held together by disulfide bonds in accordance to the 11S plant seed storage proteins signature.

Research paper thumbnail of Effect of Heating and Glycation on the Allergenicity of 2S Albumins (Ara h 2/6) from Peanut

Research paper thumbnail of Boiling peanut Ara h 1 results in the formation of aggregates with reduced allergenicity

Molecular Nutrition & Food Research, 2011

Roasting rather than boiling and Maillard modifications may modulate peanut allergenicity. We inv... more Roasting rather than boiling and Maillard modifications may modulate peanut allergenicity. We investigated how these factors affect the allergenic properties of a major peanut allergen, Ara h 1. Ara h 1 was purified from either raw (N-Ara h 1) or roasted (R-Ara h 1) peanuts. Boiling (100°C 15 min; H-Ara h 1) resulted in a partial loss of Ara h 1 secondary structure and formation of rod-like branched aggregates with reduced IgE-binding capacity and impaired ability to induce mediator release. Glycated Ara h 1 (G-Ara h 1) formed by boiling in the presence of glucose behaved similarly. However, H- and G-Ara h1 retained the T-cell reactivity of N-Ara h 1. R-Ara h 1 was denatured, comprised compact, globular aggregates, and showed no evidence of glycation but retained the IgE-binding capacity of the native protein. Ara h 1 aggregates formed by boiling were morphologically distinct from those formed by roasting and had lower allergenic activity. Glycation had no additional effect on Ara h 1 allergenicity compared with heating alone. Taken together with published data on the loss of Ara h 2/6 from boiled peanuts, this supports the hypothesis that boiling reduces the allergenicity of peanuts.

Research paper thumbnail of Food allergy in adolescence and adulthood

Chemical immunology and allergy, 2015

In young children, food allergy is usually acquired via the gastrointestinal tract and directed t... more In young children, food allergy is usually acquired via the gastrointestinal tract and directed toward egg and milk. Adolescent and adult patients, however, mainly acquire food allergy via primary sensitization to inhalant allergens on the basis of cross-reactivity between proteins in inhalant sources and in food. This type of food allergy is frequently mediated by sensitization to broadly represented allergens, or so-called panallergens. Food allergic reactions in adult patients - similar to those in children - range in severity from very mild and local symptoms, as in contact urticaria of the oral mucosa, to systemic symptoms involving distal organs, to a fatal outcome. Plant foods, such as fruits, nuts, and vegetables, are the most prevalent allergenic foods in this age group. © 2015 S. Karger AG, Basel.

Research paper thumbnail of Recombinant food allergens in the diagnosis of pollen-related food allergy

Arbeiten aus dem Paul-Ehrlich-Institut (Bundesamt für Sera und Impfstoffe) zu Frankfurt a.M, 2003

Research paper thumbnail of Heterogeneity of banana allergy: characterization of allergens in banana-allergic patients

Research paper thumbnail of A novel approach for investigation of specific and cross-reactive IgE epitopes on Bet v 1 and homologous food allergens in individual patients

Research paper thumbnail of The serum bank of EuroPrevall – The prevalence, cost and basis of food allergy across Europe

Research paper thumbnail of Hazelnut allergy across Europe dissected molecularly: A EuroPrevall outpatient clinic survey

Journal of Allergy and Clinical Immunology, 2015

Hazelnut allergy is birch pollen-driven in Northern/Western Europe and lipid transfer protein-dri... more Hazelnut allergy is birch pollen-driven in Northern/Western Europe and lipid transfer protein-driven in Spain and Italy. Little is known about other regions and other allergens. Establishing a molecular map of hazelnut allergy across Europe. In 12 European cities, subjects reporting reactions to hazelnut (n = 731) were evaluated and sensitization to 24 foods, 12 respiratory allergen sources, and latex was tested by using skin prick test and ImmunoCAP. A subset (124 of 731) underwent a double-blind placebo-controlled food challenge to hazelnut. Sera of 423 of 731 subjects were analyzed for IgE against 7 hazelnut allergens and cross-reactive carbohydrate determinants by ImmunoCAP. Hazelnut allergy was confirmed in 70% of those undergoing double-blind placebo-controlled food challenges. Birch pollen-driven hazelnut sensitization (Cor a 1) dominated in most cities, except in Reykjavik, Sofia, Athens, and Madrid, where reporting of hazelnut allergy was less frequent anyhow. In Athens, IgE against Cor a 8 dominated and strongly correlated with IgE against walnut, peach, and apple and against Chenopodium, plane tree, and mugwort pollen. Sensitization to seed storage proteins was observed in less than 10%, mainly in children, and correlated with IgE to nuts, seeds, and legumes. IgE to Cor a 12, observed in all cities (10% to 25%), correlated with IgE to nuts, seeds, and pollen. In adulthood, the importance of hazelnut sensitization to storage proteins, oleosin (Cor a 12), and Cor a 8 is diluted by the increased role of birch pollen cross-reactivity with Cor a 1. Cor a 8 sensitization in the Mediterranean is probably driven by diet in combination with pollen exposure. Hazelnut oleosin sensitization is prevalent across Europe; however, the clinical relevance remains to be established.

