The role of regulatory T cells in the acquisition of tolerance to food allergens in children

Food allergy is a pathological immune reaction that identifies certain harmless food proteins, usually tolerated by the majority of the people, as a threat. The prevalence of these food allergies is increasing worldwide and currently affects 8% of children. Exacerbated reactions to milk, egg and peanut are the most frequent in the pediatric population. It is well known that allergic diseases are a type 2 T-helper (Th2) immune response, characterized by the elevated production of IgE antibodies. However, little is known about the immune mechanisms responsible for the development of clinical tolerance toward food allergens. Recent studies have suggested the key role of regulatory T cells (Tregs) in controlling allergic inflammation. In this review, we discuss the importance of Tregs in the pathogenesis of food allergy and the acquisition of oral tolerance in children. Further investigation in this area will be crucial for the identification of predictive markers and the development of new therapies, which will represent a clinical and social benefit for these allergic diseases

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The role of regulatory T cells in the acquisition of tolerance to food allergens in children.

Food allergy is a pathological immune reaction that identifies certain harmless food proteins, usually tolerated by the majority of the people, as a threat. The prevalence of these food allergies is increasing worldwide and currently affects 8% of children. Exacerbated reactions to milk, egg and peanut are the most frequent in the pediatric population. It is well known that allergic diseases are a type 2 T-helper (Th2) immune response, characterized by the elevated production of IgE antibodies. However, little is known about the immune mechanisms responsible for the development of clinical tolerance toward food allergens. Recent studies have suggested the key role of regulatory T cells (Tregs) in controlling allergic inflammation. In this review, we discuss the importance of Tregs in the pathogenesis of food allergy and the acquisition of oral tolerance in children. Further investigation in this area will be crucial for the identification of predictive markers and the development of new therapies, which will represent a clinical and social benefit for these allergic diseases.

Role of antiretroviral therapies in mucocutaneous manifestations in HIV-infected children over a period of two decades.

BACKGROUND: Human immunodeficiency virus (HIV) infection causes a severe cellular immunodeficiency, which results in a greater susceptibility to infectious, inflammatory and malignant conditions. Among these, pathologies of the skin seem to be those most frequently observed in HIV+ patients. However, there are few reports on how antiretroviral therapy affects skin disorders in HIV-infected children. OBJECTIVE: To study the incidence and prevalence of skin disorders in a cohort of HIV-infected children, in relation to the antiviral therapy [nontreated, monotherapy, combined therapy and highly active antiretroviral therapy (HAART)] received, and their impact on immunological and virological markers. The treatments were those available in different calendar periods in the history of antiviral treatment. MATERIALS AND METHODS: A retrospective, observational study in a cohort of 210 HIV-infected children was carried out. These children were followed up every 3 months throughout 22 years. The viral load (HIV RNA copies mL(-1)) was quantified using reverse transcriptase-polymerase chain reaction and the viral phenotype of HIV-1 isolates was determined by in vitro culture. T-lymphocyte subsets in peripheral blood were quantified by flow cytometry. RESULTS: Mucocutaneous manifestations were diagnosed in 17% of the untreated infected children. Of the treated children in different treatment periods, 22% in the monotherapy period, 25% in the combined therapy period but only 10% on HAART had some type of mucocutaneous manifestation, concordant with a higher number of CD4+ T cells, a lower viral load and less cytopathic virus in the last group. Mucocutaneous manifestations of infectious aetiology were most frequently observed; they were detected in 13% of the children during the first calendar period (untreated children), 16% during the second and third periods (monotherapy and combined therapy) and only 5% in the last period (HAART). Interestingly, syncytium-inducing virus was present in 69% of all children with mucocutaneous manifestations of infectious aetiology. CONCLUSION: Only in the last calendar period (HAART) was a significant decrease observed in the prevalence of mucocutaneous manifestations with HIV infection associated with an increase in CD4+ T cells. In addition, we found a strong association between children who had mucocutaneous manifestations with an infectious aetiology and a more cytopathic (X4/SI) viral phenotype.