Fetal exposure to intact immunoglobulin E occurs via the gastrointestinal tract

Abstract

Amniotic fluid contains intact IgE that might bind to CD23+ cells within the lymphoid follicles of the fetal gastrointestinal tract. The evolutionary significance of these interactions might be to prepare the immune system for helminthic parasite exposure at birth via IgE-mediated antigen focusing, or "education" of the developing immune system about the prevailing extrauterine environment. However, at present in societies where helminthosis is not a significant health issue, this pathway may still be operational and associated with the development of atopic disease.