Research paper thumbnail of Component-resolved diagnosis with recombinant allergens in patients with cherry allergy

The Journal of allergy and clinical immunology, 2002

In pollen-related food allergy, extracts for skin prick tests (SPTs) are often not standardized, ... more In pollen-related food allergy, extracts for skin prick tests (SPTs) are often not standardized, and the test reliability is affected by false-negative reactions. We sought to evaluate a panel of recombinant allergens (RAs) derived from one allergenic food for use in component-resolved in vivo diagnosis, taking cherry as a model food. Seventy-nine subjects were included in the study: 24 Swiss patients (group 1) with a positive double-blind placebo-controlled food challenge result to cherries, 23 patients with birch pollen allergy but without cherry allergy (group 2), 23 nonatopic subjects (group 3), and 9 Spanish patients with a history of a cherry allergy (group 4). SPTs were performed in duplicate by using recombinant cherry allergens (Bet v 1-related allergen: recombinant (r) Pru av 1; profilin: rPru av 4; and lipid transfer protein: rPru av 3) in concentrations of 10, 50, and 100 microg/mL. Furthermore, IgE reactivity to rPru av 1, rPru av 4, and rPru av 3 was assessed by means ...

Research paper thumbnail of Enlarging the Toolbox for Allergen Epitope Definition with an Allergen-Type Model Protein

Research paper thumbnail of Low preparedness for food allergy as perceived by school staff: a EuroPrevall survey across Europe

The journal of allergy and clinical immunology. In practice

Research paper thumbnail of Neurodermitis

Therapeutische Umschau, 2010

Atopic eczema (AE) is a multifaktoriell skin disease caused by a variety of factors such as genet... more Atopic eczema (AE) is a multifaktoriell skin disease caused by a variety of factors such as genetic conditions, alterated skin structure, immunologic deviations, psychological and environmental factors, among others. There are two main subtypes of AE, i.e. the IgE-associated ("extrinsic atopic eczema") and the non-IgE-associated type ("intrinsic atopic eczema") with different prognosis concerning the development of respiratory diseases ("atopy march"). The role of allergens varies: while in early childhood food allergens may play a role, mites and microbial antigens may become more relevant in adolescence and adulthood. Recently, it was demonstrated that Filaggrin is a major gene for atopic eczema. The altered skin structure and a deficiency in antimicrobial peptides favour colonization with Staphylococcus aureus; their enterotoxins with superantigenic activity stimulate activation of T cells and macrophages. Also sensitization to the yeast Malassezia spp. occurs almost exclusively in AE patients. So far, AE skin lesions are orchestrated by the local tissue expression of proinflammatory cytokines and chemokines with activation of T lymphocytes, dendritic cells, macrophages, keratinocytes, mast cells, and eosinophils which lead to the skin inflammatory responses. From the therapeutic point of view, a step wise approach using emollients as a basic treatment is recommended. Modern topical corticosteroids of moderate to medium potency applied once per day and only on several days per week offer an efficient anti-inflammatory treatment with moderate side effects. Topic immunomodulatory drugs (tacrolimus and pimecrolimus) have in addition substantially improved the treatment of AE. Proactive treatment approaches also in disease-free intervals may reduce exacerbations and total drug use. Phototherapy and wet dressings are both efficient and safe additional tools in more severe forms. For generalized severe forms systemic drugs such as Cyclosporin A are very helpful. Various Biologicals and antipruriginous substances are under clinical investigation and may add to an improved therapy in the future.

Research paper thumbnail of Food allergy in the Netherlands: differences in clinical severity, causative foods, sensitization and DBPCFC between community and outpatients

Clinical and Translational Allergy, 2015

Research paper thumbnail of Urtikaria – die häufigste dermatologische Erkrankung

Therapeutische Umschau, 2010

Urticaria is a very frequent disease. The life time risk to experience at least one episode of ur... more Urticaria is a very frequent disease. The life time risk to experience at least one episode of urticaria is around 15 - 25 %. This article summarizes the most important definitions, classifications and diagnostic procedures in urticaria, as well as the evidence based management of urticaria. The recommendations given in this article are in accordance with two recent position papers by the European Academy of Allergology and Clinical Immunology (EAACI), the Global Allergy and Asthma European Network (GA2LEN), the European Dermatology Forum (EDF), and the World Allergy Organization (WAO).

