High prevalence of lupin allergy among patients with peanut allergy: Identification of γ-conglutin as major allergen.

BACKGROUND: Lupin is a protein-rich legume with a growing presence in the food market worldwide. With increased consumption, lupin allergy (LA) reports are also rising. Uncertainties exist on the cross-reactivity between peanut and lupin, the allergenic potential of different lupin species, and sensitization patterns among different populations. OBJECTIVE: To evaluate the molecular basis of LA and to determine lupin allergens from 3 different species that may be involved in peanut allergy (PA) cross-reactivity. METHODS: A total of 43 subjects with PA, those with LA, or controls without food allergy were evaluated with skin prick tests (SPTs) and specific IgEs (sIgEs). Lupin-sensitized subjects were offered a lupin oral food challenge (OFC). Immunoblots and enzyme-linked immunosorbent assays were performed on sera from lupin-sensitized subjects. RESULTS: In this study, 44% of the PA subjects were confirmed to have LA by OFC. Anaphylaxis was the most frequent manifestation after lupin consumption, with a minimal eliciting dosage of 1 g lupin flour. There was no difference in lupin sIgE or SPT wheal size between lupin-sensitized and confirmed LA subjects or in the severity of symptoms among confirmed LA subjects. Sera from lupin-sensitized subjects uniformly reacted to all 3 different lupin species. Immunoblotting and enzyme-linked immunosorbent assays revealed immunoglobulin E binding to α- and γ-conglutin in all analyzed sera, whereas α- and ß-conglutin recognition was variable. CONCLUSION: Our findings reveal a high prevalence of LA among PA subjects, emphasizing lupin must be labeled as an allergen in foods. Owing to high variability in lupin-sIgE and lupin-SPT results, LA diagnosis may require OFC. In our population, γ-conglutin is the major allergen of lupin.

Clinical characterization of Chilean patients with IgE-mediated food allergy. / Caracterización clínica de pacientes chilenos con alergia alimentaria mediada por IgE.

BACKGROUND: Food allergy (FA) is an entity of high and growing prevalence, which can be mediated by IgE or cellular immunity. It can have a wide range of symptoms and be triggered by multiple food antigens, which vary in different geographical areas. OBJECTIVES: To describe clinical characteristics of Chilean patients with IgE-mediated FA. PATIENTS AND METHOD: Retrospective review of patients with IgE-mediated FA treated at a tertiary healthcare center in Santiago, Chile, between 2006 and 2016. Demographic characteristics, clinical manifestations, and trigger foods were evaluated. RESULTS: A to tal of 282 patients diagnosed with IgE-mediated FA were included. 89% had FA onset before 18 years of age and most of these before one year of age (median of age: one year; range: one month-55 years). The most common clinical manifestations were hives, angioedema, dyspnea, and vomiting. 40% had symptoms compatible with anaphylaxis. The foods most frequently involved were egg, cow's milk, peanut, shellfish, walnut, tomato, wheat, avocado, fish, and legumes. Egg, cow's milk, and peanut allergies were the most frequent at pediatric age, while seafood allergy was the most frequent among adults. CONCLUSION: Foods causing IgE-mediated FA in Chile were similar to those described in other countries, although the frequency of tomato and avocado allergy, which are unusual in international series, stands out. Anaphylaxis incidence was high, emphasizing the need for epinephrine autoinjec tors in Chile.

Guía clínica chilena de urticaria crónica espontánea / Chilean guidelines for chronic urticaria

Chronic urticaria (CU) is characterized by itchy wheals, angioedema or both lasting six weeks or more. It is classified as spontaneous (CSU) and inducible urticaria (CIndU), depending whether there is an identifiable trigger or not. CSU is the predominant form, affecting more than 75% of patients, although overlaps often occur. The prevalence of CSU throughout life is around 1.8% and predominates in women at a ratio of 2:1. The higher incidence of CSU is between 20 and 40 years of age and lasts between one to five years. However, in up to 20% of patients the disease may last longer. CSU not only hampers quality of life, but also affect performance at work and school. The diagnosis of CSU is mainly clinical, and laboratory tests are required depending on the clinical history of the patient. Extensive laboratory tests are usually unnecessary. Second generation anti-histamines are used as first line treatment for CSU treatment. In refractory patients, systemic treatments, such as cyclosporine or omalizumab are suggested. We herein report the first Chilean CSU guidelines.

