Cuantificación de IgG1 en pacientes alérgicos a LTPs

Abstract

Food allergy affects approximately 7% of the adult population and 10% of children. It remains unclear whether the prevalence of food allergy is increasing. Lipid transfer proteins (LTPs), present in vegetables, pollen, nuts and fruits, are true plant food allergens, i.e. they are able to induce IgE production by plasma cells. Recent studies in mice have demonstrated the existence of an alternative anaphylactic route mediated by IgG. Moreover, it has been proven that the first stages of the allergic response in mice are mediated by IgG1, while later exposures to the allergen induce the generation of IgE. In humans, it is known that most of the IgE comes from IgG1 isotype class switching. Clinical observations about the existence of a group of patients allergic to LTPs that present low levels of Pru p 3-specific IgE, and a rapid progression to severe reactions led us to hypothesize that IgG1 could be implicated in these LTP-allergic phenotypes. Thus, the main objective of this project was to elaborate a method to detect Pru p 3-specific IgG1 in serum samples of LTP-allergic patients using the ELISA technique. Pru p 3-specific IgG1 was found in around 70% of the samples. The results suggested that Pru p 3-specific IgG1 levels inversely correlate with Pru p 3-specific IgE levels. However, further optimization of the current protocol could be implemented in future assays. IgG1 determinations may help identify allergic patients with a particular phenotype.