Research paper thumbnail of How much is too much?: Threshold dose distributions for 5 food allergens

The Journal of allergy and clinical immunology, Jan 18, 2014

Precautionary labeling is used to warn consumers of the presence of unintended allergens, but the... more Precautionary labeling is used to warn consumers of the presence of unintended allergens, but the lack of agreed allergen thresholds can result in confusion and risk taking by patients with food allergy. The lack of data on threshold doses below which subjects are unlikely to react is preventing the development of evidence-based allergen management strategies that are understood by clinician and patient alike. We sought to define threshold dose distributions for 5 major allergenic foods in the European population. Patients with food allergy were drawn from the EuroPrevall birth cohort, community surveys, and outpatient clinic studies and invited to undergo a food challenge. Low-dose, double-blind, placebo-controlled food challenges were undertaken with commercially available food ingredients (peanut, hazelnut, celery, fish, and shrimp) blinded into common matrices. Dose distributions were modeled by using interval-censoring survival analysis with 3 parametric approaches. Of the 5 fo...

Research paper thumbnail of Die hypoallergene Diät

Therapeutische Umschau, 2000

Research paper thumbnail of The Utility of an International Sera Bank for Use in Evaluating the Potential Human Allergenicity of Novel Proteins

Toxicological Sciences, 2007

Research paper thumbnail of Bet v 1 homologous proteins in kiwi fruit- relevant allergens?

World Allergy Organization Journal, 2007

... Background: In Central and Northern Europe birch pollen related food allergy is mainly based ... more ... Background: In Central and Northern Europe birch pollen related food allergy is mainly based upon cross reactive IgE to Bet v 1 and homologues present in various plant derived foods. So far, actinidin, kiwellin and the thaumatin ...

Research paper thumbnail of The EuroPrevall allergen library

World Allergy Organization Journal, 2007

Research paper thumbnail of Analysis of the composition of an immunoglobulin E reactive high molecular weight protein complex of peanut extract containing Ara h 1 and Ara h 3/4

PROTEOMICS, 2005

Peanuts (Arachis hypogaea) contain some of the most potent food allergens. In recent years an inc... more Peanuts (Arachis hypogaea) contain some of the most potent food allergens. In recent years an increasing prevalence of peanut allergies both in children and adults has been observed in the USA and in Europe. In vitro identification and characterization of allergens including those from peanut have been frequently performed by Western blotting. However this method may alter the immunoglobulin E (IgE) antibody reactivity since the proteins are denatured by detergent treatment and/or reduction of disulfide bonds by reducing reagents and does not answer the question how peanut allergens interact with the human digestive apparatus and immune system. Size exclusion chromatography of peanut extract shows that approximately 90% of the total protein content is eluted as one peak in the exclusion volume with a molecular mass of over 200 kDa. The proteins of this fraction were analyzed by blue-native polyacrylamide gel electrophoresis (PAGE), immunoblotting, two-dimensional PAGE and Western blotting. A complex of Ara h 1 (Acc. no. P43237), Ara h 3/4 (AAM46958), Ara h 3 (AAC63045), Ara h 4 (AF086821), Gly 1 (AAG01363) and iso-Ara h 3 (AAT39430) was identified using patients' IgE and allergen-specific monoclonal antibodies; N-terminal sequencing and matrix-assisted laser desorption/ionisation-time of flight analysis verified these findings. A comparison of the peanut allergen sequences of Ara h 3/4, Ara h 3, Ara h 4 and peanut trypsin inhibitor (AF487543) and the proteins Gly 1 and iso-Ara h 3, not yet described as allergens, leads to the conclusion that these proteins are isoallergens of each other. It was shown that these isoallergens are post-translationally cleaved and held together by disulfide bonds in accordance to the 11S plant seed storage proteins signature.

Research paper thumbnail of Effect of Heating and Glycation on the Allergenicity of 2S Albumins (Ara h 2/6) from Peanut

Research paper thumbnail of Boiling peanut Ara h 1 results in the formation of aggregates with reduced allergenicity

Molecular Nutrition & Food Research, 2011

Roasting rather than boiling and Maillard modifications may modulate peanut allergenicity. We inv... more Roasting rather than boiling and Maillard modifications may modulate peanut allergenicity. We investigated how these factors affect the allergenic properties of a major peanut allergen, Ara h 1. Ara h 1 was purified from either raw (N-Ara h 1) or roasted (R-Ara h 1) peanuts. Boiling (100°C 15 min; H-Ara h 1) resulted in a partial loss of Ara h 1 secondary structure and formation of rod-like branched aggregates with reduced IgE-binding capacity and impaired ability to induce mediator release. Glycated Ara h 1 (G-Ara h 1) formed by boiling in the presence of glucose behaved similarly. However, H- and G-Ara h1 retained the T-cell reactivity of N-Ara h 1. R-Ara h 1 was denatured, comprised compact, globular aggregates, and showed no evidence of glycation but retained the IgE-binding capacity of the native protein. Ara h 1 aggregates formed by boiling were morphologically distinct from those formed by roasting and had lower allergenic activity. Glycation had no additional effect on Ara h 1 allergenicity compared with heating alone. Taken together with published data on the loss of Ara h 2/6 from boiled peanuts, this supports the hypothesis that boiling reduces the allergenicity of peanuts.