Caracterización clínica de pacientes chilenos con alergia alimentaria mediada por IgE / Clinical characterization of Chilean patients with IgE-mediated food allergy

INTRODUCCIÓN: La alergia alimentaria (AA) es una entidad de elevada y creciente prevalencia, pudiendo ser mediada por IgE o inmunidad celular. Puede presentar amplia sintomatología y ser gatillada por múltiples antígenos alimentarios, lo que varía en diversas zonas geográficas. OBJETIVO: Describir las características clínicas de pacientes chilenos con AA IgE-mediada. PACIENTES Y MÉTODO: Revisión retrospectiva de pacientes con AA IgE-mediada atendidos en un centro terciario de salud de Santiago, Chile entre los años 2006 y 2016. Se evaluaron características demográficas, manifestaciones clínicas y alimentos gatillantes. RESULTADOS: Se incluyeron 282 pacientes con diagnóstico de AA IgE-mediada. El 89% debutó con AA antes de los 18 años de edad y de estos, la mayoría antes del año (mediana: 1 año; rango: 1 mes - 55 años). Las manifestaciones clínicas más frecuentes fueron urticaria, angioedema, disnea y vómitos. Un 40% tenía historia compatible con anafilaxia. Los alimentos más frecuentes fueron huevo, leche de vaca, maní, mariscos, nuez, tomate, trigo, palta, pescados y legumbres. Alergia a huevo, leche de vaca y maní fueron más frecuentes en edad pediátrica, mientras que en adultos fueron los mariscos. CONCLUSIONES: Los alimentos causantes de AA IgE-mediada en Chile fueron similares a los descritos en otros países, aunque destaca la elevada frecuencia de alergia a tomate y palta, poco habituales en series internacionales. La incidencia de anafilaxia fue alta, lo que instala la necesidad de contar con autoinyectores de adrenalina a nivel nacional.

BACKGROUND: Food allergy (FA) is an entity of high and growing prevalence, which can be mediated by IgE or cellular immunity. It can have a wide range of symptoms and be triggered by multiple food antigens, which vary in different geographical areas. OBJECTIVES: To describe clinical characteristics of Chilean patients with IgE-mediated FA. Patients and Method: Retrospective review of patients with IgE-mediated FA treated at a tertiary healthcare center in Santiago, Chile, between 2006 and 2016. Demographic characteristics, clinical manifestations, and trigger foods were evaluated. RESULTS: A to tal of 282 patients diagnosed with IgE-mediated FA were included. 89% had FA onset before 18 years of age and most of these before one year of age (median of age: one year; range: one month-55 years). The most common clinical manifestations were hives, angioedema, dyspnea, and vomiting. 40% had symptoms compatible with anaphylaxis. The foods most frequently involved were egg, cow's milk, peanut, shellfish, walnut, tomato, wheat, avocado, fish, and legumes. Egg, cow's milk, and peanut allergies were the most frequent at pediatric age, while seafood allergy was the most frequent among adults. CONCLUSION: Foods causing IgE-mediated FA in Chile were similar to those described in other countries, although the frequency of tomato and avocado allergy, which are unusual in international series, stands out. Anaphylaxis incidence was high, emphasizing the need for epinephrine autoinjec tors in Chile.

Role of dendritic cells in peanut allergy.

INTRODUCTION: The prevalence of peanut allergy (PA) has increased, affecting approximately 1.1% of children in Western countries. PA causes life-threatening anaphylaxis and frequently persists for life. There are no standardized curative therapies for PA, and avoidance of peanuts remains the main therapeutic option. A better understanding of the pathogenesis of PA is essential to identify new treatment strategies. Intestinal dendritic cells (DCs) are essential in the induction and maintenance of food tolerance because they present dietary allergens to T cells, thereby directing subsequent immune responses. Areas covered: In this review, we discuss the factors related to the acquisition of oral tolerance to peanut proteins. We focus on intestinal DC-related aspects, including the latest advances in the biology of intestinal DC subtypes, effect of tolerance-inducing factors on DCs, effect of dietary components on oral tolerance, and role of DCs in peanut sensitization. Expert commentary: Given the increasing prevalence of PA, difficulty of avoiding peanut products, and the potentially serious accidental reactions, the development of novel therapies for PA is needed. The ability of DCs to trigger tolerance or immunity makes them an interesting target for new treatment strategies against PA.