[Sensitization and oral challenge with ovoalbumin in an animal model of food allergy].

Background: Gut-associated lymphoid tissue (GALT) is mainly formed by the gut mucosa and associated lymphatic structures that under normal conditions induces hyporesponsiveness, a phenomenon termed oral tolerance. However, the potential brakeup of oral tolerance could otherwise lead to disorders such as food allergy.

Objective: The aim of the study is to characterise the histopathological and immunohistochemical modifications in intestinal gut mucosa in an animal model of food allergy.

Methods: New Zealand rabbits were subcutaneously sensitized twice with ovalbumin (OVA), on day 30 after first sensitization, animals were oral challenged with the same antigen. Lymphatic cell population and accessory cells from gut mucosa were studied by conventional histology, histochemistry and immunohistochemistry.

Results: An important increase in number of eosinophils were observed in sensitized and challenged group as well as CD25+cells increase in sensitized animals without challenge.

Conclusions: Data obtained demonstrated that subcutaneous sensitization and challenge with OVA induced generation of specific IgE antibodies and an anaphylactic inflammatory response. This pattern induced quantitative modifications in studied cells and structural changes in mucosa like oedema at intestinal villi in sensitized and challenged rabbits in this animal model of food allergy.